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American Mature Series 
Group I. Classification of Nature 


AMERICAN INSECTS 


BY 


VERNON L. KELLOGG 


Professor of Entomology and Lecturer on Bionomics 
in Leland Stanford Jr, University 


WITH MANY ORIGINAL ILLUSTRATIONS 
BY 


MARY WELLMAN 


SECOND EDITION, REVISED 


Oy 
fy 


Cer Bitean) 


Neqennsy 
BS: SOK: ur 


NEW YORK 
HENRY HOLT AND COMPANY 


1908 


BY ) 
HENRY HOLT AND CO 


ROBERT DRUMMOND COMPANY, PRINTERS, NEW YORK 


JOHN HENRY COMSTOCK 


PREFATORY NOTE 
TO SECOND EDITION, REVISED 


In this new and revised edition of American Insects a detailed analytical 
table of contents has been substituted for the simple list of chapter titles 
used in the first edition, and an additional chapter (Chapter XIX) on the 
subject of insect behavior and psychology has been added. While descrip- 
tive accounts of the reflexes and instincts of insects are to be found on 
almost every page of the book—insect instinct is indeed one of the primary 
subjects of the book—the author has believed that a special discussion and 
attempt at analysis of the springs and control of insect behavior would be 
of interest to the reader. This special though necessarily all too condensed 
and brief treatment of the subject has therefore been introduced into the 
present edition. Welln 1S 


STANFORD UNIVERSITY, 
March 26, 1908. 


PREFATORY NOTE 


Ir man were not the dominant animal in the world, this would be the 
Age of Insects. Outnumbering in kinds the members of all other groups 
of animals combined, and showing a wealth of individuals and a degree 
of prolificness excelled only by the fishes among larger animals, and among 
smaller animals by the Protozoa, the insects have an indisputable claim on 
the attention of students of natural history by sheer force of numbers. Bu: 
their claim to our interest rests on securer ground. Their immediate and 
important relation to man as enemies of his crops, and, as we have come to 
know only to-day, as it were, as a grim menace to his own’ health and life— 
this capacity of insects to destroy annually hundreds of millions of dollars’ 
worth of grains and fruits and vegetables, and to be solely responsible for 
the dissemination of some of the most serious diseases that make man to 
suffer and die, forces our attention whether we will or not. Finally, the 
amazing variety and specialization of habit and appearance, the extraor- 
dinary adaptations and “‘shifts for a living” which insects show, make a 
claim on the attention of all who harbor the smallest trace of that ‘‘scientific 
curiosity” which leads men to observe and ponder the ways and seeming of 
Nature. Some of the most attractive and important problems which modern 
biological study is attacking, such as the significance of color and pattern, 
the reality of mechanism and automatism in the action and behavior of 
animals as contrasted with intelligent and discriminating performances, 
the statistical and experimental study of variation and heredity, and other sub- 
jects of present-day biological investigation, are finding their most available 
material and data among the insects. 

This book is written in the endeavor to foster an interest in insect biology 
on the part of students of natural history, of nature observers, and of general 
readers; it provides in a single volume a general systematic account of all 
the principal groups of insects as they occur in America, together with special 
accounts of the structure, physiology, development and metamorphoses, and 
of certain particularly interesting and important ecological relations of insects 
with the world around them. Systematic entomology, economic entomology, 
and what may be called the bionomics of insects are the special subjects of 
the matter and illustration of the book. An effort has been made to put 
the matter at the easy command of the average intelligent reader; but it has 
been felt that a little demand on his attention will accomplish the result 
more satisfactorily than could be done with that utter freedom from effort 


vii 


vill Prefatory Note 


with which some Nature-books try to disseminate knowledge. The few 
technical terms used are all explained in the text in connection with their 
first use, and besides are inserted in the Index with a specific reference, in 
black-faced type, to the explanation. So that the tyro reading casually in 
the book and meeting any of these terms apart from their explanation has 
only to refer to the Index for assistance. Readers more interested in account? 
of the habits and kinds of insects than in their structure and physiology 
will be inclined to skip the first three chapters, and may do so and still find 
the rest of the book “‘easy reading” and, it is hoped, not devoid of entertain- 
ment and advantage. But the reader is earnestly advised not to spare the 
little attention especially needed for understanding these first chapters, and 
thus to ensure for his later reading some of that quality which is among 
the most valued possessions of the best minds. 

In preparing such a book as this an author is under a host of obligations 
to previous writers and students which must perforce go unacknowledged. 
Some formal recognition, however, for aid and courtesies directly tendered 
by J. H. Comstock of Cornell University, whose entomological text-books 
have been for years the chief sources of knowledge of the insects of this 
country, I am able and glad to make. To my artist, Miss Mary Wellman, 
for her constant interest in a work that must often have been laborious and 
wearying, and for her persistently faithful endeavor toward accuracy, I extend 
sincere thanks. ‘To Mrs. David Starr Jordan, who read all of the manuscript 
as a ‘‘general reader” critic, and to President Jordan for numerous sugges- 
tions I am particularly indebted. For special courtesies in the matter of 
illustrations (permission to have electrotypes made from original blocks) 
I am obliged to Prof. F. L. Washburn, State Entomologist of Minnesota (for 
nearly one hundred and fifty figures), Prof. M. V. Slingerland of Cornell 
University, Dr. E. P. Felt, State Entomologist of New York, Mr. Wm: 
Beutenmiiller, editor of the Journal of the New York Entomological Society, 
and Dr. Henry Skinner, editor of the Entomological News. 


VERNON L. KELLOGG. 
STANFORD UNIVERSITY, CALIFORNIA, 
June 1, 1904. 


— 


———————————— eo Sm 


CONTENTS 


CHAPTER I 


‘STRUCTURE AND SPECIAL PHYSIOLOGY OF INSECTS. .....:.-...-s--cececneeeee I 
Structural characteristics of the class Insecta, 3. External anatomy, 4. 
Body-wall, 4. Divisions of body, 5. Mouth-parts, 8. Wings, 9. Size and 
form of body, 12 Internal anatomy, 13. Muscles, 13. Alimentary canal, 
13. Reproductive system, 14. Circulatory system, 16. Respiratory system, 
19. Nervous system, 20. Special sense-organs, 24. Insect psychology, 33. 


CHAPTER II 


DEVELOPMENT) AND) METAMORPHOSIS( < [<< <.c/-te-/clotclsis, Hehe siel vassperyelteicyncsierr sat 35 
Eggs and embryonic development, 36. Post-embryonic development, 4o. 
Development without metamorphosis, 41. Development with incomplete meta- 
morphosis, 41. Development with complete metamorphosis, 43. Internal 
changes during development, 47. Significance of development, 49. 


CHAPTER III 


KG TAS SIRIGAMIONT ORMUNSE GIS! loys) stele lagelstete elle) niece) ot fated nseatetets cater et tatalor=)-15 tha /ctaloleet= 52 
Various schemes of classification into orders, 52. Analytical key to the orders 
of insects, 54. 


CHAPTER IV 


AEA SIMEPESTMINSECTS (ORDER APTER A) career «jonarajeltsrsrersin slerstsi.) s//Ale/ejoysieiare «i 58 
Fish-moths and springtails, 58. Primitiveness among insects, 59. Struc- 
tural characteristics, 59. Key to the suborders, 60. Thysanura, 60. Key to 
the families of Thysanura, 60. Key to genera of Lepismidz, 61. Collembola, 
62. Key to families of Collembola, 63. 


CHAPTER V 


May-FLies (ORDER EPHEMERIDA) AND STONE-FLIES (ORDER PLECOPTERA)....... 65 
May-fly swarms, 65. Life-history, 66. Structure of adults, 68. Stone-flies, 
7o. Life-history, 71. Structure of adults, 71. Table of North American 
genera of Plecoptera, 73. 


x : Contents 


CHAPTER VI 


DRAGON-FLIES AND DAMSEL-FLIES (ORDER ODONATA).... 00000000 e ess cr ee eeeee 
Characteristics and distribution of dragon-flies, 76. Structure of adults, 79. 
Habits, 81. Life-history, 84. Methods of collecting and studying, 87. Various 
kinds of dragon-flies, 89. Keys to suborders, 89. Key to families of Zygoptera, 

89. Key to families of Anisoptera, 91. 


CHAPTER VII 


TERMITES OR WHITE ANTS (ORDER ISOPTERA). ...+-- +++ ++ esses eee e re eereree 
Characteristics and structure of Termites, 99. Life-history, ror. Key to 
genera, 102. Habits and characteristics of various kinds of termites, 102. 
Termites of Africa, 106. The problem of caste determination, 108. The 
Embiide, 109. 


CHAPTER VIII 


BOOK-LICE AND BARK-LICE (ORDER CORRODENTIA) AND THE BITING BIRD-LICE 

(ORDER MALLOPHAGA). .... 0.0.0 erence ere tenet eet eter eee eee 

Structure and life-history of book-lice, 111. Keys to families and genera, 

112. Characteristics and life-history of bird-lice, 113. Problems of distri- 

bution, 116. Keys to suborders, families, and genera, 118. Various species, 
119. 


CHAPTER IX 


THE COCKROACHES, CRICKETS, Locusts, GRASSHOPPERS, AND KATYDIDS (ORDER 
QORTHOPTERA) «oo 5 oasis ays ia = 5ya/o afd apace abs» Myre cle eee RnR Raed tet eee ee 
Sounds of crickets, etc., 123. Key to families, 126. Cockroaches or Blat- 
tide, 126. Mantide, 129. Phasmide, 132. Key to genera of Phasmide, 
132. Locusts (Acridiide), 133. Sounds of locusts, 134. Life-history of 
locusts, 136. Key to subfamilies of Acridiida, 136. Rocky Mountain locust, 
137. Various kinds of locusts, 140. Locustide, 149. Various kinds, 150. 
rae (Gryllide), 157. Sound-making of crickets, 157. Ear-wigs (Forficu- 
lidx), 162. 


CHAPTER X 


Tue True Bucs, CIicApAs, APHIDS, SCALE-INSECTS, ETC. (ORDER HEMIPTERA), 
AND THE Tries (ORDER THYSANOPTEBA)® 50 c's viv: 0) «10s assis eerste 
Characteristics of. Hemiptera, 164. Key to suborders, 165. Key to families 

of Homoptera, 166. Cicadas (Cicadide), 166. Tree-hoppers (Membracid) 
and lantern-flies (Fulgoride), 168. Leaf-hoppers (Jasside), 169. Spittle 
insects (Cercopide), 170. Jumping plant-lice (Psyllide), 171. Plant-lice 
(Aphidiide), 171. Grape-phylloxera, 176. Scale-insects (Coccida), 180. San 
José scale, 181. Remedies for scale-insects, 189. Mealy-winged flies (Aleyro- 
didw), 190. Key to families of Heteroptera, 194. | Water-striders (Hydroka- 
tide), 196. Water-boatmen (Corisidz), 198. Back-swimmers (Notonectidz), 


99 


LET 


123 


. 


Contents x1 


PAGE 

198. Water-creepers (Naucoride), 199. Giant water-bugs (Belostomatide), 
199. Water-scorpions (Nepide), 201. Toad-bugs (Galgulide), 202. Shore- 
bugs (Saldidz), 202. Assassin-bugs (Reduviide), 203. Thread-legged bugs 
(Emesid), 204. Damsel-bugs (Nabide), 204. Bedbugs (Acanthiidz), 205. 
Key to families of plant-feeding Heteroptera, 207. Lace-bugs (Tingitide), 207. 
Flat-bugs (Aradidx), 208. Flower-bugs (Capsidz), 209. Red-bugs (Pyrrho- 
coride), 210. Chinch-bugs and others (Lygewide), 211. Squash-bugs and 
others (Coreidz), 213. Stilt-bugs (Berytide), 214. Shield-bodied bugs (Pen- 
tatomide), 214. Lice (Pediculide), 216. Thrips (Thysanoptera), 219. 


CHAPTER XI 
THE NERVE-WINGED INSECTS (ORDER NEUROPTERA), SCORPION-FLIES (ORDER 
MECOPTERA), AND CADDIS-FLIES (ORDER TRICHOPTERA)............----055 223 


Key to the families of Neuroptera, 224. Key to the genera of Sialide, 224. 
Lace-winged flies (Chrysopide), 228. Aphis-lions (Hemerobiide), 229. Ant- 
lions (Myrmeleonide), 230. Key to subfamilies, 231. Key to genera of Myr- 
meleonine, 232. Key to Ascalaphine, 233. Snake-flies (Raphidiide), 233. 
Mantispide, 234. Coniopterygide, 235. Scorpion-flies and others (Mecoptera), 
235. Key to genera, 236. Caddis-flies (Trichoptera), 239. Cases of caddis- 
flies, 240. Life-history, 241. Key to families (adults), 244. Key to families 
(larvae), 244. 

CHAPTER XII 


MEEV BEETLES (ORDERN COLEOPTERA) tan .loieineielclelercreiehotioielcciiaetalocleveteilolakeroaterss 246 

External structure, 247. Internal structure, 248. Character of antenne and 
legs, 250. Key to sections and tribes, 251. Key to families of Adephaga, 252. 
Tiger-beetles (Cicindelide), 252. Predaceous ground-beetles (Carabide), 253. 
Diving beetles (Dyticide), 255. Whirligig beetles (Gyrinide), 257. Key to 
families of Clavicornia, 258. Water-scavenger beetles (Hydrophilide), 258. 
Rove-beetles (Staphylinide), 260. Carrion-beetles (Silphide), 261. Grain- 
beetles and others (Cucujide), 262. Larder-beetles and others (Dermestidz), 
263. Water-pennies (Parnide), 264. Beayer-beetles (Platypsyllide), 265. Key 
to families of Serricornia, 265. | Metallic wood-borers (Buprestide), 265. Click- 
beetles (Elateridz), 267. Fire-flies (Lampyridz), 269. Checker-beetles (Cleridz), 
270. Drug-store beetles and others (Ptinide), 271. Key to families of Lamellicor- 
nia, 272. Stag-beetles (Lucanide), 272. Leaf-chafers and others (Scarabei- 
dz), 273. Keyto families of Tetramera, 277. Leaf-eating beetles (Chrysome- 
lide), 277. Pea- and bean-weevils (Bruchide), 281. Long-horn boring beetles 
(Cerambycide), 282. Lady-bird beetles (Coccinellide), 286. Key to families 
of Heteromera, 288. Darkling ground-beetles (Tenebrionide), 288. Blister- 
and oil-beetles (Meloide), 289. Wasp-beetles (Stylopide), 293. Key to fami- 
lies of Rhynchophora, 294. Scarred snout-beetles (Otiorhynchide), 295. Cur- 
culios and weevils (Curculionide), 295. Rice- and grain-weevils (Calandride), 
297. Engraver beetles (Scolytide), 298. 


CHAPTER XIII 


SLWO=WINGEDNHDIES)| (ORDER) IDTPTERA) er) --jeleleteseieta)</s/sfele)atereyolel sft felelelele/ovelsle}e(0) Lele 301 
Characteristics of the Diptera, 301. Table to suborders and sections, 303. 
Key to families of Nematocera, 304. Mosquitoes (Culicide), 305. Mosquitoes 


xii Contents 


PAGE 

and human disease, 308. Midges (Chironomid), 310. Black-flies (Simuliide), 

313. Net-winged midges (Blepharoceride), 314. Dixide, 318. _Moth-flies 
(Psychodide), 319. Crane-flies (Tipulida), 321. Gall-midges (Cecidomyide), 

322.  Fungus-flies (Mycetophilide), 324. | March-flies (Bibionide), 325. 
Orphnephilide and Rhyphide, 327. Section Brachycera, 327. Key to 
families, 327.  Horse-flies (Tabanide), 328. Soldier-flies (Stratiomyide), 

329. Snipe-flies (Leptide), 330. Midas flies (Midaide), 330. Robber-flies 
(Asilide), 330. Key to families of Brachycera, 332. Bee-flies (Bombyliide), 

333- Dance-flies (Empidide), 334. Long-legged flies (Dolichopodide), 335. . 
Wasp-flies (Conopidx), 336. Bot-flies (Oestridz), 337. Flower-flies (Syrphi- 
de), 339. Calyptrate Muscide, 341. Key to subfamilies, 341. House-flies, 
etc., 342. Tachina flies, 345. Acalyptrate Muscide, 346. Ephydride, Pio- 
philide, Drosophilide, Trypetide, Oscinidi, etc., 347. Suborder Pupipara, 
351. Key to families, 351. Sheep-ticks, bat-ticks, bee-lice, etc., 351. Order 
Siphonaptera, 353. Fleas, 353. Key to families, 355. 


CHAPTER XIV 


MorTHS AND BUTTERFLIES (ORDER LEPIDOPTERA). ....--++-+-eeeeeeeeeee eee eee 358 
Structural characteristics, 358. Life-history, 360. Classification into sub- 
orders, 364. Key to superfamilies and families of moths, 367. Jugate moths 
(Micropterygide), 371. Ghost-moths (Hepialid), 372. Microlepidoptera, 374. 
Clothes-moths (Tineide), 374. | Pryalidina, 376. | Plume-moths and others 
(Pterophoride), 377. Close-wings (Crambide), 377. Meal-moths, flour-moths, 
bee-moths, and others (Pyralidz), 378. Leaf-rollers (Tortricide), 379. Flannel- 
moths (Megalopygide), 383. Slug-caterpillar moths (Eucleidz), 384. Car- 
penter-moths (Cosside), 385. Bag-worm moths. (Psychidz), 385. Smoky- 
moths (Pyromorphide), 386. Clear-wing moths (Sesiidz), 388. Puss-moths, 
handmaid-moths, prominents, etc. (Notodontide), 392. Inchworm-moths 
(Geometrina), 395. Owlet-moths (Noctuide), 399. | Tussock-moths (Lyman- 
triide), yoy. Oak-moths (Dioptide), 407. Pericopide, 407. Wood-nymph 
moths (Agaristide), 407. Footman-moths (Lithosiide), 409. Zyganid moths. 
(Syntomide), 410. Tiger-moths (Arctiidae), grr. ~ Tent-caterpillar moths. 
(Lasiocampide), 415. Bombyx moths (Saturniina), 417.  Silkworm-motks, 
418. Mulberry silkworm, 429. Sphinx-moths (Sphingide), 431. _ Butterflies,. 
439. Key to families of butterflies, 441. Giant-skippers (Megathymidz), 441. 
Skipper-butterflies (Hesperide), 442. Blues, coppers, and hair-streaks (Lyce- 
nidx), 443. | Cabbage-butterflies and others (Pieride), 444. Swallow-tails. 
(Papilionide), 446. Brush-footed butterflies (Nymphalidz), 450. 


CHAPTER XV 


SAW-FLIES, GALL-FLIES, ICHNEUMONS, Wasps, BEES, AND ANTS (ORDER HYMEN- 
OPTERA)s 6 < 0iemis aie oisiejnicitn wo isiss,« nists oie wiete elteatetaiate letter dics a (ei aa 459 
Structural characteristics, 459. Life-history, 461. Key to superfamilies and 
families, 463. Saw-flies and slugs (Tenthredinide), 464. Horntails (Siricidz), 
466. Gall-flies (Cynipide), 467. Parasitic Hymenoptera (Proctotrypoide, 
Chalcidiide, Ichneumonide), 477. Fig-insects, 487. Wasps, solitary and social, 
490. Classification into superfamilies and families, 490. Habits and instincts 


Contents Xi 


PAGE 
of solitary wasps, 491. Velvet-ants (Mutillide), 497. Cuckoo-flies (Chrysidide), 
498. Mason- or potter-wasps, 498. Eumenide, 498. Digger-wasps (Sphecide, 
Larride, Bembecide, Pompilide), 499. Wood-mining wasps (Mimeside, Pem- 
phredinide, Crabronidz), etc., 502. Social wasps (Vespide), 503. Key to 
genera, 503. Life-history of community of yellow-jackets, 503. Bees, 510. 
Characteristics, 511. Solitary bees, 513. Mining-bees and carpenter-bees, 513. 
Mason-bees and potter-bees and leaf-cutters, 514. | Mining-bees, 516. Social 
bees, 517. Bumblebees, 517. Honey-bees, 520. Life-history of community, 521. 
Ants (Formicina), 533. Characteristics and life-history, 535. Key to families, 
540. Poneride, 540. Myrmicide, 541. Camponotide, 545. Artificial nests, 
548. Myrmecophily, 552. Problems of ant behavior, 554. 


CHAPTER XVI 


EN SEGUSPANT) SHOWERS yersratetel ceva tortie eerie iete/ae are eee isitorscle eit 562 
Relations between plants and insects, 562. Cross-pollination in flowers, 563. 
Means of avoiding self-fertilization, 565. Specialization for cross-pollination, 
566. Uses of nectar and odor, 567. Modifications of insect visitors, 569. Par- 
ticular cases of flower specialization for cross-pollination, 571. Tubular corollas, 
571. Irregular tubular flowers, 572. Cross-pollination in Asclepias, 573. 
Cross-pollination of Aracea# and Aristolochiacee, 575. Cross-pollination of 
orchids, 575. Cross-pollination of Yucca by Pronuba, 576. Origin of speciali- 
zations for cross-pollination, 579. 


CHAPTER XVII 


GOLORMANDSLATTERN AND) HEIR) USES: sc cece acne ree eee one. 583 

Wide distribution of color and pattern among insects, 583. Explanations of 
some color phenomena in insects, 583. How color in organisms is produced, 
586. Classification of insect colors, 587. Color patterns of the butterflies and 
moths produced by scales, 589. Characteristics of the scales, 589. Ontogenetic 
appearance of color pattern in insects, 596. General protective resemblance, 599. 
Variable protective resemblance, 599. Special protective resemblance, 602. 
Warning colors, 604. Terrifying appearances, 605. Directive coloration, 607. 
Mimicry, 608. Criticisms of hypotheses of color use, 611. 


CHAPTER XVIII 


INSECES VANDI ISHASES Jag (01s cleye 414s iciele Parse ay eon aR Ee meeaNaie eissaielers cyticcniere Gites 615 
Economic relations between insects and man, 615. Dissemination of human 
diseases by insects, 616. Mosquitoes and malaria, 617. Mosquitoes and yel- 
low fever, 630. Mosquitoes and filariasis, 632. 


CHAPTER XIX 


IRERVEXES wINSHINCIS: AND! INDELIIGENGES cyevceieicis siaieclelevelereiaie aleloteleleiclets eyelet ¢. save 635 
Theories of insect behavior, 635. Points of view of Loeb and Jennings; tro- 
pisms and method of trial and error, 635. Distinguishing among reflexes, 


XIV ; Contents 


PAGE 
instincts, and intelligence, 636. Reflexes and tropisms, 638. Davenport’s 
analysis of behavior of Poduride, 639. ‘The swarming reflex of honey-bees, 639. 
Reflexes of silkworm-moths, 640. Instincts, 641. Complex behavior of solitary 
wasp, 643. Fabre’s experiments and conclusions, 643. Peckham’s experiments 
and conclusions, 650. An increasing mass of evidence favoring mechanical 
explanation of insect behavior, 655. 


APPENDIX 


(COLLECTING AND REARING! INSECTS 2. 0/5 o/0.5.5 215 «0001s «cls aise oly eben etetieeia tetas 656 
Collecting equipment, 656. When and how to collect, 660. Rearing insects, 
661. Aquarium, 665. 


INDEX s/ce sie ereters ooo bn de ce secesesienececevecevevesscesevassisseccccescanes OOG 


AMERICAN INSECTS 


CHAPTER! 


— 
BSS 


es SCE, 2 THE STRUCTURE AND SPECIAL 
PHYSIOLOGY OF INSECTS 


ERHAPS no more uninteresting matter, for 
the general reader or entomological amateur, 
can be written about insects than a descrip- 
tive catalogue of the parts and pieces of the 
insect body. And such matter is practically 
useless because it doesn’t stick in the reader’s 
mind. If it is worth while knowing the 

intimate make-up of a house-fly’s animated little body, it is worth 

getting this knowledge in the only way that will make it real, that is, 
by patient and eye-straining work with dissecting-needles and micro- 
scope. This book, anyway, is to try to convey some information about 
the kinds and ways of insects, and to stimulate interest in insect life, rather 
than to be a treatise on insect organs and their particular functions. Life 
is, to be sure, only the sum of the organic functions, but this sum or com- 
bination has an interest disproportionate to that of any of its component 
parts, and has an aspect and character which cannot be foretold in any com- 
pleteness from ever so careful a disjoined study of the particular functions. 
And so with the body, the sum of the organs: it is the manner and seeming 
of the body as a whole, its symmetry and exquisite adaptation to the special 
habit of life, the fine delicacy of its colors and pattern, or, at the other 
extreme, their amazing contrasts aud bizarrerie, on which depend our first 
interest in the insect body. A second interest, although to the collector and 
amateur perhaps the dominant one, comes from that recognition of the 
differences and resemblances among the various insects which is simply 
the appreciation of kinds, i.e., of species. This interest expanded by oppor- 
tunity and observation and controlled by reason and the habit of order and 
arrangement is, when extreme, that ardent and much misunderstood and 
scoffed at but ever-impelling mainspring of the collector and classifier. 


iOS 


ZW 
SS 
IES D) 


2 The Structure and Special Physiology of Insects 


Of all entomologists, students of insects, the very large majority are col- 
lectors and classifiers, and of amateurs apart from the few who have “‘crawl- 
eries” and aquaria for keeping alive and rearing “‘ worms” and water-bugs 
and the few bee-keepers who are more interested in bees than honey, prac- 
tically all are collectors and arrangers. So, as collecting depends on a 
knowledge of the life of the insect as a whole, and classifying (apart from 
certain primary distinctions) on only the extérnal structural character of 
the body, any detailed disquisition on the intimate character of the insec- 
tean insides would certainly not be welcome to most of the users of this 
book. 

That insects agree among themselves in some important characteristics 
and differ from all other animals in the possession of these characteristics 
is implied in the segregation of insects into a single great class of animals. 
Class here is used with the technical meaning of the systematic zoologist- 
He says that the animal kingdom is separable into, or, better, is composed 
of several primary groups of animals, the members of each group possessing 
in common certain important and fundamental characteristics of structure 
and function which are lacking, at any rate in similar combination, in all 
other animals. These primary groups are called phyla or branches. All 
the minute one-celled animals, for example, compose the phylum Protozoa 
(the simplest animals); all the starfishes, sea-urchins, sea-cucumbers, and 
feather-stars, which have the body built on a radiate plan and have no back- 
bone, and have and do not have certain various other important things, 
compose the phylum or branch Echinodermata; all the back-boned ani- 
mals and some few others with a cartilaginous rod instead of a bony column 
along the back compose the class Chordata; all the animals which have 
the body composed of a series of successive rings or segments, and have 
pairs of jointed appendages used as feet, mouth-parts, feelers, etc., aris- 
ing from these segments, compose the phylum Arthropoda. There are 
still other phyla—but I am not writing a zoology. The insects are Arthro- 
poda; and any one may readily see—it is most plainly seen in such forms as 
a locust, or dragon-fly, or butterfly, and less plainly in the concentrated 
knobby little body of a house-fly or bee—that an insect’s body shows the 
characteristic arthropod structure; it is made up of rings or segments, and 
the appendages, legs for easiest example, are jointed. An earthworm’s 
body is made up of rings, but it has no jointed appendages. A worm is 
therefore not an arthropod. A crayfish, however, is made up of distinct 
successive body-rings, and its legs and other appendages are jointed. And 
so with crabs and lobsters and shrimps. And the same is true of thousand- 
legged worms and centipeds and scorpions and spiders. All these creatures, 
then, are Arthropods. But they are not insects. So all the back-boned 
animals, fishes, amphibians, reptiles, birds, and mammals are Chordates, 


The Structure and Special Physiology of Insects 3 


but they are not all birds. The phylum Chordata is subdivided into or 
composed of the various classes Pisces (fishes), Aves (birds), ete. And 
similarly the phylum Arthropoda is composed of several distinct classes, 
viz.: the Crustacea, including the crayfishes, crabs, shrimps, lobsters, 
water-fleas, and barnacles; the Onychophora, containing a single genus 
(Peripatus) of worm-like creatures; the Myriapoda, including the thousand- 
legged worms and centipeds; the Arachnida, including the scorpions, spiders, 
mites, and ticks; and finally the class Insecta (or Hexapoda, as it is some- 
times called), whose members are distinguished from the other Arthro- 
antenne 


, 


auditory organ 
H 


“head compound eye ; 


1 


Ze 1 
pare ronotum / 
we 2 be dhonax 


tarsal segments 


Fic. 1.—Locust (enlarged) with external parts named. 


pods by having the body-rings or segments grouped into three regions, called 
head, thorax, and abdomen, by having jointed appendages only on the body- 
rings composing the head and thorax (one or two pairs of appendages may 
occur on the terminal segments of the abdomen), and by breathing by means 
of air-tubes (trachee) which ramify the whole interior of the body and 
open on its surface through paired openings (spiracles). The insects also 
have three pairs of legs, never more, and less only in cases of degeneration, 
and by this obvious character can be readily distinguished from the Myria- 
pods, which have many pairs, and the Arachnids, which have four pairs. 
Centipeds are not insects, nor are spiders and mites and ticks. What 
are insects most of this book is given to showing. 

To proceed to the classifying of insects into orders and families and 
genera and species inside of the all-including class is the next work of the 
collector and classifier. And for this—if for no other reason—some further 
knowledge of insect structure is indispensable. The classification rests 


4 The Structure and Special Physiology of Insects 


mostly on resemblances and differences in corresponding parts of the body, 
apparent in the various insect kinds. What these parts are, with their names 
and general characters, and what their particular use and significance are, 
may be got partly from the following brief general account, and partly from 
the special accounts given in connection with special groups of insects else- 
where in this book. A little patience and concentration of attention in 
the reading of the next few pages will make the reader’s attention to the 
rest of the book much simpler, and his understanding of it much more 
effective. 

The outer layer of the skin or body-wall of an insect is called the cuticle, 
and in most insects the cuticle of most of the body is firm and horny in char- 


Fic. 2.—Longitudinal section of anterior half of an insect, Menopon titan, to show chitin- 
ized exoskeleton, with muscles attached to the inner surface. (Much enlarged.) 
acter, due to the deposition in it, by the cells of the skin, of a substance called 
chitin. This firm external chitinized * cuticle (Fig. 2) forms an enclosing 
exoskeleton which serves at once to protect the inner soft parts from injury 


Fic. 3.—Bit of body -wall, greatly magnified, of larva of blow-fly, Calliphora erythrocephala, 
to show attachment of muscles to inner surface. 

and to afford rigid points of attachment (Figs. 2, 3 and 4) for the many small 

but strong muscles which compose the insect’s complex muscular system. 

Insects have no internal skeleton, although in many cases small processes 

project internally from the exoskeleton, particularly in the thorax or part 


* It is not certainly known whether the cuticle is wholly secreted by the skin cells, or 
is in part composed of the modified external ends of the cells themselves. 


The Structure and Special Physiology of insects 5 


of the body bearing the wings and legs. Where the cuticle is not strongly 
chitinized it is flexible (Fig. 6), thus permitting 
the necessary movement or play of the rings 
of the body, the segments of the legs, antenne 
and mouth-parts, and other parts. The small 
portions of chitinized cuticle thus isolated or 
made separate by the thin interspaces or sutures 


| i 


l 


wi 


Na 


v.n.c. 
Fic. 4. Fic. 5. 


Fic. 4.—Diagram of cross-section through the thorax of an insect to show leg and wing 
muscles and their attachment to body-wall. h., heart; ai.c., alimentary canal; v.7.c. 
ventral nerve-cord; w., wing; /., leg; m., muscles. (Much enlarged; after Graber.) 

Fic. 5.—Left middle leg of cockroach with exoskeleton partly removed, showing muscles. 
(Much enlarged; after Miall and Denny.) 


are called sclerites, and many of them have received specific names, while 
their varying shape and character are made use of in distinguishing and 
classifying insects. 


Fic. 6.—Chitinized cuticle from dorsal wall of two body segments of an insect, showing 
sutures (the bent places) between segmental sclerites. Note that the cuticle is not 
less thick in the sutures than in the sclerites, but is less strongly chitinized (indi- 
cated by its paler color). 


The whole body is composed fundamentally of successive segments 
(Figs. 1 and 7), which may be pretty distinct and similar, as in a caterpilla= 
or termite or locust, or fused together, and strongly modified, and hence 
dissimilar, as in a house-fly or honey-bee. The segments, originally five 
or six, composing the head, are in all insects wholly fused to form a single 
box-like cranium, while the three segments which compose the thorax are 
in most forms so fused and modified as to be only with difficulty distinguished 
as originally independent body-rings. On the other hand, in most insects 


6 The Structure and Special Physiology of Insects 


the sezmen‘s of the abdomen retain their independence and are more or 


compound eye, 
antenn®......}-.- 
ae) 
} 


prothorax \ 


lahial= 
palpr~ 


proboscis’ 


. \metathoraz 
N mesothorax 
4 Score 
“trochanter 
| Ssfemur 
uibia 


‘ ‘ 
tarsal segments 


Fic. 7.—Body of the monarch butterfly, Anosia plexippus, with scales removed to show 
external parts. (Much enlarged.) 


less similar, thus preserving a generalized or ancestral condition. On the 
head are usually four pairs of jointed appendages (Fig. 8), viz., the 
antenna and three pairs of mouth-parts, 
known as mandibles, maxilla, and labium or 
under-lip. Of these the mandibles in most 
cases are only one-segmented, while the two 
members of the labial pair have fused along 
their inner edges to form the single lip-like 
labium. The so-called upper lip or labrum, 
closing the mouth above, is simply a fold of 
the skin, and is not homologous, as a true 
appendage or pair of appendages, with the 
other mouth-parts. In some insects with highly 
modified mouth structure certain of the parts 
Fic, 8—Dorsal aspect of head ™2Y be wholly lost, as is true of the mandibles 
of dobson-fly, Corydalis cor- in the case of all the butterflies. The head 
nuta, female, showing mouth- hears also the large compound eyes and the 
parts. /6., labrum, removed; 5 ; ‘ 2 
md., mandible; mx., maxilla; Smaller simple eyes or ocelli (for an account of 
li., labium; gl, glosse of la- the eyes see p- 30). Attached to the thorax are 
bium; st., stipes of maxilla; | caer f] sail hiclbare jointed. d 
mxp., palpus of maxilla; ant, thtee pairs of legs, which are jointed appendages, 
antenna. homologous in origin and fundamental struc- 
ture with the mouth-parts and antenna, and two pairs of wings (one or 


—— 


The Structure and Special Physiology of Insects 7 


both pairs may be wanting) which are expansions of the dorso-lateral 
skin or body-wall, and are not homologous with the jointed ventral 
appendages. The thorax usually has its first or most anterior segment, 
the prothorax, distinct from the other two and freely movable, while 
the hinder two, called meso- and meta-thoracic segments, are usually 
enlarged and firmly fused to form a box for holding and giving attachment 
to the numerous strong muscles which move the wings and legs. The 
abdomen usually includes ten or eleven segments without appendages or 
projecting processes except in the case of the last two or three, which bear 
in the female the parts composing the egg-laying organ or ovipositor, or 


FIG. 1c. 

Fic. 9.—Head, much enlarged, of mosquito, Culex sp., showing piercing and sucking 
mouth-parts. (After Jordan and Kellogg.) 

Fic. 1o.—Head and mouth-parts of honey-bee, much enlarged. Note the short, trowel- 
like mandibles for moulding wax when building comb, and the extended proboscis 
for sucking flower-nectar. (Much enlarged.) 


in certain insects the sting, and in the male the parts called claspers, cerci, 
etc., which are used in mating. On the abdomen are usually specially notice- 
able, as minute paired openings on the lateral aspects of the segments, the 
breathing-pores or spiracles, which admit air into the elaborate system of 
trachee or air-tubes, which ramify the whole internal body (see p. 19). 

Of all these external parts two groups are particularly used in schemes 
of classification because of their structural and physiological importance 
in connection with the special habits and functions of insect life, and because 


8 The Structure and Special Physiology of Insects 


of the pronounced modifications and differences in their condition: these 
are the mouth-parts and the wings. 

Insects exhibit an amazing variety in food-habit: the female mosquito likes 
blood, the honey-bee and butterfly drink flower-nectar, the chinch-bug sucks 
the sap from corn-leaves, the elm-leaf beetle and maple-worm bite and chew 
the leaves of our finest shade-trees, the carrion-beetles devour decaying 
animal matter, the house-fly laps up sirup or rasps off and dissolves loaf- 
sugar, the nut- and grain-weevils nibble the 
dry starchy food of these seeds, while the 
apple-tree borer and timber-beetles find 
sustenance in the dry wood of the tree- 
trunks. The biting bird-lice are content 
with bits of hair and feathers, the clothes- 
moths and carpet-beetles feast on our rugs 
and woolens, while the cigarette-beetle has 
the depraved taste of our modern youth. 


FIG. 11. 


Fic. 1r.—Mouth-parts, much enlarged, of the house-fly, Musca domestica. mx.p., maxil- 
lary palpi; /b., labrum; /7., labium; /a., labellum. 

Fic. 12.—Head and mouth-parts, much enlarged, of thrips. ant., antenna; /b., labrum; 
md., mandible; mx., maxilla; mx.p., maxillary palpus; /i.p., labial palpus; m.s., 
mouth-stylet. (After Uzel; much enlarged.) 


With all this variety of food, it is obvious that the food-taking parts must 
show many differences; one insect needs strong biting jaws (Fig. 8), another 
a sharp piercing beak (Figs. 9, 13, and 14), another a long flexible sucking 
proboscis (Figs. ro and 16), and another a broad lapping tongue (Fig. 11). 
Just this variety of structure actualy exists, and in it the classific entomolo- 
gis: has found a basis for much of his modern classification. 

Throughout all this range of mouth structure the insect morphologists 
and students of homology, beginning with Savigny in 1816, have been able 
to trace the fundamental three pairs of oral jointed appendages, the mandi- 
bles, maxilla, and labium. Each pair appears in widely differing condi- 
tions; the mandibles may be large strong jaws for biting and crushing, as 
with the locust, or trowel-like, for moulding wax, as with the honey-bee, or 


The Structure and Special Physiology of Insects g 


long, flat, slender, and saw-toothed, as with the scorpion-flies, or needle-like, 
as in all the sucking bugs, or reduced to mere rudiments or wholly lacking, 
as in the moths and butterflies. Similarly with the other parts. But by 
careful study of the comparative anatomy of the mouth structure, and par- 
ticularly by tracing its development in typical species representing the 
various types of biting, sucking, and lapping mouths, all the various kinds of 
mouth structure can be compared and the homologies or structural cor- 
respondences of the component parts determined. Figs. 8 to 16 illustrate 


AUN IAIN 


Fic. 13. Fic, 14. Fic. 15. 

Fic. 13.—Seventeen-year cicada, Cicada septendecim, sucking sap from twig. (After 
Quaintance; natural size.) 

Fic. 14.—Section of twig of Carolina poplar showing beak of cicada in position when 
sucking. (After Quaintance; much enlarged.) 

Fic. 15.—Mouth-parts, much enlarged, of net-winged midge, Bibicocephala doanei, 
female. md., mandible; mx., maxilla; mx.l., maxillary lobe; mx.p., maxillary 
palpus; /7., labium; hyp., hypopharynx; pg., paraglossa of labium; /.ep., labrum 
and epipharynx. 


examples of different mouth structures, with the corresponding parts similarly 
lettered. 

The most conspicuous structural characteristic of insects is their poses- 
sion of wings. And the wings undoubtedly account for much of the success 
of the insect type. Insects are the dominant animal group of this age, as 
far as number of species constitutes dominance, their total largely sur- 
passing that of the species of all the other kinds of living animals. Flight 
is an extremely effective mode of locomotion, being swift, unimpeded by 
obstacles, and hence direct and distance-saving, and an animal in flight 
is safe from most of its enemies. The wings of insects are not modified true 
appendages of the body, but arise as simple sac-like expansions (Fig. 17) 
of the body-wall or skin much flattened and supported by a framework of 


10 The Structure and Special Physiology of Insects 


strongly chitinized lines called veins. 


framework 


class. 
been 


(Fig. 18). 


Fic. 
at left the proboscis is shown coiled up 
on the under side of the head, the nor- 


16.—Sphinx moth, showing proboscis; 


mal position when not in use. (Large 
figure, one-half natural size; small fig- 
ure, natural size.) 


These veins are corresponding cutic- 


ular thickenings, in the upper and lower walls of 
the flattened wing-sac, which protect, while the 
wing is forming, certain main tracheal trunks that 
carry air to the wing-tissue. 
expanded and dry, the trachee mostly die out, and 
the veins are left as firm thick-walled branching 
tubes which serve admirably as a skeleton or 


After the wing is 


for the thin membranous wings. _ It 


has been found that despite the obvious great 
variety in the venation, or number and arrange- 
ment of these veins of the wing, a general type- 
plan of venation is apparent throughout the insect 
The more important and constant veins have 
given names, and their branches numbers 


By the use of the same name or 


number for the corresponding vein throughout all 
the insect orders, the homologies or morphological 
correspondences of the veins as they appear in the 
variously modified wings of the different insects 
are made apparent. Many figures scattered through 


this book show the venation of insects of 
different orders, and the corresponding 
lettering and numbering indicate the 
homologies of the veins. As the wing 
venation presents differing conditions 
readily noted and described, much use is 
made of it in classification. 

The differences in the wings them- 
selves, that is, in number, relative size 
of fore and hind wings, and in struc- 
ture, i.e., whether membranous and 
delicate, or horny and firm, etc., have 
always been used to distinguish the 
larger groups, as orders, of insects, 
and the first classification, that of 
Linneus (1750 app.), divides the class 
into orders almost solely on a basis 


of wing characters. The ordinal names expressed, to some degree, the 
differences, as Diptera,* two-winged; Lepidoptera, scale-winged; Coleoptera, 


sheath-winged, and so on. 


As a matter of fact, there may be much differ- 


* The derivation of the Linnwan ordinal names is given on p. 223. 


The Structure and Special Physiology of Insects 11 


ence in the wings within a single order; most beetles, for example, have 
four wings, but some have two and some none. There are indeed wingless 
species in almost every insect order. But a typical beetle has quite dis- 
tinctive and commonly recognized wing characters; that is, it has two pairs 
of wings, the fore pair being greatly thickened, and developed to serve as 
sheaths for the larger, membranous under-pair, which are the true flight 
wings. Similarly, practically all moths and butterflies have two pairs of 


Fic. 17. Fic. 18. 

Fic. 17.—Wing of cabbage-butterfly, Pieris rape, in early sac-like stage. ¢r., trachea; 
u., tracheoles; /.v., lines of future veins. (After Mercer; greatly magnified.) 
Fic. 18.—Diagram of wings of monarch butterfly, Anosia plexippus, showing venation. 
c., costal vein; s.c., subcostal vein; 7., radial vein; cu., cubital vein; a., anal veins. 
In addition, most insects have a vein lying between the subcostal and radial veins, 

called the median vein. (Natural size.) 


membranous wings completely covered above and below by small scales, 
which give them their distinctive color and pattern. 

The exoskeleton, or cuticle, of the insect body is sometimes nearly 
smooth and naked, but usually it is sculptured by grooves and ridges, punc- 
tures or projections, and clothed with hairs or those modified flattened hairs 
known as scales (especially characteristic of butterflies and moths). This 
clothing of hairs or scales, or the skin itself, is variously colored and pat- 
terned, often with the obvious use of producing protective resemblance or 
mimicry, but often without apparent significance. (For an account of the colors 
and patterns of insects and their uses see Chapter XVII.) The hairs may serve 
for protection, or may be tactile organs, or even organs of hearing (see p. 26). 
The projecting processes may be spines or thorns or curious and inexplicable 


12 The Structure and Special Physiology of Insects 


knobs and horns. The rhinoceros-beetle (Dynastes) (Fig. 19) and the sacred 
scarabeus are familiar examples of insects with such prominent processes. 
The insect body, as a whole, appears in great variety of form and range 
of size, as our knowledge of the variety of habit and habitat of insects would 
lead us to expect. In size they vary from the tiny four-winged chalcids 
which emerge, after their parasitic immature life, from the eggs of other 
insects, and measure less than a millimeter in length, to the giant Phasmids 


Fic. 19.—Rhinoceros-beetle, Dynastes tityrus, showing chitinous horns. 


(walking-sticks) of the tropics, with their ten or twelve inches of body length, 
and the great Formosan dragon-flies with an expanse of wing of ten 
inches. A Carboniferous insect like a dragon-fly, known from fossils found 
at Commentry, France, had a wing expanse of more than two feet. 
Insects show a plasticity as to general body shape and appearance that results 
in extreme modifications corresponding with the extremely various habits 
of life that obtain in the class. Compare the delicate fragility of the gauzy- 
winged May-fly with the rigid exoskeleton and horny wings of the water- 
beetle; the long-winged, slender-bodied flying-machine we call a dragon- 
fly with the shovel-footed, half-blind, burrowing mole-cricket; the plump, 
toothsome white ant that defends itself by simple prolificness with the spare, 
angular, twig-like body of the walking-stick with its effective protective 
resemblance to the dry branches among which it lives. Compare the leg- 
less, eyeless, antennaless, wingless, sac-like degraded body of the orange- 
scale with the marvelous specialization of structure of that compact expo- 
nent of the strenuous insect life, the honey-bee; contrast the dull colors of the 
lowly tumble-bug with the flashing radiance of the painted lady-butterfly. 
But through all this variety of shape and pattern, complexity and degenera- 
tion, one can see the simple fundamental insect body-plan; the successive 
segments, their grouping into three body-regions, the presence of segmented 
appendages on head and thorax and their absence on abdomen (except 
perhaps in the terminal segments), and the modification of these append- 
ages into antenne and mouth-parts on the head, legs on the thorax, and 
ovipositor, sting, or claspers in the abdomen. 

In the character of the structure and functions of the internal organs 


The Structure and Special Physiology of Insects 13 


or systems of organs of insects, a special interest attaches to the conditions 
shown by the circulatory and respiratory systems, and by the special sense- 


Fic. 20.—Diagram of lateral interior view of monarch butterfly, Anosia plexippus, show- 
ing the internal organs in their natural arrangement, after the removal of the right 
half of the body-wall together with the trachee and fat body; I to III, segments 
of the thorax; 1 to 9, segments of the abdomen. Alimentary Canal and Appen- 
dages: ph., pharynx; sd. and sgl., salivary duct and gland of the right side; oe., 
cesophagus; /.r., food-reservoir; st., stomach; 7., small intestine; c., colon; r., rec- 
tum; @., anus; m.v., Malpighian tube. Hzmal System: h., heart or dorsal vessel; 
ao., aorta; d.c., aortal chamber; Nervous System (dotted in figure): br., brain; 
g., subcesophageal ganglion; /.g., compound thoracic ganglia; ag.,, ag.,, first and 
fourth abdominal ganglia. Female Reproductive Organs: cp., copulatory pouch; 
v., vagina; 0., oviduct, and oo., its external opening; r.ov., base of the right ovarian 
tubes turned down to expose the underlying organs; /.ov., left ovarian tubes in posi- 
tion, and ov.c., their termination and four cords; sp., spermatheca; a.g/.,, part 
of the single accessory gland; a.g/.,, one of the paired accessory glands; only the 
base of its mate is shown. Head: a., antenna; m-x., proboscis; /., labial palpus. 
(After Burgess; three times natural size.) 


organs and their manner of functioning. The muscular system varies from the 
simple worm-like arrangement of segmentally disposed longitudinal and 
ring muscles possessed by the caterpillars, grubs, and other worm-like larve, 
to the complicated system of such 
specialized and active forms as the 
honey-bee and house-fly. Lyonnet 
describes about two thousand dis- 
tinct muscles in the caterpillar of 
the goat-moth. Insect muscles are 
similar, in their finer structure, to 
those of other animals, most of Fic. 21.—Bit of muscle of a biting bird-louse, 
them being composed of finely Eurymetopus taurus, (Greatly magnified.) 
cross-striated fibers (Figs. 21 and 22) held together in larger or smaller 
masses and attaching to the rugosities of the inner surface of the exo- 
skeleton. The muscle substance, when fresh, is peculiarly transparent 
and delicate-looking, but it has great contractile power. 

The alimentary canal (Figs. 23-27), like that of other animals, is a tube 
but little longer than the body in flesh-eating forms, and much longer in 
plant-feeders; it runs, more or less curving and coiled, through the body 
{rom mouth to anal opening, which lies in the last segment of the abdomen. 


14 The Structure and Special Physiology of Insects 


This tube is expanded variously to form crop, gizzard, or stomach, and 


AE, 
a 


COUT; 
AE 
AD ne 
aa igi 
eT ety 
i Na a 


SAL Sf 


Sy 


la lem] 
as tomlin 


a 


( 


Fic. 22.—Diagrammatic figures of bits of insect muscle, variously treated. (After Van 


Fic. 23. Alimentary 
canal of a locust. At 
upper end the cesoph- 
agus, then the ex- 
panded crop, then sev- 
eral large gastric coeca, 
then the true stomach, 
the thread-like Malpig- 
hian tubules, the bent 
intestine, and the ex- 
panded rectum. (After 
Snodgrass; enlarged.) 


Gehuchten; greatly magnified.) 

contracted elsewhere to be cesophagus or intestine. 
One or two pairs of salivary glands pour their fluid into 
the mouth, while the digesting stomach or ventriculus 
usually possesses two or more pairs of diverticula known 
as gastric coeca, which are lined with glands believed 
to secrete special digestive fluids. Neither liver 
nor kidneys are present in the insect body, but the 
secretory function of the latter are undertaken by a 
number of usually long thread-like tubular diverticula 
of the intestine known as Malpighian tubules. The 
intestine itself is usually obviously made up of three 
successive parts, a large intestine, small intestine, 
and rectum. There are also 
present not infrequently in- 
testinal covca. 

Two striking peculiarities 
about the reproductive system 
of insects are the possession 
by the female of one or more 
spermathece (Fig. 66, 7.s.) in 
which the male fertilizing 
cells, the spermatozoa, are re- 
ceived and held, and the com- 
pletion of all the envelopes of Fis. -24 2c 
the egg, including the outer cockroach to show (al.c.) 
hard shell, before its specific alimentary canal. (After 


ste Ages oh ne ; Hatschek and Cori; twice 
fertilization takes place. Fer-  jatural size.) ‘ 


The Structure and Special Physiology of Insects 15 


tilization is itself accomplished in the lower end of the egg-duct just before the 
egg is laid, by the escape of spermatozoa from the spermatheca (the female 


Fic. 26. 

Fic. 25.—Alimentary canal of larva of harlequin-fly (Chironomus sp.). oes., oesophagus; 
s.g., salivary gland; ca., cardiac chamber of stomach; mt., Malpighian tubules; ci., 
intestinal chamber; s/., small intestine; co/., colon. (After Miall and Hammond; 
much enlarged.) 

Fic. 26.—Alimentary canal of two species of thrips; at left Trichothrips copiosa, male, 
at right Aelothrips fasciata. sal.g., salivary gland; oes., cesophagus; prov., proven- 
triculus; vent., ventriculus; m.t., Malpighian tubules; imt., intestine; rec., rectum. 
(After Uzel; greatly enlarged.) 


having of course previously mated) and their entrance into the egg through a 
tiny opening, the micropyle (Fig. 67), in the egg-shell and inner envelopes. 
A queen bee mates but once, but she may live for four or five years after 
this and continue to lay fertilized eggs during all this time. She must 


16 The Structure and Special Physiology of Insects 


receive several million spermatozoa at mating, and retain them alive in the 
spermatheca during these after-years. 


Fic. 27.—Alimentary canal of dobson-fly, Corydalis cornuta. A, larva; B, adult; C, pupa; 
oes., esophagus; prov., proventriculus; g.c., gastric coeca; vent., ventriculus; r.g., 
reproductive gland; m.t., Malpighian tubules; imt., intestine; imt.c., intestinal 
caecum; rec., rectum; drg., oviduct. (After Leidy; twice natural size.) 


The circulatory system of insects presents two particular features of inter- 
est in that the blood does not, as in our bodies, carry oxygen to the tissues, and 


Fic. 28.—Cross-section and longitudinal section of salivary gland of giant crane-fly, 
Holorusia rubiginosa. (Greatly magnified.) 
that there is a contractile pulsating heart-like organ, but no arteries or veins, 
The so-called heart is a delicate-walled, narrow, subcylindrical vessel com- 
posed of a series of most commonly from three to eight successive cham- 
bers lying longitudinally along the median line just underneath the dorsal 
wall of the abdomen and thorax (Figs. 30 and 31). Each chamber opens, 
guarded by a simple valvular arrangement (Fig. 33), into the chambers 


The Structure and Special Physiology of Insects 17 


behind and before it, the posterior one being closed behind and the anterior 


Fic. 29.—Cells of digestive epithelium of stomach (ventriculus) of crane-fly, Ptychoptera 
sp-, showing secretion of digestive fluids, or expulsion of cell-content. (After Van 


Gehuchten; greatly magnified.) 


one extending forward into or near the head as a narrowed tubular anterior 


portion, which is sometimes called the 
aorta. From the anterior open end of 
this aorta the blood, forced by pulsations 
of the heart-chambers, which proceed 
rhythmically from the posterior one 
forward, pours out into the body-cavity, 
proceeding in more or less regular cur- 
rents or paths, but never enclosed in 
arterial vessels, bathing all the tissues, 
and carrying food to them. Finally 
taking up fresh supplies of food by bath- 
ing the food-absorbing walls of the 
alimentary canal, it enters the chambers 
of the heart through lateral openings in 
these (either at the middle or anterior end 
of each), which thus establish communi- 
cation between the body-cavity and heart- 
The blood receives no more oxygen than 
it needs for its own use, and thus does 
not play nearly so complex a function in 
the insect’s body as in ours. And this 
simplicity of function probably explains 
in some degree the extreme primitiveness 
of the make-up of the circulatory system. 
It will be seen that the respiratory 


FIG. 30. FIG. 31. 


Fic. 30.—Diagram of circulatory 
system of a young dragon-fly; in 
middle is the chambered dorsal 
vessel, or heart, with single artery. 
Arrows indicate direction of blood- 
currents. (After Kolbe.) 

Fic. 31.—Dissection showing dorsal 
vessel, or heart, of locust, Dis- 
sosteira carolina. (After Snodgrass; 
twice natural size.) 


system, on the other hand, is particularly highly developed, as it devolves 


18 The Structure.and Special Physiology of Insects 


a $ 
a OT ee 
a ei 


Fic. 32. Fic. 33. 


Fic. 32.—Portion of dorsal vessel and pericardial membrane of locust, Dissosteira caroe 
lina. (After Snodgrass; greatly magnified.) 

Fic. 33.—Cross-section of dorsal vessel or heart in pupa of tussock-moth, Hemerocampa 
leucostigma, showing valves. (Greatly magnified.) 


= ae 


y 


Fic. 34. Fic. 35. Fic. 36. 
Fic. 34.—Diagram of tracheal system in body of beetle. sp., spiracles; ¢r., trachex. 
(After Kolbe.) 
Fic. 35.—Diagram showing main trachee in respiratory system of locust, Dissosteira 
carolina. (After Snodgrass; twice natural size.) 
Fic. 36.—Diagram showing respiratory system in thrips. s?., spiracles. (After Uzel; 
much enlarged.) 


The Structure and Special Physiology of Insects 19 


on it not merely to take up oxgyen from the outer air and give up the 


FIG. 37. 


Fic. 37.—Diagram showing respiratory system of pupa 
of mealy-winged fly, Aleyrodes sp.; only two pairs 
(After Bemis; much 


of spiracles are present. 
enlarged.) 


Fic. 38.—Diagram of trachee in head of cockroach. 
Note branches to all mouth-parts, and the an- 
(After Miall 


tenne. &£, trachez, or air-tubes. 
and Denny.) 


waste carbon dioxide of the 
body, but also to convey these 
gases to and from all the tis- 
sues of the body. The blood 
is not red, but pale yellowish 
or greenish, and is really more 
like the lymph of the ver- 
tebrate body than like its 
blood 

Insects do not breathe 
through the mouth or any 
openings on the head, but have 
a varying number (usually 
from two to ten pairs) of 
small paired openings on the 
sides of the thorax and abdo- 
men. These openings, called 
spiracles, or stigmata, are ar- 
ranged segmentally and in 
most insects are to be found 
on two of the thoracic seg- 
ments and on all the abdomi- 


nal segments except the last two or three. The openings are guarded by fine 


hairs or even little valvular lids to prevent 
the ingress of dust, and are the entrances to 
an extended system of delicate air-tubes or 
trachee which branch and subdivide until 
the whole of the internal body is reached 
and ramified by fine capillary vessels bring- 
ing fresh air to all the tissues and carrying 
off the waste carbon dioxide made by the 
metabolism of these tissues. The usual 
general arrangement of this elaborate re- 
spiratory system is shown in Figs. 34, 35, 
and 36. Short broad trunks lead from 
each spiracle to a main longitudinal trunk 
on each side of the body, from which 
numerous branches arise, these going to 
particular regions of the body (Fig. 38) 
and there branching repeatedly until 
even individual cells get special tiny 


Fic. 39.—Piece of trachea (air-tube), 


greatly magnified, showing spiral 
thread (tznidia). (Photomicro- 
graph by George O, Mitchell.) 


20 The Structure and Special Physiology of Insects 


respiratory capillaries. The trachex are readily recognized under the micro- 
scope by their finely transversely ringed or striated appearance (Fig. 39). 
These transverse ‘“‘rings” are really spirally arranged short chitinized 
thread-like thickenings on the inner wall of the tube, which by their elasticity 
keep the delicate air-tubes open. The tubes are filled and emptied by a 
rhythmic alternately contracting and expanding 
movement of the abdomen, called the respiratory 
movement. When the ring-muscles contract, the 
walls of the abdomen are squeezed in against 
the viscera, which, compressing the soft air-tubes, 
force the air out of them through the spiracles; 
when the body-walls are allowed to spring back 
to normal position fresh air rushes in through the 
spiracles and fills up the air-tubes, which expand 
because of the elastic spiral thickenings in their 
walls. Insects which live in water either come 
up to the surface to breathe and in some cases 
to take down a supply of air held on the outside 
of the body by a fine pubescence like the pile of 
velvet, or they are provided with tracheal gills 
(Fig. 40) which enable them to breathe the air 
mixed with, or dissolved in, the water. Gilled 
insects do not, of course, have to come to the 
surface to breathe. The gills may be thin plate- 
ae 4°.—Young (nymph) of ike flaps on the sides or posterior tip of the 
ay-fly showing (g.) tra- i 
cheal gills. (After Jenkins body, or may be tufts of short thread-like tubes 
and Kellogg.) variously arrangc:d over the body. Or they 
may be, as in the dragon-fly nymphs, thin folds along the inner wall of the 
rectum, the water necessary to bathe them being taken in and ejected again ~ 
through the anal opening. In all cases these insect gills differ from those 
of other animals, as crabs and fishes, in that they are not organs for the 
purification of the blood, i-e., effecting an exchange of carbon dioxide and 
oxygen carried by it, but are means for an osmotic exchange of the fresh 
air dissolved in water for carbon-dioxide-laden air from air-tubes or trachex 
which run out into the gills. Probably no more blood enters these gills 
than is necessary to bring food to them. Impure air is brought to them 
by air-tubes, and exchanged by osmosis through the thim walls of air-tube 
and gill-membrane for fresh air, which passes from these gill air-tubes to 
the rest of the respiratory system of the body. 
The nervous system of insects shows the fundamentally segmental make-up 
of the body better than any of the other systems of internal organs, although 
probably in the successive chambers of the dorsal vessel or heart, and certainly 


The Structure and Special Physiology of Insects 21 


in the paired arrangement of the spiracles and tracheal trunks leading from 
them, a segmental condition is obvious. The central nervous system consists 


Fic. 41.—Larva of giant crane-fly, Holorusia rubiginosa, A, entire; B, dissected, show- 
ing all organs except the muscles and ventral nerve-chain. /h., head; ant., antenna; 
i.b.res., imaginal bud of pupal respiratory tube; 7.b.wg., imaginal bud of wing; 
i.b.ms.l., imaginal bud of mesothoracic leg; 7.b.h., imaginal bud of balancer; 
i.b.mt.l., imaginal bud of metathoracic leg (the imaginal buds of fore legs are con- 
cealed by head-capsule); sa/.gi., salivary gland (the other salivary gland is removed) ; 
br., brain; @s., cesophagus; prov., proventriculus; swsp., suspensorium; g.c., gastric 
ceecum; vent., ventriculus; /7., trachea; ad.tis., adipose tissue; mal.tub., Malpi- 
ghian tubule; d.v., dorsal vessel; w.m., wing-muscles of pericardium; sm.znt., 
small intestine; /es., testis; int.c., intestinal cecum; v.d., vas deferens; /.int., large 
intestine; sp., spiracle; ferm.pr., terminal processes. (Twice natural size.) 


of a brain and a ventral chain of pairs of ganglia segmentally arranged and 
connected by a pair of longitudinal cords or commissures (Figs. 42, 43, 44)- 
The two members of each of the pairs of ganglia as well as of the pair of 


22 The Structure and Special Physiology of Insects 


i= 


AG 


Fic. 42. FIG. 43. Fic. 44. 


Fic. 42.—Diagram of ventral nerve-cord of locust, Dissosteira carolina. (After Snod- 
grass; twice natural size.) 
Fic. 43.—Diagram of the nervous system of the house-fly. (After Brandt; much 
: enlarged.) 
Fic. 44.—Nervous system of a midge, Chironomus sp. (After Brandt, much enlarged.) 


commissures are in most insects more or less fused to form single ganglia 
and a single commissure, but in others the commissures, 
at least, are quite distinct. In the simpler or more 
generalized condition of the nervous system as seen 
in the simpler insects and the larve of the higher 
ones there are from three or four to seven or eight 
abdominal ganglion pairs, one pair to a segment, a 
pair in each of the three thoracic segments, and one 
in the head just under the cesophagus. From this 
ganglion (or fused pair) circumcesophageal commis- 
sures run up around the cesophagus to an important 
Fic. 45.—Brain, com- ganglion (also composed of the fused members of a 
pear alas pair) lying just above the cesophagus and called the 
ous system of locust, brain, or supracesophageal ganglion (Figs. 45, 46, and 
Dissosteira carolina. 47). From this proceed the nerves to those impor- 
Cea Sr tant organs of special sense situated on the head, the 
antenne and eyes. From the subcesophageal gan- 

glion nerves run to the mouth-parts, from the thoracic ganglia to the 


The Structure and Special Physiology of Insects 23 


wings and legs and the complex thoracic muscular system, while from 
the abdominal ganglia are innervated the abdominal muscles and sting, 
ovipositor, or male claspers. In addition to this main or ventral nervous 
system there is a small and considerably varying sympathetic system (Figs. 
46 and 48) to which belong a few minute ganglia sending nerves to those 
viscera which act automatically or by reflexes, as the alimentary canal and 
heart. This sympathetic system is connected with the central or principal 


Fic. 46. Fic. 47. 


Fic. 46.—Brain, circumcesophageal commissures, and suboesophageal ganglion of the 
red-legged locust, Melanoplus femur-rubrum. oc., ocellus; op.n., optic nerve; a.n., 
antennal nerve; m.oc., middle ocellus; op./., optic lobe; a./., olfactory lobe; a.s.g., 
anterior sympathetic ganglion; .s.g., posterior sympathetic ganglion; /.g., frontal 
sympathetic ganglion; /br., nerve to labrum; 0e.c., circumcesophageal commissure; 
g', suboesophageal ganglion; md., nerve to mandible; mx., nerve to maxilla; /.n., 
nerve to labium; 2., unknown nerve, perhaps salivary. (After Burgess; greatly 
magnified.) 

Fic. 47.—Cross-section of brain, cesophagus, circumcesophageal commissures, and 
suboesophageal ganglion of larva of the giant crane-fly, Holorusia rubiginosa. 


nervous system by commissures which meet the brain just at the origin 
from it of the circumcesophageal commissures. 

The specialization of the ventral nerve-chain is always of the nature of 
a concentration, and especially cephalization of its ganglia (Figs. 49 and 
50). The abdominal ganglia may be fused into two or three or even into 
one compound ganglion; or indeed all of them may migrate forward and 
fuse with the hindmost thoracic ganglion, thus leaving the whole abdomen 


24 The Structure and Special Physiology of Insects 


to be innervated by long nerves running from the thorax. The thoracic 
ganglia may fuse to form one, and in extreme cases all the abdominal and 
thoracic ganglia may be fused into one large mid- 
thoracic center. 

In tracing the development of the nervous 
system during the ontogeny of one of the special- 
ized insects, the changes from generalized condi- 
tion, i.e., presence of numerous distinct ganglia 
segmentally disposed, shown in the newly hatched 


: 
Hl 


Fic. 48 Fic. 49. 


Fic. 48.—Part of sympathetic nervous system of larva of harlequin-fly, Chironomus 
dorsalis. oes., esophagus; /.g., frontal ganglion; r.., recurrent nerve; d.v., dorsal 
vessel; m‘, nerve passing from brain to frontal ganglion (Newport’s fourth nerve); 
br., brain; rm., point of division of recurrent nerve; /r., trachee; pg., paired ganglia; 
d.v.n., nerve of dorsal vessel; d.v.g., ganglia of dorsal vessel; g.m., gastric nerve 
to cardiac chamber. The course of the recurrent nerve beneath the dorsal vessel is 
dotted. (After Miall and Hammond; greatly magnified.) 

Fic. 49.—Stages in the development of the nervous system of the honey-bee, A pis melli- 
fica; 1 showing the ventral nerve-cord in the youngest larval stage, and 7 the system 
in the adult. (After Brandt; much enlarged.) 


larva, to specialized condition, i.e., extreme concentration and cephalization, 
that is, migration forward and fusion of the ganglia, shown in the adult, 
are readily followed (Figs. 49 and 50). 

The special senses of insects and the sense-organs are of particular inter- 
est because of the marked unusualness of the character of the specialization 
of both the organs and senses, as compared with the more familiar condi- 
tions of the corresponding organs and functions of our body. The world 
is known to animals only by the impressions made by it on the sense-organs, 


The Structure and Special Physiology of Insects 25 


and the particular condition of functioning of these organs, therefore, is of 
unique importance in the life of any particular animal. If the senses vary 
much in their capacities among different animals, the world will have a differ- 
ent seeming to different creatures. It will be chiefly known to any par- 
ticular species through the dominant sense of that species. To the con- 
genitally blind the world is an experience of touched things, of heard things, 
and of smelled and tasted things. To the bloodhound it is known chiefly 
by the scent of things. It is a world of odors; the scent of anything deter- 
mines its dangerousness, its desirableness, its interestingness. As insects 
know it, then, the world depends largely upon the particular character and 
capacity of their sense-organs, and we realize on even the most superficial 
examination of the structure of these organs, and casual observation of the 


Fic. 50.—Stages in the development of the nervous system of the water-beetle, 4cilius 
sulcatus; 1 showing the ventral nerve-cord in the earliest larval stage, and 7 the 
system in the adult. (After Brandt; much enlarged.) 

responses of insects to those stimuli, like sound-waves, light-waves, dis- 

solved and vaporized substances, which affect the sense-organs, that the 

insects have some remarkable special sense-conditions. But the difficul- 
ties in the way of understanding the psychology of any of the lower animals 
are obvious when it is recalled that our only knowledge of the character 
of sense-perceptions has to depend solely on our experience of our own per- 
ceptions, and on the basis of comparison with this. We do not know if 
hearing is the same phenomenon or experience with insects as with us. 

But a comparison of the morphology of the insect sense-organs with that 

of ours, and a course of experimentation with the sight, hearing, smelling, 

etc., of insects, based on similar experimentation with our own senses, leads 
us to what we believe is some real knowledge of the special sense-condi- 
tions of insects. 


26 The Structure and Special Physiology of Insects 


Insects certainly have the senses of touch, hearing, taste, smell, and sight. 

If they have others, we do not know it, and probably cannot, as we have 
; no criteria for recognizing others. 
The tactile sense resides especially 
in so-called ‘‘ tactile hairs,” scattered 
more or less abundantly or regu- 
larly over the body. Each of these 
hairs has at its base a ganglionic 
nerve-cell from which a fine nerve 
runs to some body ganglion (Fig. 51). 
They are specially numerous and 
conspicuous on the antenne or 
Fis. 51.— Diagram showing innervation of s “ feelers,” and often on certain pro- 
tactile hai. oh tactile Batch <hitnized cesses called cerci, projecting from 
of the skin; s.c., ganglion cell; c.o., gan- the tip of theabdomen. They may 
eae central nervous system, (After occur, however, on any part of the 
body, and are usually recognizable 

by their length and semi-spinous nature. The sense of taste resides 
in certain small papille, usually two-segmented, or in certain pits, which 


Fic. 52. Fic. 53. 
Fic. 52.—Nerve-endings in tip of maxillary palpus of Locusta viridissima. s.h., sense- 
c hairs; s.c., sense-cells; b.c., blood-cells. (After vom Rath; greatly magnified.) 
Fic. 53.—Nerve-endings in tip of labial palpus of Machilis polypoda. (After vom 
Rath; greatly magnified.) 
occur on the upper wall of the mouth (epipharynx) and on the mouth- 
parts, especially the tips of the maxillary and labial palpi, or mouth- 


feelers. As substances to be tasted have to be dissolved, and have to 


The Structure and Special Physiology of Insects 27 


come into actual contact with the special taste nerves, it is obvious 
that insects, to taste solid foods, have first to dissolve particles of these 
foods in the mouth-fluids, and that the taste-organs have to be situated 
in the mouth or so that they can be brought into it to explore the food, as 
are the movable, feeler-like palpi. What experimentation on the sense of 
taste in insects has been carried on shows that certain insects certainly taste 
food substances, and indicates that the sense is a common attribute of all 
insects. Lubbock’s many experiments with ants, bees, and wasps present 
convincing proof of the exercise of the taste sense by these insects. Forel 
mixed morphine and strychnine with honey, which ants, attracted by the 
honey smell, tasted and refused. Will’s experiments show that wasps 
recognize alum and quinine by taste. He found bees and wasps to have 
a more delicate gustatory sense than flies. 

Smell is probably the dominant special sense among insects. It exists 
at least in a degree of refinement among certain forms that is hardly 
equalled elsewhere in the animal kingdom. The smelling organs are micro- 
scopic pits and minute papilla seated usually and especially abundantly 
on the antenne, but probably also occurring to 
some extent on certain of the mouth-parts. The 
fact that the antenne are the principal, and in 
many insects the exclusive, seat of the olfactory 
organs has been proved by many experiments in 
removing the antenne or coating them with par- 
affine. Insects thus treated do not find food or 
each other. As substances to be smelled must 
actually come into contact, in finely divided con- 
dition, with the olfactory nerve-element, these 
pits and papillae are arranged so as to expose 
the nerve-end and yet protect it from the 
tuder contact with obstacles against which the 
antenne may strike. It is certain that most 
insects find their food by the sense of smell, and 
the antenna of a carrion-beetle (Fig. 54) shows 
plainly the special adaptation to make this sense 
highly effective. On the “leaves” of each antenna 


Fic. 54.—Antenna of a 


of June-beetles nearly 40,000 olfactory pits occur. ROMER Cte with the 
Some of the results of experimentation on smell terminal three segments 
indicate a delicacy and specialization of this sense enlarged and flattened, 

: J om and bearing many smell- 
hardly conceivable. A few examples will illustrate ing-pits. | (Photomicro- 


graph by George O. Mit- 


this. It is believed that ants find their way back 
/ chell; much enlarged.) 


to their nests by the sense of smell, and that 
they can recognize by scent among hundreds of individuals taken from 


28 ‘The Structure and Special Physiology of Insects 


various communities the members of their own community. Miss Fielde’s 
experiments show that the recognition of ants by each other depends on the 
existence of a sense of smell of remarkable differentiative capacity. The 
odors of the nest, of the species, of the female parent, and of the individ- 
ual are all distinct and perceivable by the smelling-organs, situated on 
distinct particular antennal segments. In the insectary at Cornell University 
a few years ago a few females of the beautiful large promethea moth were 
put into a covered box which was kept inside of the insectary building. 
No males of this moth species had been seen about the insectary nor in 
its immediate vicin- 
ity for several days, 
although they had 
been specially sought 
for by collectors. 
Yet in a few hours 
after the female 
moths were first con- 
fined nearly fifty 
male prometheas 
were fluttering about 
outside over the glass 
roof of the insectary. 
They could not see 
the females, but un- 
doubtedly discovered 
them by the sense of 
smell. These pro- 
methea moths have 


Fic. 55- Auditory organ of a locust, Melanoplus sp. The elaborately branched 
large clear part in the center of the figure is the thin tym- feat Ry etant 
panum with the auditory vesicle (small, black, pear-shaped OF eathered anten- 
spot) and auditory ganglion (at left of vesicle and connected ne, affording area 
with it by a nerve) on its inner surface. (Photomicrograph 

- ¢ * 2 r , « y Ss >} }- 
by George O, Mitchell; greatly magnified.) for WeSay ate S mell 


ing-pits. 

Mayer’s experiments with promethea also reveal the high specialization 
of the sense of smell. This investigator carried 450 promethea cocoons 
from Massachusetts to the Florida keys. Here on separated small 
islands the moths issued from the cocoons, hundreds of miles south of their 
natural habitat. This isolation insured that no other individuals than 
those controlled by the experimenter could confuse the observations. 
Female moths were confined in glass jars with the mouth closed by 
netting. Other females were confined in smaller glass jars turned upside 
down and the mouth buried in sand. Males being released at various 


The Structure and Special Physiology of Insects 29 


distances soon found their way to the jar (containing females) which had 
its mouth open to the air, but no male came to the jar with its mouth her- 


metically sealed. Through the glass sides of both 
jars the females were plainly visible. The antennz 
of certain males were covered with shellac. These 
males, when released, never found the females, and 
often paid no attention to them when brought within 
an inch of their bodies. Of other males the eyes 
were covered with pitch; but these males had no 
difficulty whatever in finding the females. It is 
plainly obvious from these experiments that the 
males found the females wholly by scent and not at 


all by sight. 


That some insects hear is proved by their posses- 
sion of auditory organs, and has also been demon- 
The fact, too, that many 


strated by experiment. 
insects have special sound-making 
do make characteristic sounds is a 
that they can also hear. 


Fic. 56.—Male mosquito, 
showing (a.h.) antennal 
hairs. (After Jordan 
and Kellogg; three times 
natural size.) 


apparatus and 
kind of proof 


The auditory organs of insects, curiously enouch, 


are of several kinds and are situated on different parts of the body, in 


Fic. 57.—Diagram of longitudinal section 
through first and second antennal seg- 
ments of a mosquito, Mochlonyx culici- 
jormis, male, showing complex auditory 
organ composed of fine chitinous rods, 
nerve-fibers, and _nerve-cells. (After 
Child; greatly magnified.) 


various species. Among the locusts, 
katydids, and crickets, the most con- 
spicuous of all the sound-making in- 
sects except the cicada, the ears are 
small tympanic membranes on the 
base of the abdomen in the locusts 
(Fig. 55), and on the tibiz of the fore 
legs in the katydids 
Associated with each tympanum is a 
small liquid-filled vesicle and a special 
auditory ganglion from which 


and crickets. 


an 
auditory nerve runs to one of the 
ganglia of the thorax. Among the 
midges and mosquitoes the antennz 
those all-important sensitive structures 
—are abundantly provided with cer- 
tain fine long hairs, the auditory hairs 
(Fig. 56), which take up the sound- 
waves and transmit the vibrations to an 


elaborate percipient structure composed of many fine chitin-rods and ganglion- 


ated nerves contained in the next to basal antennal segment (Fig. 57). 
this segment runs a principal auditory nerve to the brain. 


From 
Many other insects 


30 ©The Structure and Special Physiology of Insects 


besides the midges and mosquitoes possess this type of auditory organ; 
in fact such an organ, more or less well developed, has been found in almost 
every order except the Orthoptera (the order of locusts, crickets, katydids, 
etc.) in which the tympanic auditory organs occur. 
Special isolated hairs scattered sparsely over the 
body, connected with a special peripheral nervous 
arrangement, are believed by some entomologists 
to be a third kind of auditory structure, and are 
called chordotonal organs. Experimentally the 
sense of hearing has been surely determined for 
certain insects. A single striking example of this 
experimentation must here suffice. Mayer fastened 
a live male mosquito to a glass slide, put it under 
Fic. 58.—Longitudinal sec- @ microscope, and had a series of tuning-forks of 


tion through ocellus of the 
honey-bee, A pis mellifica. 
/., cuticular lens; 7.c., cell- 
ular layer of skin; c.b., 
crystalline layer; r.c., ret- 
inal cells; 0.7., optic 
nerve. (After Redikor- 


different pitch sounded. When the Ut, fork of 
512 vibrations per second was sounded many of 
the antennal hairs were set, sympathetically, into 
strong vibration. Tuning-forks of pitch an octave 
lower and an octave higher also caused more 


zew; greatly magnified.) vibration than any intermediate notes. The male 


mosquito’s auditory hairs, then, are specially fitted to respond to, i.e., be 
stimulated by, notes of a pitch produced by 512 vibrations. Other, but 
fewer, hairs of different length vibrated in response to other tones. Those 
auditory hairs are most affected which are at right angles to the direction 
from which the sound comes. From this it is obvious that, from the position 
of the antenna and the hairs, a sound will be loudest or most intense if it is 
directly in front of the head. If the mosquito is attracted by sound, it will 
thus be brought straight head end on toward the source of the sound. As a 


Fic. 59.—Ocellar lens of larva of a saw-fly, Cimbex sp., showing its continuity with the 
chitinized cuticle. (After Redikorzew; greatly magnified.) 

matter of fact, Mayer found the female mosquito’s song to correspond nearly 

to Ut,, and that her song set the male’s auditory hairs into vibration. With 

little doubt, the male mosquitoes find the females by their sense of hearing. 
Insects have two kinds of eyes, simple and compound. On most 

species both kinds are found, on some either kind alone, and in a few no 

eyes at all, Blind insects have lost the eyes by degeneration. The most 


ee 


The Structure and Special Physiology of Insects 31 


primitive living insects, Campodea and others, have eyes, although only 


Fic. 60.—Part of corneal cuti- 
cle, showing facets, of the 
compound eye of a_horse- 
fly, Therioplectes sp. (Photo- 
micrograph by George O. 
Mitchell; greatly magnified.) 


simple ones. The larve of the specialized 
insects, i.e., those with complete metamor- 
phosis, also have only simple eyes. The com- 
pound eyes are not complex or specialized 
derivations of the simple ones, but are of in- 
dependent origin and of obviously distinct 
structural character. The simple eyes, also 
called ocelli (Fig. 58), which usually occur to 
the number of three in a little triangle on 
top of the head, are small and inconspicuous, 
and consist each of a lens, this being simply 
a small convexly thickened clear part of the 
chitinized cuticle of the head-wall (Fig. 59) 
and a group of modified skin-cells behind it 
specially provided with absorbent pigment and 


capable of acting as a simple light-sensitive or retinal 
surface. The ocellus is supplied with a special nerve 
from the brain. The compound eyes are always 
paired and situated usually on the dorso-lateral parts 
of the head; they are usually large and conspicu- 
ous, sometimes, as in the dragon-flies and _horse- 
flies, even forming two-thirds or more of the mass 
of the head. Externally each compound eye pre- 
sents a number (which varies all the way from a 
score to thirty thousand) of facets or microscopic 
polygonal cuticular windows (Fig. 60). These are 
the cornea of the eye. Behind each facet is a dis- 
tinct and independent subcylindrical eye-element or 
ommatidium composed of a crystalline cone (want- 
ing in many insects) enveloping pigment (which pre- 
sumably excludes all light-rays except those which 
fall perpendicularly or nearly so to the corneal 
lens of that particular ommatidium), and a slender 


tapering part including or composed of the nervous Fic, 61.—Longitudinal 


or retinal element called rhabdom (Fig. 61). Each 
of these ommatidia perceives that bit of the external 
object which is directly in front of it; i.e., from which 
light is reflected perpendicularly to its corneal facet. 
All of these microscopic images, each of a small part 
of the external object, form a mosaic of the whole 
object, and thus give the familiar name mosaic 


section through a few 
facets and eye-elements 
(ommatidia) of the 
compound eye of a 
moth. /., corneal fac- 
ets; cc., crystalline 
cones; p., pigment; r., 
retinal parts; 0.7., optic 
nerve. (After Exner; 
greatly magnified.) 


32 The Structure and Special Physiology of Insects 


vision to the particular kind of seeing accomplished by the compound 
eye. 

The character or degree of excellence of sight by the two kinds of 
eyes obviously varies much. The fixed focus of the ocelli is extremely short, 


gs, es 


—— 


Fic. 64. 


Fic. 62.—Longitudinal sections through outer part of eye-clements (ommatidia) of com- 
pound eyes of Lasiocampia quercifolia; ommatidia at left showing disposition of 
pigment in eyes in the light, at right, in the dark. (After Exner; greatly magnified.) 

Fic. 63.—Longitudinal section through a few eye-elements of the compound eye of Cato- 
cola nupta; left ommatidia taken from an insect killed in the dark, right ommatidium 
taken from insect killed in the light. (After Exner; greatly magnified.) 

Fic. 64.—Section through the compound eyes of a male May-fly, showing division of 
each compound eye into two parts, an upper part containing large eye-elements 
(ommatidia), and a lower part containing small eye-elements (ommatidia). (After 
Zimmerman; greatly magnified.) 


and probably the range of vision of these eyes is restricted to an inch or 
two in front of the insect’s head. Indeed entomologists commonly believe 
that the ocelli avail little beyond distinguishing between light and darkness. 
With the compound eyes the focus is also fixed, but is longer and the range 
of vision must extend to two or three yards. It is obvious that the larger 


The Structure and Special Physiology of Insects 33 


and more convex the eyes the wider will be the extent of the visual field, 
while the smaller and more abundant the facets the sharper and more dis- 
tinct will be the image. Although no change in focus can be effected, cer- 
tain accommodation or flexibility of the seeing function is obtained by the 
movements of the pigment (Figs. 62 and 63) tending to regulate the amount 
of light admitted into the eye (as shown by Exner), and by a difference in size 
and pigmental character of the ommatidia (Fig. 64) composing the com- 
pound eyes of certain insects tending to make part of the eye especially 


Fic, 65.—A section through the compound eye, in late pupal stage, of a blow-fly, Ca/l7- 
phora sarracenie. In the center is the brain with optic lobe, and on the right-hand 
margin are the many eye-elements (ommatidia) in longitudinal section. (Photomi- 
crograph by George O. Mitchell; greatly magnified.) 


adapted for seeing objects in motion or in poor light, and another part for 
seeing in bright light and for making a sharper image (as shown by Zim- 
merman for male May-flies, and by myself for certain true flies (see p. 318)). 
Our careful studies of the structure of the insect eye, and the experimentation 
which we have been able to carry on, indicate that, at best, the sight of 
insects cannot be exact or of much range. 

The psychology of insects, that is, their activities and behavior as deter- 
mined by their reflexes, instincts, and intelligence, is a subject of great inter- 
est and attractiveness, but obviously one difficult to study exactly. The 


34 The Structure and Special Physiology of Insects 


elaborateness of many insect instincts, such as those of the ants, wasps, and 
bees, to choose examples at once familiar and extreme in their complexity, 
makes it very difficult to analyze the trains of reactions into individual ones, 
and to determine, if it is indeed at all determinable, the particular stimuli 
which act as the springs for these various reactions. The attitude of the 
modern biologist in this matter would be to keep first in mind the theory 
of reflexes, to look keenly for physico-chemical explanations of the reac- 
tions, and only when forced from this position by the impossibility of find- 
ing mechanical explanations for the phenomena to recognize those com- 
plex reflexes which we call instincts, and finally those acts which we call 
intelligent, or reasonable, and which are possible only to the possessors of 
associative memory. The investigations, mostly recent, which have been 
directed toward a determination of the immediate springs or stimuli of 
insect reactions indicate clearly that many of these responses, even some 
which were formerly looked on as surely indicative of considerable intelli- 
gence on the part of their performers, are explicable as rigid reflex (mechan- 
ical) reactions to light, gravity, the proximity of substances of certain 
chemical composition, contact with solid bodies, etc. On the other hand 
the position of the extreme upholders (Bethe, Uexkull, and others) of the 
purely reflex explanation of all insect behavior will certainly prove untenable. 
As one of the phases of insect biology to which this book is particularly 
devoted is that which includes the study of habits, activities, or behavior, 
we may dispense with any special discussion of instinct in this introductory 
chapter. It is sufficient to say that no other class of invertebrate animals 
presents such an interesting and instructive psychology as the insects. 


CHARTER it 


"i, DEVELOPMENT AND META- 
AUN MORPHOSIS 


HAT animals are born or hatch from eggs in 
an immature condition is such familiar natural 
history that we are likely to overlook the 
significance and consequences of the fact unless 
our attention is particularly called to them. 
This condition of immaturity makes it necessary 
that part of the free life of the organism has 
to be devoted to growth and development and 
has to be undergone in an imperfect condition, 

a condition of structure and physiology, indeed, which may be very different 

from that of the parents or of maturity. While most animals that are born 

alive resemble the parents in most respects, always excepting that of size, 
many of those animals which hatch from eggs deposited outside the body 
of the mother issue from the egg with few indeed of the characteristics of the 
parents and may be so dissimilar from them that only our knowledge of 
the life-history of the animal enables us to recognize these young individuals 
as of the same species as the parent. The butterfly hatching as the worm- 
like caterpillar, and the frog as the fish-like tadpole, are the classic examples 
of this phenomenon. The mammals, our most familiar examples of animals 
which give birth to their young alive and free, nourish, for weeks or months 
before birth, the developing growing young. But with egg-laying animals 
usually only such nourishment is furnished the young as can be enclosed 
as food-yolk within the egg-shell. As a matter of fact, some young which 
hatch from eggs, as, for example, chickens, quail, etc., hatch in well- 
developed condition; and some young mammals, nourished by the mother’s 
body until birth, are in a conspicuously undeveloped state, as a young 
kangaroo or opossum. But nevertheless it is generally true that an animal 
hatched from an egg has still a larger amount of development to undergo 
before it comes to the stature and capacity of its parents than one which is 
35 


36 Development and Metamorphosis 


born alive, after having passed a considerable time growing and developing 
in the body of the mother. And this difference in degree of development at 
birth is largely due simply to the difference in amount of nourishment 
which can be afforded the young. The embryo in the egg uses up its food 
early in its developmental career and before it has reached the stage of 
likeness to its parents. It issues in a condition picturing some far-distant 
ancestor of its species, or more frequently, perhaps, in a modified, adapted 
condition, fit to make of this tender unready creature thus thrust before 
its time into the struggle for living an organism capable of caring for itself, 
although not yet endowed with capacities as effective as, or even similar to, 
those of the parent. 

It is familiar to us, then, that development is not wholly postnatal or 
postembryonic; that before birth or hatching a greater or-less amount of 
development, requiring a longer or shorter 
period of time, has already been undergone. 
Every animal begins life as a simple cell; all 
animals except the Protozoa (the simplest ani- 
mals, those whose whole body for its whole 
life is but a single cell) finish life, if red 
Nature permits them to come through myriad 
dangers safely to maturity, as a complex of 
thousands or millions of cells united into 
great variety of tissues and organs. This 
great change from most simple to most complex 
condition constitutes development: the actual 
increase of body-matter and extension of 
dimensions is growth. 

Most insects hatch from eggs; being born 


Fic. 66.—Ovaries and oviducts are Z - 
of a thrips. o.., ovarialtubes; alive is the exceptional experience of the young 
o.d., ets r.S.y tees of but few kinds, and even this is a sort of 
receptacle, or s t & . . 
ire. duct of therceninal se. pseudo-birth. Such hatch alive, one may better 


ceptacle. (After Uzel; much say, for they begin life in eggs, not laid out- 


tec) side the mother body to be sure, but held in 


the egg-duct until hatching-time. With very few exceptions, young insects 
are not nourished by the mother except in so far as she stores a supply of 
yolk around or by the side of each embryo inside the egg-shell. The form- 
ing of the egg is a matter which does not lend itself readily to the observa- 
tion and study of amateurs, but is a phenomenon of unusual interest to 
whomever is privileged to discover it. The insect ovaries consist of a pair 
of little compact groups of short tapering tubes (Fig. 66). In the anterior or 
beginning end of each tube is a microscopic space or chamber from whose 
walls cells loosen themselves and escape into the cavity. These cells become 


Development and Metamorphosis a7 


either the germinal or the food part of the eggs. There seems to exist no 
differentiation among these cells at first, but soon certain ones begin to 
move slowly down through the egg-tube in single file, each becoming sur- 
rounded and enclosed by yolk, ie., reserve foodstuff. This gathering of 
yolk increases the size of the forming eggs, so that they appear as a short 
string of beads of varying size enclosed in the elastic egg-tube. When of 
considerable size each egg in the lower end of the tube becomes enclosed 


Fic. 67.—Insect eggs and parts of eggs, showing micropyle. a, egg of Drosophila cel- 
laris; b, upper pole of egg of robber-fly, A si/us crabriformis; c, upper pole of egg 
of hawk-moth, Sphinx populi; d, egg of head-louse, Pediculus capitis; e, egg of 
dragon-fly, Libellula depressa; jf, upper surface of egg of harpy-moth, Harpyia 
vinula; g, upper pole of egg of Hammalicherus cerdo; h, upper pole of egg of sul- 
phur-butterfly, Colias hyale. (After Leuckart; much enlarged.) 


in two envelopes, a membranous inner one (yolk or vitelline membrane) and 
an outer horny one, the chorion or egg-shell. But both of these envelopes 
are pierced at one pole by a tiny opening, the micropyle (Fig. 67), and 
through this opening the fertilizing spermatozoa enter the egg from the 
seminal receptacle just before the egg is extruded from the body. 

The development of the embryo within the egg is also securely sealed 
away from the eyes of most amateurs. The study of insect embryology 
requires a knowledge of microscopic technic, and facilities for fixing and 


38 Development and Metamorphosis 


imbedding and section-cutting which are not often found outside the college 
laboratory. But the particularly interesting and suggestive stages in this 
development may be outlined and illustrated in brief space. First, the 
germinal cell near the center of the egg divides repeatedly (Fig. 68 A) and 
the resulting new cells migrate outward against the inner envelope of the 
egg and arrange themselves here in a single peripheral layer, called the 
blastoderm (Fig. 68 D, bl). On what is going to be the ventral ‘side of the 
egg the cells of the blastoderm begin to divide and mass themselves to form 
the ventral plate (Fig. 69 C). The embryo is forming here; the rest of the 
blastoderm becomes modified and folded to serve as a double membranous 
envelope (called amnion and serosa) for the embryo. Stretching nearly from 
pole to pole as a narrow streak along the ventral aspect of the egg, the 


A 


developing embryo begins soon to show that fundamental structural charac- 
teristic of insects, a segmental condition (Fig. 69 D). One can now make 
out the forming body-rings or segments, and each soon shows the beginnings 
or rudiments of a pair of appendages (Fig. 69 Z). The appendages of the 
head and thoracic segments continue to develop and begin soon to assume 
their definitive character of antenne, mouth-parts, and legs, but those of the 
abdominal segments never get farther than a first appearance and indeed 
soon disappear. In the mean time the internal systems of organs are grad- 
ually developing, the ventral nerve-chain first, then the alimentary canal, 
and later the muscles, trachee, and the heart. All the time the yolk is 
being gradually used up, fed on, by the cells of the developing and growing 
embryo, until finally comes the disappearance of all the stored food, and the 
time for hatching. 


Development and Metamorphosis 39 


The eggs have been laid, because of the remarkable instinct of the 
mother, in a situation determined chiefly by the interests of the young 
which are to hatch from them. The young of many kinds of insects take 
very different food from that of the mother—a caterpillar feeds on green 
leaves, the butterfly on flower-nectar—or live under very different circum- 
stances—young dragon-flies and May-flies live under water, the adults in 
the air. A monarch butterfly, which does not feed on leaves, nor has ever 
before produced young, seeks out a milkweed to lay its eggs upon. The 
young monarchs, tiny black-and-white-banded caterpillars, feed on the 


Beane 


So 


f° f 
ai 
“4 
5 
«a 


Fic. 69.—Early stages in the development of the egg of saw-fly, Hylotoma beriberidis. 
C, ventral plate removed from egg; D, ventral plate, showing segmentation of body; 
E, embryo, showing developing appendages; F, same stage, lateral aspect; G, older 
stage, lateral aspect. amt., antenna; md., mandible; mx., maxilla; /i., labium; /', /, 13, 
legs; sg., salivary glands; st., spiracles; ab.ap., abdominal appendages; 1.c., nerve- 
centers; a., anal opening; /b., labrum; sd., cesophageal invagination; y., yolk; 
b.s., abdominal segments; /d., intestinal invagination; am., amnion; s., serosa. 
(After Graber; greatly magnified.) 


green milkweed leaf-tissue; indeed they starve to death if they cannot have 
leaves of precisely this kind of plant! The reason that the butterfly, whose 
only food is the nectar of almost any kind of flower, ranges wide to find a 
milkweed for its eggs, is one not founded on experience or teaching or rea- 
son, but on an inherited instinct, which is as truly and as importantly an 
attribute of this particular species of butterfly as its characteristic color 
pattern or body structure. And the female of the great flashing strong- 
winged dragon-fly, queen insect of the air, when egg-laying time comes, 
feels a strange irresistible demand to get these eggs into water, dropping 
them in from its airy height, or swooping down to touch the tip of the abdo- 


40 Development and Metamorphosis 


men to the water’s surface, there releasing them, or even crawling down 
some water-plant beneath the surface and with arduous labor thrusting the 
eggs into the heart of this submerged plant-stem. From the eggs hatch 
wingless dwarf-dragons of the pond bottom, with terrible extensile, clutch- 
ing mouth-parts and an insatiable hunger for living prey. 

So our young insects, after completing their embryonic development, 
come to the time of their appearance as free individuals compelled to find 
their own food and no longer sheltered by a firm egg-shell from the strenu- 


Fic. 70.—Series of stages in development of egg of fish-moth, Lepisma sp. A, begin- 
ning embryo; B, embryo showing segmentation; C, embryo showing appendages; 
D, embryo more advanced; E, embryo still more advanced; F, embryo still older 
and removed from egg; G, embryo remoyed from egg at time of readiness to hatch. 
y., yolk; emb., embryo; ser., serosa; am., amnion; ant., antenna; 1b., labrum; 


md., mandible; mx., maxilla; mx.p., maxillary palpus; /i., labium; /i.p., labial 
palpus; l'. P, 1, legs; pr., proctodeum, or intestinal invagination; cer., cercij mp., 
middle posterior process. (After Heymons; greatly magnified.) 


ous fighting and hiding of the open road. Now these young insects, depend- 
ing upon how far they have carried their developmental course in the egg, 
latch either almost wholly like their parents (excepting always in size), or 
in a condition fairly resembling the parents, but lacking all traces of wings 
and showing other less conspicuous dissimilarities, or finally they may appear 
in guise wholly unlike that of their parents, in such a condition indeed that 
they would not be recognized as insects of the same kind as the parents. 
But in all cases the young are certain, if they live their allotted days or weeks 


Development and Metamorphosis 4 


or months, to attain finally the parent structure and appearance. This 
attainment is a matter of further development, of postembryonic develop- 
ment, and the amount or degree of this development or change is obviously 
determined by the remoteness or nearness of the young at the time of hatch- 
ing to the adult or parental condition. The young of many of our most 
familiar insects, as beetles, flies, moths and butterflies, and ants, bees, and 
wasps, hatch out extremely unlike their parents in appearance: the well- 
known worm-like caterpillars of butterflies and moths are striking examples 
of this unlikeness. The changes necessarily undergone in the develop- 
ment from caterpillar to butterfly are so great that there actually results 
a very considerable degree of making over, or metamorphosis of the insect, 
and for convenience of roughly classifying insects according to their develop- 
ment, entomologists have adopted the terms complete metamorphosis, 
incomplete metamorphosis, and no metamorphosis to indicate three not 
very sharply distinguished kinds or degrees of postembryonic development. 

In the latter category are comparatively few species, because most insects 
have wings, and no insect is winged at birth. But the members of the sim- 
plest order (Aptera) are all primitively wingless, and their 
young are, in practically all particulars except body size and 
the maturity of the reproductive glands, like the adults 
(Fig. 71); their development may fairly be said to take place 
without metamorphosis. In addition to these primitively 
simple insects there are certain degenerate wingless species 
like the biting bird-lice, for example, whose young also 
reach the parental stature and character without meta- 
morphosis. 

In the next category, that of development with in- 
complete metamorphosis, are included two large orders 
of insects and several smaller ones. All the sucking-bugs Fyc. 71. — Young 
(order Hemiptera) and all the locusts, katydids, crickets, and adult of Po- 

: dura sp., one of 
and cockroaches (composing the order Orthoptera), as well simplest in- 
as the May-flies, dragon-flies, white ants, and several other sects, showing 
small groups of unfamiliar forms, agree in having their Core OR ment 
young hatched in a condition strongly resembling the morphosis. 
parents, although lacking wings, and in some cases, particu- (Much enlarged.) 
larly those in which the young live on different food and in a different habjtat 
from the adults, differing rather markedly in several superficial characters. 
Such is the case, for example, with the dragon-flies, whose young are aquatic 
and breathe by means of tracheal gills, and are provided with specially con- 
structed seizing and biting mouth-parts. But in such essential character- 
istics as number of legs, character of eyes and antenne, and, usually, char- 
acter of mouth-parts, the young and parent agree. During postembryonic 


42 Development and Metamorphosis 


Fic. 72.—Developing stages, after hatching, of a locust, Melanoplus femur-rubrums 
a, just hatched, without wing-pads; 6, after first moulting; ¢, after second moulting. 
showing beginning wing-pads; d, after third moulting; e, after fourth moulting, 
j, adult with fully developed wings. (After Emerton; younger stages enlarged; 
adult stage, natural size.) 


Fic. 73.—Stages in development of the wings of a locust. /., developing rudiment of 
fore wing; /., developing rudiment of hind wing; w., wing-pad. (After Graber; 
twice natural size.) 


Development and Metamorphosis 43 


development the young have to develop wings and make what other change 
is necessary to reach the adult type, but the life is continually free and active 
and the change is only a simple gradual transformation of the various parts 
in which differences exist. A common locust is an excellent example of 
an insect with such incomplete metamorphosis. Fig. 72 shows the develop- 
ing locust at different successive ages, or stages, as these periods are called 
because of their separation from each other by the phenomenon, common 
to all insects, of moulting. As the insect grows it finds its increase of girth 
and length restrained by the firm 
inelastic external chitinized cuticle, 
or exoskeleton. So at fixed periods 
(varying with the various species 
both in number and duration) this 
cuticle is cast or moulted. From 
a median longitudinal rent along 
the dorsum of the thorax and head, 
the insect, soft and dangerously 
helpless, struggles out of the old 
skin, enclosed in a new cuticle 
which, however, requires some little 
time to harden and assume its 
proper colors (often protective). 


Fic. 74.—Metamorphosis, incomplete, of an 
assassin-bug (family Reduviide, order 


After each moulting the young 
locust appears markedly larger and 
with its wing-pads better developed 


Hemiptera). A, young just hatching from 
eggs; B, young after first moulting, showing 
beginning wing-pads; C, older stage with 


complex wing-pads; D, adult with fully 
developed wings. (One-half larger than 
natural size.) 


(Fig. 73). But not until the final 
moulting—in the case of the locust 
this is the fifth—are the wings usable as organs of flight. So that there 
is after all likely to be a rather marked difference between the habits of 
the young and those of the adult of an insect with incomplete metamor- 
phosis, that difference being primarily due to structural differences. The 
young are confined to the ground, and their locomotion is limited to walking 
or hopping. The adults can live, if they like, a life in the air, and they 
have a means of locomotion of greatly extended capability. 

The insects with complete metamorphosis are the beetles, the two- 
winged flies, the butterflies and moths, the ichneumons, gall-flies, ants, 
bees, and wasps, the fleas, the ant-lions, and several other small groups 
of insects with less familiar names. 
species in these groups, the young when hatched from the egg differ very 
much in structure and appearance, and also in habits and general economy, 
from the parents. 
and ‘‘worms” of the moths and butterflies, the grubs of beetles, the mag- 


In the case of all the thousands of 


Familiar examples of such young are the caterpillars 


44 Development and Metamorphosis 


gots of the flesh- and house-flies, and the helpless soft white grubs in the 
cells of bees and wasps. These strange young, so unlike their parents, 
have the generic name larvae, and the stage or life of the insect passed as a 
larva is known as the larval stage. In almost all cases these larve have 
mouth-parts fitted for biting and chewing, while most of the adults have 
sucking-mouth parts; the larve have only simple eyes and small inconspicu- 


Fic. 75.—Metamorphosis, complete, of monarch butterfly, Anosta plexippus. a, egg 
(greatly magnified); b, caterpillar or larva; c, chrysalid or pupa; d, adult or imago. 
(After Jordan and Kellogg. Natural size.) 


ous antenne; the adults have both simple and compound eyes and well- 
developed conspicuous antenne; the larva may have no legs, or one pair or 
two or any number up to eight or ten pairs; the adults have always three 
pairs; the larve are wholly wingless, nor do external wing-pads (i.e., 
developing wings) appear outside the body during the larval stage; the 
adults have usually two pairs (sometimes one or none) of fully developed 
wings. Internally the differences are also great. The musculation of the 


Development and Metamorphosis 45 


larva is like that of a worm, to accomplish wriggling, crawling, worm-like 
locomotion; in the adult it is very different, particularly in head and thorax; 
the alimentary canal is usually adapted in the larva for manipulating and 
digesting solid foods; in the adult, usually (except with the beetles and 
a few other groups), for liquid food; there may be large silk-glands in the 
larva, which are rarely present in the 
adult; the respiratory system of the larve 
of some flies and Neuroptera is adapted 
for breathing under water; this is only 
rarely true of the adults. The heart 
and the nervous system show lesser dif- 
ferences, but even here there is no iden- 
tity: the ventral nerve chain of the larve 
may contain twice as many distinct gan- 
glia as in the adult. 

The larva lives its particular kind of 
life: it grows and moults several times; 
but externally it shows at no time any 
more likeness to the adult than it did at Fic. 76.—Larva, pupa, and adult of 

- ; the flesh-fly, Calliphora erythroce- 
hatching. But after its last moult it ap- phala, with complete metamor- 
pears suddenly in the guise of a partially phosis. (Two times natural size.) 
formed adult in (usually) quiescent mummy-like form, with the antenne, 
legs, and wings of the adult folded compactly on the under side of the 
body, and the only sign of life a feeble bending of the hind-body in re- 
sponse to the stimulus of a touch. This is the insect of complete meta- 
morphosis in its characteristic second stage (or third if the egg stage 
is called first), the pupal stage. The 
mummy is called pupa or chrysalid. As 
the insect cannot, in this stage, fight or 
run away from its enemies, its defence 
lies in the instinctive care with which the 
e larva, just before pupation, has spun a 
Fic. 77.—Adult worker (2) andlarva protecting silken cocoon about itself, or 

(b) of honey-bee. (Adult natural 4s burrowed below the surface of the 
size; larva twice natural size.) Le 5 : 
ground, or has concealed itself in crack 
or crevice. Or the defence may lie in the fine harmonizing of the color and 
pattern of the naked exposed chrysalid with the bark or twig on which it 
rests; it may be visible but indistinguishable. The insect as pupa takes 
no food; but the insect as larva has provided for this. By its greed and 
overeating it has laid up a reserve or food-store in the body which is drawn 
on during the pupal stage and carries the insect through these days or weeks 
or months of waiting for the final change, the transformation to the renewed 


46 Development and Metamorphosis 


active food-getting life of the adult or imaginal stage. Familiar examples 
of this kind of metamorphosis, the real metamorphosis, are provided by 
the life of the monarch butterfly, the honey-bee, and the blow-fly. The great 
red-brown monarch lays its eggs on the leaves of a milkweed; from the eggs 
hatch in four days the tiny tiger-caterpillars (larve) (Fig. 75) with biting 
mouth-parts, simple eyes, short antenne, and eight pairs of legs on its elon- 
gate cylindrical wingless body. The caterpillars bite off and eat voraciously 
bits of milkweed-leaf; they grow rapidly, moult four times, and at the end 
of eleven days or longer hang themselves head downward from a stem or 


Fic. 78.—Brood-cells from honey-bee comb showing different stages in the metamor- 
phosis of the honey-bee; worker brood at top and three queen-cells below; begin- 
ning at right end of upper row of cells and going to left, note egg, young larva, old 
larva, pupa, and adult ready to issue; of the large curving queen-cells, two are cut 
open to show larva within. (After Benton; natural size.) 


leaf and pupate, i.e., moult again, appearing now not as caterpillars, but as 
the beautiful green chrysalids dotted with gold and black spots. The form- 
ing antenne legs and wings of the adult show faintly through the pupal 
cuticle, but motionless and mummy-like each chrysalid hangs for about 
twelve days, when through a rent in the cuticle issues the splendid butterfly 
with its coiled-up sucking proboscis, its compound eyes, long antenne, its 
three pairs of slender legs (the foremost pair rudimentary), and its four great 
red-brown wings. The queen honey-bee lays her eggs, one in each of the 
scores of hexagonal cells of the brood-comb (Fig. 78). From the egg there 
hatches in three days a tiny footless, helpless white grub, with biting mouth- 
parts and a pair of tiny simple eyes. The nurses come and feed this larva 
steadily for five days; then puta mass of food by it and “cap” the cell; the 
larva has grown by this time so as nearly to fill the cell. It uses up the 
stored food, and ‘“‘changes” to the pupa, with the incomplete lineaments 
of the adult bee. It takes no more food, but lies like a sleeping prisoner 


Development and Metamorphosis 47 


in its closed cell for thirteen days, and then it awakens to active life, gnaws 
its way through the cell-cap and issues into the hive-space a definitive honey- 
bee with all the wonderful special structures that make the honey-bee body 
such an effective little insectean machine. The blow-fly (Fig. 76) lays a hun- 
dred or more little white eggs on exposed meat. From these eggs come in 
twenty or thirty hours the tiny white wriggling larvee (maggots), footless, eye- 
less, wingless, nearly headless, with a single pair of curious extensile hooks 
for mouth-parts. For ten to fourteen days these larvae squirm and feed and 
grow, moulting twice in this time; they then pupate inside of the larval 
cuticle, which becomes thicker, firmer, and brown, so as to enclose the deli- 
cate pupa in a stout protective shell. The blow-fly now looks like a small 
thick spindle-shaped seed or bean, and this stage lasts for twelve or fourteen 


Fic. 79.—Dipterous larve showing (through skin) the imaginal discs or buds of wings, 
these buds being just inside the skin. 4A, larva of black fly, Simudium sp.; B, anterior 
end of larva of midge, Chironomus sp.; C, anterior end, cut open, of larva of giant 
crane-fly, Holorusia rubiginosa; h.pr., bud of prothoracic respiratory tube; /.f/., 
bud of prothoracic leg; h.mw., bud of mesothoracic wing; /.ml., bud of mesothoracic 
leg; h.mtb., bud of metathoracic balancer; /v.mil., bud of metathoracic leg. (Much 


enlarged.) 


days. Then the winged imago, the buzzing blow-fly, as we best know it, 
breaks its way out. In the house-fly the same kind of life-history, with 
complete metamorphosis of the extremest type, is completed in ten days. 
Nor do we realize how really extreme and extraordinary this metamorpho- 
sis is until we study the changes which take place inside the body, as well 
as those superficial ones we have already noted. 

The natural question occurs to the thoughtful reader: “Is the meta- 
morphosis or transformation in the postembryonal development of such 
insects as the butterfly, bee, and blow-fly as sudden or discontinuous and 
as radical as the superficial phenomena indicate?” The answer is no, and 
yes; the metamorphosis is not so discontinuous or saltatory and yet is 
even more radical and fundamental than the external changes suggest. To 


48 Development and Metamorphosis 


take a single example, the case of the blow-fly (admittedly an extreme one), 
the phenomena of internal change are, put briefly, as follows: The imaginal 
wings, legs, and head-parts begin to develop as deeply invaginated little 
buds of the cell-layer of the larval skin early in larval life. This develop- 
ment is gradual and continuous until pupation, when the wing and leg rudi- 


Fic. 80.—Stages in development of wing-buds in the larva of the giant crane-fiy, 
Holorusia rubiginosa (the wing-buds have been dissected out and sectioned, so 
as to show their intimate anatomy). A, B, C, D, four stages successively older ch., 
chitinized cuticle; hyp., hypoderm or cellular layer of skin; /r., trachea; #l., 
tracheoles; .m., peritrophic membrane; w., developing wing; ¢.v., tracheal branch 
indicating position of future wing-vein. (Greatly magnified.) 


ments and the new head are pulled out upon the exterior of the body. Just 
before pupation, when the larva has given up its locomotion and feeding, 
the larval muscles, trachee, salivary glands, alimentary canal, and some other 
tissues begin to disintegrate, and rapidly break wholly down, so that in the 
pupa there appear to be no internal organs except the nervous system, 
reproductive glands, and perhaps the heart, but the whole interior of the 


Development and Metamorphosis 49 


body is filled with a thick fluid in which float bits of degenerating larval 
tissue. At the same time with this radical histolysis or breaking down of 
tissue a rapid histogenesis or developing of imaginal parts from certain 
groups of undifferentiated primitive cells, derived probably mostly from 
the larval skin-cells, is going on. Thus many of the larval organs and tissues, 
instead of going over into the corresponding imaginal ones, wholly disinte- 
grate and disappear, and the imaginal parts are newly and independently 
derived. In connection with the Fe 

breaking down of the larval tissues 
phagocytes or freely moving, tissue- 
eating, amoeboid blood-cells play an 
important part, although one not 
yet fully understood. They are 
either the causal agents of the 
histolysis, or are assisting agents in 
it, the tissue disintegration beginning 
independently, or—a recent sugges- 
tion—they are perhaps more truly 
to be looked on as trophocytes, 
that is, carriers of food, namely, 223: Es : 
disintegrating tissue, to the develop- Fic. 81.—A cross section of the body of the 
ing centers of the imaginal parts,  fupeolshone) ee showing the bodycauty 
Much investigation remains to be cytes, and (at the bottom) a budding pair 
done on this interesting subject 115, of the adult, the lave beng 
of histolysis and histogenesis in ©. Mitchell; greatly magnified.) 

insects with complete metamor- 

phosis, but enough has been already accomplished to show the basic and 
extreme character of the transformation from larva to adult. 

If we ask for the meaning of such unusual and radical changes in the 
development of insects, we confront at once an important biological prob- 
lem. Most biologists believe that in a large and general way the develop- 
ment of animals is a swift and condensed recapitulation of their evolution; 
meaning by development the life-history or ontogeny of an individual, and 
by evolution the ancestral history or phylogeny of the species. According 
to this ‘‘biogenetic law’ the interpretation of the significance of the various 
stages and characters assumed by an animal in the course of its development 
from single fertilized egg-cell to the complex many-celled definitive adult 
stage is simple: These stages correspond to various ancestral ones in the 
long genealogical history of the species. Every vertebrate, for example, is 
at some period in its development more like a fish than any other living 
kind of animal; it has gill-slits in its throat, is tailed, and is indeed a fish- 
like creature. This is its particular developmental stage, corresponding 


50 Development and Metamorphosis 


to the ancestral fish-like ancestors of all vertebrates. Do then the larve 
and pupz of insects with complete metamorphosis represent ancestral stages 
in insect evolutionary history? In some degree the larval stage does, but 
in no degree does the pupal. 
Insects are certainly not de- 
scended from an animal that, 
like a pupa, could neither move 
Fic. 82.—A bit of degenerate muscle from tussock- nor eat and which had no in- 
moth, Hemerocampa leucostigma, Note phago- ternal organs except a nervous 
cytic cells attacking muscle at the margins. system, heart, and rudimentary 
(Greatly magnified.) ihe z i 
reproductive glands. Biologists 
recognize that the exigencies of life during adolescence may profoundly 
modify what might be termed the normal course of development. As 
long as the developing animal is shielded from the struggle for existence, 
is provided with a store of food and protected from enemies by lying in an 
egg-shell or in the body of the mother, it may pursue fairly steadily its reca- 
pitulatory course of development; but once emerged and forced to shift for 


Fic. 83.—Degenerating muscle from pupa of giant crane-fly, Holorusia rubiginosa, show- 
ing phagocytic cells penetrating and disintegrating the muscle-tissue. (Greatly 
magnified.) 


itself, it must be, at whatever tender age it is turned out, or whatever ancient 
ancestor it is in stage of simulating, adapted to live successfully under the 
present-day and immediate conditions of life. If the butterfly gets hatched 
long before it has reached its definitive butterfly stage, and while it is in 
a stage roughly corresponding to some worm-like ancestors—and from such 
ancestors insects have undoubtedly descended—it must be fitted to live 


Development and Metamorphosis I 


successfully a crawling, squirming, worm-like life. That those insects which 
hatch as worm-like larve do in fact owe their wingless, worm-like body con- 
dition partly to being born in a stage simulating a worm-like ancestor is proba- 


h- 


Fic. 84.—Degeneration, without phagocytosis, of salivary glands in old larva of giant 
crane-fly, Holorusia rubiginosa. A, cross-section of salivary gland before degen- 
eration has begun; B, cross-section of salivary gland after degeneration has set in. 
(Greatly magnified.) 


bly true. But to be a successful worm demands very different bodily adapta- 
tions from those of a successful butterfly. And so far does the larval butterfly 
go, or so far has it been carried, in meeting these demands that nature finds it 
more economical—to get into figurative language— 
or easier to break down almost wholly the larval 
body—after a new food-supply for further develop- 
ment has been got and stored away, and to 
build up from primitive undifferentiated cell begin- 
nings the final definitive butterfly body, than to 
make over these very unlike larval parts into the 
adult ones. The pupal stage, quiescent, non-food 
taking, and defended by a thick chitinous wall, 
often enclosed in a silken cocoon, buried in the 
ground or crevice, or harmonizing so perfectly with 
its environment as to be indistinguishable from it, 
is the chief period of this radical and marvelous Fic. 85.—Cross-section 
breaking down and building anew. It is an inter- So eerie: 
polated stage in the development of the butterfly honey-bee, Apis mel- 
corresponding to nothing in the phyletic history; eae meee 
an adaptation to meet the necessities of its life- 

conditions. To my mind, this is the interpretation of the phenomena of 


complete metamorphosis. 


CHAPTER au 
THE CLASSIFICATION OF INSECTS 


As has been explained in the preceding chapter, insects are primarily classi- 
fied on the basis of their postembryonic development. Insects with incom- 
plete metamorphosis, that is, those which do not undergo a non-feeding, 
usually quiescent, pupal stage in their development are believed to be more 
nearly related to each other than to any of the insects which undergo a so- 
called complete metamorphosis. So they are spoken of collectively as the 
Hemimetabola, while all the insects with a distinct pupal stage are called 
the Holometabola. But when one has collected an adult insect, as a fly 
or moth or grasshopper, and wishes to classify it, this primary classification 
based on character of development often cannot be made for lack of informa- 
tion regarding the life-history of the particular insect in hand. The next 
grouping is into orders, and this grouping is based chiefly on structural 
characters, and corresponds to one’s already more or less familiar knowledge 
of insect classification. Thus all the beetles with their horny fore wings 
constitute one order, the Coleoptera; the moths and butterflies with their 
scale-covered wings another order, the Lepidoptera; the two-winged flies 
the order Diptera, the ants, bees, wasps, and four-winged parasitic flies 
the order Hymenoptera, and so on. So that the first step in a beginner’s 
attempt to classify his collected insects is to refer them to their proper orders. 

Now while entomologists are mostly agreed w:th regard to the make-up 
of the larger and best represented orders, that is, those orders containing 
the more abundant and familiar insects, there are certain usually small, 
obscure, strangely formed and more or less imperfectly known insects with 
regard to whose ordinal classification the agreement is not so uniform. While 
some entomologists incline to look on them simply as modified and aberrant 
members of the various large and familiar orders, others prefer to indicate 
the structural differences and the classific importance of these differences 
by establishing new orders for each of these small aberrant groups. Most 
entomologists of the present incline toward this latter position, so that whereas 
Linnzus, the first great classifier of animals, divided all insects into but 
seven orders, the principal modern American * text-book of systematic ento- 


* Comstock, J. H., A Manual of Insects, 1898. 
52 


The Classification of Insects 53 


mology recognizes nineteen distinct ones. This does not mean, of course, that 
twelve new orders of insects have been found since Linnzus’s time, although 
two or three of the orders are in fact founded on insects unknown to him, 
but means that certain small groups classified by Linnzus simply as families 
in his large orders have been given the rank of distinct orders by modern 
systematists. And as our knowledge of insects and their relationship to 
each other is certainly much larger now than it was one hundred and fifty 
years ago, we may feel confident that the many-order system of classifica- 
tion is more nearly a true expression of the natural interrelationships of 
insects than was the old seven-order system. But not all entomologists 
agree on the nineteen-order system. Few, indeed, still use the Linnean 
system, but many believe that the division of the insect class into nineteen 
orders gives too much importance to certain very small groups and to some 
others which are not markedly aberrant, and these entomologists recognize 
a lesser number of orders, varying with different authors from nine to about 
a dozen. In this book we shall adopt the nineteen-order system as used 
in Comstock’s Manual. In the first place the author believes that this classi- 
fication best represents our present knowledge of insect taxonomy; in the 
second place this is the classification taught by nearly all the teachers of 
entomology in America. 

To determine the order to which an insect belongs we make use of a 
classifying table or key. In the Key to Orders which follows this para- 
graph, all the insect orders are characterized by means of brief statements of 
structural features more or less readily recognized by simple inspection of 
the superficies of the body; to determine some of the conditions a simple 
lens or hand-magnifier will be needed. The orders are so arranged in the 
key that by choosing among two or more contrasting statements the student 
may ‘‘trace’”’ his specimen to its proper order. Inspection of the Key with 
an attempt or two at tracing some familiar insect, as a house-fly, moth, or 
wasp whose order is already known, will make the method of use apparent. 
It must be borne in mind that young insects, such as caterpillars of moths, 
grubs of beetles, and the wingless nymphs of locusts, dragon-flies, etc., cannot 
be classified by this key. Indeed the young stages of most of the insects 
which we know well as adults are unknown to us, and there is, besides, such 
manifold adaptive variety in the external structure of those forms which we 
do know that no key for the classification into orders of immature insects 
can now be made. 


54 The Classification of Insects 


KEY TO THE ORDERS OF INSECTS. 


(ARRANGED By Pror, H. E. SUMMERS.) 


(For adult insects only. If in any paragraph all the italicized characters agree with 
the specimen in hand, the remaining characters need not be read; these latter are for use 
in doubtful cases, or where the organs characterized in italics are rudimentary or absent. 
The technical terms used in this Key have all been defined in Chapter I.) 


A. - Primitive wingless insects; mouth-parts well developed, but all except the apices oj the 
mandibles and maxille withdrawn into a cavity in the head; tarsi (feet) always one- 
or two-clawed; body sometimes centiped-like, with well-developed abdominal legs, 
in this case tarsi two-clawed.....-....-......- (The simplest insects.) APTERA. 

AA. Normally winged insects, wings sometimes rudimentary or absent; mouth-parts 
not withdrawn into a cavity in the head. 

B. Mouth-parts, when developed, with both mandibles and pe fitted for biting; 
abdomen broadly joined to thorax; tarsi never bladder-shaped; when mouth- 
parts are rudimentary, if the wings are two, there are no halteres (p. 303); if 
the wings are four or absent, the body is not densely clothed with scales. 

C. Posterior end of abdomen with a pair of prominent unjointed forceps-like 

appendages; fore wings, when present, short, veinless, horny or leathery. 

(Earwigs.) EUPLEXOPTERA, 

CC. Posterior end of abdomen usually without prominent unjointed forceps-like 

appendages; when these are present the fore wings are always developed, 
veined. 

D. Fore wings, when present, veined and membranous, parchment-like or 
leathery; when absent, the labium (under-lip) either cleft in the 
middle, or the mouth-parts prolonged into a distinct beak. 

E. Fore wings, when present, thicker than hind wings, somewhat 
leathery or parchment-like; hind wings folded several times 
lengthwise, like a fan, in repose; when wings are absent, pro- 
thorax large. 

(Locusts, crickets, cockroaches, etc.) ORTHOPTERA. 

EE. Fore wings membranous, of same structure as hind wings; 
hind wings usually not folded, but occasionally folded like a jan; 
when wings are absent, prothorax small. 

F. Antenne inconspicuous. 
G. Hind wings smaller than fore or absent; posterior end of 
abdomen with two or three many-jointed filaments. 
(May-flies.) EPHEMERIDA. 
GG. Hind wings not smaller than fore; posterior end of 
abdomen without many-jointed filaments. 
(Dragon-flies and damsel-flies.) _ODONATA. 
FF. Antenne conspicuous. 
G. Tarsi less than five-jointed; labium clejt in the 
middle. 

H. Wings always present, although sometimes very 
small; hind wings broader than fore wings, 
jolded in repose; prothorax large, nearly flat 
on dorsal surface. 

(Stone-flies.) PLECOPTERA. 


The Classification of Insects Bis 


HH. Hind wings, when present, not broader than fore 
wings, not folded in repose; prothorax small, 
collar-like. 

I. Tarsi four-jointed; wings, when present, 
equal in size.....(Termites.) ISOPTERA. 
II. Tarsi one- to three-jointed. 
J. Tarsi one- or two-jointed; always 
wingless. 
(Biting bird-lice.) MALLOPHAGA. 
JJ. Tarsi usually three-jointed; occasionally 
two-jointed, in which case wings always 
present, fore wings larger than hind 
wings. (Book-lice, etc.) CORRODENTIA. 
GG. Tarsi five-jointed, but with one joint sometimes 
difficult to distinguish; labium usually entire in 
middle, sometimes slightly emarginale. 

H. Wings, when present, naked or slightly hairy; 
hind wings with or without folded anal space; 
in former case prothorax large and nearly 
flat on dorsal surface; in wingless forms 
mouth prolonged into a distinct beak. 

I. Mouth-parts not prolonged into a distinct 
beak, at most slightly conical. 

(Dobsons, ant-lions, etc.) NEUROPTERA. 

II. Mouth-parts prolonged into a distinct beak, 

(Scorpion-flies, etc.) MECOPTERA. 

HH. Wings, when present, thickly covered with hairs; 
hind wings usually with folded anal space; pro- 
thorax small, collar-like; mouth not prolonged 

_ into a beak. (Caddis-flies.) 'TRICHOPTERA. 

DD. Fore wings, when present, veinless; horny or leathery; when absent, 
labium entire, and mouth-parts not prolonged into a distinct beak. 
(Beetles.) COLEOPTERA, 


BB. Mouth-parts, when developed, more or less fitted for sucking; sometimes also 
fitted in part (the mandibles) for biting: in this case either (1) base of abdomen 
usually strongly constricted, joined to thorax by a narrow peduncle, or (2) the 
tarsi bladder-shaped, without claws; when mouth is rudimentary either the 
wings are two and halteres are present, or the wings are four or none and 
the body (and wings if present) are densely clothed with scales. 


(Ga 


CE; 


Prothorax free; body (and wings if present) never densely clothed with 
scales; maxillary palpi usually absent; when present, tarsi bladder- 
shaped, without claws. 
D. Tarsi bladder-shaped, without claws; wings four (sometimes absent), 
narrow, fringed with long hairs; maxille triangular, with palpi. 
(Thrips.) THYSANOPTERA. 
DD. Tarsi not bladder-shaped, usually clawed; wings not fringed with 
long hairs; maxilla (when mouth is developed) bristle-like, without 
palpi. (Bugs.) HEMIPTERA. 
Prothorax not free; maxillary palpi present, sometimes rudimentary 
and difficult to see, in which case body (and wings if present) densely 
clothed with scales; tarsi never bladder-shaped, usually clawed. 


56 The Classification of Insects 


D. Mandibles often rudimentary, when present bristle-like. 

E. Wings four (sometimes wanting), clothed with scales; body 
covered thickly with scales or hairs; mouth, when developed, a 
slender sucking proboscis, closely coiled under head. 

(Moths and butterflies.) LEprpopTrErRa. 

EE. Wings two (or wanting), naked or with scattered hairs; hind 
wings in winged forms represented by halteres; body either 
naked or with scattering hairs; mouth a soft or horny beak, not 
coiled under head. 

F. Prothorax poorly developed, scarcely visible from dorsal 


SHO a ira, asayerts veVstoya lute oiatetepeNenene eye cefersuein (Flies.) Drprera. 
FF. Prothorax well developed, distinctly visible from dorsal 
side; wings never present....... (Fleas.) StPHONAPTERA. 


DD. Mandibles well developed, fitted for biting; wings four (sometimes 
two or none), naked or with scatlered hairs. 
(Ichneumon-flies, gall-flies, wasps, bees, and ants.) HyMENOPTERA. 


After one has classified an insect in its proper order there remains, first, 
the determination of the family (each order being composed of from one 
to many families), then of the genus (each family comprising one to many 
genera), and finally of the particular species of the genus (each genus includ- 
ing one to many species). This ultimate classification to species, however, 
will be possible to the amateur in comparatively few cases. There are so 
many species of insects (about 300,000 are known) that it would require 
many shelves of books to contain the descriptions of them all. . As a matter 
of fact, in only a few orders have the descriptions of the species been brought 
together in manuals available for general students. For the most part the 
descriptions are scattered in scientific journals printed in various languages 
and wholly inaccessible to the amateur. There are less than tooo different 
species of birds in North America; there are more than 10,000 known 
species of beetles. Now when one recalls the size of the systematic man- 
uals of North American birds, and realizes that ten such volumes would 
include only the insects of one order, it is apparent that complete manuals 
of North American insects are out of the question. Except in the case of 
the most familiar, wide-spread, and readily recognizable insect species we 
must content ourselves with learning the genus, or the family, or with the 
more obscure, slightly marked, and difficult members of certain large groups, 
as the beetles and moths, simply the order of our insect specimens. 

When one has determined the order of an insect by means of the above 
key he should turn to the account of this particular order in the book (see 
index for page) and find the keys and aids to the further classification of 
the specimen which the author has thought could be used by the general 
student. Comparison with the figures and brief descriptions of particular 
species which are given in each order may enable the amateur to identify 
the exact species of some of his specimens. But the specific determination 


The Classification of Insects 57 


of most of the insects in an amateur’s cabinet (or in a professional ento- 
mologist’s either, for that matter) will have to be done by systematic 
. specialists in the various insect groups. Few professional entomologists 
undertake to classify their specimens to species in more than the one or 
two orders which they make their special study. Duplicate specimens should 
be given numbers corresponding to those on specimens kept in the cabinet, 
and be sent to specialists for naming. Such specialists, whose names can 
be learned from any professional entomologist, have the privilege of retain- 
ing for their own collections any of the specimens sent them. 


CHAPTER IV 
THE SIMPLEST INSECTS (Order Aptera) 


5 as 


PAK JERTAIN household pests which are 


not moths and do not look like 
fish, but which are com monly called “‘fish-moths” (Fig. 86), are 
our most familiar repre sentatives of the order of “simplest in- 
sects.” The “fish” part of the name comes from the 
covering of minute scales which gives the body a silvery 
appearance, and the ‘‘moth” part is derived from our 
habit of calling most household insect pests ‘‘moths.” 
Thus we speak of ‘‘buffalo-moths” when we refer to the 
carpet-feeding hairy larva of certain beetles. When we 
say clothes-moths we are really using the word moth 
accurately, for in their adult condition these pests are 
true moths, although the injury to clothing is wholly done 
by the moth in its young or caterpillar stage. 


: sae Fic. 86.—The fish- 
Besides the fish-moths other not unfamiliar Aptera are moth, Lepisma 


the tiny “‘springtails” (Fig. 87), which sometimes occur osetia se 
in large numbers on the surface of pools of water or on Jatt: twice natural 
snow in the spring. Others may be easily found in damp _—_8i2e-) 
decaying vegetable matter, as discarded straw or old toadstools. They are 
provided with an odd little spring on the under side of the body by means 
of which they can leap from a few inches to a foot 
or more into the air. Hence their common name. 
In the order Aptera are included the simplest of 
living insects. By ‘‘simplest’’ is meant most primi- 
tive, most nearly related to the ancestors of the whole 
Fie hy he remnsare insect class. Also, as might be expected, these most 
face springtail, Smyn- primitive insects are simplest in point of bodily struc- 
Are ei i ane ture ; but in this respect they are nearly approached 
enlarged.) by simple-bodied members of several other orders. 
These latter forms, however, have a simple body- 
structure due to the degradation or degeneration of a more complex type. 
58 


The Simplest Insects 59 


It is familiar knowledge that animals which live parasitically on others, or 
which adopt a very sedentary life, show a marked degeneration of body 
structure, an acquired simplicity due to the loss of certain parts, such as 


organs of locomotion (wings, legs), and of 
orientation (eyes, ears, feelers, etc.). Thus 
the parasitic biting bird-lice (order Mal- 
lophaga, see p. 113), which live their whole 
lives through on the bodies of birds, feeding 
on the feathers, are all wingless and of gener- 
ally simple superficial structure. They are 
nearly as simple externally perhaps as the 
Aptera, but we believe that they are the 
degenerate descendants of winged and in 
other ways more complexly formed ancestors. 

Similarly certain species of insects in 
nearly all orders have adopted a life-habit 
which renders flight unnecessary, and these 
insects having lost their wings are in this 
character simpler than the winged kinds, 
Examples of such insects are the worker 


KJ 


by 


J 
> 


Co 


J 
A 


Fic. 88. — Diagrammatic figures 
showing the segmental disposi- 
tion of the ovarial tubes in three 
Apteran genera. A, Japyx; B, 
Lepisma; C, Campodea. (After 
Targioni- Tozzetti; much en- 
larged.) 


ants and worker termites, many household insects, as the bedbugs and fleas, 


and many ground-haunting forms, as some 
of the crickets, cockroaches, and beetles. 
The Aptera, however, owe their sim- 


Fic. 89.—Diagrammatic figures show- 
ing the respiratory system in three 
Apteran genera. A, Machilis; B, 
Nicoletia; C, Japyx. (After Tar- 
gioni-Tozzetti; much enlarged.) 


plicity to genuine primitiveness; among all 
living insects they are the nearest repre- 
sentatives of the insectean ancestors. But 
not: all the Aptera are “simplest.” That 
is, within the limits of this small order a 
considerable complexity or specialization of 
structure is attained, although all the 
Aptera are primitively wingless, as the 
name of the order indicates. 

These insects develop ‘‘without meta- 
morphosis”’; that is, the young (Figs. go 
and 94) are almost exactly like the parents 
except in size. They have simply to grow 
larger and to become mature. In internal 
structure the simpler Aptera show some 
most interesting conditions. Their internal 


systems of organs have a segmental character corresponding to the external 
segmentation of the body. The ovarial tubes, which are gathered into 


60 The Simplest Insects 


two groups or masses, one on each side of the body, in all other insects 
(Fig. 66), are separate and arranged segmentally in Japyx (Fig. 88), and 
less markedly so in Machilis; the respiratory system of Machilis (Fig. 89) 
consists of nine pairs of distinct, segmentally arranged groups of trachex 
(air-tubes), while the ventral nerve-cord has a ganglion in almost every seg- 
ment of the body. As insects are certainly descended from ancestors whose 
bodies were composed of segments much less interdependent and coordi- 
nated than those of the average living insect, those present-day insects which 
have the body both externally and internally most strongly segmented are 
believed to be the most generalized or primitive of living forms. In addi- 
tion to the segmented character of the internal organs we have also another 
strong evidence of the primitiveness of the order in the possession by several 
Aptera of rudimentary but distinct external pairs of appendages on the 
abdominal segments, appendages undoubtedly homologous with the thoracic 
legs, and probably well developed in the insect ancestors as abdominal legs 
like those of the centipeds. 

The order Aptera is composed of two suborders, which may be dis- 

tinguished as follows: 

Abdomen elongate, composed of ten segments, and bearing long bristle-like or 
shorter forceps-like appendages at its tip; no sucker on ventral side of first 
abdominal segment; antenne# many-segmented..........-..--- ‘THYSANURA. 

Abdomen short and robust, composed of six segments, and usually with a forked 


spring at tip (usually folded underneath the body), and with a ventral sucker 
on first abdominal segment; antennae 4- to 8-segmented. .....- COLLEMBOLA. 


THYSANURA.—This suborder includes three families (a problematical 
fourth family is found in Europe), as follows: 


Body, covered with scales...) <5 uc. ss, seesacisine <0 ee ee see eee LEPISMIDZ 
Body not covered with scales. 
Tip of abdomen with forceps-like appendages. ...............+.. JAPYGID. 
Tip of abdomen with slendcr many-segmented appendages ....-. CAMPODEID®. 


To the last family in the above key belongs the interesting creature 
Cam podea staphylinus (Fig. 90), which zoologists regard as the most primi- 
tive living insect. It is small, white, flattened, wingless, and so soft-bodied 
and delicate that it can hardly be picked up uninjured with the most deli- 
cate forceps. It is about + inch long (exclusive of caudal appendages), and 
is to be looked for under stones and bits of wood. I have found it in Ger- 
many, in New York, and in California, which indicates its wide distribu- 
tion. Other collectors have taken it in Italy, England, and in the Pyrenees. 
It is said to live also in East India. Is it not a little surprising that this 
most primitive, wholly defenceless, and ancient insect should be able to live 
successfully the world over in the face of, and presumably in competition 
with, thousands of highly developed specialized modern insect forms? It 


The Simplest Insects 61 


is a striking proof that Nature does not inevitably crush out all of her 
first trials in favor of her later results! 

The Campodeide contain another 
genus, Nicoletia (Fig. 91), one species of 
which, N. ¢exensis, has been found in Cali- 
fornia and Texas, and which may be dis- 
tinguished from Campodea by its posses- 
sion of three caudal appendages instead 
of two as in the latter form. 

The Japygide include but a single 
genus, Japyx, represented in this country 
by two described species and several as yet 
undescribed forms found at Stanford Uni- 
versity. Japyx subterraneus is a species 
first found under stones at the mouth of 
a small grotto near the Mammoth Cave 
(Kentucky). Japyx (Fig. 92) is larger Fic. 90.—Young and adult of Cam- 
than Campodea, being about one-half inch gate seh nnes (from Cakemia) 

plest living insect. (Natural 
long, and is readily recognized by its caudal _ size indicated by line.) 
forceps. Like Campodea its body is white and soft. 

The Lepismide include the familiar household fish- 
moths and a number of similar forms which live under 
stones and logs in soft soil at the bases of tree-trunks, 
under dead leaves in woods, and sometimes on the damp 
sand of seashores. Three genera of this family occur 
in North America, which may be distinguished as 


follows: 


Caudal appendages short; prothorax very wide and body 

behind it tapering rapidly......--...--- LEPISMINA. 

Caudal appendages long; body elongate and tapering 
gradually backward. 

Eyes large and close together ..........-..-MAcHILIs. 

Eyes small and far apart . ...........-..---- LEPISMA. 


Lepisma is best known by the species L. saccharina 
(Fig. 86), which is the silverfish or fish-moth of the 
house. It is silvery white, with a yellowish tinge on 
the antenne and legs, and is from one-third to two- 
fifths of an inch long. The three long caudal appen- 


Fic. 91.—Nicoletia tex- ear, : 
ensis, from Califor- dages, characteristic of the genus, are conspicuous. St 


nia. (Eight timesnat- feeds chiefly on sweet or starchy materials, sometimes 


ural size. A meer ; 5 
) doing much damage in libraries, where it attacks the 


bindings. It attacks starched clothing, eats the paste off the wall-paper, 


62 The Simplest Insects 


causing it to loosen, and infests dry starchy foods. It runs swiftly and 
avoids the light. It can be fought by sprinkling fresh 
pyrethrum powder in bookcases, wardrobes, and 
pantries. Another species, L. domestica (Fig. 93), 
called the bake-house silverfish, is often common 
about fireplaces and ovens, running over the hot 
metal and bricks with surprising immunity from the 
effects of the heat. This habit has gained for it in 
England, according to Marlatt, the name of ‘fire- 
brat.” It can be distinguished from the species 
saccharina by the presence of dark markings on the 
Fic. 92.—Japyx sp. from back. Both saccharina and domestica are common 
bas cihica ; Five times in England, and saccharina probably came to this 
o> ire country from there. 

Machilis (Fig. 95) does not occur in houses, but is more common than 
Lepisma outdoors. It is to be found under stones, in the soil around the 
base of tree-trunks, among dead leaves and fallen pine-needles, and at least 
one species occurs in the sand of sea-beaches. 


$ 
FIG. 93. Fic. 94. 


FIG. 93.-—The fish-moth, Lepisma domestica. (After Howard and Marlatt; a little 
larger than natural size.) 
Fic. 94.—Young and adult of Lepisma sp., from California. (Twice natural size.) 


CoLLtemMBoLa.—The springtails, mostly of microscopic size, and wholly 
unfamiliar to any but persistent explorers of nature, comprise many more 
species than the Thysanura. Their most distinctive character is the pos- 
session, by most of them, of the forked spring (Figs. 96 and 97), by 
means of which they leap vigorously when disturbed. This spring is 


The Simplest Insects 


attached to the next to last body segment or to the antepenultimate one. 


It consists of a basal part and of two terminal processes. 
It is carried bent forward under the body, with the bipartite 
tip held in a little catch on the third abdominal segment. 
In some species the catch is lacking. The springtails also 
possess a curious organ on the ventral aspect of the first 
abdominal segment which appears to be a small projecting 
sucker or tube. This sucker is often more or less divided 
inte two parts, in one family consisting plainly of two 
elongate, delicate tubes (Figs. 96 and 97). The use of 
this peculiar structure has not been definitely determined. 
Some entomologists think that it serves as a clinging organ, 
enabling the insect to attach its body firmly to the object 
upon which it rests. Others believe that the sucker serves 
in some way to take up moisture, while still others be- 
lieve it to aid in respiration. The Collembola as well 
as the Thysanura cannot live in a dry atmosphere. 
This suborder is divided into five families, as follows 
(MacGillivray) : 


il, Shoiatayen See ieee Sep eeeseconcescesoosoe: APHORURID&. 


bh il aa 


bette 


ne 


43 


a 


AA. Spring present. 


Fic. 96.—The spotted 
springtail, Papirius 
maculosus, with spring 
folded underneath 
body. (Natural 
length, 2 mm.) 


Fic. 95.—Machi- 
: es : lis sp., from Cali- 
B. Spring arising from ventral side of fornia. (Three 


antepenultimate abdominal segment. times natural 
PopurIp&. Size.) 
BB. Spring arising from ventral side of penultimate abdom- 
inal segment. 
C. Abdomen elongate, cylindrical, much longer than 
broad Sere eee eerie ENTOMOBRYIDS. 
CC. Abdomen globular, but little larger than broad. 
D. Terminal segment of antenne long, tinged. 


SMYNTHURID. 
DD. Terminal segment of the antennz short, with 
a whorl othairs paseo ee PAPIRIID®. 


Of these five families the members of one, the Aphoruride, in which 


the spring is wanting, are non-saltatorial. In all of 
the others leaping is a characteristic habit. The 
Smynthuride and the Papiriide are represented by 
but one genus each, viz., Smynthurus and Papirius. 
Smynthurus hortensis is a common form in gardens, 


and may be called the ‘“garden-flea.” It is found 
in the Eastern States in May and June 
leaves of young cabbage, turnip, cucumber, and 


“ 


upon the Fic. 97—The spotted 
springtail, Papirius macu- 
losus, with spring extended. 


various other plants, and also on the ground. It (Natural length, 2 mm.) 


64 The Simplest Insects 


is dull black, with head, legs, and bases of the antennz rust-color.” Smyn- 
thurus aquaticus (Fig. 87) often occurs in great numbers on the surface of 
pools. The insects look like tiny black spots on the water surface, but a 
little observation soon reveals their 
lively character. 

The Poduride and Entomobryide 
are represented in North America by 
twelve and fourteen genera respec- 
tively. Many of the Podurids are 
covered with scales and are often 
prettily colored and patterned. The 
scales (Fig. 98) are very minute and 
bear many fine lines and cross-lines, 
regularly arranged. On this account 
they are much used as test objects 
Aner for microscopes, the quality of the 


Fic. 98. 
Fic. 98.—Scales from a springtail. 
Murray; greatly magnified.) 


Fic. 99.—The snow-flea, Achorules nivicola. lens being determined by its capacity 
(After Folsom; much enlarged.) to reveal their extremely fine mark- 


ings. One of the most interesting Podurids is 
the snow-flea, Achorutes nivicola (Fig. 99), which 
gathers in large numbers on the surface of snow 
in the late spring. Comstock says that the 
snow-flea is sometimes a pest where maple- 
sugar is made, the insects collecting in large 


quantities in the sap. 

An interesting representative of the Entomo- 
bryidz is the house springtail, Lepidocyrtus ameri- 
canus (Fig. 100), said by Marlatt to be ‘not 
infrequently found in dwellings in Washington.” 


: : : Fic. 100. — The American 
It is about one-tenth of an inch long, silvery 


springtail, Lepidocyrtus 
gray, with purple or violet markings. In Europe americanus, ventral aspect, 
also one species of springtail.is common in Showing spring folded un- 
Ppt Bligh see eho ei a gato : derneath body. (After 
houses. As these insects live on decaying vege- Howard and Marlatt; 
table matter, they probably do no special harm ™UCh enlarged.) 

in the house. They especially frequent rather moist places, and may often 


be found in window-plant boxes and conservatories. 


CHAPTERS 


THE MAY-FLIES (Order Ephemerida) and STONE- 
( FLIES (Order Plecoptera) 


AY-FLIES, lake-flies, or shad-flies, common names for 
the insects of the order Ephemerida, are familiar to 
people who live on the shores of lakes or large rivers, 
but are among the unknown insects to most high-and- 
dry dwellers. 

Travelling down the St. Lawrence River from 
Lake Ontario to Quebec one summer, I had hosts of 
day-long companions in little May-flies that clung to 

my clothing or walked totteringly across my open book. The summer 

residents of the Thousand Islands get tired of this too-constant com- 
panionship, and look resentfully on the feeble shad-fly as an insect pest. 

One evening in August, 1897, my attention, with that of other strollers along 

the shore promenade at Lucerne, was called to a dense, whirling, tossing 

haze about a large arc light suspended in front of the great Schweizerhof. 

Scores of thousands of May-flies, just issued from the still lake, were in 

violent circling flight about the blinding light, while other thousands were 

steadily dropping, dying or dead, from the dancing swarm to the ground. 

Similar sights are familiar in summer-time in this country about the lights 

of bridges, or lake piers and shore roads. This flying dance is the most 

conspicuous event in the life of the fully developed, winged May-fly, and 
indeed makes up nearly all of it. With most species of May-flies the winged 
adult lives but a few hours. In the early twilight the young May-fly floats 
from the bottom of the lake to the surface, or crawls up on the bank, the 
skin splits, the fly comes forth full-fledged, joins its thousands of issuing 
companions, whirls and dances, mates, drops its masses of eggs on to the 
the lake’s surface, and soon flutters and falls after the eggs. It takes no 
food, and dies without seeing a sunrise. Sometimes the winds carry dense 
clouds of May-flies inland, and their bodies are scattered through the streets 
of lakeside villages, or in the fields and woods. Sometimes the great swarms 


65 


66 The May-flies and Stone-flies 


fall to the water’s surface and there are swept along by wind and wave, 
until finally cast up in thick winrows, miles long, 
on the lake beach. Millions of dead May-flies 
are thus piled up on the shores of the Great 
Lakes. 

We call the May-flies the Ephemerida, after 
the Ephemerides of Grecian mythology, and the 
name truly expresses their brief existence—above 
water. But they have lived for a year at least 
before this, or for two or even three years, as 
wingless, aquatic creatures, clinging concealed 
to the under side of stones in the lake or stream 
bottom, or actively crawling about after their food, 
which consists of minute aquatic plants and animals 
or bits of dead organic matter. In this stage their 
whole environment, habits, and general appearance are 
radically different from those of the brief adult life. We 
can only guess, if our curiosity compels us to attempt some 
explanation, at the manner and the cause of such a 
strange life-history. What advantage is there in such a 
specialized condition that Nature could not have arrived 
at by less indirect means? What is indeed the utility of 
the whole modification? The quick answer “ utility,” 
which is to account for all such strange structural and 
physiological conditions on the basis of useful adapta- 
tions brought about by the slow but persistent action 
of natural selection, leaves us, confessedly, answered 
simply on a basis of belief. In hundreds of cases that 
may come under our observation, in how few are we 
really able to perceive a reason-satisfying course of adap- 
tive development based on the selection of useful small 
fluctuating variations ? 

The eggs of the May-fly fall from the body of the 
mother to the water’s surface in two packets, which, 
however, break up while sinking, so that the released 


Fic. 1or.—May-flies about an electric lamp. 


The May-flies and Stone-flies 67 


eggs reach the bottom separately. From each egg hatches soon a tiny 
flattened, soft-bodied, six-legged creature called a nymph, without wings 
or wing-pads, and looking very much like a Campodea (the simplest 
living insect, see p. 61). This nymph crawls about, feeds, grows, moults, 
grows, moults again and again (in a species observed by Lubbock there 
were twenty-one moultings), and finally at the end of a year, or of two or 
three years, depending on the species, is ready to issue as a winged adult. 
During the nymphal life wings have been slowly developing, visible as 
short pads projecting from the dorsal margins of the meso- and meta-thorax, 
and appearing visibly larger after each moulting (Fig. 102). Respiration is 
accomplished by flat, leaf-like gills (Fig. 102) (these do not appear in some 
species until after one or two moultings), arranged segmentally along the 
sides of the abdomen. The mouth-parts are well developed for biting 
and chewing, with sharp-pointed jaws (mandibles). During its aquatic 
life at the bottom of stream or pond the May- 
fly has to undergo all the vicissitudes of an 
exposed and protracted life; it is eagerly sought 
after by larger, fierce, predaceous insects, 
stronger of jaw and swifter than itself; it is 
the prized food of many kinds of fishes, and it 
has to struggle with its own kind for food and 
place. 

At the end of the immature life the nymphs 
rise to the surface, and after floating there a 
short time suddenly split open the cuticle along 
the back and after hardly a second’s pause 
expand the delicate wings and fly away. Some 
nymphs brought into the laboratory from a 
watering-trough at Stanford University emerged 
one after another from the aquarium with 
amazing quickness. Almost all other insects 
require some little time after the final moulting 
for the gradual unfolding of the wings, and dry- Fy, fore voune (nymph) of 


ing and strengthening of the body-wall, before eee suowing Gy cece! 
; : . (Aft <ins 
flight or other locomotion. Most of the May- Poller Sea ane 


fly species go through another moulting after ural size.) 

acquiring wings, a phenomenon not known to occur in the case of any other 
insect. The stage between the first issuance from the water with expanded 
wings and the final moulting is called the subimago stage, and may last, 
in various species, from but a few minutes to twenty-four hours. Such 
is, in general, the life-history of the May-flies. As a matter of fact, the 
life-history of no single May-fly species has yet been followed completely 


68 The May-flies and Stone-flies 


through. And here is an opportunity for some keen-eyed amateur ento- 
mologist to add needed facts to our knowledge of insect life. 

The breathing-organs of the nymph are of interest, as special adaptations 
to enable them to take up oxygen and give off carbon dioxide without com- 
ing to the surface, as do the water-beetles, water-bugs, mosquito-wrigglers, 
and many other familiar aquatic insects. Each plate-like gill (Fig. 102) 
is a flattened sac, with upper and lower membranous walls which run into 
each other all around the free margin. Inside this sac is an air-tube 

=~, (tracheal trunk) with numer- 
ous fine branches. By osmosis 
an interchange of gases takes 
place through the walls of the 
trachee and of the sac—car- 
bonic dioxide passing out, and 
air from that held in solution 
in the water passing in. Ifa 
nymph held in a watch-glass 
of water be watched, at times 
all the gills will be seen rap- 
idly vibrating, thus setting 
up currents and bringing fresh 
aerated water to bathe the 
gills. 

In the adult winged stage 
(Fig. 103) the May-flies are 
extremely frail and delicate- 
bodied. The wings are fine 
and gauzy, consisting of 
the thinnest of membranes 


stretched over a perfect net- 
Fic. 103.—May-fly, from California. (Naturalsize.) work of veins. The fore 


wings are always markedly larger than the hind wings; in some species 
the latter are very small indeed, or even wanting altogether (Fig. 104). 
The body-wall is weakly chitinized, and collected specimens almost always 
shrivel and collapse badly in drying. The abdomen usually bears two 
or three long filaments on its tip; the head is provided with compound eyes 
and short awllike antenna. The often-repeated statement in text-books 
that adult May-flies have no mouth nor mouth-parts is not literally true 
of all species, as weakly developed jaws and lips are present in some. But 
they are in such weak and atrophied condition that they can hardly be func- 
tional. It is probable, therefore, that no adult May-fly takes food. In 
the males of some species the compound eyes present a very interesting 


The May-flies and Stone-flies 69 


condition, being divided, each into two parts, by a narrow impressed line 
or by a broader space (Fig. 105). The two parts differ in the size of the 
facets of the ommatidia, i.e., eye-elements, and it has been ascertained (Zim- 
merman, 1897) that this difference in size of facets 
is accompanied by other and more important 
structural differences, which make it certain that 
the two parts of the eye have different powers of 
seeing. One part is especially adapted for seeing 
in the dark, or for detecting slight differences in 
intensity of light, but is ill-fitted for exact sight, 
while the other part is adapted for seeing in 
daylight, and for making a more exact picture of 
outline. As the mating flights occur usually at 
twilight or in the evening, Zimmerman believes 
that this modification of the eyes of the males 
is to enable them to discover the females in the 
whirling shadow-dances. Chun has recorded a 
similar division and difference in the eye of 
certain ocean crustaceans and believes that the 
“dark eyes” are used for seeing in the dimly FiG, 104-—May-fly, Cents 
5 5 4 dimidiata, possessing only 
lighted water below the surface, while the “‘light one pair of wings. (Much 
eyes” are for special use at the brilliantly lighted — enlarged.) 

surface. I have noted similar conditions in the eyes of both male and 
female net-winged midges (Blepharoceride), small, two-winged flies of 
particularly interesting life (see p. 319). It is unusual to find such parallel 
adaptations in forms so unrelated. 

The May-flies show an anatomical condition of much interest to ento- 
mologists in the paired openings for 
the issuance of the eggs. Insects have 
their organs arranged in pairs, one on 
each side of the middle line of the 
body, as the legs, wings, mouth-parts, 
antenne, eyes, spiracles, etc., or exact- 
ly on the middle line, as the heart, 
Fic. 105.—Section through head of alimentary canal, and ventral nerve- 

secs ct compound cord. That is, the typical insect body 
eye and two sizes of eye-elements is bilaterally symmetrical, and the 


(ommatidia). (After Zimmer; greatly 
magnified.) 


more apparent this symmetry is the sim 
pler and more generalized the insect 
is believed to be. All other insects but the May-flies have the two egg- 
ducts, one from each egg-gland, fused inside the body, so as to form a short, 


single, common duct on the median line. But the May-flies have the ducts 


70 The May-flies and Stone-flies 


separate; that is, paired and bilateral for their whole course. This is taken 
to be an indication of the primitiveness and antiquity of the order. 

If the May-flies are an ancient group of insects, and there is little doubt 
of this, we have in them another example (we have previously noted one 
in the case of Campodea, see p. 60) of primitive insects of excessively 
frail and defenceless character persisting in the face of the strenuous struggle 
for existence and of the competition, in this struggle, of highly developed, 
specialized insect forms. Perhaps the solution of this problem in the case 
of the May-flies is to be found in their extreme prolificness and in the 
ephemeral character of their adult lives. It is only in the adult condition 
that May-flies are so ill-fitted to defend themselves; so they simply make no 
attempt to do so. They lay their eggs immediately on coming of age, and 
thus accomplish the purpose of their adult stage. In their immature form 
they are not so handicapped in the struggle for existence, although they 
seem by no means in position to compete with some of their neighbors, like 
the nymphs of the stone-fly and dragon-fly. 

About 300 species of Ephemerida are known, of which 85 occur in 
North America. Their classification has been comparatively little studied 
and is a difficult matter for beginners. The differences among the adults 
are so slight, and the preserved specimens are so uniformly misshapen 
and dried up, that most of us will have to be satisfied with knowing that 
we have in hand a May-fly, without being able to assign it to its genus. 
Keys to the North American tribes and genera of May-flies may be found 
by the student who may wish to attempt the generic determination of his 
specimens, in a paper by Banks in the Transactions of the American Ento- 
mological Society, y. 26, 1894, pp. 239-250. 

There are better defined differences among the nymphs than among 
the adults, but unfortunately the nymphs have been as yet too little studied 
for the making out of a comprehensive key to the genera. Needham and 
Betten give an analytical table of genera of Ephemerid nymphs as far as 
known in the Eastern United States, in Bulletin 47 of the New York State 
Museum, toot. 


On THE under side of the same stones in the brook ‘‘riffles’’ where 
the May-fly nymphs may be found, one can almost certainly find the very 
similar nymphs (Fig. 106) of the stone-flies, an order of insects called 
Plecoptera. More flattened and usually darker, or tiger-striped with black 
and white, the stone-fly nymphs live side by side with the young May-flies. 
But they are only to be certainly distinguished from them by careful exam- 
ination. The gills of the immature stone-flies usually consist of single short 
filaments or tufts of short filaments rising from the thoracic segments, one 
tuft just behind each leg (Fig. 106), and not flat plates attached to the sides 


The May-flies and Stone-flies 71 


of the abdomen as in the May-fly nymphs. The feet of the stone-flies have 
two claws, while those of the young May-flies have but one. The stone-fly 
nymph has a pair of large compound eyes, as well as three small simple eyes, 
strong jaws for biting and chewing (perhaps for 
chewing heir nearest neighbors, the soft-bodied, 
smaller May-fly nymphs!), and two slender back- 
ward-projecting processes on the tip of the abdomen. 
The legs are usually fringed with hairs, which makes 
them good swimming as well as running organs. 
The nymphs can run swiftly, and quickly conceal 
themselves when disturbed. 

All stone-fly nymphs, as far as known, require 
well aerated water; they cannot live in stagnant 
pools or foul streams. Needham says that a large 
number of the smaller species are wholly destitute 
of gills absorbing the air directly through the skin. 
Nymphs brought in from a brook and placed in a F!G.106.—Young(nymph) 

; ; c = of stone-fly, from Cali- 
vessel of still water will be seen with claws affixed, fornia. (Twice natural 
vigorously swinging the body up and down, trying — size.) 
to get a breath under the difficult conditions into which they have been 
brought. The food-habits are not at all well known: some entomologists 
assert that small May-fly nymphs and other soft-bodied aquatic creatures 
are eaten, while others say that the food consists of decaying organic matter. 

2 Here is another opportunity for some exact observation 
by the interested amateur. On the other hand it is per- 
fectly certain that the nymphs themselves serve as food 
for fishes. 

The fully worked-out life-history of no stone-fly seems 
to have been recorded. The eggs, of which 5000 or 6000 
may be deposited by a single female, are probably dropped 
on the surface of the water, and sink to the bottom 
after being, however, well distributed by the swift current. 
Sometimes the eggs are carried about for a while by the 
female, enclosed in a capsule attached to the abdomen. 
The young moult several times in their growth, but 
Fr ., probably not nearly as many times as is common among 

G. 107. —Exuvia é 5 - i 
of nymph of stone- May-flies. When ready for the final moulting, the nymph 
fly. (Naturalsize.) crawls out on a rock or on a tree-root or trunk on the 


bank, and splitting its cuticle along the back, issues as a winged adult. 
The cast exuvie (Fig. 107) are common objects along swift brooks. 

The adults (Fig. 108) vary much in size and color, the smallest being 
less than one-fifth of an inch long, while the largest reach a length of two 


72 The May-flies and Stone-flies 


inches. Some are pale green, some grayish, others brownish to black. 
There are four rather large membranous, many-veined wings without pattern, 
the hind wings being larger than the front ones. When at rest, the fore 
wings lie flat on the back, covering the much-folded hind wings. ‘The mouth- 
parts are present and are fitted for biting, although the food-habits are not 
known. It is asserted that some species take no food. The antenna are 
long and slender. The abdomen usually bears a pair of long, many-seg- 
mented, terminal filaments. The body is rather broad and flattened, and 
there is no constriction between the thorax and abdomen. On the ventral 
aspect of each thoracic segment there is a pair of small openings whose func- 


Fic. 1o8.—A stone-fly, Perla sp., common about brooks in California. (After Jenkins 
and Kellogg; twice natural size.) 


tion is unknown. The adults of certain species retain, although in shriveled 
and probably functionless condition, the filamentous gills. This fact is of 
importance in connection with the question as to whether insects are 
descended from aquatic or terrestrial ancestors. Those who believe in 
the aquatic ancestry have found a simple origin for the spiracles (breathing- 
pores) by imagining them to be the openings left when the gills, used in 
aquatic life, were lost. But the adult stone-flies which retain their gills 
also have wholly independent spiracles. 

About roo species of stone-flies are known in North America. The 
adults are to be found flying over or near streams, though sometimes 


The May-flies and Stone-flies 73 


straying far away. They rest on trees and bushes along the banks. The 
green ones usually keep to the green foliage, while the dark ones perch on 
the trunk and branches. The various species are included in ten genera, 
which may be determined by the following table: 


TABLE OF NORTH AMERICAN GENERA OF PLECOPTERA. 


The following technical terms not heretofore defined are used in this key: cerci, 
slender processes projecting from the tip of the abdomen; radial sector, cubital vein, 
and other names of veins in the wings may be understood by reference to Fig. 109. 


Fic. ro9.—Diagram of venation of wing of a stone-fly; 7, costal vein; 2, subcostal vein; 
3, radial vein; 4, medial vein; 5, first anal vein; 6, radial sector, P, pterostigma; 
A, arculus: a,, @,, a3, apical cells. Between the medial and first anal vein is the 
cubital vein, not numbered. Cell M is the cell behind the medial vein; cell Sc is the 
cell behind the subcostal vein. 


A. With two long, many-jointed cerci. 
B. Radial sector not reduced, i.e., with four or more branches. 

C. Wings strengthened throughout by many cross-veins, there being many 
cross-veins between the branches of the media, between the accessory 
cubital veins, and in the anal areas of both pairs of wings. . PTERONARCYS. 

CC. Wings with few or no cross-veins between the branches of the media, 
between the branches of the cubital veins, and in the anal area. 

D. Radial area of the fore wings with an irregular network of veins: 


DICTYOPTERYX. 
DD. Radial area of the fore wing with no cross-veins except the radial 
cross-veins, or with a few regular cross-veins....PERLA (in part). 


BB. Radial sector reduced, i.e., with less than four branches, 
C. Hind wings much broader than the fore wings. 
D. With several cross-veins in cell M of the fore wings. 
E. Cell Sc of the fore wings with at least three cross-veins. 


He With) three \ocel lees tee PERLA (in part). 

BES Wathronly itwolocelliS22 = eee eee PSEUDOPERLA. 

EE. Cell Sc of the fore wings with only one or two cross-veins. 

Small species of a green or yellow color........ CHLOROPERLA. 

DD. With only one cross-vein in cell M of the fore wings between the 
arculus and the medio-cubital cross-vein...............- CAPNIA. 

CC. Hind wings of the same width as the fore wings; the anal area of the 
hindiwings: notyexpanded «5-2-5 = eee aes ISOPTERYX. 


AA. With the cerci rudimentary or wanting. 
B. Second segment of the tarsi equal in length to the others; rudimentary cerci 
OREO coco - sadogs pudeods ss IdebaeboDaSasebctSssosoeahe T2NIOPTERYX. 


74 The May-flies and Stone-flies 


BB. Second segment of the tarsi small, shorter than the others, cerci absent. 
C. Veins radiating from the ends of the radial cross-vein forming an X. 
NEMOURA, 
CC. Veins radiating from the ends of the radial cross-vein not forming an X. 
LEvCTRA. 


The genus Perla (Fig. 108) includes more species than any other. The 
species of Pteronarcys retain gills in the adult condition. The species of 
Chloroperla are small, delicate, and pale green. Leuctra includes the slender- 
est of the stone-flies; they are small and brownish. Comstock says that 
there are several species of stone-flies that appear on the snow on warm 
days in late winter. They become more numerous in early spring, and 
often find their way into houses. The most common one in Central New 
York is the small snow-fly, Capnia pygm@a, which is grayish black. The 
female is 9 mm. (about % in.) long, with an expanse of wings of 16 mm. 
(about # in.), while the male is but 44 mm. (about + in.) long, and has 
short wings which extend but two-thirds the length of the abdomen. 


CHAPTER VI 


DRAGON-FLIES AND DAM- 
SEL-FLIES (Order Odonata ) 


HEN it is high noon on the mill-pond,— 
when leaves droop, and sun glares upon the 
water, and the air is hot and still, when 
other creatures seek the shade, and even 
the swallows that skim the air morning 
and evening are resting,—then those other 
swallows of the insect world, the dragon- 
flies, are all abroad....One may stand 
by the side of a small pond, and follow 

for hours with his eye the evolutions of one of the large dragon-flies skim- 


=a 
SSS 


\ 


av 


reas 


i 
| 


moet ie 

ming over the surface in zigzag lines or sweeping curves, stopping still 

in midair, and starting again, seeming never to rest, nor even to tire. Poised 
75 


76 Dragon-tles and Damsel-flies 


in the air, with the sunlight dancing on its trembling wings, it is indeed a 
beautiful sight. 

““Dragon-flies? Folks call ’em devil’s-darnin’-needles in our parts, 
and they say they will sew up your ears.’ Yes; and in some localities they 
7 are called ‘snake-doctors,’ and are said 
to bring dead snakes to life; and other 
meaningless names are given them, such 
as ‘snake-feeders,’ ‘horse-stingers,’ ‘mule- 
killers,’ etc.; but in spite of all these 
silly names and the silly superstitions 
they represent, dragon-flies are entirely 
harmless to man—are indeed to be 
counted as friends, for they destroy vast 
numbers of mosquitoes and gnats and 
pestiferous little flies. To such creatures 
they must seem real dragons of the air. 
While one is standing by the pond let 
him follow awhile the actions of a dragon- 
f ya ee fly that is making short dashes in different 
Fic. 110.—A dragon-fly (from life). directions close to the bank. Let him 
fix his eye on a little fly hovering in the air, and note that after the 
dragon-fly has made a dart toward it, it is gone. Let him repeat the 
observation as the dragon-fly goes darting 
hither and thither. It will be hard to see 
the flies captured, so quickly it is done, 
but one can see that ‘the place that once 
knew them knows them no more.’ And 
the usefulness of the dragon-fly in taking 
off such water-haunting pests will be 
appreciated.” 

Thus entertainingly and truthfully writes 
Professor Needham of the strong-winged, 
brilliantly colored, graceful insects of our 
present chapter. If one could see through 
muddy water and would fix his gaze on j 
the weed-choked slimy depths of the pond, Fic. 111.—The young (nymph) of 


he would see the dragon-flies in another @ dragon-fly. (From Jenkins and 
Kellogg; twice natural size.) 


stage of their life, under very different 
conditions of existence, and in very different guise. Crawling awkwardly 
about over and through the decaying weeds and leaves and mud of the 
bottom or lying in ambush, half concealed by coverings of slime, 
would be seen certain strange big-headed, thick-bodied, dirty gray-green, 


Dragon-flies and Damsel-flies TF 


wingless creatures from half an inch to two inches long. Occasionally 
one of these creatures suddenly darts forward by spurting water from 
the hinder tip of its body; occasionally one quickly thrusts out from 
its head a vicious pincer-like organ which is more slowly withdrawn, or 
rather folded up, with an unfortunate tiny water-animal squirming in the 
toothed pincers. Still dragons, though now dragons of the deep instead of 
flying dragons, these are our insects in their immature or larval life. Their 


Fic. 112.—Young (nymph) dragon-fly, showing lower lip folded and extended. (From 
Jenkins and Kellogg; twice natural size.) 


prey, consisting of water-bugs, May-fly larve, small crustaceans, mol- 
lusks, and any of the numerous aquatic insect larve, including other 
young dragon-flies, is probably always caught alive. Not by active 
pursuit, as in the air above, but by lying in wait in the murky depths 
of the pond until the unsuspecting insect comes within reach of the 
extensible lower lip with its pair of broad spiny, jaw-like flaps at the 
clutching tip. The fierce face of the young dragon, with its great 
mouth and sharp jaws, is all concealed by this lip when folded up, 
and there is little in the appearance of the dirty, sprawling, smooth- 
faced creature to betray its dragon-like character. But appearances in 
the insect world may be as deceptive as in our own, and too -late the 
careless water-bug out on a foraging swim for lesser prey finds himself in 
range of a masked battery and becomes the preyer preyed upon. 

About three hundred different species of dragon- and damsel-flies 
(damsel-flies are the smaller, slender-bodied, narrow-winged kinds, see Fig. 
1r3) are known in North America, about two thousand having been found 
in all the world. In any single locality where conditions are at all favor- 
able to dragon-fly life, that is, where there are live streams and ponds, from 
a score to two or three times as many different dragon-flies can be found. 
One hundred species occur in Ohio, and one hundred and twenty in New 
York, states offering specially favorable natural conditions for them, while 
only about fifty species have been found in California, a much larger but 
more arid region. The young of no dragon-fly species is known to live in 
sait water, although nymphs have been found in brackish water and in 


78 Dragon-flies and Damsel-flies 


streams impregnated with sulphur from sulphur springs. Nor do dragon- 
flies like cold weather. Although a few species are found in the far North 
(recorded at 70° N. in Norway, 65° N. in Alaska, and 63° N. in Siberia) 
and a few at high cold altitudes (as high as 10,000 feet) on mountain flanks, 
the great majority of them need considerable temperature for growth and 
development and even for activity during adult life. Calvert says that but 
one species is known See regularly passes the winter in adult stage, and 

SS that most dragon-flies live as adults from 
but twenty-five to forty-five days, and 
these in the summer. In California, where 
the winter temperature at sea-level only 
occasionally falls to 32° F., adult dragon- 
flies can be found in most of the months 
of the year. 

The adult dragon-flies are to be seen 
pursuing their prey, like hawks, with 
swift darting flights over ponds, along 
streams, and even scattered widely inland 
over fields and in woods. <A few kinds 
have a liking for the vicinity of houses. 
Needham, a careful student of these 
insects, has found that the hunting region 
above a and along the shores of a pond may 
Fic. 113.—Damsel-flies (narrow- be imaginarily divided into zones one 

winged dragon-flies). (Natural above the other, each zone characterized 
size; from life.) 
by the aeegeS of a few particular 
dragon-fly species. “‘So, in fact,” he writes, “we find the smaller damsel- 
flies flying over the water in a straight course an inch or less above the 
surface, and rarely venturing higher; the larger damsel-flies a little higher; 
the amber wings at an average of about six inches; the larger skimmers 
a foot or more from the surface, and upland skimmers and darters still 
higher. One has only to stand a little while by some small area of water 
where all these are flying to see that each keeps rather closely to his proper 
altitude. Why do damsel-flies keep so close to water? The reason is 
not far to seek. Dragon-flies eat one another—the strong destroy the 
weak. If to venture up into the altitude of the larger species means to run 
the risk of being eaten, we can readily see why the damsel-flies should 
stay down below. The hawk may roam the air at will, but sparrows must 
keep to the bushes.” 

We think of dragon-flies, as of albatrosses and Mother Carey’s chickens, 
as being always on the wing. They catch their prey while flying, eat it 
while flying, mate while flying, and some of them deposit their eggs while 


Dragon-ftlies and Damsel-flies 79 


on the wing. But of course all dragon-flies rest sometimes, and some of 
them, especially the damsel-flies, are at rest most of the time, clinging to 
stems or leaves by the water’s edge. The larger kinds may be found 
occasionally perched on the tips of tall swaying reeds, or on a stump or 
projecting dead limb. From these coigns of vantage they swoop like 
a hawk on any rash midge that ventures awing in the neighborhood. 
Cold or cloudy weather, or a strong wind, will drive most dragon-flies to 
shelter. 

The Odonata are unexcelled among insects for swiftness, straightness, 
and quick angular changes in direction of flight. The successful main- 
tenance of their predatory life depends upon this finely developed flight 
function together with certain structural and functional body conditions 
which might be said to be accessory or auxiliary to it. And this may be 
an appropriate place to describe briefly a few of their salient structural 
characteristics. 

All dragon-flies have four well-developed wings, and all show such a 
similar general bodily make-up and appearance, that from an acquaintance- 
ship with two or three familiar species any member of the order can be 
recognized as really belonging to the group. The body in all is long, smooth, 
and subcylindrical or gently tapering. This clean, slender body offers 
little resistance to the air in flight, and serves as an effective steering-oar. 
The wings are long and comparatively narrow, fore and hind wings being 
much alike, almost exactly alike indeed in the damsel-flies. The venation 
is of the general type known as net-veining (Fig. 1140), the few strong longi- 
tudinal veins being connected by many short cross-veins. The fore wings 
are greatly strengthened along their costal (front) margin by having the 
first longitudinal (subcostal) vein behind the margin placed at the bottom 
of a groove, and the cross-veins in that groove so enlarged vertically as 
to take on the character of flat, plate-like braces or buttresses. As, in 
the figure-of-eight movement of the wing in flight, the front margin first 
meets the resistance of the air, it is necessary that swiftly and strongly beat- 
ing wings should be especially strengthened along this edge, and this is just 
what the peculiar folding and bracing of the costal region of the dragon-fly’s 
fore wing accomplishes. 

The head is unusually large and is more than two-thirds composed of 
the pair of great compound eyes. More than 30,000 facets have been 
counted in the cornea of certain dragon-fly species, and this means that each 
eye is made up of more than 30,000 distinct eye-elements or ommatidia, 
each capable of seeing a small part or point of any object in range of vision. 
Thus an image of a near-by object is made in fine mosaic, and the finer the 
mosaic the more definite and precise is the vision by means of compound 
eyes. These great eyes, too, have facets directed up and down and sidewise 


80 Dragon-flies and Damsel-flies 


as well as forward, and by a special sort of articulation of the head on the 
thorax it can be rotated readily through 180°, so that the principal part of 
each eye can be directed sidewise or even straight down. For accurate 
flight and successful pursuit of flying prey the dragon-fly has full need of 
good eyes. It is to be noted, too, that the eyes are relatively largest in those 
particular dragon-fly kinds which have the most powerful flight. On the 
head, also, are three simple eyes (ocelli), the pair of very small awl-like 
antenne, and the great mouth. The mouth is overhung as by a curtain 
by the large flap-like upper lip (labrum). The jaws (mandibles) are strong 
and toothed, and obviously well adapted for tearing and crushing the cap- 
tured prey. 

When the prey is come up with, however, it is caught not by the mouth 
but by the “leg-basket.”. The thorax is so modified, and the insertion of 
the legs such, that all the legs are brought close together and far forward, 
so that they can be clasped together like six slender, spiny grasping arms 
just below the head. Although the catching and eating is all done in the 
air and very quickly, observers have been able to see that the prey is caught 
in this ‘‘leg-basket”’ and then held in the fore legs while being bitten and 
devoured. These slender legs are used only very slightly for locomotion, 
but they serve well for the light unstable perching which is characteristic 
of the dragon-flies. 

The internal anatomy is specially characterized, as might well be 
imagined, by a finely developed system of thoracic muscles for the rapid 
and powerful motion of the wings and the delicate and accurate move- 
ments of the legs. The respiratory system is also unusually well developed, 
such active insects needing a large quantity of oxygen, and generating a 
large amount of carbon dioxide. The respiratory movements, according 
to Calvert, consist in an alternate expansion (inspiration through the ten 
pairs of breathing-holes, or spiracles, arranged segmentally on thorax and 
abdomen) and contraction (expiration) of the abdomen. The rate of 
movement varies greatly at different times owing to unknown causes, but 
is always quickened by exercise, increased temperature, or mechanical irri- 
tation. In different dragon-flies the inspirations have been noted to be 
from 73 to 118 a minute. 

The dragon-flies are famous for their beautiful metallic colors. As they 
dart through the air one gets glimpses of iridescent blue and green and cop- 
per, of tawny red and violet and purple reflections that are most fascinating 
and tantalizing. Seen close at hand in the collections, however, they are 
mostly dull-colored and, except for their ‘‘pictured”? wings and the sym- 
metry and trim outline of their body, rather unattractive “‘specimens.” But 
a freshly caught dragon-fly shows the real glory of the coloring: delicate 
changing shades of green and violet and copper quiver in the great eyes; 


Dragon-tlies and Damsel-flies 81 


the thorax is translucent green or blue, and the long symmetrical body is 
warm red or deep blue or purple or green. It is often covered with a soft 
whitish “bloom,” that tones down the brilliant metallic iridescence. But 
as the body dries, the colors fade. They are due not so much to pigment 
as to the interference in reflection of the various color-rays, this interference 
being caused by the structure of the body-wall. Just as soap-bubbles or 
weathered plates of glass or mica produce brilliant colors by interference 
effects, so does the semi-transparent laminate outer body-wall of the 
dragon-fly produce its fleeting color glories. While the wings of many 
kinds are clear, unmarked by blotches or line, the wings of others bear a 
definite “‘picture” or pattern, usually light or dark brown or even blackish, 
reddish, thin yellow, or whitish. These wing-patterns make the determination 
of many of the dragon-fly species a very simple matter. 

When the dragon-flies go winging about over ponds and streams they 
are engaged in one of three things: in eating, in mating, or in egg-laying. 
The prey of the dragon-fly may be almost any flying insect smaller than 
itself, although midges, mosquitoes, and larger flies constitute the majority 
of the victims. Howard says that the voracity of a dragon-fly may easily 
be tested by capturing one, holding it by its wings folded together over its 
back, and then feeding it on live house-flies. Beutenmiiller found that 
one of the large ones would eat forty house-flies inside of two hours. Howard 
says that a dragon-fly will eat its own body when offered to it (query, to 
its head?) and that a collected dragon-fly, if insufficiently chloroformed and 
pinned, will when it revives cease all efforts to escape if fed with house-flies, 
the satisfying of its appetite making it apparently oblivious to the discom- 
fort or possible pain of a big pin through its thorax. That dragon-flies 
are sometimes cannibalistic has been repeatedly confirmed by observation. 
The nymphs have been seen to devour nymphs of their own and other 
species; the nymphs of a European form have been observed to come out of 
water at night and attack and devour newly transformed imagoes of the 
same species, while several instances are recorded of the capture and devouring 
of an imago of one species by an imago of another. 

The good that is done by dragon-flies through their insatiable appetite 
for mosquitoes is very great. Now that we recognize in mosquitoes not 
only irritating tormentors and destroyers of our peace of mind, but alarm- 
ingly dangerous disseminators of serious diseases (malaria, yellow fever, 
filariasis), any enemy of them must be called a friend of ours. A prize was 
once offered for the best suggestions looking toward practicable means of 
artificially utilizing dragon-flies for the destruction of mosquitoes and house- 
flies, but no very efficient improvement on the dragon-fly’s natural tastes 
and practices were brought out by this essay competition. 

In Honolulu, the principal city of our mid-Pacific territory, the mosqui- 


82 Dragon-flies and Damsel-flies 


toes are so abundant that no one neglects to enclose his bed carefully each 
night in mosquito-netting, and all bedrooms are equipped with an ingenious 
canopy which can be folded closely in the daytime and readily spread over 
the bed at night. The continuous and abundant presence of mosquitoes 
is such a matter of fact that it has dictated certain particular habits of life 
to the inhabitants of Honolulu. But in the daytime one is singularly free 
from mosquito attack. Coincidentally with this one notes the surprising 
abundance and strangely domestic habits of great dragon-flies. I have 
watched dozens of dragon-flies hawking about a hotel Janai (porch) in the 
heart of the town. No pond or stream is nearer than the city’s outskirts. 
Dragon-flies are in the main streets, in all the gardens, and they are chiefly 
engaged in the laudable business of hunt:ng the hordes of ‘“‘day’’ mosquitoes 
to their death. The most conspicuous features of insect life in Hawaii are 
the hosts of dragon-flies by day and the hordes of mosquitoes by night. As 
the dragon-flies unfortunately are not night flyers (although some forms 
keep up the hunting until it is really dark), it is by night that one realizes 
what a plague the mosquito is in the islands. Were it not for the dragon- 
flies, life in the islands would be nearly intolerable. The rice-swamps and 
taro-marshes and the heavily irrigated banana and sugar plantations offer 
most favorable breeding-grounds for the mosquitoes, but also fortunately 
for the dragon-flies as well. The mosquitoes of Hawaii are not indigenous; 
they were introduced with white civilization. It is told, and is not improb- 
able, that the skipper of a trading schooner in early days, to revenge himself 
for some slight put on him by the natives, purposely put ashore a cask of 
water swarming with mosquito wrigglers. It needed no more than that 
to colonize this fascinating tropic land with the mosquito plague. How 
the saving dragon-flies came is not yet come to be tradition; indeed, few 
Hawaiians understand how important a part the dragon-fly plays in their 
life. They do appreciate the mosquito. 

In the Samoan Islands, too, where we have another tropical colony, 
the mosquitoes are a great plague. Here the matter is made more serious. 
The Samoan mosquitoes are carriers and disseminators of a dreadful disease 
known as elephantiasis from the enormous enlargement of the legs and 
arms of sufferers from it. This disease is the great scourge of these islands, 
more than 30% (from my own observation; 40% and 50% are estimates 
given by other observers) of the natives having~ it. (For an account of 
the rdle of mosquitoes in the dissemination of malaria, yellow fever, and 
elephantiasis, see Chapter XVIII of this book.) The dragon-flies are, in 
Samoa as in Hawaii, conspicuous by their abundance and variety, and they 
do much to keep in’ check the quickly breeding mosquitoes. 

Watching the flying dragon-flies over a pond, you may occasionally 
see one poising just over the surface of the water, and striking it with the 


Dragon-flies and Damsel-flies 83 


tip of the abdomen; or another kind may be seen to swoop swiftly down to 
the surface occasionally in its back-and-forth flight, and to dip the tip of 


Fic. 114a. 


Pr, 


a x (Eomnrsen TO fe N 


) 


Fic. 114). 

Stages in the development of the giant dragon-fly, Anax junius. a, youngest stage; 8, 
c, and d, older stages, showing gradua! development of the wings. (Young stage, 
slightly enlarged after Needham; adult three-fourths natural size.) 


the body for a moment into the water. These are females engaged in laying 
their eggs. The eggs issue in small masses, usually held together by a gelat- 
inous substance. From several hundred to several thousand eggs are laid by 


84 Dragon-flies and Damsel-tlies 


each female. Needham counted 110,000 eggs in a single egg-mass of Libellula. 
Sometimes the eggs may be laid on wet mud or attached to moist water- or 
shore-plants. The damsel-flies and a few of the dragon-flies insert the eggs 
in the stems of dead or living water-plants below the surface of the water. 
To do this they have to cling to the stem, with the abdomen or sometimes 
the whole body under water, and cut slits in it with the sharp ovipositor, 
The eggs are sometimes laid on submerged timbers and moss- or alga-covered 
stones. Kellicott observed females of Argia putrida (a damsel-fly abundant 
along Lake Erie) to remain wholly under water for from five to fifty-five 
minutes at a time. These females were accompanied by males which also 
stayed under for similar lengths of time. 

The eggs hatch after various periods, depending on the species of dragon- 
fly and on the time of year of oviposition. In midsummer Needham found 
the eggs of some species to hatch in from six to 
ten days, while others laid in autumn did not hatch 
until the following spring. In the same lot of eggs 
the period of incubation may vary even in midsum- 
mer from a week to more than a month. 

From the eggs come tiny, spider-like nymphs 
with long, slender legs, thin body, and no sign of 
wings. Even in the largest dragon-fly species the 
just-hatched young are only about one-twelfth of 
an inch long, while the nymphs of the common 
Libellulas are only one-twenty-fifth of an inch long 
at hatching. They begin their predatory life, con- 
fining their attention at first to the smaller aquatic 
creatures, but with increasing size and strength 
and confidence being ready to attack almost any of 
the under-water dwellers. Even fish are seized by 
EY ene eet oe ae meee the larger nymphs, Needham having seen the 

fly Gasowavinesd dra- nymphs of one species seize and devour young 

gon-fly), Lestessp. The )rook-trout as long as themselves. 

three leaf-like processes = : 3 A S 

at the tip of the abdo- The young of different species differ consider- 

men are gills (Twice ably in size, shape, and duration of their nymphal 

naturahsize:) existence. The nymphs of some species require 
more than a year to develop into adults, while those of some others are ready 
to transform in a few months, not a few dragon-fly species having two gener- 
ations a year. The one-year life cycle, however, is usual among the more 
familiar dragon-flies, the eggs laid during midsummer hatching in late sum- 
mer, the nymphs hibernating and being ready to emerge the following sum- 
mer. Needham thinks that the damsel-flies have a number of broods in 
a season, the processes of transformation and oviposition beginning as soon 


Dragon-flies and Damsel-flies 85 


as the weather permits, and continuing industriously to the close of the 
season. 

The nymphs cast the skin repeatedly during their growth and develop- 
ment, although the exact number of moultings is not known for any species. 
After two or three moults the wing-pads appear and with each successive 
moult increase in size. Immediately after moulting the nymphs are light 
greenish or gray, and their characteristic color pattern is distinct, but they 
gradually darken, the pattern becoming more and more obscure until by 
the t me for another moulting the body is uniformly dark and dingy. The 
nymphs (Fig. 115) of the damsel-flies are elongate and slender, and have 
three long conspicuous gill-plates at the tip of the abdomen, which they 
can also use as sculls for swimming. The dragon-fly nymphs are robust- 
bodied, some of them indeed having the abdomen nearly as wide as long 
and much flattened. All the nymphs are provided with the long grasping 
lower lip, which can be folded mask-like over the face when not engaged 
in seizing prey. The mandibles are strong and sharp and the whole mouth 
is well fitted for its deplorable but necessary business. 

The true dragon-fly nymphs do not have plate-like gills, like those of the 
damsel-flies, nor any other external kind, but have the posterior third of 
the intestine lined with so-called internal gills. These internal or rectal 
gills are in six longitudinal bands, each consisting of two thin rows of small 
plates or tufts of short slender papilla. Water is taken into the intestine 
through its posterior opening and, after bathing the gills, giving up its dis- 
solved oxygen, and taking up carbon dioxide, it is ejected through the same 
opening. When this water is ejected violently it serves to propel the nymph 
forward. It is also apparently occasionally used for defence. 

Just as the adult flying dragon-flies keep to certain regions above or 
in the neighborhood of the pond, so Needham has found the nymphs to 
have various preferred lurking-places in the pond. The damsel-fly nymphs 
and a few of the more active dragon-fly nymphs clamber among submerged 
vegetation or inhabit driftwood and submerged roots or brush. The heavier 
sprawling Libellulid nymphs usually crawl over the bottom or climb over 
fallen rubbish, while certain other Libellulids and some similar forms occupy 
the mud or sand of the bottom. The nymphs of one of these latter kinds 
is described as each scratching a hole for itself and descending into it like 
a chicken into a dust-bath, kicking the sand over its back and burrowing 
until all but hidden, only the tops of its eyes, the tips of its treacherous labium, 
and the respiratory aperture at the end of the abdomen reaching the surface. 

After the few weeks or month or year which the nymph requires for its full 
growth and development it is ready to transform. If in early summer, when 
the dragon-flies are beginning to appear, one will go out to the dragon-fly 
pond a little after daylight, he will see this transforming or issuance of the 


86 Dragon-flies and Damsel-flies 


winged imagoes busily going on. The nymphs crawl out of the water, and 
up on stones or projecting sticks, or on bridge-piles or the sides of boats, 
or on the stems of weeds growing by the water’s edge. Here they cling quietly, 
awaiting the moment when the chi- 
tinous body-wall shall split lengthwise 
along the back of the thorax, and the 
made-over body inside with its damp, 
compressed wings, its delicate trans- 
parent skin, and changed mouth-parts 
and legs shall slowly work its way out 
of the old nymphal coat. The nymphs 
of some dragon-flies and damsel-flies 
Fic. 116.—The issuance of an adult white crawl out among the weeds and grass 
tail, Plathemis trimaculata, (After Need- of the shore for some distance before 
ham; natural size.) . : 

choosing a resting-place, and none of 

these will be very readily seen. But careful searching in a place from which 
winged individuals are occasionally arising will soon reveal the transforming 
in all of its stages (Fig. 116). It takes some time for the emergence of the 
damp, soft imago from the nymphal skin, and some further time for the 
slow expanding and drying of the wings, and the hardening of the body- 
wall so that the muscles can safely pull against it. When all this has come 
about the imago can fly away. But even yet the colors are not fully acquired 


Fic. 117.—Adult and last exuvia of the whitetail, P/athemis trimaculata. 
(Natural size.) 


and fixed, and these fresh imagoes have an unmistakably new and shiny 
appearance. They are called teneral specimens. Usually the emergence 
of nymphs from the pond and the subsequent transforming cease by the 
middle of the forenoon, and after that one can find only the frail, drying 


Dragon-flies and Damsel-flies 87 


cast nymphal skins or exuvis, clinging here and there to stones and plant- 
stems. Attached to these exuvie there may be often noted two or three short, 
white, thread-like processes. These 
are the dry chitinous inner linings 
of the main tracheal trunks of the ¢ 
dragon-fly which were moulted with 
the outer body-wall. As the main 
tracheal tubes are really invagina- 
tions of the outer skin, it is obvious 
that the inner lining of the trachea 
is continuous with the outer coat 
(chitinized cuticle) of the body-wall 
and so is naturally cast off with it. 
Although the habits of the adult 
dragon-flies must be studied out of 
doors, the nymphs can be brought 
indoors and kept alive so that their 
walking and swimming and hiding Fic. 118.—Adult and last exuvia of the damsel- 
and capturing of prey, and ohen fly, Lestes uncata. (Natural size.) 
their transformation into winged imagoes, can be readily observed. In 
their natural habitat some of these observations are nearly impossible, 
and for school-room or private-study aquaria 
hardly any other animals can be found of 
more interest to the observer, whether child or 
grown-up, than the dragon-fly nymphs. 
Professor Needham, who has done more 
and better work in the study of the immature 
life of dragon-flies than anybody else, gives 
the following directions for collecting and 


rearing the nymphs: 

“Tf one wishes to collect the nymphs which 
lie sprawling amid fallen trash, a garden-rake 
with which to draw the trash aside, fingers not 
too dainty to pick them up when they make 
themselves conspicuous by their active efforts 
to get back into the water, and a pail of 
water in which to carry them home, are all 


Fic. 119.—A home-made water- the apparatus required. 
net for collecting dragon-fly “A rake will bring ashore those other 


Bie weer Needham.) nymphs which burrow shallowly under the 
sediment that lies on the bottom, and also a few of those that cling to vegeta- 
tion near the surface; but for getting these latter a net is better. Fig. 119 


88 Dragon-flies and Damsel-flies 


shows the construction of a good water-net that can be made at home out 
of a piece of grass-cloth, two sizes of wire, and a stick. 

“The best places to search for dragon-fly nymphs in general are the 
reedy borders of ponds and the places where trash falls in the eddies of 
creeks. The smaller the body of water, if permanent, the more likely it 
is to yield good collecting. The nymphs may be kept in any reasonably 
clean vessel that will hold water. Some clean sand should be placed in 
the bottom, especially for burrowers, and water-plants for damsel-fly nymphs 
to rest on. They may be fed occasionally upon such small insects (smaller 
than themselves) as a water-net or a sieve will catch in any pond. Their 
habits can be studied at leisure in a dish of water on one’s desk or table. 

“The best season for collecting them is spring and early summer. April 
and May are the best months of the year, because at this time most nymphs 
are nearly grown, and, if taken then, 
will need to be kept but a short time 
before transforming into adults. And 
this transformation every one should 
see; it will be worth a week’s work at 
the desk; and as it can be appreciated 
only by being seen, some simple direc- 

tions are here given for bringing the 
Fic. 120.—A simple aquarium for rear- nymphs to maturity. Place them in a 
ing dragon-fly nymphs. (After Need- ~~ zi : 3 
ham.) wooden pail or tub (Fig. 120). If 
the sides are so smooth that they cannot crawl up to transform, put some 
sticks in the water for them to crawl out on. Tie mosquito-netting tightly over 
the top, or, better, make a screen cover; leave three or four inches of air 
between the water and the netting; feed at least once a week, set them where 
the sun will reach them; and after the advent of warm spring weather look 
in on them early every morning to see what is going on.” 

Elsewhere Professor Needham says that nymphs may be fed bits of 
fresh meat in lieu of live insects. If meat is fed, it must be kept in motion 
before them, as they will refuse anything that does not seem alive. Some 
nymphs will take earthworms. Care must be taken to keep cannibalistic 
kinds apart from others. When the nymphs transform the freshly issued 
imagoes should be transferred each with its cast skin (exuvia) to dry boxes 
for a short time, till their body-wall and wings gain firmness and the colors 
are matured. The imago and its exuvia should always be kept together. 

Specimens of the adults for the cabinet should have the wings spread 
like butterflies and moths (for directions for spreading see the Appendix). 
The slender and brittle dred abdomen breaks off very easily, and a bristle 
or fine non-corrosive wire should therefore be passed lengthwise through 
the body as far as the tip of the abdomen. A couple of insect-pins, inserted 


Dragon-flies and Damsel-flies 89 


lengthwise one at each end of the body, are used by some. Specimens 
intended for exchange should not be pinned up, but ‘“‘papered,” i.e., put 
with folded wings into an enclosing little triangular paper envelope made 
by folding an oblong paper sheet once diagonally and then folding over 
slightly the two margins. 


Fic. 121.—Diagram of venation of wing of dragon-fly. a, antecubitals; b, postcubitals; 
N, nodus; P, pterostigma; A, arculus; #, triangle. (After Banks.) 


TABLES FOR CLASSIFICATION. 
Key To SUBORDERS (IMAGOES). 


Front and hind wings nearly similar in outline, and held vertically over the back 
when at rest; head wide and with eyes projecting and constricted at base. 
(Damsel-flies.) Suborder ZyGopTERA. 

Front and hind wings dissimilar, hind wings usually being much wider at base, and 
both pairs held horizontally outstretched when at rest; eyes not projecting 

and constricted at base...........- (Dragon-flies.) Suborder ANISOPTERA. 

KEY TO SUBORDERS (NYMPHS). 

Posterior tip of abdomen bearing three, usually long, leaf-like tracheal gills. 
(Damsel-flies.) Suborder ZyYGOPTERA. 

Posterior tip of abdomen with five, converging, short, spine-like appendages. 
(Dragon-flies.) Suborder ANISOPTERA. 


SUBORDER ZYGOPTERA. 
Key To FAmILies (IMAGOES). 


Wings with not less than five antecubital cross-veins (Fig. r2r). 
Family CALOPTERYGID#. 
Wings with not more than three, usually two, antecubitals (Fig. 121). 
Family AGRIONID&. 
Key To FAMILIES (NYMPHS). 
Basal segment of the antennae extremely elongate...... Family CALOPTERYGID®. 
Basal segment of the antenne short, subrotund...........-- Family AGRIONID#. 


The family Calopterygide includes but two genera, Calopteryx, in which 
the basilar space of the wings is open and the wings themselves are rather 
broad near the tip, and Hetzrina, in which the basilar space is net-veined 
and the wings narrow. 

Calopteryx maculata (Fig. 122), the most familiar representative in the 
Eastern States of the first genus, has velvety black spoon-shaped wings, 


go Dragon-flies and Damsel-flies 


(brownish in freshly moulted, or teneral specimens), and a long, slender body, 
of striking metallic blue or green. The females can be distinguished from 
the males by their possession of a milk-white pterostigma (Fig. 121). These 
beautiful “black wings” are found ‘n gentle fluttering flight, usually along 
small streams in woods or meadows. The female lays her eggs “among 
the rubbish and mud along the 
borders of ditches,” and the 
nymphs found in the ditches 
and streamlets have the middle 
one of the three caudal gills flat 
and shorter than the other two. 
Kellicott has seen the males of 
this species fight fiercely with 
each other. ‘‘ Two will fly about 
each other, evidently with con- 
suming rage, when one finally 
appears to have secured a posi- 
tion of advantage and darts at 
his enemy, attempting, often suc- 

Fic. 122.—The black wing, Calopteryx cessfully, to tear and damage 

maculata. his wings.” 

The best known representative of the other genus is a perfect master- 
piece of insect beauty and grace. Entomologists know it as Heterina 
americana (Fig. 123); I suggest that we call it the “‘ruby-spot,” although 
only the males bear the gem. The head and thorax of the males are 
coppery red, the abdomen me- 
tallic green to coppery, and the 
basal fourth of each of the long, 
slender, and otherwise clear wings 
is bright blood-red. In the females 
the whole body is metallic green, 
with the basal third of the wings 
pale yellowish brown. These dam- 
sel-fly beauties are shy and retiring, 
rarely venturing more than a few 
feet away from the willow-overhung 
bank of their favorite swift-running 


. 


stream. Sometimes hundreds of 


Fic. 123.—The ruby-spot, Heterina 
them come together and cling in americana. 
graceful festoons to the drooping willow branches. Then they look like 
strings of rubies, or of warm red flowers or seeds. 

The family Agrionide includes the host of slender-bodied, narrow- and 


Dragon-flies and Damsel-flies ot 


clear-winged true damsel-flies. Most of them are small, and many keep 
so closely in low herbage or shrubby woodland that they attract little atten- 
tion. A few of the longer-bodied and longer-winged forms, however, fly 
in the open along the stream-banks or over the ponds. Some are strikingly 
varied with black and orange or yellow, and all, whether brightly colored 
or dull, are graceful and charming. There are at least a dozen genera of 
Agrionids in this country, comprising about seventy-five species, but their 
classification is too difficult to be undertaken by general students. Damsel- 
flies deposit their eggs in the tissue of aquatic plants by cutting slits in the 
stems with their sharp ovipositor. The nymphs are slender and elongate, 
and can readily be known by the three caudal leaf-like tracheal gills. The 
nymph stage of these forms is much shorter than with the true dragon-flies, 
lasting usually probably but a few weeks, or at most two or three months. 
When ready to transform the nymphs crawl out of the water and into the 
low herbage on the stream or pond bank. I have seen scores of freshly 
emerged damsel-flies rising from a few square yards of tall grass near a pond, 
although it required close search to discover the nymphs, so well concealed 
were they in the dense tangle. 


SUBORDER ANISOPTERA. 
Key TO FAmILiEs (IMAGOES). 


Antecubitals of the first and second rows mostly meeting each other; triangle of 
fore wings with long axis at right angles to the length of the wings, triangle 
of hind wing with long axis in direction of the length of the wing. 

LIBELLULID&. 

Antecubitals of the first and second rows not meeting (or running into each other) 
except the first and another thick one; triangles of fore and hind wings of 
similar shape (Fig. 121). 

Eyes meeting above on middle line of head; abdomen with lateral ridges. 

7ESCHNID#. 

Eyes just touching at a single point or barely apart; abdomen without lateral 

MA PES Sees steep cnn cis<ncocee ae see ene aa CORDULEGASTERID. 

Eyes distinctly separated; abdomen without lateral ridges. ....- GoMPHID#. 
Key to FAmiLies (NYMPHS). 

Under-lip (labium) flat, not concealing most of the face, with jaw-like or oblong 
side pieces (lateral lobes). 

Antenn®& 7-segmented, tarsi 3-segmented, climbing nymphs. .A2scHNID®. 
Antenne 4-segmented, the fourth segment rudimentary; fore tarsi 2-seg- 
mented;) burrowing mymphss- 22. -cesesee seer see == GOMPHID. 

Under-lip (labium) spoon-shaped, covering most of the face, when closed, with nearly 
trianguiar side pieces (lateral lobes). 

Two stout teeth with a notch between them on the middle lobe of the under- 
Hip abit) jf. 2'<.c:sa0-/acin cre aioe cemtenieees CORDULEGASTERID®. 
A single median tooth on the middle lobe of the under-lip...-LiBELLULID. 


g2 Dragon-flies and Damsel-flies 


The family Cordulegasteride includes only seven species of dragon-flies 
found in the United States, all belonging to one genus, Cordulegaster. They 
are large, with eyes barely touching on top of the head, without metallic 
body-colors, and with clear wings. The nymphs burrow into the sand or 
vegetable silt on the bottom of shallow places. Thus buried, with only 
the top of the eyes and tip of the abdomen showing, they remain motionless 
for a long time, if prey does not come near. ‘‘In a dish of sand on my table,” 
says Needham, “I have had a nymph remain without change of position 
for weeks, no food being offered it. Let any little insect walk or swim near 
the nymph’s head, and a hidden labium springs from the sand with a mighty 
sweep and clutches it.” The imagoes are strong flyers and have the habit 
of flying back and forth, as on a regular beat, over some small, clear stream. 

The family Gomphide includes six genera, comprising about fifty species 
in our country. They are mostly large forms, clear-winged and with bodies 
striped with black and green or yellow. They are readily distinguished 
by the wide separation of the rather small eyes. The abdomen is stiff and 
spike-like. The eggs, held in a scanty envelope of gelatin, are deposited 
by the repeated descent of the flying female to the water of a clear pond 
or flowing stream, the tip of the abdomen first striking the surface. The 
gelatin dissolves and the eggs, scattering, sink to the bottom and become 
hidden in the silt. The nymphs are active burrowers, capturing their prey 
either on or beneath the surface of the bottom silt. The adults often alight 
on foliage, or on the surface of some log stretching across a stream, or on 
the bare soil of a path or roadway. They do not fly about in apparent 
sportiveness as the skimmers (Libellulide, p. 95) do, nor, like the skim- 
mers, perch atop a slender twig. June is the best month in the East for 
these dragon-flies. The principal genus of the family is Gomphus, which 
includes one-third of all our Gomphide. Of these Gomphus exilis is 
probably the most common one in the Northeastern States. Its head is pale 
green, thorax brownish with two oblique green bands on each side, and 
abdomen blackish brown with a basal green spot or band on the back 
of each segment. The nymphs transform at the very edge of the water, 
seldom crawling more than an inch or two above it. Hagenius brevistylus 
is a large black-and-yellow species common in the East, South, and Middle 
West. The nymph has an unusually wide, flattened body. 

The Aischnide include our largest, swiftest, and most voracious dragon- 
flies. Various species are flying through the whole season from early spring 
to late summer. Some roam far from water, being found over dry fields 
and roadways, and even in houses. Some forms fly until late in the even- 
ing, making life a burden for the mosquitoes gathering for their night’s 
singing and feasting. The eggs are thrust into the stems of aquatic plants, 
in floating timbers, in the wood of piers, etc., at or near the surface of the 


Dragon-flies and Damsel-flies 93 


water. The nymphs are slender, clean creatures, with smooth bodies pat- 
terned with green and brown, and very active, strong, and brave. They 
climb among green plants and roots or submerged driftwood along the border 
of open water or the edge of a current. The imagoes of this family can be 
recognized by the meeting of the eyes all along the top of the head. The 
wings are long, broad, and clear, and the body-colors are mostly bright blue 
and green. The family is represented in the United States by about twenty-five 
species, belonging to six genera. Anax junius, one of the commonest dragon- 
flies all over the United States, and found also from Alaska to Costa Rica, 
in China, Siberia, and in various islands of the Pacific, notably the Hawaiian 
group, is the most inveterate enemy that the mosquito has. It is conspicu- 
ously on the wing from early spring to 
late fall, flying from daylight to dark, 
and doing untold good by its cease'ess 
warfare on the mosquito hosts. It 
can be recognized by its clear wings, 
large size (wings over two inches long), 
and bright-green thorax and head, the ; 
latter bearing on the upper front a F124 Top of heath showing charac 
round black spot surrounded by yellow, junius. (Enlarged.) : 
the yellow encircled by a dark-blue F's. 1245.—Top of head, showing charac- 
‘ < teristic mark in front of eyes, of Eschna 
ring (Fig.124a). Acstilllarger member  constricta. (Enlarged.) ~ 
of this family is the great “‘hero” 
dragon-fly, Epieschna heros, which is like Anax junius in general appear- 
ance, but has wings two and one-half inches long, and abdomen nearly three 
inches long. It has a black T spot on the upper face, instead of a round 
one. Another similar, widely distributed and common form is schna 
constricta, about the size of Anax junius, reddish brown marked with bright 
green, and with a black T spot on the upper front of face (Fig. 124b). The 
males have the abdomen marked with blue, with little or no green, while 
the females have but little blue or none at all. 

The members of the family Libellulide are called ‘“‘skimmers.’”’ ‘They 
may be seen continually hovering over the surface of still water, or swiftly 
foraging over fields. Many of them have the wings strongly marked with 
large black or brown or milk-white blotches, and the abdomen is often 
covered with a whitish powder or ‘“‘bloom.”” They outnumber all the other 
true dragon-flies in point of species, and except for Anax junius, Aischna 
constricta, and perhaps the giant hero dragon-fly, include the most familiar 
and wide-spread members of the order. One of the best known and most 
beautiful of the skimmers is the pond-loving “‘ten-spot,” Libellula pulchella 
(Fig. 125), found all over the country. Each of its wings has a longitudinal 
basal blotch, a median blotch (at the nodus), and an apical blotch of black- 


Fic. 1244. Fic. 124). 


94 Dragon-tlies and Damsel-flies 


ish brown. The males have the space between these blotches milky white. 
In old individuals the abdomen has a strong whitish bloom. Other familiar 


Fic. 125.—The ten-spot dragon-fly, Libellula pulchella. (After Needham; nat. size.) 


and well-marked species of Libellula are L. basalis, with blackish-brown body 
and with the basal third to half of the wings dark brown or black and the 
rest of the wing clear, or in the old males chalky white out as far as the 


Fic. 126.—Libellula semi-fasciata, (After Needham; natural size.) 


pterostigma, and in the females with brownish apices; L. quadrimaculata, 
with olive or yellowish body marked with black, front wings with more 


Dragon-tlies and Damsel-flies 95 


or less yellowish at base and along the front margin, and a small fuscous 
nodal spot, hind wings with a yellowish-black triangular basal spot and 
fuscous nodal spot; and L. semt-jasciata, whose complex wing-markings are 


Fic. 127.—The water-prince, Epicordulia princeps, female. 
(After Needham; natural size.) 


shown in Fig. 126. Tramea is a genus of large swift dragon-flies whose 
hind wings have the base expanded and conspicuously colored. Tramea 
lacerata is a familiar species. The water-prince, Epicordulia princeps (Fig. 


Fic. 128.—The amber wing, Perithemis domitia, male at left, female at right. 
(After Needham; natural size.) 


127), is a common large dragon-fly, but one hard to capture because of its 
fine flight. The wings show a basal patch, often nearly wanting on the 
front pair, a patch at the nodus, and a black apex. It likes “‘ponds or slug- 


96 Dragon-flies and Damsel-flies 


gish streams with muddy reed-grown banks, and seems absolutely tireless 
in flight; very rarely indeed is one seen resting.” One of the smallest of 


Fic. 129.—The wind sprite. Celithemis eponina. (After Needham; natural size.) 


Fic. 130.—Tetragoneuria epinosa, female. (After Needham; natural size.) 


the true dragon-flies is the amber wing, Perithemis domitia (Fig. 128). The 


wings are clear amber, unmarked in the male, but richly spotted with dark 


? 


Dragon-flies and Damsel-flies 97 


brown in the female. It has a slow hovering flight and often rests on the 
tips of erect reeds with wings held perfectly horizontal. It is only on wing 
in quiet, warm sunshine; clouds or cold breezes send them quickly into 
hiding. Among the familiar Libellulids with unblotched wings is Meso- 
themis simplicicollis, an abundant species east of the Rockies. The 
females and young males have head, thorax, and front half of abdomen 
green, the hinder half blackish brown. In old males the body becomes 
grayish blue with a whitish bloom. Williamson says that sometimes two 
males will flutter motionless, one a few inches in front of the other, when 
suddenly the rear one will rise and pass over the other, which at the same 
time moves in a curve downwards, backwards, and then upwards, so that 
the former position of the two is just reversed. These motions kept up 


Fic. 131.—The whitetail, Plathemis lydia. (After Needham; natural size.) 


with rapidity and regularity give the observer the impression of two inter- 
secting circles which roll along near the surface of the water. 

The whitetail, Plathemis lydia (Fig. 131), resembles the ten-spot, but 
is one-fourth smaller. In the males also the apex of the wings is usually 
clear, not brown. The whitetail rather likes slow-flowing brooks and 
open ditches. When alight it has the habit of setting its wings aslant down- 
ward and forward with a succession of jerks. Needham thinks that the 
powdery whiteness of the body of the old males (in females and young males 
the body is brown marked with yellow) must render it more easily seen by 
its enemies, the king-birds and others, and thus be a disadvantage in the 
struggle for existence. He says, indeed, that the whitest ones avoid rest- 


98 Dragon-flies and Damsel-flies 


ing-places over a dark background and settle oftenest on white sticks, on 
bleached stumps, or on light-colored earth. Very frequently one will alight 
on a white insect-net when it is laid down, or even when still held in the 


hand. 


CHAPTER Vil 
THE TERMITES, OR WHITE ANTS (Order Isoptera) 


NCE when camping in the King’s River 
Cafion, one of the great vertical-walled, flat- 
floored cafions of the Sierra Nevada, the 
boldest axeman-of our party attacked the 
fallen trunk of a once towering yellow pine. 
The practical outcome of this attack was 
a sufficient supply of firewood for the 
cook’s stone-built stove, but the great log 
yielded better things than chips and chunks. 
A few blows showed it to be the home of 

: a thriving colony of the largest of the 

American termites (Termopsis angusticollis), and the thousands of indi- 

viduals in this insect household were objects of interested observation 

the summer through. We had heard of the rarity of white-ant queens in 
collections, and saw in this isolated and apparently easily ‘“‘rounded-up” 
community an easy chance to discover the egg-laying queen of this species. 

But we had not reckoned with the Californa manner of tree-trunk: it 

outlasted the summer’s chopping by two score feet of log four feet thick. 

Yellow pines grow 250 feet high in the Sierran forests. But although 

no queen was found, the make-up of the buried termite city was revealed. 

Galleries and chambers, secret ways and narrow tunnels were all ex- 

posed, and the interesting communal: life of these soft, white-bodied little 

creatures was made partly’ known to us. 

We have in the United States but few kinds of termites, and these 
much less interesting in habit than those of tropic lands. The Amazons 
and Central Africa are the centers of termite life, and there, because of their 
great mounds, their serious ravages on all things wooden, and their enor- 
mous numbers, the white ants come to be nearly the most conspicuous of 
the insect class. Drummond’s account, in his Tropical Africa, of the habits 
and life of the termites of the Central African region is simply a tale of 
marvels. And the scattered accounts of the Brazilian species are hardly 
less wonderful. In the South Sea, too, the termites play their part promi- 
99 


100 The Termites, or White Ants 


nently. I have seen scores of cocoanut-palms in Samoa with their trunks 
traced over from ground to “‘feather-duster” top, a hundred feet above, by 
the laboriously builded wood-pulp tunnels of the termites. Each of these 
trees carried also on its trunk, about four feet from the ground, a termite 
“shed” or depot (Fig. 133), a foot thick, a foot wide, and two feet long, 
made, like the tunnels, of pellets of chewed wood, glued together with saliva, 
and filled with crowded galleries and chambers. 


. 


= 


Fic. 132.—Giant hillock-nests of termites in tropical Africa. 
(Adapted from Drummond.) 

But in the United States our few species make their communal nests 
in dead and dying wood, or underground, and not being given to building 
great dome-like mound-nests, or making covered ways up all the trees of 
a great forest or plantation, are not as conspicuous as their tropical cousins. 
Still, few observers of insects have failed to notice the little, white, wingless 
worker termites, scurrying about when some dead stump is overturned or 
split open, or to see the winged males and females swarming out of the 
ground some sunny day, and, after a brief period of flight, pursued by birds 
and predaceous insects, settling to earth again and losing their wings. 

Before proceeding to take up the incompletely known life-history of our 
American termites it will be advisable to describe their general structural 


The Termites, or White Ants IO 


characters and the composition of the termite communities. The body 
is always soft, and usually milky-whitish in color, though sometimes light 
or dark brown. It is plump, and slightly broader than thick. The abdo- 
men is joined broadly to the thorax, not by a little stem or peduncle as in 
the ants, with which insects the name ‘‘ white 
ants” (unfortunately too long and widely 
used to be done away with) confuses the 
ermites in the popular mind. The termites 
not only are not ants, but are neither nearly 
re'ated to them nor of similar structure. 
The only resemblances between the two forms 
exist in the communal life and in the com- 
position of the community by different kinds 
o individuals. The termites are either blind 
or have only simple eyes, have slender an- 
tenn which look as if made up of tiny beads 
strung a-row, and have biting mouth-parts 
with strong jaws. They live in small or large 
communities, the individuals in any one of 
which, although belonging to the same species, 
being of from three to eight different kinds 
or castes. That is, each community is com- 
posed of winged and wingless individuals, 
the winged being males and females, while 
the wingless include immature individuals, 
sexually incomplete workers and _ soldiers, 
and also so-called complemental males and 
females which are individuals able to help 
in the.increase of the community. In some 
species there are no workers, while in others 
the workers may be of two kinds. The 
soldiers differ from all the others in he 


Fic. 133.— Termite shed on 
cocoanut-palm in Samoa. From 


extraordinary development of their jaws the shed note numerous tunnels 
. s . . . leading down to the ground, in 

© os =cissor-lile: > 29d1< = i ; wy 
which are long and scissor-like; their heads eTHGTNaSMELECANAIA GSE Of tbe 
are also much enlarged and strongly chitin- community; a few tunnels (only 


one visible in the picture) lead 
4 up the trunk of the tree. (Pho- 
dead wood, and of curious pellets excreted tograph by the author.) 


from the intestine and called ‘‘proctodeal 
food.” In addition some species attack live wood and even soft plants, 


ized. The food of all consists mainly of 


and cloth, books, papers, etc., suffer from termite ravages. The serious 
nature of their attacks on wood will be referred to later. 
The development of the termites is apparently simple; the wingless 


To? The Termites, or White Ants 


workers resemble closely, except in size, the just-hatched young; the soldiers 
have but to acquire their largeness of head and mandibles, and the perfect 
insects their wings. But there is a serious complexity in termite develop- 
ment in that at hatching all the young are alike, and the different castes 
or kinds of individuals become differentiated during the postembryonic 
development, i.e., after hatching. This matter is discussed later. 

In the United States but seven species of this order of insects are known. 
They represent three genera, which may be distinguished by the following 
table: 


Key TO GENERA, 
Simple: eyes iabsente 2s /< dcers cledaiesieticlseie seem el ene ore eee TERMOPSIS. 
Simple eyes present. 
Tarsi with a pulvillus (little pad) between the claws; prothorax large and 
oblong; costal (anterior) area of the wings veined. .CALOTERMES. 
Tarsi without terminal pulvillus; prothorax cordate; costal area of wings 
WIEHOUG VEINS 22). commen einai Cie eae eee eee TERMES. 


Termopsis and Calotermes each include two species, all four limited 
to the Pacific Coast; while Termes includes three species, of which but one, 
T. flavipes, is found in the northeastern states. This has been introduced from 
America into Europe, and is well known there. The other two species, and 
flavipes also, are found in the southwestern and Pacific coast states. Thus 
Termes ieee (Figs. 134 and 135) is the only representative of the order Isop- 

tera which can be observed and studied in the East, 
but it is so commonly distributed that the student of 
‘insects in almost any locality can find its communities. 
Despite its abundance, however, the long time it has 
been known, and the very interesting nature of its 
habits, its life-history is not yet wholly worked out. 
Fic. 134.—T. flavi- It makes its nest in or under old logs and stumps. 
pes, worker. (After ; 5 , ; 
Marlatt; natural SOmetimes it mines a nest in the beams and rafters of 
size indicated by old houses. Howard records the serious injuries done 
line) to a handsome private residence in Baltimore through 
the mining of the first-floor timbers by the hidden termites. Comstock 
has found them in the southern states infesting living plants, particularly 
orange-trees, guava-bushes, and sugar-cane. According to Comstock, they 
attack that part of the living plant which is at or just below the surface 
of the ground. In the case of pampas-grass the base of the stalk is 
hollowed; with woody plants, as orange-trees and guava-bushes, the bark 
of the base of the trunk is eaten, and frequently the tree is completely 
girdled; with sugar-cane the most serious injury is the destruction of the 
seed-cane. 


@ 


The Termites, or White Ants 103 


The workers of 7. flavipes (Fig. 134) are, when full grown, about } in. 
long, while the soldiers are a little larger. Both of these castes are whitish. 
But the winged males (Fig. 135a) and females which come from the nest 
and swarm in the air in late spring or early summer are chestnut-brown 
to blackish and measure about | in. in length. The four wings are of about 
equal size, and when the insect is in flight expand about 3 in. When at 
rest they lie lengthwise on the back, projecting beyond the tip of the abdo- 
men. They have many veins and are pale brown in color. After flying 
some time and to some distance, the insects alight on the ground and shed 
their wings (Fig. 135). This they are enabled to do because of a curious 
suture or line of weakness running across each wing near its base. All the 
wing beyond this suture falls off, leaving each now wingless male or female 
with four short wing-stumps. These swarming flights 
attract the birds. Hagen noted fifteen different species 
of birds following such a termite flight one May-day in 
Cambridge, Mass. ‘‘Besides the common robins, blue- 
birds, and sparrows,” he says, 
“were others not seen before 
near the house. The birds 
caught the Termes partly in 
flight, partly on the ground, 
and the robins were finally 
so gorged in appearance that 
their bills stood open!”’ 

After the swarming flight 
the few uneaten males and Fic. 1354. Fic. 135). 
females pair, and each pair Fic. 135a.—T. flavipes, winged male. (After Mar- 

latt; natural size indicated by line.) 

probably founds a new colony. Fic. 135b.—T. flavipes, complementary , queen. 
Perhaps some of the pairs (After Marlatt; natural size indicated by line.) 
are found by workers, and 

taken possession of as the royal couple for a new community. Exactly 
how the new communities of flavipes begin is not known; and this is 
an excellent opportunity for some amateur observer to distinguish himself! 
The egg-laying queen mother of a flavipes colony also has yet to be 
discovered. There exist in many species of termites individuals called com- 
plemental males and females. These are forms which, in case of the loss 
of the real king or queen, can develop into substitute royalties. Whether such 


forms exist in all flavipes colonies does not seem to be certainly kncwn. 
It is obvious that there is still much to learn about the interesting life of 
our commonest and most wide-spread termite species. 

Of the other six species of our country, all of which are limited to the 
southern, southwestern, and Pacific states, three, representing all of the 


104 The Termites, or White Ants 


three genera, and found about Stanford University, have been recently 
studied by Professor Harold Heath. These are Termopsis angusticollis, 
the largest of the American termites, Calotermes castaneus, a small species with 
brown-bodied winged forms, and Termes lucijugus, a small white species 
common in Europe, and probably brought to this country from there. The fol- 
lowing account of Termopsis augusticollis is based chiefly on Heath’s * studies. 

Termopsis angusticollis (Fig. 136) is the largest of the three species and 
the most abundant. In favorable localities colonies may be found in almost 
every stump and decaying log, and even in dead branches on otherwise healthy 
trees. The galleries are made in the deeper portions of the wood, and 
usually follow the grain. The colonies with the primary royal pair number 
usually from 50 to 1000 individuals, and include workers, soldiers, and im- 
mature forms. The full-grown workers (Fig. 136) are $ in. long, the soldiers 
(Fig. 136) % in., and the kings and queen (Fig. 137) a little less, while the 
wings expand 14 in. After the death of the primary royalties and the 
development of several substitute royal 
forms the egg-laying and consequent 
increase of the colony are much more 
rapid. Heath counted 3221 individuals 


Fic. 136. FIG. 137- 


Fic. 136.—The large termite of California, Termopsis angusticollis; workers, young, 
and a soldier. (From life; natural size.) 

Fic. 137.—A, Dealated primary queen of Termopsis angusticollis, at least four years 
old; B, complemental queen. (After Heath; three times natural size.) 


in one colony, in which were also thousands of eggs. The colony which we 
found in the yellow-pine log in the King’s River Canon certainly num- 
bered many thousands. In the late summer or early autumn the nymphs 
(young stage, with visible wing-pads of perfect insects) that have developed 
during the year moult, the operation taking from ten to twenty minutes, 
after which they rest for two hours, while the wings expand, and the 
body-wall hardens and darkens; they take flight usually about dusk. Some 


* Heath, H., The Habits of California Termites, Biological Bulletin, vol. 4, 1902, 
pp- 47-93. 


The Termites, or White Ants 105 


soon fall to the ground, but others may fly a mile. The swarm is pursued 
by birds until dark, and then bats take a turn at the chase. The few ter- 
mites that escape fly from tree to tree, seeking a spot of decaying wood. 
Heath has noted them dashing against door-knobs and nail-holes and against 
discolored spots on trees and logs, in their search for a place where decay 
has begun. After finding a suitable spot they usually shed their wings, 
not by biting them off, as said of some species, but by curving the abdomen 
until it rests across the wings of one side and then moving backwards 
and sidewise until the wing tips are brought against some obstruction, 
thus causing the wings to buckle and break along the transverse suture or 
line of weakness at the base. Sometimes the wings are not shed until after 
the nest is begun. The spot is usually selected by the female, and she begins 
the mining and does most of it. She is accompanied by one or more males, 
who may occasionally help in excavating. When the burrow is large enough 
for two, one male usually crowds in beside the queen and fights off the others. 
Sometimes two males may remain with the queen; Heath thinks that such 
a condition may last for a year or more. He has found a few cases where 
two, three, and even six pairs live in company. The actual mating does 
not take place, probably, until some time after the nest is begun. Heath 
has noted pairing from a week to a fortnight after swarming. 

The egg-laying may be long postponed. Usually, however, about two 
weeks after pairing the first egg is laid, and from one to six are deposited 
daily until the total number amounts to from fifteen to thirty. When the 
habitat is unusually moist the royal pair may remain together for a year 
without producing young. Heath has found the Termopsis royalties to 
mate readily in captivity, and has had more than 500. pairs of primary kings 
and queens in excellent condition after a year of captivity. Royal pairs 
with small colonies are readily found by stripping off the bark of trees from 
three to nine months after the swarming period. Heath has been the first 
to find actual egg-laying queen termites in this country. 

After from fifteen to thirty eggs are laid the laying ceases, and the 
parents give their time to enlarging the nest and to caring for the eggs, 
which are kept scrupulously clean, and frequently shifted from place to 
place in the nest. The young are all alike when first hatched. After three 
moults, one of them appears as a large-headed individual, and after three 
more moults develops into a perfectly formed soldier, although little more 
than one-half the size of the soldiers in old communities. Three months 
later another soldier appears, larger than the first, and later others still 
larger, until after a year the full-sized form appears. The first workers, 
too, are smaller than the later ones. Nymphs, i.e., young of the winged 
individuals, do not appear until after the first year, so that the swarm of 
winged individuals cannot leave a nest until the end of the second year of 


106 The Termites, or White Ants 


its existence. The life of these early, undersized individuals is short. 
They disappear, perhaps are killed, when the full-sized individuals appear. 
These latter, both workers and soldiers, live at least two years and perhaps 
longer. 

The primary king and queen live for at least two years, and almost cer- 
tainly longer. Heath believes he has evidence of five years of life. After 
the death of the royal pair from natural or other causes, the members of 
the orphaned colony develop from the young nymphs from ten to forty sub- 
stitute royal forms. By some unknown process, perhaps peculiar feeding, 
these selected nymphs are quickly brought to sexual maturity, and the queens 
begin egg-laying. As they are fed and cleaned by the workers, their only 
business is to lay eggs. Heath observed some of the larger queens to lay 
from seven to twelve eggs a day continuously. In exceptional cases a 
worker, or even a soldier, may be developed into an egg-laying queen. 
One may also occasionally find a few winged soldiers. 

In Africa forty-nine species of Termites are known * (Sjostedt), and it is 
on this continent that ‘‘the results of Termitid economy have reached their 
climax.” More than a century ago an exploring Englishman, Smeathman, 
startled zoologists with his account of the marvelous termite communities 
of West Africa. He told of the great mound- 
nests of Termes bellicosus, twenty feet high, and 
so numerous that they had the appearance of 
native villages (Fig. 132). The soldiers are fifteen 
times as large as the workers, and the fertile 
queen has her abdomen so enlarged and stretched 
by the thousands of eggs forming inside that it 
comes to be ‘‘fifteen hundred or two thousand 
times the bulk of the rest of her body and 
twenty or thirty thousand times the bulk of a la- 
borer.”” He describes the egg-laying as proceed- 
ing at the rate ‘‘of sixty a minute, or eighty thou- 
sand and upward in one day of twenty-four 
hours.”” In the South Kensington Museum at 
London there is such a prodigious queen resem- 

bling simply a cylindrical whitish sausage four 
Fic. 138.— Worker and inches long. A similar specimen is to be found 
queen of Termes red- IS 


mani. (After Nassonow; in the natural-history museum of the University 
natural size.) 


of Kansas. . 
The enormous number of individuals in a great village of nests cannot 


* Sjostedt, Y., Monographie der Termiten Afrikas, Kongl. Svenska, Vetensk. Ak. 
Handl., v. 34, 1900, pp. 1-236, Stockholm. 


The Termites, or White Ants 107 


even be imagined. But according to African travelers the direct results 
of the presence of such a population are very apparent. Drummond 
(Tropical Africa, 1891) writes: ‘‘You build your house, perhaps, and for 
a few months fancy you have pitched upon the one solitary site in the coun- 
try where there are no white ants. But one day suddenly the door-post 
totters, and lintel and rafters come down together with a crash. You look 
at a section of the wrecked timbers, and discover that the whole inside is 
eaten clean away. The apparently solid logs of which the rest of the house 
_is built are now mere cylinders of bark, and through the thickest of them 
you could push your little finger. Furniture, tables, chairs, chests of drawers, 
everything made of wood, is inevitably attacked, and in a single night a 
strong trunk is often riddled through and through, and turned into match- 
wood. There is no limit, in fact, to the depredation of these insects, and 
they will eat books, or leather, or cloth, or anything; and in many parts of 
Africa I believe if a man lay down to sleep with a wooden leg it would be 
a heap of sawdust in the morning! So much feared is this insect now that 
no one in certain parts of India and Africa ever attempts to travel with such 
a thing as a wooden trunk. On the Tanganyika plateau I have camped on 
ground which was as hard as adamant, and as innocent of white ants appar- 
ently as the pavement of St. Paul’s, and awakened next morning to find a 
stout wooden box almost gnawed to pieces. Leather portmanteaus share 
the same fate, and the only substances which seem to defy the marauders 
are iron and tin.” 

But more impressive than this devastation of houses, tables, and boxes is the 
sight of millions of trees in some districts plastered over with tubes, galleries, 
and chambers of earth due to the amazing toil of the termites in their search 
for dead or dying wood for food. According to Drummond, these tunnels 
are made of pellets of soil brought from underground, and stuck together 
with saliva. The quantity of soil thus brought above ground is enormous, 
and Drummond sees in this phenomenon a result very similar to that accom- 
plished by earthworms in other parts of the world, and made familiar to 
us by Darwin, namely, a natural tillage of the soil. As Drummond says: 
“Tnstead of an upper crust, moistened to a paste by the autumn rains and 
then baked hard as adamant in the sun, and an under soil hermetically sealed 
from the air and light, and inaccessible to all the natural manures derived 
from the decomposition of organic matters—these two layers being eter- 
nally fixed in their relations to one another—we have a slow and continued 
transference of the layers always taking place. Not only to cover their 
depredations, but to dispose of the earth excavated from the under- 
ground galleries, the termites are constantly transporting the deeper 
and exhausted soils to the surface. Thus there is, so to speak, a con- 
stant circulation of earth in the tropics, a ploughing and harrowing, not 


108 The Termites, or White Ants 


furrow by furrow and clod by clod, but pellet by pellet and grain by 
grain.” 

With a few references to certain special conditions and problems in the 
termite economy, we must finish our consideration of these highly inter- 
esting insects. Do the termite individuals of a community communicate 
with each other, or is the whole life of the colony so inexorably ruled by 
instinct that each individual works out its part without personal reference 
to any other individual, although with actual reference to all the others, 
that is, to the community as a whole? It is pretty certain that termites have 
a means of communication by sounds. The existence of a tympanal audi- 
tory organ in the tibie of the front leg, like that of the crickets and katy- 
dids, has been shown by Fritz Miiller, and the individuals have a peculiar 
jerking motion which seems likely to be connected with the making of 
sounds by stridulation, sounds, however, that are not audible to us. 

The spread of termites from one continent to another, as in the case of 
Termes flavipes from America to Europe, and Termes lucifugus from 
Europe to America, can be easily explained by involuntary migration in 
ships. In unpacking several cases of chemicals received from Ger- 
many at Stanford University, scores of termites were exposed when the 
wooden boxes were broken up. The insects, mining in the wood of the 
boxes, had protection, food, and free transportation on their long ocean 
journey from Hamburg around Cape Horn to California! 

In termite nests are often found individuals of other insect orders. So 
often are such cases noted, and so many are the kinds of strangers likely 
to be present, that entomologists recognize a special sort of insect economy 
which they term termitophily, or love of termites! The strangers seem to 
be tolerated by the termites, and apparently live as guests or conmensals. 
More than 100 species of insects have been recorded as termitophiles. This 
curious guest-life exists on even a much larger scale in the nests of true 
ants, in which connection it is called myrmecophily (see p. 552). 

The most important problem, and one whose solution will require much 
exact observation (and, if possible, experimentation), is that of the origin, 
or causes of production, of the different castes or kinds of individuals in 
the termite community. It has been determined by various observers that 
all the termites of a community are apparently alike at birth. That is, 
there is no apparent distinction of caste, no separation into workers, soldiers, 
and perfect insects. The soldiers and workers are not, as was formerly 
thought, the result of the arrested development of the reproductive organs. 
They are not restricted to one of the sexes. If then it is not arrested develop- 
ment, or sex, or embryonic (hereditary) differentiation, what is the causal 
factor? Grassi, an Italian student of the termites, thinks that it is food; 
that the feeding of the young with food variable in character brings about 


The Termites, or White Ants 109 


the differentiation of individuals. To understand this claim it is necessary 
to attend more closely to the feeding habits. The food of termites con- 
sists almost exclusively, as has already been said, of wood. But this wood 
may be taken directly from the walls of the burrow or secured indirectly 
from another individual. In this latter case it consists of disjecta of undi- 
gested material, which, while mostly wood, must be mixed with other or- 
ganic material: because the termites keep their nests clean by eating their 
cast skins and the dead bodies of other individuals. This undigested mate- 
rial is called proctodeal food. In addition, a certain amount of evidently 
very different matter is regurgitated through the mouth from the anterior 
part of the alimentary canal. This is called stomodzal food. As the young 
receive all their food from the workers, it is apparent that there is oppor- 
tunity for a choice, on the part of the nurses, in the kind of food given the 
young. And it is presumed by Grassi that such a choice is made, and that 
it results in the differentiation of the castes. As a matter of fact, such a 
differentiation of individuals is accomplished in the honey-bee community 
by feeding those larvae which the workers wish to make fertile queens ‘“‘royal 
jelly” —a rich food regurgitated through the mouth from the anterior part 
of the alimentary canal. This is done for the queens during the whole 
larval life, while larvee which are fed royal jelly for only one or two days, 
and then mixed pollen and honey for the rest of larval life, develop into 
workers. With the honey-bee, however, the workers are to be looked on 
as probably only arrested females. But in the case of Termopsis angusti- 
collis Heath has experimented by feeding members of 
various colonies, both with and without primary royal 
pairs, ‘on various kinds and amounts of food—procto- 
dea! food dissected from workers, or in other cases from 
royal forms, stomodeal food from the same sources, 
sawdust to which different nutritious ingredients had 
been added—but in spite of all I cannot,’ he says, 
“feel perfectly sure that I have influenced in any un- 
usual way the growth of a single individual.” 

This is by all odds the most important and interesting 
problem in termite economy, and the solver of it will do 
much for zoological science. 

A singular and primitive family of small insects, the 


Fic. 139.—Em bia 


Embiide, of doubtful affinities, is represented by not texana. (After 
more than twenty living species, of which but four a en- 
arged. 


occur in this country. The individuals do not live in 
communities as the termites do, but in structural characters they probably 
more nearly resemble these insects than any others. Fig. 139 _ illus- 
trates a typical Embiid. This species, Embia texana, is about one-quarter 


110 The Termites, or White Ants 


of an inch long, and of rufous color. It was described from a few specimens 
found at Austin, Texas. ‘This insect seems to be very susceptible to differ- 
ing degrees of humidity, and specimens were visible only after the ground 
had been moistened by rains. As the sun dries the ground, the insects 
burrow into the soil. They spin small silken webs in which they live singly. 
These webs are tunnels made in some crevice of the rock which shelters 
them, or are spun between grains of soil. They are an inch or more in 
length and closed at one end, and probably serve simply for protection. The 
spinning-organs of the insect are located in its fore feet, a condition unique 
among animals. The food-habits of the Embiids are not yet known. 


CHAPTER’ V LU 


THE BOOK-LICE AND BARK-LICE (Order Corrodentia) 
AND THE BITING BIRD-LICE (Order Mallophaga) 


OMETIMES in taking from the shelves an old 
book, long untouched, there may be seen, on 
turning its leaves, numerous extremely minute, 
pale-colored, wingless insects, the book-lice, or 
dust-lice. So small are they, indeed, that a 
reading-glass or hand-lens will be needed to make 
out anything of their real appearance. They 

run about rather swiftly and seek to conceal their soft, defenceless little 
bodies somewhere in the binding. Under the lens they are seen to have 
a rather broad, flattened body (Fig. 140), six short legs, no wings (although 
sometimes tiny wing-pads are present), long, slender antenne, and a pair of 
small black spots on the head, the simple eyes. There is a distinct neck, 
the head being free, and plainly wider than the prothorax. The abdomen 
is nearly oval in outline. There are no distinctive markings or pronounced 
chitinization of the soft body-wall. These book-lice can be found else- 
where than in old books; they feed on dry, dead organic matter, the 
paste of the book-bindings and the paper, and are common in birds’ nests, 
where they feed on the cast-off feathers, in the crevices of bark, and on 
old splintered fences, where they feed on moulds and dead lichens. 

Certain other insects closely related to the book-lice are not so small and 
simple, however, some having two pairs of wings and a plump, rounded 
body (Fig. 141); these look much like plant-lice (Aphids). These winged 
kinds do not live in libraries, moreover, and the name ‘‘book-lice”’ is a 
misnomer for them. They are rarely seen by persons not trained entomolo- 
gists, and indeed are not at all familiar to professed students of insects. 

The life-history of these obscure insects has been but little studied, but it 
is of a simple kind, the metamorphosis being incomplete, and in the case 
of the wingless forms certainly very slight. The young of the wingless forms 
“greatly resemble the old, but have no ocelli or wings, and sometimes the 
tarsi are of two joints, while in the adult they have three.’’ The structure 
of the adults presents no points of particular interest except in the case of 
the mouth. The book-lice have biting mouth-parts, the jaws being strong 


and heavy for the successful mastication of the hard dry food. In the throat 
Itt 


hie Book-lice and Bark-lice; Biting Bird-lice 


there is a peculiar little chitinized structure, which may be called the 
cesophageal sclerite (Fig. 145). This structure is situated in the floor of 
the pharynx (forward end of the cesophagus), and has some special function 
in connection with the peculiar food-habits. It was first described by Bur- 
gess, and was for a long time supposed to be peculiar 
to the book-lice alone. But, in a study of the mouth 
structure of the biting bird-lice (Mallophaga), I found 
an almost identical cesophageal sclerite in thirteen out 
of the twenty-two genera of the Mallophaga. On 
the basis of this common possession of a curious 
and undoubtedly important mouth structure by the 
book-lice and the bird-lice (and on the basis of other 
strong similarities) it seems certain that these two 
groups of insects have a common ancestry not very 
remote, and probably should be included in a single 
Fic. 140—A wingless order. 
book-louse, Atropos sp. The order Corrodentia as at present known con- 
(Much enlarged.) 4 < 4 
tains about two hundred described species, scattered 
over the world. The largest species occur in Brazil, and have an ex- 
panse of wing of nearly an inch. Ceylon and the Hawaiian Islands are 
said by Sharp to be specially rich in species. 
The members of the order can be divided into two families as follows: 


Wings well developed; ocelli present (in addition to compound eyes). ..Psocip#. 
Wings wanting or present as small scales or pads; ocelli absent ....ATROPID. 


The winged Corrodentia or Psocidee (which may be called bark-lice to 
distinguish them from the wingless book-lice) are 
too rarely seen to be at all familiar. They may 
most commonly be found in small clusters on bark, 
each cluster or colony being covered over by fine 
silken threads spun from the mouth. The wings 
are held roof-shape over the back (Fig. 141), and 
the body and wings are usually pale smoky in py, yyy 4 ainren 
general color. The small white eggs are laid on the _ bark-louse. (Thirteen 
surface of the bark in small patches, and in a cluster "™5 natural size.) 
of bark-lice, individual in all stages, from very young to adult, may be seen. 

Banks gives the following key to the North American genera: 


The techinal terms discoidal cell and posterior cell may be understood by reference to 


Fig. 142. 
1. Wings with scales and long hairs .---..----------.-------- AMPHIENTOMUM. 
Wings without hairs and scales, hyaline. .....----------- 2-20-00 0---uneeneaa= 2. 
2. Tarsi 3-jointed. ... 2.2.02 e eee e cece cece eee nen e een esc ces ence csteenasn 3: 


Tarsi 2-jointed..... -. .... 2 00- <2 02 eens cree eens sn wenn annem senmesseee 4. 


Book-lice and Bark-lice; Biting Bird-lice 113 


Pambrecoidalicell closed Satan sedis east: 2 Meo Bee ates Myopsocus. 
Mseeordal cellOpen at a= ceric atic ota a <tanielsieitalote ea ctoeineree reer E.ipsocus. 
4. Discoidal cell closed........... Be 
Discoidal cell open. ...--.--.-.- 6. 
5. Discoidal cell four-sided. Psocus. 
Discoidal cell five-sided. 

AMPHIGERONTIA. 

6. Third posterior cell elliptical. 
CCILIUS. 


Third posterior cell elongated. ; ; 
Fic. 142.—Diagram of venation of a Psocid. 


PoLyPsocus. Huidiecertalicells a, 3a terior cells 
Third posterior cell absent. (Afler Banks.) i 


PERIPSOCUS. 


The few North American species of the true book-lice or Atropide are 
included in five genera, which may be distinguished as follows: 


The technical terms, hitherto undefined, used in the following table are the following: 
squame, wings in the condition of small scales or pads; hyaline, clear, not colored. 


1. Mesc- and metathorax united, no wings.............-....-..-..-- ATROPOS. 
Meso- and metathorax separate, rudimentary wings. ....-.....--------------- 2. 
A WARES Malily SEMIS. sso oagoeseanbuee ecco coda dap sca anbponeecoucc DORYPTERYX. 
Wings veinless, in form of squamz or tubercles. ..........------------------- £5 
Gp SUNS rail, yee oe eee spe oe Sep nsencssnsoocesecbsc CLOTHILLA. 
Sle MEMEES at WNL anal MOE NR nos Aner Soe asoocddscepHnouesonce LEPINOTUS. 
Smallitubercles/ inthe) place! of squamea) = 22-2220. ca nee ce alee HYPERETES. 


The genera Atropos and Clothilla were named for two of the three Fates 
of mythology, and a third genus was named Lachesis for the third Fate, but 
unfortunately the last genus was not a valid one, so the book-lice have lost 
their third Fate, and by the rigid laws of zoological nomenclature can never 
regain her! The few species of these two Fate-named genera are the com- 
monest of the book-lice. Alropos divinatoria is the species usually 
found in books. It is about 1 mm. long, is grayish-white, and the small 
eyes show as distinct black specks on the head. It does not limit its feeding 
to the paste of book-bindings, but does much damage to dried insects in 
collections. ‘To this insect has long been attributed the power of producing 
a ticking noise known as the “‘death-watch,”’ but McLachlan, an authority 
on the Corrodentia, does not believe that this minute insect “with a body 
so soft that the least touch annihilates it can in any way produce a noise 
sensible to human ears.’’ A small beetle, called Anobium, is well known 
to make such a ticking (by knocking its head against the wood of door-casings, 
floors, etc., in which it lives) and probably the “death-watch” is always 
made by this beetle. 

BIRD-COLLECTORS are often annoyed by small, wingless, flat-bodied, swift- 
running insects which sometimes escape from the feathers of bird specimens 
to the hands and arms of the collector. Poultry-raisers are sometimes more 
seriously troubled by finding them so abundant on their fowls as to do con- 


114 Book-lice and Bark-lice; Biting Bird-lice 


siderable injury. They are called bird-lice, but they should not be confused, 
because of this name, with the true blood-sucking lice that infest many kinds 
of animals, particularly domestic mammals and uncleanly persons. The 
biting bird-lice (Fig. 143), constituting the order Mallophaga, never suck 
blood, but feed exclusively on bits of the dry feathers, which they bite off 
with small but strong and sharp-edged mandibles. The true lice have 
mouth-parts fitted for piercing and sucking, and 
constitute one of the numerous families of the 

order of sucking bugs, Hemiptera (see p. 217). 

More than a thousand species of biting bird- 
lice, or Mallophaga, are known, of which about 
two hundred and fifty have been found on North 

American birds. Although by far the larger num- 

ber of Mallophaga infest birds, numerous species 

are found on mammals. On these hosts the insect 

feeds on the hair or on epidermal scales. On 

both birds and mammals, therefore, the food con- 

sists of dry and nearly or quite dead cuticular sub- 

stances, and never of blood or live flesh. Those 

species of Mallophaga which infest birds are never 
Sune found on mammals, and vice versa. 

Serne pre ae The injury done to the hosts by these parasites 
stans, from a tern, consists not in the character of the food-habits, but 
ree Mager: See chiefly in the irritation of the skin caused by the 
George E. Mitchell; scratching of the sharp-clawed little feet of the insects 
ee cee in their migrations over the body. When, as hap- 

pens sometimes in poultry-yards and dovecotes, 

a fowl or pigeon is infested by hundreds of these active little pests, the 

afflicted bird becomes so restless and excited that it takes too little food 

and gets too little rest and thus grows thin and weak. The dust-baths 
taken by fowls and other birds are chiefly to get rid of the bird-lice. The 
fine dust, getting into the breathing-pores (spiracles) of the insects, suffocates 
them. So that the best remedies for these pests of the barn-yard are to 
see that the fowls have plenty of dust to bathe in, and also to keep 
thoroughly clean their roosting- and breeding-places. By tightly closing 
up the hen-house and burning sulphur inside (the fowls, it is hardly necessary 
to say, first being excluded) most of the infesting parasites can be killed. 
The life-history of the Mallophaga is very simple. The small elongate 
eggs are glued separately to the hair or feathers of the host, and from them 
young soon hatch (Fig. 144,3), which, except in size and, to some degree, in 
marking, closely resemble the parents. These young begin immediately their 
hair or feather diet, grow larger, moult a few times, and ina few weeks reach 


Book-lice and Bark-lice; Biting Bird-lice TS 


maturity. There is never, in young or old, any sign of wings or wing-pads. 
The body is flattened, so much so indeed that it is difficult to hold a live 
specimen securely between thumb and finger-tip. The body-wall is strongly 
chitinized, and is firm and smooth. The markings are often very distinct, 
and sometimes bizarre, but the coloration varies only from white to black 
through various shades of pale yellowish brown, tawny, reddish brown, and 
blackish brown. The antenne are short and in one suborder (see classifica- 
tion key) are wholly concealed in pits or grooves on the under side of the 


Fic. 144.—Immature and adult stages of the biting bird-louse, Lipeurus forficulatus, 
taken from a pelican. 1, adult female; 2, adult male; 3, very young stage; 4, 
older immature stage. (Natural size of adult specimens 5 in.) 


flattened head. The legs are strong, and each foot bears two claws. These 
small creatures run very swiftly. 

Ferhaps the oddest thing about the structure of the Mallophaga is the 
presence in the throat of the curious cesophageal or pharyngeal sclerite 
already referred to in the account of the Corrodentia. This sclerite is a 
sort of bonnet-shaped piece (Fig. 145) lying in the lower wall of the throat 
and seems to be an arrangement for starting the little bitten-off pieces of 
feather barbs straight, that is, lengthwise down the cesophagus! The bark- 
lice and book-lice, which have a similar cesophageal sclerite, also bite off 
and swallow small bits of hard, dry organic substance. 


116 Book-lice and Bark-lice; Biting Bird-lice 


The most interesting thing in connection with the Mallophaga, excepting 
their parasitic life and strange food-habits, is the puzzling problem of their 
distribution. The problem in its largest phase is this: the species of Mal- 
lophaga are, ina majority of cases, peculiar (so far as recorded) each to some 
one host species. But the instances are many where a single parasite species 
is common to a few or even to many host species. How does this condition 
of commonness to several hosts come to exist ? 

As the Mallophaga are wingless, their power of migration from bird to 
bird is limited. Moreover, they can live for but a short time off the body 
of a warm-blooded host. After a bird is 
shot, the Mallophaga on it die in from 
two hours to three or four days: in rare 
cases living individuals are found on the 
drying bird-skin after a week. Although 
the parasites in a badly infested hen-house 
will be seen on the roosts and in the nests, 
in Nature the insects are rarely found off 
the host’s body. On such a likely place 
as an ocean rock from which I had just 
frightened hundreds of perching pelicans, 
cormorants, and gulls no parasites could 
be found. Practically migration must be 

accomplished while the bodies of the hosts 

ene rrr Game caeegay are in contact. Such cases occur during 

bird-louse, Eurymopetus taurus, from mating and nesting, and when gregarious 

an albatross. (Greatly magnified.) }irds roost or perch closely together. 

Occasional migration might occur from a bird of prey to its captured 
victim, or from victim to hawk. 

The general character of the cases in which a single Mallophagan species 
is common to several host-species may now be considered. Docophorus 
lari has been found on thirteen species of sea-gulls, and Nirmus lineolatus 
on nine. Gulls are gregarious, perching together on large food-masses 
and on ocean rocks. But on these rocks gulls are closely associated with 
other coast birds, as cormorants, pelicans, murres, etc. And the gull-para- 
sites might have opportunities to migrate to these other bird-species. 
Docophorus icterodes and Trinoton luridum are common to many duck species 
(each has been collected from nine), but ducks also are gregarious, and in 
addition are much given to hybridizing. But a parasite may be common to 
several host-species of non-gregarious habits. Docophorus platystomus is 
common to several hawk-species, D. cursor to several owl-species, D. excisus 
to several swallows, D. californiensis to several woodpeckers, and D. com- 
munis to several passerine birds. In the other genera of Mallophaga are 


Book-lice and Bark-lice; Biting Bird-lice 117 


similar cases, and in all these cases it is hard to see how actual migration 
of the parasite from host to host of different species could take place. Indeed 
there are cases in which such migration is absolutely impossible. Of the 
262 species of Mallophaga taken from North American birds, 157 have 
been described as new species, while 105 are specifically identical with Mal- 
lophaga originally described from European and Asiatic birds; hosts, that 
is, not only of different species, but geographically widely separated from 
the North American hosts! Eliminating the few cases of importations of 
living European birds to this country, and the few species of cicumpolar 
range, there remain to be accounted for about too cases in which a single 
species of Mallophaga is common to both Old World and New World hosts. 

It will have been noted that in all the cases above mentioned of parasite 
species common to several North American host-species, the host-birds are 
closely allied forms, that is, species of the same genus or allied genera. 
This condition holds good also for practically all of the cases in which both 
European and American hosts have a common parasite. For example, 
Docophorus pertusus is common to the European coot (Fulica atra) and 
the American coot (Fulica americana); Nirmus pileus is common to the 
European avocet (Recurvirostra avocetta), and to the American avocet 
(Recurvirostra americana); Lipeurus forficulatus is common to the European 
pelican (Pelecanus onocrotalus) and to the American pelicans (Pelecanus 
erythrorhynchus and P. calijornicus), and so on through the list. From 
this fact of near relationship of hosts in all the cases of parasite species com- 
mon to several host-species it seems almost certain that this common occur- 
rence, under circumstances not admitting of migration of the parasites from 
host to host, is due to the persistence of the parasite species unchanged from 
the time of the common ancestor of the two or more now distinct but closely 
allied bird-species. In ancient times geographical races arose within the limits 
of the ancestral host-species; these races or varieties have now come to be dis- 
tinct species, distinguished by superficial differences in color and mark- 
ings of plumage, etc. But the parasites of the ancient hosts have remained 
unchanged; the plumage as food, the temperature of the body, practically 
the whole environment of the insect, have remained the same; there has 
been no external factor at work tending to modify the parasite species, and 
it exists to-day in its ancient form, common to the newly arisen descendants 
of the ancient host. 

To classify Mallophaga the following keys to suborders, families, and 
genera may be used. In these keys are included only genera which have 
been found in the United States. Seven other genera of Mallophaga are 
known. 


In the following tables the following technical terms are used which have not been 
previously defined: clavate, club-shaped; capitate, with the tip swollen like a ball; ftra- 


118 Book-lice and Bark-lice; Biting Bird-lice 


becul@, triangular membranous processes projecting laterally from the head and situated 
one in front of each antenna; /emples, the hinder lateral parts of the head; ocular emar- 
gination, a bending in of the lateral margins of the head just in front of the eyes; /abral 
lobes, short blunt membranous processes projecting laterally from near the front angles 
of the head; sternal markings, blackish markings, bars or spots, on the ventral aspect of 
the thorax. 

Key TO SUBORDERS OF MALLOPHAGA. 


With short slender 3- or 5-segmented, exposed antenne; no palpi; mandibles 
VOTECA ioe males nln wivtee oe etetefeele ete ee ee ISCHNOCERA. 
With short clavate or capitate, 4-segmented antenne concealed in shallow cavities 
on under side of head; 4-segmented palpi; mandibles horizontal. 
AMBLYCERA, 
Key TO GENERA OF THE SUBORDER ISCHNOCERA. 
A. With 3-segmented antenne; tarsi with one claw; infesting mammals only (family 


Trichodechda@) oclacce cic s(oaae cee eriemee eee oe eee ‘TRICHODECTES. 
AA. With 5-segmented antenne; tarsi eae two claws; infesting birds only (family 
Philopteride). 
B. Antenne alike in both sexes. 
C. Frontideeply angularly notched: - 222 wee oie ele oe AKIDOPROCTUS. 


CC. Front convex, truncate, and rarely with a curving emargination, but never 
angularly notched. 
D. Body broad and short; head with large movable trabecule. 
E. Forehead with a broad, transverse membranous flap, project- 
ing beyond lateral margins of the head in the male, barely 


projecting inthe stemalezce ene cer to ee eee GIEBELIA, 

EE. Without such membranous flap.............. DocopHorvs. 
DD. Body elongate, narrow; head with very small or no trabeculae. 
Nirmvs. 


BB. Antenne differing in the two sexes. 
C. Body wide, elongate oval to suborbicular. 
D. Temples rounded; tip of abdomen with shallow, curving emargina- 
tion; antenne with no appendage; third segment unusually long. 
EURYMETOPUS. 
DD. Temples usually angulated; tip of abdomen convex, rarely angularly 
emarginated with two points. 
E. First antennal segment of male large, and sometimes with 
an appendage; third segment always with appendage. 
GONIODES. 
EE. First antennal segment of male large, but always without 
appendage; third segment without appendage. .GoNIOcOTES. 
CC. Body elongate, narrow, sides subparallel. 

D. Antenne and legs long; a semicircular depression in front of 
IM OUEH erate race eran ete eater fiesta (elei= Oe Seite ee eee LIPEuRUS. 
DD. Antenne and legs short; depression in front of mouth narrow and 
elongate, extending as a furrow to the anterior margin of the head. 
ONCOPHORUS. 

Key TO GENERA OF THE SUBORDER AMBLYCERA. 
A. Tarsi with one claw; infesting mammals only (family Gyropid@)......... GyYRoPUS. 

AA. Tarsi with two claws; infesting birds only (family Liotheide). 

B. Ocular emargination distinct, more or less deep. 


Book-lice and Bark-lice; Biting Bird-lice 119 


C. Forehead evenly rounded, without lateral swellings; antenne projecting 


slightly beyond border of the head.............------- COLPOCEPHALUM. 
CC. Forehead with strong lateral swellings. 

D. Mesothorax separated from metathorax by a suture. ...TRINOTON. 

DD. Meso- and metathorax fused; no suture........ L2MOBOTHRIUM. 


BB. Ocular emargination absent or very slight. 

C. Sides of the head straight or slightly concave, with two small laterally 
projecting | labralMlobese recite stereos ee = cee eerste PHYSOSTOMUM. 

CC. Sides of the head sinuous; forehead without labral lobes. 
D. Ocular emargination filled by a strong swelling; sternal markings 
forming a quadrilateral without median blotches.....- NITZSCHIA. 
DD. Ocular emargination without swelling, hardly apparent or entirely 

lacking; median blotches on sternum. 

E. Very large; with two-pointed appendages on ventral aspect 
of hind head; anterior coxe with very long lobe-like append- 


Ei So Sat abb cose ce ae deaamanemBandocotoosa6e ANCISTRONA. 
EE. Small or medium; without bi-partite appendages of hind head. 
MENOPON. 


The Mallophaga most likely to come under the observation of people 
not collectors of birds are the species which infest domestic fowls and mam- 
mals, and the following few descriptions and figures of particular species 
are therefore limited to such kinds. 

The most notorious member of the order is the common chicken-louse, 
Menopon pallidum (Fig. 146). It is of a pale straw-yellow color, from 
r mm. (;'; in.) to r.5 mm. 
in length, and is an un- 
usually swift and active 
little pest. Other Mallo- 
phaga infesting chickens 
are Goniocotes hologaster, 
recognized by its squarish 
head with angulated 
temples, and Lipewrus 
variabilis, 2 mm. (75 in.) 
long and slender, with dis- 
tinct black markings on 
the otherwise smooth, 
white body. 

Ducks are infested by 
several species. Com- 


, Fic. 146. Fic. 147. 
mon among them is the Fy. 146.—The biting chicken-louse, Menopon pallidum. 
little Docophorus icterodes (After Piaget; natural size, 1 to 1.5 mm.) 


; . Fic. 147.—The biting louse of wild ducks Docophorus 
5 y 1 ; j z Be Sanat Pt aa 

(Fig. 147), 1 mm. (3; in.) icterodes. (Natural size indicated by line.) 

long, with head curiously 

expanded and rounded in front, darkish-red head, and thorax with darker 


120 Book-lice and Bark-lice; Biting Bird-lice 


bands, and a white region in the middle of the abdomen. Trinoton luridum 
is another common duck-louse unusually large, being from 4 to 5 mm. (; in.) 
long and readily distinguished by the triangular 
head with lateral swellings, and the abdomen with 
pronounced blackish-brown transverse bands. 


Fic. 152. 


Fic. 148.—A biting louse of pigeons, Lipeurus baculus. (Natural size indicated by line.) 

Fic. 149.—Biting louse of the dog, Trichodectes latus. (After Nitzsch; natural size, 
I to 1.5 mm.) 

Fic. 150.—Biting louse of the horse, Trichodectes parumpilosus, male. (After Morse; 
natural size shown by line.) 

Fic. 151.—Biting louse of cattle, Trichodectes scalaris. (After Lugger; natural size, 1.5 
to 2mm.) 

Fic. 152.—Biting louse of fringilline birds, Docophorus communis. (Natural size in- 
dicated by line.) 


Book-lice and Bark-lice; Biting Bird-lice 121 


Pigeons are almost always infested by a long and very slender louse, 
Lipeurus baculus (Fig. 148). The head and thorax are reddish brown, 
while the abdomen is dusky with darker segmental blotches. This bird- 
louse was described and named more than two hundred years ago. 

All of the species infesting domestic mammals belong to the genus Tricho- 
dectes. Dogs are often infested by Trichodectes latus (Fig. 149), a short, 
wide-bodied species about 1 mm. long; while cats are less often infested by 
T. subrostratus, distinguishable by the rather pointed head with a short, 
longitudinal furrow on the under side. Horses and donkeys are troubled 
by two or three species, of which 7. pilosus, a hairy form with antenne rising 
near the front of the head, and 7. parumpilosus (Fig. 150), a broader-bodied 
form with head larger and less flatly rounded in front, are most common. 
Trichodectes scalaris (Fig. 151) infests cattle the world over, while sheep 
and goats have species peculiar to themselves. Comparatively few species 
of Trichodectes have been recorded 
from wild mammals, but this is 
simply because they have not been 
sought with care. Species have 


CS 
Bis nvncevaey , an A S 


Fic. 153. Fic. 154. 


Fic. 153.—A biting louse of gulls, Nirmus felix, male. (Natural size indicated by line.) 
Fic. 154.—Giant bird-louse of the albatrosses, Ancistrona gigas, male. (Natural size 
indicated by line.) 


been found on the bear, raccoon, fox, coyote, weasel, gopher, beaver, deer, 
skunk, and porcupine. Gyropus, the other mammal-infesting genus of 


122. Book-lice and Bark-lice; Biting Bird-lice 


Mallophaga, has been found only on the guinea-pig. Washing the body of 
the infested animal with kerosene emulsion (see p. 190) is probably the 
mos! effective remedy for biting lice. 

Of the nearly three hundred species of Mallophaga which I have recorded 
(Proc. Nat. Mus., v. 22, 1899, pp. 39-100) from wild North American birds, 
mention may be made of the largest, Lemobothrium loomis, taken from the 
Canada goose; of Docophorus communis (Fig. 152), the most abundant and 
widely distributed parasite of perching and song birds; of the pretty Nirmus 
felix (Fig. 153), with its clean white body and sharply marked black spots; 
of the fierce-looking Lipeurus ferox, found on albatrosses; and of Ancistrona 
gigas (Fig. 154), found on fulmars, the broadest of the Mallophaga. 

As there are nearly one thousand different species of North American 
birds, and Mallophaga have been taken from but two hundred and fifty of 
them, it is obvious that the collector and student of these parasites has a 
profitable field open to him, 


CHAPTER IX 


THE COCKROACHES, CRICKETS, LOCUSTS, GRASS- 
HOPPERS, AND KATYDIDS 
(Order Orthoptera ) 


E do not shut up our singing insects in cages 
as the Japanese do, and bring them into 
the house to cheer or amuse us, but we do 
enjoy them, and were our summer and 
early fall days and nights to become sud- 
denly silent of chirping and shrilling, we 
should realize keenly how companionable 
crickets and grasshoppers and katydids 
had been for us. A wholesome blitheness 
and vigor and ecstasy of living rings out 
in the swift and steadfast song of most of 
our field and wood insect singers, while 
the cheeriness of the cricket on the hearth 


is familiar poetry and proverb. 

Almost all this insect music comes from the members of one order, the 
Orthoptera. Indeed there is but one famous insect maestro, the cicada (of the 
order Hemiptera), which does not belong to the group of crickets, locusts, green 
grasshoppers, and katydids. Besides being singers, too, the Orthoptera 
are the characteristic leapers of the insect world; crickets and locusts easily 
surpass the world’s athletes for high jumping if the record takes into account 
the comparative size of the athletes. And, curiously, the singing Orthoptera 
are the leaping ones. Of the six families composing the order, three include 
insects which do not sing nor leap, while the other three are made up of 
singers and leapers. 

As one tramps the roadways or dry pastures in summer and autumn, 
the steady shrilling of the locusts on the ground, or their sharp “clacking” 
as they spring into air, are most familiar sounds. When you ramble through 
the uncut meadows and lush low grounds the still shriller singing of the 
slender-bodied, thin-legged, meadow green grasshopper is heard, while 
in the orchards and woods the snowy tree-crickets and broad-winged katydids 


123 


124 Cockroaches, Locusts, Grasshoppers, and Crickets 


keep up the chorus. At home, in house and garden, the domestic cricket 
offers its music to the already over-full ears. All this choiring is done by 
singers without a voice; that is, without the 
production of sound from the throat and 
mouth by means of vocal cords set into vi- 
bration by air. Insects are orchestral per- 
formers, using their legs and wings, for the 
most part, to make their music. When the lo- 
cust sings while at rest, it is rasping the inner 
surface of the broad hind thighs across the 
roughened outer surface of the folded fore 
wings; when it ‘‘clacks”’ in the air, it is strik- 
ing the front margin of the hind wing back 
and forth past the hinder margin of the 
thickened fore wings. When the cricket 
shrills on the hearth, or anywhere else, he, for 
only the male crickets have the musical gift, is holding 
his fore wings up over his body at an angle with it of 
about 45° and is rubbing together the upper surfaces of 
the basal region of the fore wings, which are specially 
modified for this purpose. The tree-crickets, katydids, 
and meadow green grasshoppers have, in the males, 
the same general sort of music-making apparatus as 
the cricket, and sing by similarly rasping or rubbing 
together the modified parts of the fore wings. This 


Fic. 155.—Longitudinal section through head and neck of locust, 
showing disposition of alimentary canal, brain, and sub- 
cesophageal ganglion. (After Snodgrass; much enlarged.) 


music-making by rasping is called stridulation, and for the most part 
insect stridulation is strictly strident, and sounds to better advantage in the 
field than it would from caged songsters in the parlor. 


Cockroaches, Locusts, Grasshoppers, and Crickets 125 


All the Orthoptera have biting mouth-parts, and bite off and chew their 
food, which is usually live vegetable matter, especially green leaves, 
although the members of one family are predaceous, preying on other insects, 
and those of another family prefer dried vegetable or animal matter. The 
metamorphosis is incomplete, the young, when hatched, resembling the parents 
except for small size and lack of wings. The young have the same feeding 
habits and same haunts as the adults, and by development and growth the 


Fic. 156.—The immature stages of a locust, Melanoplus femur-rubrum. a, just hatched, 
without wing-pads; 6, c, d, and e after first, second, third, and fourth moultings 
respectively, showing appearance and development of wings; /, adult, with fully 
developed wings. (After Emerton.) 


wings and parental stature are soon acquired. The name of the order is 
derived from the straight-margined leathery fore wings, or elytra, whose 
chief function is to cover and protect the larger membranous hind wings 
on which the flight function depends. Among the leaping Orthoptera the 
hindmost legs are very large and long, and when at rest or in walking the 
“knee-joints” of these legs are much higher than the back of the insect. 

The three singing and leaping families are the Acridiida, locusts and 
grasshoppers with short antenna; Locustide, meadow green grasshoppers 


126 Cockroaches, Locusts, Grasshoppers, and Crickets 


and katydids, all with long thread-like antenne; and Gryllide, the crickets. 
The three silent and walking or running families are the Blattide,. cock- 
roaches; Mantidz, praying-horses and soothsayers; and Phasmide, walk- 
ing-sticks or twig-insects. These families can be distinguished by the follow- 
ing table: 


KEY TO FAMILIES OF ORTHOPTERA. 


Non-leaping and mute; hind femora closely resembling those of the other legs and 
scarcely stouter or longer than the middle femora; tarsi 5-segmented; ovipositor 
concealed. 

Body oval, depressed; head nearly horizontal and nearly or quite concealed by 
the flattish shield-like pronotum; quickly running....(Cockroaches.) BLatTiD&. 
Body elongate, generally narrow; head free, often with constricted neck; pronotum 
elongate, never transverse; slowly walking. 
Fore legs spined and fitted and held for grasping; antenne usually shorter than 
body; pronotum usually longer than any other body segment; anal cerci 


NoWteil noe ose Secon setesorscocsetetetee (Praying Mantes.) MantTip&. 
Fore legs not fitted for grasping; antenne usually longer than body; pronotum 
Short 2. osasis ook eee eeeee ee (Leaf-insects and Walking-sticks.) PHASMID&. 


Leaping and usually capable of stridulation; hind femora stouter or longer, or both, 
than the other femora; the hind legs enlarged, for leaping; tarsi 4- or 3-segmented; 
head vertical; ovipositor usually visible. 

Antenne much shorter than the body (with few exceptions); ocelli three; tarsi 3-seg- 
mented; auditory organs, when present, situated on basal abdominal segment; 
ovipositor composed of two pairs of short, strong, slightly curving pieces. 

(Locusts.) ACRIDIIDE. 

Antenne much longer than the body, delicately tapering; tarsi 3- or 4-segmented; 
auditory organs usually near the base of the fore tibia; ovipositor usually pro- 
longed into a compressed blade, or needle, its parts compact. 

Tarsi 4-segmented; ocelli usually absent; ovipositor usually exserted and forming 
a strongly compressed, usually curving, blade with tip not expanded. 
(The long-horned grasshoppers.) Locustip&. 
Tarsi 3-segmented; ocelli variable; ovipositor usually exserted and forming a 
nearly cylindrical straight needle, the tip somewhat expanded. 
(Crickets.) GRYLLIDE. 


Mrs. Smith takes it amiss when you ask permission to collect ‘‘roaches”’ 
in her house, and will prove to you any day the conspicuous absence of these 
unwelcome guests in the scrubbed and spotless pantry and kitchen. But 
with a candle go stocking-footed at night into the same kitchen and you 
will not unlikely find “good hunting.” Although but few of the thousand 
different kinds of cockroaches known in the world are to be found in the 
United States, these few, and particularly three or four imported foreigners 
among them, are very abundant, and, after dark, very much in evidence in 
their favorite habitat. Their chosen abiding-place is in kitchens, pantries, 
laundries, restaurants, bakeshops, etc., where the atmosphere is warm 


Cockroaches, Locusts, Grasshoppers, and Crickets 127 


and humid and the roach’s table is well set with good things. Almost any 
sort of dry organic matter suits their taste; bread, crackers, miscellaneous 
cold-lunch delicacies, the paste of bookbindings and wall-paper, leather, 
woolens, and even their own egg-cases and cast skins making up the dietary. 
The fo’k’sel and galley of ships are the roaches’ special joy; the hotels and 
restaurants of tropic and subtropic lands house swarms of these bill-evading 
guests. From Mazatlan, Mexico, a naturalist sent me quarts of large native 
American roaches (Periplaneta americana), which he readily scooped up 
from his bedroom floor. Ships come into San Francisco from their long 
half-year voyages around the Horn with the sailors wearing gloves on their 
hands when asleep in their bunks in a desperate effort to save their finger- 
nails from being gnawed off by the hordes of roaches which infest the 
whole ship. A few of our species still live outside under stones and old 
logs, but most of them have learned that an easier life awaits them in the 
kitchen. 

The roaches compose the Orthopterous family Blattide, and are an 
ancient and persistent insect group. In Carboniferous times, before flies, 
butterflies, bees, and wasps had come into existence, cockroaches were 
the dominant insects. The body in all is flattened and slippery with the 
legs adapted for quick running, so that the insects are well fitted to escape 
safely into narrow cracks and crevices. The head is concealed from above 
by the expanded shield-shaped dorsal wall of the prothorax (pronotum). 
Wings are present in most species, the front pair 
leathery and serving, when the wings are folded, to 
cover and protect the larger, thin, membranous 
hind pair. In some forms the females are wingless, 
and the indoor habit may be held responsible for 
the lessened usefulness and resultant loss of the Fic. 157.— Egg-case of 

: os cockroach. (Three times 
wings. The mouth-parts are fitted for biting hard  patural size.) 
dry substances, the jaws being strong and toothed. 
The eggs are laid in small purse-like, horny, brown cases (Fig. 157), which 
are usually carried about by the female until the young are ready to issue. 
The young grow slowly, requiring probably about a year, in most species, 
to become fully developed. From the beginning, the young can run about 
and take care of themselves, eating the same kind of food as the adults. 
They moult several times during growth, and at each moult the wing-pads 
are a little larger. 

There are four common species of cockroaches found in dwellings in this 
country, only one of which is native. This is the large American roach, 
Periplaneta americana, about 14 inches long (to tip of folded wings), light 
brown in color, and with the wings expanding nearly 3 inches. This species 
is abundant in the middle and western states, having gradually extended 


128 Cockroaches, Locusts, Grasshoppers, and Crickets 


its range north from its native region in Mexico and Central America. The 
Australian roach, Periplaneta australasia, resembles P. americana, but is 
darker in ground color, a quarter of an inch shorter, and has a conspicuous 
yellow submarginal band running around the shield-shaped pronotum. 
Each fore wing has also a strong yellow tapering bar in the basal part of 
the costal region. It came originally from the Australian Pacific region, 
and is now spread widely over the world, being common in this country 
in Florida and other southern states. The most abundant and destruc- 
tive house-roach in the eastern states is the small German cockroach, 
Ectobia germanica (Fig. 158), about half an inch long, and pale yellowish 
brownish with a pair of distinct black longitudinal stripes on the pro- 


Fic. 158. Fic. 159. Fic. 160. 
Fic. 158.—The croton-bug, or German cockroach, Ectobia germanica. (Twice natural 
size.) . 
Fic. 159.—The black beetle, or Oriental cockroach, Periplaneta orientalis. (One and 
one-half times natural size.) 
Fic. 160.—The common wood cockroach, Ischnoptera pennsylvanica. (After Lugger; 
natural size indicated by line.) 


notum. This roach is often called croton-bug, from its intimate asso- 
ciation with the pipes of New York City’s Croton-water system. It is an 
importation from Europe, where it is especially abundant in Germany. Its 
real nativity is unknown, but it is: now of world-wide distribution. The 
fourth species is the black or Asiatic roach, or black beetle, as it is sometimes 
called, Periplaneta orientalis (Fig. 159). This roach is about one inch 
long, with brownish-black body; in the female the wings are rudimentary, 
and in the male the wings when folded do not quite reach the tip of the 
abdomen. This species is common in all the eastern and Mississippi 
Valley states and extends as far west as the great piains. It is the 
commonest cockroach in England and Europe. The native outdoor species 
most familiar in this country is the common wood-cockroach, Ischnoptera 


Ss 


Cockroaches, Locusts, Grasshoppers, and Crickets 129 


pennsylvanica (Fig. 160), with long, light-colored wing-covers, and wings 
which extend considerably beyond the tips of the abdomen. The margin 
of the pronotum is light, the disk being dark, and the front margins 
(lateral when folded) of the wing-covers are lighter than the discal 
parts. The body is an inch long and rather narrow and slender. This 
species is common in the woods and sometimes comes into houses in 
summer-time. 

In the southern states and those of the Mississippi Valley a large insect 
may be not infrequently seen standing motionless in a corner of a window, 
in a striking attitude. This attitude may be taken as one of hopeful prayer, 
as those who gave the name praying-mantis to the insect seem to have taken 
it, or one of self-confident readiness to do violent work with those upraised, 
sharply spined, and very willing fore feet. This is the way the house-flies 
rightfully take the mantis’s attitude. Watch an unwary bluebottle crawl or 
buzz into the fatal corner. Blundering buzziness is finished for that blue- 


Fic. 161.—The praying-mantis, Mantis religiosa. (After Slingerland; natural size.) 


bottle; and the first course of a square meal has come to him who waits 
and watches. Other names, as rearhorse, camel-cricket, and soothsayer, 
have been given the mantis, all suggested by the attitude and curious body 
make-up of the creature. The prothorax is long and stem-like, the head 
broader than long, with protuberant eyes, and the fore legs are not used 
for locomotion, but are large, strongly spined, and fitted for seizing and hold- 
ing the prey. The wings are short and broad and usually rather leaf-like 
in coloration and texture, the whole insect when at rest resembling somewhat 
a part of the plant on which the mantis ordinarily stands. The window-corner 
‘is a new and unnatural /ocale for the insects, but the abundance of prey here 
in summer-time makes it a good feeding-ground. 

The family Mantide includes less than a score of species in this country, 
all of them southern in range, and only a few occurring north of the Rio 


130 Cockroaches, Locusts, Grasshoppers, and Crickets 


Grande and Gulf coast regions. All the species are carnivorous, and 
undoubtedly do much good in making away with many noxious insects. In 
1899 some specimens of the common European praying-mantis, Mantis 
religiosa (Fig. 161), were found in and 
near Rochester, N. Y. They had 
probably been accidentally imported 
into this country in nursery stocks from 
France. As this species seems able 
to live farther north than our native 
species, Professor Slingerland is laud- 
ably trying to establish it in our coun- 
try. He takes care of a colony, and 
is distributing many of the egg-cases 
over the entire country. All the man- 
tids lay their eggs in curious masses 
(Figs. 162 and 163), covered with a 
quickly drying tough mucus. These 
egg-cases are attached to branches and 
plant-stems in the fall, and the young 
hatch in the following summer and 
soon grow (moulting several times 
and developing wings) to full stature, 
which for our most common native 
species, Stagmomantis carolina, is 
about 24 inches long. 


Fic. 162.—Egg-cases of the praying- ~y° 
mantis, Mantis  religiosa. (After Slingerland has collected a num- 


Slingerland; natural size.) ber of the old accounts of the Euro- 
pean mantis which are of interest as proofs of the light and graceful fancy 


of some of the early author-naturalists. 
The ancient Greeks gave the insects 
the name Mantis, that is, ‘‘ prophet.” 
Mouffet, writing over three hundred 
years ago, says: “‘They are called 
Mantes, that is, foretellers, either 
because by their coming (for they first 
of all appear) they do show the spring 
to be at hand, so Anacreon the poet 
sang; or else they foretell death and Fic. 163.—Egg-case of praying-mantis, 
famine, as Celius the Scoliast of prettier gots" pe 
Theocritus has observed; or, lastly, size.) 

because it always holds up its fore feet like hands praying as it were, after 
the manner of their Diviners, who in that gesture did pour out their sup- 


Cockroaches, Locusts, Grasshoppers, and Crickets 131 


plications to their Gods.” And he says again: “They resemble the Diviners 
in the elevation of their hands, so also in likeness of motion; for they do not 
sport themselves as others do, nor leap, nor play, but walking softly, they 
retain their modesty, and shewes forth a kind of mature gravity. . . . So 
divine a creature is this esteemed, that if a childe aske the way to such a 
place, she will stretch out one of her feet, and shew him the right way, and 
seldome or never misse.’’ Piso in his works states that mantids ‘‘ change into 
a green and tender plant, which is of two 
hands’ breadth. The feet are fixed into 
the ground first; from these, when neces- 
sary, humidity is attracted, roots grow out 
and strike into the ground; thus they 
change by degrees, and in a short time 
become a perfect plant.” 

Almost everywhere that mantids occur, 
strange superstitions are held concerning 
them. Most of these ascribe some degree 
of sanctity to them, and to kill them 
maliciously is considered sinful. Cowan 
says that “the Turks and other Moslems 
have been much impressed by the actions 
of the common Mantis religiosa, which 
greatly resemble some of their own attitudes 
of prayer. They readily recognize intelli- 
gence and pious intentions in its actions, 
and accordingly treat it with respect and 
attention, not indeed as in itself an object 
of reverence or superstition, but as a fel- 
low worshipper of God, whom they believe 
that all creatures praise with more or less 
consciousness and intelligence. Other su- 
perstitions with respect to the Mantis are 
current: when it kneels it sees an angel 
in the way, or hears the rustle of its wings; 
when it alights on your hand you are about 
to make the acquaintance of a distin- 
guished person; if it alights on your head, 
a great honor will shortly be conferred F1G. 164.—The walking-stick, Diaphe- 
upon you. If it injures you in any way, areca: [emcr aia. 
which it does but seldom, you will lose a valued friend by calumny. Never 
kill a Mantis, as it bears charm against evil.’ Finally, monkish legends 
teli us, says Slingerland, that St. Francis Xavier, seeing a Mantis moving 


132 Cockroaches, Locusts, Grasshoppers, and Crickets 


along in its solemn way, holding up its two fore legs as in the act of devo- 
tion, desired it to sing the praise of God, whereupon the insect carolled 
forth a fine canticle! 

More amazing than the Mantids for modification of form and appear- 
ance away from the usual insect type are the members of the family Phas- 
mide. The only representatives of this family in the United States are 
the walking-sticks, or twig insects (Fig. 164), of which half a dozen genera, 
with from one to three species each, have been recorded. The only one 
of these genera which is found in the East is Diapheromera, of which D. 
jemorata is the common species. Our other Phasmids are found in the 
West or extreme South. All of our species are wingless and are generally 
sluggish in movement, and depend for protection largely on their amazingly 
faithful resemblance in shape and color to twigs, and on their capacity to 
emit an ill-smelling fluid from certain glands on their prothorax. Diaphero- 
mera femorata (Fig. 164) feeds on the leaves of oaks, walnuts, and probably 
other trees. It drops its hundred seed-like eggs loosely and singly on the 
ground, where they lie through the winter, hatching irregularly through 
the following summer. Some may even go over a second winter before 
hatching. Femorata may be either brown or green; so it frequents dead 
or leafless, or live and green-leaved parts, according to the correspondence 
of its body color with the one or the other of these environments. The long, 
slender, wingless body, the thin, long legs held angularly, and the harmonizing 
body color, all serve to make the walking-stick well-nigh indistinguishable 
when at rest on the twigs. 

In tropic and subtropic countries the Phasmids are numerous (over 600 
species are known) and present other striking resemblances to the details 
of their habitual environment. A conspicuous and perfect example of 
resemblance is the green leaf-insect Phyllium (PI. XIII, Fig. 2), whose wings, 
flattened body, and expanded plate-like legs, head, and prothorax, all bright 
green and flecked irregularly with small yellowish spots, like those made 
by the attacks of fungi on live leaves, combine to simulate with wonderful 
effect a green leaf. 

Other examples of such protective resemblance and a discussion of the 
origin and significance of the phenomenon may be found in Chapter XVII 
of this book. 

The genera of Phasmide occurring in the United States may be distin- 
guished by the following key: 


Tibia with a groove at tip to receive the base of the tarsi when bent upon them. 
Antenne with less than twenty segments, and much shorter than the fore femora. 
BAcILLws. 


Cockroaches, Locusts, Grasshoppers, and Crickets 133 


Antenne with many segments, and longer than the fore femora. 
Mesothorax twice as long as prothorax...........-.---.---.---/ ANISOMORPHA. 
Mesothorax no longer than ‘prothorax:5.....0.---.---220--+-s-------- TINEMA. 

Tibie without groove at tip, as above described. 
Hind femora with one or more distinct spines on the median line of the under side 
BERIT WS CB Spaces ere aunondeeuoa rE atcdhaSoeeONBOSeEIas DIAPHEROMERA. 
Hind femora without such spines. 

Head, especially in female, with a pair of tubercles or ridges on the front between 
MREKEYV ES fee siec sete ace awe es 8 me ete aleve eters Se eae oe Se eine steele SERMYLE. 
Head without such tubercle or ridges............------------- - .-.- BACUNCULUS. 


One day in early summer of the Centennial Year (1876) the people all 
over Kansas might have been seen staring hard with shaded eyes and serious 
faces up towards the sun. By persistent looking one could see high in the 
air a thin silvery white shifting cloud or haze of which old residents sadly 
said, ‘“‘It’s them again, all right.’ Now this meant, if it were true, that, 
far from being all right, it was about as wrong as it could be for Kansas. 
“Them” meant the hateful Rocky Mountain locusts, and the locusts meant 
devastation and ruin for Kansas crops and farmers. In 1866 and again 
in 1874 and 1875 the locusts had come; first a thin silvery cloud high over- 
head—sunlight glancing from millions of thin membranous fluttering 
wings—and then a swarming, crawling, leaping, and ever and always 
busily eating horde of locusts over all the green things of the land. And 
the old residents spoke the truth in that summer of 1876. It was ‘‘them,” 
uncounted hosts of them, and only such patriotic farmers as had laid by 
money for a rainy day or a grasshopper year could visit the Centennial 
Exposition. 

Not all locusts are migratory or appear in such countless swarms as 
this invader from the high plateau of the northern Rocky Mountains. In 
South America another locust species, larger than ours, has similar habits; 
having its permanent breeding-grounds on the great plateau at the eastern 
foot of the Chilean Andes and descending almost every year in swarms on 
the great wheat-fields of Argentina. And in Algeria and Asia Minor occurs 
the migratory locust of the Scriptures, a still other and larger species. But 
of the 500 (app.) locust species, members of the family Acridiide, which 
are known in the United States but three or four can be fairly called 
migratory, and of these the Rocky Mountain locust, Melanoplus spretus, is 
the most conspicuous. The lesser migratory locust, Melanoplus ailanis, 
does much injury in New England and other eastern states, while the 
peliucid locust, Camnula pellucida, is a migratory species that often does 
much harm in California and other western states. Sometimes large 
bodies of immature wingless individuals of the large species Dissosteira 
longipennis, abundant on the plains of eastern Colorado and western Kansas 


134 Cockroaches, Locusts, Grasshoppers, and Crickets 


will move slowly on, walking and hopping for many miles, eating every 
green weed and grass-blade in their path, but this is only a limited and 
local sort of migration. 

Almost all the Acridiide, despite the many species in the family, are 
readily recognizable as_ locusts 
or grasshoppers — short-horned 
grasshoppers they may be called, 
to distinguish them from the 
meadow green grasshoppers with 
long thread-like antennae—because 
of their general similarity in ap- 
Fic. 165.—Locust from lateral aspect (left wings + pee and habit. The body 

removed), showing (ao.) auditory organ. is rather robust, the head is set 

(Natural size.) with its long axis at right angles 
with the axis of the body, so that the mouth with its strong biting and 
crushing jaws is directed downwards (Fig. 165); the antenne are never 
as long as the body and are composed of not more than twenty-five 
segments; the prothorax is covered laterally as well as dorsally by its large 
saddle-like horny pronotum, which projects so as also to cover and protect 
from the sharp grass-blades the soft thin-walled neck and the equally 
thin-walled suture between prothorax and mesothorax; the abdomen is 
broadly and closely joined to the metathorax, and 
in the female ends in a short and strong ovipositor 
composed of four horny pointed pieces; the hind 
legs are much larger than the others and fitted 
for leaping, and the fore wings, called tegmina, 
are narrow and _ straight-margined, and serve 
specially to cover and protect the much larger 
thin membranous hind wings, which are plaited 
and folded like a fan when the locust is at rest. 

The sounds or stridulation of locusts are 
made in two ways. When at rest certain species 
draw the hind legs up and down across the wing- 
covers so that numerous fine little ridges on the 
inner surface of the broad femora are rasped yi, 166, = Tacuebienialee on 


across a thickened and ridged longitudinal vein thorn by shrike (butcher- 
ve When bird). (Natural size.) 


on the outer surface of the wing-covers. 
in flight certain locusts rub or strike together the upper surface of the 
front edge of the hind wings and the under surface of the fore wings 
or tegmina. This produces a loud, sharp clacking which can be heard 
for a distance of several rods. The loudest “‘clacking” of this kind 


Cockroaches, Locusts, Grasshoppers, and Crickets 135 


that I have heard is made by a species of Trimerotropis, abundant in 
the beautiful little glacial “parks” of the Colorado Rockies. Locusts 
undoubtedly make sounds to be heard by each other, and it is not difficult 
to find in them—a matter of more difficulty in most other insects—certain 
organs which are almost certainly auditory organs, or ears. On the outer 
faces of the upper part of the first abdominal segment is a pair of sub- 


eg amene: 
oe aie 


SS 
ee 


tS 
Iie Q 


Ky 


Fic. 167.—The red-legged locust, Melanoplus femur-rubrum, female. 
(After Lugger; natural size indicated by line.) 


circular clear window-like spots (Figs. 165 and 55). ‘These are thin places 
in the body-wall serving as tympana; on the inner face of each is a small 
vesicle, and from it a tiny nerve runs to a small auditory ganglion (nerve- 
center) at one side of the tympanum. From this auditory ganglion a nerve 
runs to the large ventral ganglion in the third thoracic segment. Similar 
auditory organs are found in the other singing Orthoptera, the crickets and 
katydids, but situated in the front legs-instead of on the back. 


136 Cockroaches, Locusts, Grasshoppers, and Crickets 


The life-history of all our locusts is, in general characteristics, very similar. 
The eggs are deposited in oval or bean-shaped packets enclosed in a glutin- 
ous substance. They are usually laid just below the surface of the soil, 
but in some cases are simply pushed to the ground among the stems of 
grasses, while a few locust-species thrust them into soft wood. The strong, 
horny ovipositor at the tip of the abdomen is worked into the ground, the 
four pieces separated, and the eggs and covering mucous material extruded. 
The eggs in a single mass number from twenty-five to one hundred and 
twenty-five, varying with different species, and the females of some species 
lay several masses. The different species also select different times and 
places for egg-laying, some ovipositing in the fall and some in the spring, 
while some select hard, gravelly, or sandy spots or well-traveled roads, and 
others choose pastures and meadows and the uncultivated margins of irriga- 
tion-ditches. 

If the eggs are laid in the fall, the more usual case, they do not hatch 
until the following spring. The young hoppers are of course wingless, very 
small, and pale-colored, but they have the general body make-up of their 
parents, with the biting mouth and long-leaping hind legs. They push 
their way above ground and feed, as do the adults, on the green foliage of 
grasses, herbs, or trees, and in two or three months become full grown and 
mature, having moulted five or six times during this growth and developed 
wings. The wings begin to appear as minute scale-like projections from 
the posterior margins of the back of the meso- and meta-thoracic segments, 
and with each moulting are notably larger and more wing-like in appear- 
ance. During all this development the wing-pads are so rotated that the 
hinder wings (always underneath the fore wings in the adult locust) lie out- 
side of and above the fore wings (Fig. 156). 

The family Acridiide includes in the United States about 500 species, 
representing 107 genera. These genera are grouped in four subfamilies 
as follows: 

KEY TO SUBFAMILIES OF ACRIDIID. 
Pronotum (dorsal wall of prothorax) extending back over the abdomen nearly or quite 
to its tip; tegmina (fore wings) short and scale-like.............. TETTIGINE. 
Pronotum not extending back over abdomen or only slightly; Epa usually well 


developed (sometimes short or wanting). 
Prosternum (ventral aspect of prothorax) with a prominent thick Spr or cylindrical 


SPINE. o6. oon oa claw De nace ale cece Ree See see as eee eee ee ACRIDIINE. 
Prosternum not spined (sometimes a short, oblique, inconspicuous, obtuse tubercle). 
Face very oblique)>..<. . 2-2 sec sn cee eee See eee eee TRYXALINE. 
Face nearly or, quite: vertical... =e eee eee (EDIPODIN. 


In the subfamily Acridiinze the most conspicuous and economically 
important member is the Rocky Mountain or hateful migratory locust, 


Hy 


- 


Cockroaches, Locusts, Grasshoppers, and Crickets 137 


Melanoplus spretus. The invasions of the grain-growing Mississippi Valley 
states by this species have been already mentioned. In 1866, 1874, and 
1876 such invasions occurred, and before these still others. ‘‘Kansas grass- 
hoppers” had gained a notoriety which spelled ruin to the state. But, 
strangely, these grasshoppers, or locusts, not only were not Kansas born, 
but could not even adopt Kansas as a home. The Rocky Mountain locust 


Fic. 168. Fic. 169. 
Fic. 168.—The lesser migratory locust, Melanoplus atlanis, female. (After Lugger; 
natural size indicated by line.) 
Fic. 169.—The differential locust, Melanoplus differentialis, female. (After Lugger; 
natural size indicated by line.) 


has its permanent breeding-grounds on the plains and plateaus of Colorado, 
Idaho, Wyoming, Montana, and British Columbia, at an altitude of from 
2000 to 10,000 feet above sea-level, and while able to maintain itself for 
a generation or two in the low, moist Mississippi Valley, cannot take up 
any permanent residence there. But in those days there were few ranches 
and farms on the great plains, and succulent corn and wheat were not at 


138 Cockroaches, Locusts, Grasshoppers, and Crickets 


hand to feed the millions of young which hatched each spring. So, after 
exhausting the scanty wild herbage of their breeding-grounds, and develop- 
ing to their winged stage, hosts of locusts would rise high into the air until 
they were caught by the great wind-streams bearing southeast, and, with 
parachute-like wings expanded and air-sacs in the body stretched to their 
fullest, would be borne for a thousand miles to the rich grain-fields of the 


SO OT a ay, 
SN 227 
>. lee 


Fic. 170.—The two-striped locust, Melanoplus bivittatus, female. 
(After Lugger; natural size indicated by line.) 


Mississippi Valley. As far east as the middle of Iowa and Missouri and 
south to Texas these great swarms would spread; and once settled to ground 
and started at their chief business, that of eating, not a green thing escaped. 
First the grains and grasses; then the vegetables and bushes; then the 
leaves and fresh twigs and bark of trees! A steady munching was audible 
over the doomed land! And this munching was the devouring of dollars. 
Fifty millions of dollars were eaten in the seasons of 1874-76 alone. 


Cockroaches, Locusts, Grasshoppers, and Crickets 139 


Remedies there were practically none; when the summer hosts laid 
their eggs in the ground for the one generation that could be reared in the 
invaded land, these eggs could be plowed up, a remedy that is used with 
much success in the far western locust-infested states; also when the wingless 
young ‘“‘hoppers”’ appeared in the spring they could be crushed by heavy 


SPEULDS LLP ELTA LSS 9 
Ese ra Ea, 


Fic. 171.—The American locust, Schistocerca americana, female. 
(After Lugger; natural size.) 


rollers drawn across the fields by horses, or burned by scattering straw over 
the helpless host and lighting it. Both of these remedies are also used in 
western locust-fighting. But against the winged adults there is little that 
can be done. 

In Asia and South America, where there are also migratory locusts (of 
different, much larger species) the natives sometimes try to frighten away 
an alighting swarm by smoke, and noise, but such a swarm as that which 
passed over the Red Sea in November, 1889, spread out for over 2000 square 


140 Cockroaches, Locusts, Grasshoppers, and Crickets 


miles in area, would be little affected by a bonfire. In Cyprus in 1881, 
1300 tons of locust-eggs were destroyed; how many eggs go to make a ton 
one can only faintly conceive of. 

There has been no serious Rocky Mountain locust invasion of the Missis- 
sippi Valley since 1876, and there will probably never be another. The 
locust is being both fed and fought in its own breeding range; many are 


FIG. 172. Fic. 175. 
i fo 


Fic. 172.—The emarginate locust, Schistocerca emarginata, male. (After Lugger; nat- 
ural size.) 

Fic. 173.—Tke pale-green locust, Hesperotettix pratensis, female. (After Lugger; 
natural size indicated by line.) 

Fic. 174.—The short-winged locust, Stenobothrus curtipennis, female. (After Lugger; 
natural size indicated by line.) 

Fic. 175.—The sprinkled locust, Chlwaltis conspersa, male. (After Lugger; natural size 
indicated by line.) 


killed every year, and for those that are left there is food enough and to spare 
in the great grain-fields of the northwest plains. 

The genus Melanoplus, to which the Rocky Mountain locust belongs, 
is the largest of all our Acridiid genera, one hundred and twenty species 
found in the United States belonging to it. Of these species a very common 
one all over the country is the red-legged locust, Melanoplus jemur-rubrum 
(Fig. 167), which is about one inch long, with olivaceous brownish body, 
clear hind wings and brownish fore wings that have an inconspicuous 
longitudinal median series of black spots in the basal half (these spots 


Cockroaches, Locusts, Grasshoppers, and Crickets 141 


sometimes wanting). The hind tibie are normally red (sometimes yellow- 
ish), hence the name, although these red hind legs are common to many 
other locust species. The lesser migratory locust, M. atlanis (Fig. 168), 
is a species of about the same size and appearance which sometimes 
appears in great swarms and does much injury to crops. The largest 
species of the genus is M. differentialis (Fig. 169), over an inch and a half long, 
with brownish-yellow body, fore wings without spots, and hind wings clear. 
It is common in the Southwest, where, in company with M. bivittatus (Fig. 
170), nearly as large but readily distinguished by the pair of longitudinal 


Ae 


¥, 
bd 


i 
N 

N 

3 


Fic. 176. Fic. 177. Fic. 178. - 

Fic. 176.—The short-winged green locust, Dichromorpha viridis, female. (After Lugger; 
natural size indicated by line.) : 
Fic. 177.—The spotted-winged locust, Orphula pelidina. (After Lugger; natural size 

of male 16-19 mm., of female, 20-24 mm.) 

Fic. 178.—The Carolina locust, Dissosteira carolina, female. (After Lugger; natural 
size indicated by line.) 

pale-yellowish stripes extending from the head across the thorax and along the 

folded wing-covers nearly to their tips, it often becomes sufficiently abundant 

to do serious injury. These two species are always to be found commonly 

in western Kansas, and bivittatus ranges far to the north, being one 

of Minnesota’s destructive species. 

Among the other genera of the subfamily Acridiine Schistocerca is con- 
spicuous because of the large size and wide distribution of its species. The 
American locust, S. americana (Fig. 171), measures three inches from head 
to tips of tegmina, with reddish-brown body and a longitudinal yellowish 
strip extending along the head, thorax, and closed tegmina nearly to their 


142 Cockroaches, Locusts, Grasshoppers, and Crickets 


tips. The tegmina are opaque and reddish at base, subtransparent dis- 
tally; the great hind wings are clear and transparent. This locust is com- 
mon in the South, where it sometimes assumes a migratory habit and 
becomes very injurious to crops. The leather-colored locust, S. alutaceum, 
with dirty brownish-yellow body and paler stripe on top of head and thorax, 


Fic. 179.—The coral-winged locust, Hippiscus tuberculatus, female. (After Lugger; 
natural size indicated by line.) 

semi-transparent tegmina, and clear transparent hind wings, and the rusty 
locust, S. rubiginosum, with light dust-red body and opaque tegmina, are 
the common eastern representatives of this genus. Both are large and 
striking forms. 

The subfamily Tryxaline includes a number of locusts distinguished 
by the sharp oblique sloping of the face, and in some cases by the much 


prolonged and pointed vertex (region of the head between the eyes). In, 


the East the short-winged locust, 
Stenobothrus curtipennis (Fig. 174), 
recognizable by its short narrow 
wings, yellow under-body, and prom- 
inent yellowish hind legs with black 
knees, is a common example of this 
group. It likes to hide among tall 
grasses, where its sprightly tumbling 


Fic. 180.— Young coral-winged _ locust, and dodging usually save it from 
HTippiscus tuberculatus. (After Lugger; capture despite its poor flying and 
natural size indicated by line.) " * 

, leaping powers. The — sprinkled 
locust, Chlawaltis conspersa (Fig. 175), is an abundant species through- 
out the East. It is light reddish brown sprinkled with black spots, 
and has pale yellowish-brown tegmina with many small dark-brown spots, 
the wings being clear; it is about three-fourths of an inch long. The 
males have the sides of the pronotum shining black. This locust lays its 
eggs in rotten stumps or other slightly decayed wood. Blatchley discovered 
a female in the act of boring a hole for her eggs in the upper edge of the 
topmost board of a six-rail fence. One of the most grotesque of all the 
locusts is a member of this subfamily named Achurum brevipenne. The 
body is very long and thin, measuring an inch and a half in length by one- 


Cockroaches, Locusts, Grasshoppers, and Crickets 143 


tenth of an inch wide in the broadest part; the head is pointed and pro- 
jects far forward and upward, the face being very oblique. The wings 
are short and the body color brown. Comstock found this locust quite 
common in Florida on the ‘“‘wire-grass’’ which grows in the sand among 
the saw-palmettoes, and ‘‘so closely did their brown linear bodies resemble 
dry grass that it was very difficult to perceive them.’”’ So the grotesqueness 
has its use. 

The subfamily Cdipodine is well represented in the United States, 


Fic. 181.—Hippiscus tigrinus, female. (After Lugger; nat. size indicated by line.) 


containing twenty-four genera and about 140 species. Almost all the familiar 
locusts with showy colored hind wings belong to this subfamily. One 
of the commonest species all over the United States and Canada is the 
Carolina locust, Dissosteira carolina (Fig. 178), easily recognized by its 
black hind wings with broad yellow or yellowish-white margin covered with 
dusky spots at the tip. Its body color is pale yellowish or reddish brown, 
and it measures 14-2 inches in length. It flies well; the males have the 
habit of hovering in the air a few feet above the ground and making a loud 


144 Cockroaches, Locusts, Grasshoppers, and Crickets 


“clacking.”’ The species of Hippiscus are heavy, broad-bodied forms 
with wings reddish or yellow- 
ish at base, then a broad black- 
ish band, and the apex and 
margin clear. The fore wings 
and body are yellowish to 
brown, with darker blotches 
and speckles. H. discoideus, 
with wings red on basal half, 
is common in the East. #H, 
tuberculatus (Figs. 179 and 180), 
the coral-winged locust, or king 
grasshopper, also with red 
wing-disks, is common in the 
Mississippi Valley; it makes 
a very loud rattling while in 


Fic. 182.—The yellow-winged locust, Arphia ‘ ; 3 
sulphurea. (After Lugger; natural size of the air. The genus Arpbia, 
male 23-26 mm., of female 28-30 mm.) also characterized by wings 

with bright red or yellowish 

disks but having the fore wings 
without large spots or blotches, 
usually not even speckled, and 
with the body slenderer than 
in Hippiscus, comprises about 
twenty species scattered over 
the whole country. <A. xan- 
thoptera, with plain smoky 
brown fore wings and upper 
body, and hind wings with 
bright yellow disk, broad smoky 
outer band and clearer apex, 
is common in the East; A. 
tenebrosa (Fig. 183), with brown 
and clayey-speckled fore wings 
and upper body and_ hind 
wings with coral-red disk and 
smoky broad outer band fad- 
ing out in apex, is common 


Fic. 183.—Arphia tenebrosa. (After Lugger; nat- in the West. The green- 
ural size indicated by line.) 


striped locust, Chortophaga 
viridijasciata (Figs. 184 and 185), abundant and familiar in the East and 
Mississippi Valley, appears in two forms; in one, the head, thorax, and 


Cockroaches, Locusts, Grasshoppers, and Crickets 145 


Fic. 184.—The green-striped locust, Chortophaga viridifasciata, form virginiana, female. 
(After Lugger; natural size indicated by line.) 


Se ge nt 
DES aoe 


Fic. 186. Fic. 187. 


Fic. 185.—The green-striped locust, Chortophaga viridifasciata, form virginiana, male. 
(After Lugger; natural size indicated by line.) 

Fic. 186.—The clouded locust, Encoptolophus sordidus, male. (After Lugger; nat- 
ural size indicated by line.) 

Fic. 187.—The pellucid locust, Cammnula pellucida, female. (After Lugger; natural 
size indicated by line.) 


(46 Cockroaches, Locusts, Grasshoppers, and Crickets 


femora are green and there is a broad green stripe on each wing-cover; 
the other form is dusky brown all over; both are about 1 inch (male) to 1} 
inches (female) long, and have a distinct sharp little median crest on the 


Fic. 189. 


Fic. 188. 


FIG. 190. Fic. ror. 


Fic. 188.—Barren-ground locust, Spharagemon bolli, male. (After Lugger; natural size 
of male 20-22 mm., of female 27-33 mm.) 

Fic. 189.—Spharagemon collare, race scudderi, male. (After Lugger; natural size in- 
dicated by line.) 

Fic. 190.—The long-horned locust, Psinidia fenestralis, male. (After Lugger; natural 
size indicated by line.) 

Fic. 191.—Circotettix verruculatus, male. (After Lugger; natural size indicated by line.) 


pronotum. The clouded locust, Encoptolophus sordidus (Fig. 186), is another 
species very common in the fall; it is about an inch long, dusky brown 
mottled with darker spots; the wing-covers are blotched and the wings 


Cockroaches, Locusts, Grasshoppers, and Crickets 147 


clear and transparent; the prothorax looked at from above appears to be 
“pinched”’ at its middle. The males make a loud crackling when in the 
air. 

It is familiar knowledge that locusts which are readily seen in the air 
are extremely difficult to distinguish when alighted. This concealment, 
resulting from a harmonizing of the body color with that of the grass or 
soil, is of course an advantage to the locust in its “struggle for existence” 
and is technically known as protective resemblance (see Chapter XVII). No 
locusts show this protective resemblance better : , 
than the species of Trimerotropis (Fig. 193) \ f 
especially familiar in the western states. The | 
colors of various individuals of a single species 
vary with the soil colors of the locality, ranging 
from whitish to 
brownish to — slaty 
and bluish. I have 
taken series of spe- 


cimens of Tvrimero- ¢ 
tro pis sp. in Colorado 
showing this whole 
range of ground 
coloration. 


4 * 
N 


Fic. 192. Fic. 193. 
Fic, 192.—Mestobregma cincta, male. (After Lugger; natural size indicated by line.) 
Fic. 193.—The maritime locust, Trimerotropis maritima, female. (After Lugger; nat- 
ural size indicated by line.) 

The subfamily Tettigine includes the strange little Acridiids known as 
“grouse-locusts.”” They are all under 3 inch in length, and most of 
them are less than 4 inch. They have the wing-covers reduced to mere 
scales, but the pronotum is so long that it extends back over the rest of the 


148 Cockroaches, Locusts, Grasshoppers, and Crickets 


thorax to the abdomen and more or less covers it. In some species the 
pronotum actually extends beyond the tip of the abdomen. The head is 
deeply set in the prothorax, the prosternum being expanded into a broad 
border which nearly covers the mouth. As all the grouse-locusts are dark- 
colored and without any conspicuous markings, and choose for habitat the 
dark ground along streams and ponds, or swampy meadows, they are 


FIG. 194. FiG. 195. Fic. 196, 


Fic. 194.—Nomotettix parvus. (After Lugger; natural size indicated by line.) 

Fic. 195.—Tettigidea lateralis. (After Lugger; natural size indicated by line.) 

Fic. 196.—Tettix granulatus, and pronota of two varieties. (After Lugger; natural size 
indicated by line.) 


infrequently seen except by persistent students. They vary much in colora- 
tion and slight markings, and harmonize thoroughly with the soil on which 
they habitually live. They feed on lichens, moulds, germinating seeds, 
and sprouting grasses, and are said to eat 
surface mud and muck containing or largely 
consisting of decaying vegetable matter. The 
eggs are laid in a pear-shaped mass in a 
shallow burrow; in May and June the young 
hatch in from sixteen to twenty-five days, 
becoming mature in late fall, or sometimes 
not until the following spring. The nymphs 
and adults hibernate, becoming active again 
early in spring. A common species is Teltix 
Fie! 107. a. an granulatus (Fig. 196), slender, length about 
Fic. 197.—Tettix ornatus. (After % inch, and with the narrow pointed pronotum 
Lugger; natural size indicated extending beyond the abdomen. ‘This species 
ay a te nia hibernates among rubbish and loose bark, but 
(After Lugger; natural size is more or less active on warm winter days. 
indicated by line.) It is plentiful all through the rest of the year 
on its feeding-grounds. 7. ornatus (Fig. 197) is a shorter, more robust 
species, and is marked with black spots and indefinite yellow blotches as 


Cockroaches, Locusts, Grasshoppers, and Crickets 149 


indicated in the figure. In the genus Tettigidea the antenne have from 
15 to 22 segments, while in Tettix they have only 12 to 14 segments. Tet- 
tigidea lateralis (Fig. 195) is a common spécies yellowish brown in color, 
more yellowish underneath. It is rather robust and the pronotum extends 
beyond the tip of the abdomen. 

Included in the family Locustide are katydids, meadow grasshoppers, 
cave-crickets, wingless crickets, western crickets, Jerusalem crickets, and 
what not, but no locusts. The general reader of natural history should 
always keep clearly in mind the 
sharp distinction made by natu- 
ralists between “‘scientific’” and 
“vernacular” names. ‘The ver- 
nacular name locust is applied 
to insects of the family Acri- 
diide, but not to any of the 
members of the. family whose 
scientific name is Locustide. 
Of the Locustids the best 
known representatives are un- 
doubtedly the katydids. Anna 
Botsford Comstock, the nature- 
study teacher of Cornell Uni- 
versity, introduces them to her 
readers as follows: ‘‘The 
chances are that he who lies 
awake of a midsummer night 
must listen, whether he wishes 
to do so or not, to an oft- 
repeated, rasping song that 
says, ‘Katy did, Katy did; she 
did, she didn’t,’ over and over 
again. There is no use of won- 
dering what Katy did or didn’t 
do, for no mortal will ever 
know. If, when the dawn 
comes, the listener has eyes Fic. 199.—Broad-winged katydid, and leaf with 
sharp enough to discern one of katydid eggs along edge. (Natural size.) 
these singers among the leaves of some neighboring tree, never a note of 
explanation will he get. The beautiful, finely veined wings folded close 
over the body keep the secret hidden, and the long antennz, looking like 
threads of living silk, will wave airily above the droll green eyes as much 
as to say, ‘Wouldn’t you like to know?’” 


150 Cockroaches, Locusts, Grasshoppers, and Crickets 


The katydids are rather large, almost always green insects that live in 
trees and shrubs, where they feed upon the leaves and tender twigs, some- 
times doing considerable injury. With almost all the other Locustids, 
they will also take animal food if accessible, and some of the ground- 
inhabiting forms undoubtedly depend largely on animal substances for 
food. The color and form of the wing-covers and body serve to make them 
nearly indistinguishable in the foliage, and as they do not flock together 
in numbers, they are not frequently seen. Their love-calls or songs, how- 
ever, make the welkin ring at night from 
midsummer until the coming of frost. Few 
katydids sing by day: it would bring their 
enemies, the birds, down on them; but as 
twilight approaches, the males begin their 
shrilling, which is kept up almost constantly 
till daylight. Like the sound-making Acri- 
diids the musical Locustids have a pair of 
special auditory organs, or ears, for hearing 
these love-songs. ‘These ears are tympanal 
organs situated one in the base of each fore 
tibia (the Acridiid ears are on the upper 
part of the first abdominal segment), and 
consist of a thin place in the chitinized 
body-wall (the tympanum), a resonance- 
chamber inside, and a special arrangement 
of nerves and ganglia. There are several 
genera of these Locustids, corresponding to 
the distinctions popularly made under the 
vernacular names narrow-winged, round- 
winged, angular-winged, oblong leaf-winged, 
and broad-winged katydids. The true 
katydid is one of the last-named forms, 
Fic. 200.—Broad-winged katydid, the commonest and most wide-spread species 

Cyrtophyllus concavus, male. being Crytophyllus concavus (Fig. 200). 
(After Harris; natural size.) ; 5 : 

It is bright dark-green, and is rarely 
distinguished when at rest in the foliage, although familiar to all from its 
shrill singing. When specimens of katydids are collected and examined, 
concavus may be readily distinguished by the fact that its wings are shorter 
than the wing-covers, and these latter are very convex and so curved around 
the body that their edges meet above and below. ‘The ovipositor of the 
female is short, compressed, slightly curved and pointed. This katydid 
is most in evidence in late summer. People disagree about the melody 
and alleged charm of the song. Many cannot distinguish the ‘‘katydid” 


Cockroaches, Locusts, Grasshoppers, and Crickets 151 


syllables, and Scudder, an experienced student of the Orthoptera, says that 
the note, which sounds like xr, has a shocking lack of melody, adding that 
the poets who have sung its praises must have heard 
it at the distance that lends enchantment. The sounds 
are made by the males exclusively, and result from 
the rubbing together of the bases of the wing-covers, 
which have the veins and membrane specially modified 
for this purpose (see Fig. 201). Concavus lays, in the 
autumn, flattened dark slate-colored eggs, about $ inch 
long and one-third as wide, in two rows along a twig, 
the eggs overlapping a little. These eggs hatch in the 
following spring, and the young, like the adults, feed price BOT eC IAOP BD 
“ Us CONCAVUS Sp. 
on the foliage of the tree. 

The oblong leaf-winged and round-winged katydids belong to the genus 
Amblycorypha, and they can be readily recognized by the broad, oblong, 
and rounded wing-covers, and the strongly curved ovipositor of the female, 
with serrated tip. They are grass-green and have the wings longer than 
the wing-covers. The oblong leaf-winged species, A. oblongifolia (Fig. 202), 
is 2 inches long to tips of folded 
wings, while the round - winged 
species, A. rotundifolia, is 14 in- 
ches or less in length. These 
katydids prefer bushes and tall 
weeds or even grass-clumps to 
tree-tops. Oblongifolia is said by 
x McNeill to make a ‘“‘quick shuf- 

Say 6 ~ fling sound which resembles 
Fic. 202. — The oblong leaf-winged katydid, ‘katy’ or ‘katydid’ very slight- 


Amblycorypha oblongifolia, female. (After 
Lugger; natural size.) 


ly,” while the song of rotun- 
difolia is said by Scudder to be 
made both day and night without variation and to consist of two to four 
notes, sounding like chic-a-chee, run together and repeated generally once 
in about five seconds for an indefinite length of time. 


Noas 


Fic. 203.—Angular-winged katydid, Microcentrum laurifolium, male. 
(After Riley; natural size.) 


The angular-winged katydids, genus Microcentrum, are large, numerous, 


152 Cockroaches, Locusts, Grasshoppers, and Crickets 


and the most familiarly known of all. The best-known species, M. retinervis, 
is over 2 inches long (from head to tip of folded wings); the overlapping 
dorsal parts of the wing-covers form a conspicuous angle with the lateral 
parts, hence the name “‘angular-winged.”” The ovipositor of the female is 
very short, strongly curved, and with a bluntly pointed, finely serrate tip. The 
song of M. laurijolium (Fig. 203) is said to sound like tic repeated from 
eight to twenty times, at the rate of foura second. The eggs, of which each 
female lays from roo to 150 in the fall, are grayish brown, flat, and long- 
oval, about } inch long by $ inch wide, and are glued in double rows along 
twigs or on the edges of leaves (Fig. 199). I have found them on thorns 
of the honey-locust, and Howard once received ‘‘a batch from a western 
correspondent which was found on the edge of a freshly laundried collar 
which had lain for some time in a bureau drawer.’’ The rows are side by 
side, and the flat eggs overlap each other in their own row. The young 
hatch in spring and, slowly growing, moulting, and developing wings, reach 
full size and maturity by the middle of the summer. 


FIG. 2044. Fic. 2040. 
Fic. 204a.—The fork-tailed katydid, Scudderia jurcata, female. (After Lugger; nat. size.) 


Fic. 2046.—The fork-tailed katydid, Scudderia jurcata, male. (After Lugger; nat. size.) 

The narrow-winged katydids, belonging to the genus Scudderia (Figs. 204— 
206), are smaller than the broader-winged kinds, being not more than 14 
inches in length to tip of folded wing-covers, and the wing-covers are narrow 
and of nearly equal width for their whole length. The ovipositor is broad, 


FIG. 205. Fic. 206. 
Fic. 205.—Scudderia pistillata, female. (After Lugger; natural size.) 


Fic. 206.—Scudderia pistillata, male. (After Lugger; natural size.) 


compressed, and curves sharply upward. These insects frequent shrubbery 
and bushes, or coarse grasses and weeds along ravines or ponds; also 
marshes, cranberry-bogs, and similar wet places. Their flight is noiseless 


Cockroaches, Locusts, Grasshoppers, and Crickets 153 


and zigzag, and when pursued they will take to the lower branches of trees, 
especially oaks if near by. The males sing somewhat in daytime as well 
as at night, and have different calls for the two times. The females lay 
their eggs in the edges of leaves, thrusting them in between the upper and 
lower cuticle by means of their flattened and pointed ovipositor. 

While almost all katydids are green, a few exceptions are known. 
Scudder has found certain pink individuals belonging to a species normally 
green. In mountain regions a few species of gray- or granite-colored katy- 


Fic. 207.—The sword-bearer, Conocephalus ensiger, female. (After Lugger; nat. size.) 


dids are known, the color here being quite as protective as the green of the 
lowland forms, for these mountain species alight to rest on the granite rocks 
of the mountainside. I have found these granite katydids in the Sierra 
Nevada of California. 


Fic. 208. FIG. 209. 
Fic. 208.—The sword-bearer, Conocephalus ensiger, male. (After Lugger; nat. size.) 
Fic. 209.—A common meadow grasshopper, Orchelimum vulgare, female. (After 
Lugger; natural size indicated by line.) 


The meadow grasshoppers are small, katydid-like Locustids, green and 
long-winged, with long, slender hind legs and with the characteristic slender 
thread-like antenne longer than the body. These antenne readily distinguish 
them from any of the locusts (Acridiide) which may be found in their com- 
pany. The meadow green grasshoppers abound in pastures and meadows, 


154 Cockroaches, Locusts, Grasshoppers, and Crickets 


and they dislike to take to wing, trusting, when alarmed, to spry leaping or 
clever wriggling away and hiding among the lush grasses. Their green 
color of course aids very much in protecting them from enemies. They 
include three common genera, viz.: 
Conocephalus (Figs. 207 and 208), or 
cone-headed grasshoppers or sword- 
bearers with head produced into a 
long, pointed, forward-projecting, cone- 
like process, slender body, and very 
Fic. 210.—A common meadow grasshop- long, slender, straight or angled, sword- 

per, Orchelimum vulgare, male. (After like ovipositor; Orchelimum (Figs. 209 

Lugger; natural size indicated by line.) and 210), the stout meadow grasshop- 
pers, with blunt head, robust body, and short, slightly curved ovipositor; 
and Xiphidium (Fig. 211), the slender or lance-tailed meadow grasshoppers, 
with blunt head, small and slender, graceful body, and nearly straight, 
slender ovipositor, sometimes larger than the body. The eggs of all these 


Fic. 211.—The lance-tailed grasshopper, Xiphidium attenuatum, female. 
(After Lugger; natural size indicated by line.) 


are laid usually in the stems or root-leaves of grasses, or the pith of twigs. 
The color is usually green, but a few are light reddish brown. The song 
of the males is faint and soft, and is made by day as much as by night. 


FIG. 212. Fic. 213. 
Fic. 212.—Udeopsylla robusta, female. (After Lugger; nat. size indicated by line.) 
Fic. 213.—The spotted wingless grasshopper, Ceutophilus maculatus, female. (After 
Lugger; natural size indicated by line.) 


The family Locustide includes numerous wingless forms, some with 
no remaining trace of wing-covers or wings, some with rudimentary or scale- 


Cockroaches, Locusts, Grasshoppers, and Crickets 155 


like remnants of wing-covers. These latter kinds can sing because the parts 
retained are the sound-producing bases of the wing-covers. The genus 


Fic. 214.—Diestrammena marmorata, male; a Japanese locust species found in Minnesota. 
(After Lugger; natural size.) 


Ceuthophilus (Figs. 213 and 215) includes the various species of stone, 
or camel, crickets found all over the country, recognizable by their thick, 


Fic. 215.—Ceuthophilus lapidicolus, female. (After Lugger; natural size 
indicated by line.) 


smooth, wholly wingless, brownish body with arched back and head bent 
downwards and backwards between the front legs. They are nocturnal, 


Fic. 216. FIG. 217. 


Fic. 216.—The shield-backed grasshopper, Atlanticus pachymerus, male. (After Lug- 
ger; natural size indicated by line.) 

Fic. 217.—The California shield-backed grasshopper, Tropizaspis sp., female. (Nat. size ) 

and during the day hide under stones or logs along streams or in damp woods. 

The individuals of a species which live in the burrows of certain turtles in 

Florida are called “gophers.” Perhaps the commonest species, extending 

from New England to the Rocky Mountains, is the “spotted wingless grass- 


156 Cockroaches, Locusts, Grasshoppers, and Crickets 


hopper,’ C. maculatus (Fig. 213), with sooty brown body dotted with 
pale spots. Some of the wingless Locustids are found in caves, and these 
are either blind or have the eyes much reduced. One of these cave-crickets, 
Hadenucus subterraneus, is common in the larger caves of Kentucky, where 
it may be found creeping about on the walls. Garman states that it speedily 
dies when removed from the cave. The genus Atlanticus comprises dull- 


Fic. 218.—The western cricket, Anabrus purpurascens, male. (After Lugger; nat. size.) 


. 


colored species with the pronotum extending like a shield back over the 
base of the abdomen, and although the hind wings are wanting, rudimentary 
wing-covers are present, and in the males carry a circular stridulating organ. 
These are called ‘“‘shield-backed grasshoppers” 
and are to be found in dry upland woods and on 
sloping hillsides with sunny exposure. The two 
common species in the East and the Mississippi 
Valley are A. dorsalis, with pronotum well rounded 
behind, and A. pachymerus (Fig. 216), with pro- 
notum nearly square. 

A genus similar to Atlanticus found commonly 
in California is Tropizaspis (Fig. 217), the males 


ys 


Lip 
SE 
aN a" 
a 


FIG. 219. Fic. 220. 
Fic. 219.—The western cricket, Anabrus purpurascens, female. (After Lugger; nat- 
ural size.) 


Fic. 220.—The Jerusalem cricket, Stenopelmatus sp. (Natural size.) 


Cockroaches, Locusts, Grasshoppers, and Crickets 157 


of which sing very pleasantly. In Idaho and other northwestern states 
a large corpulent wingless Locustid, called the western cricket, Anabrus 
purpurascens (Figs. 218 and 219), often occurs in 
such numbers as to be very destructive to crops. 
The body of this cricket is 14 inches long and 
% inch thick. The ovipositor is three-fourths as 
long as the body, slightly curved, and sword-shaped 
with a sharp point. This species forms march- 
ing armies in Nevada, with two miles of front and 
a thousand feet of depth. On the Pacific Coast 
occurs a large, awkward, thick-legged, transversely 
striped form, Stenopelmatus, called sand-cricket or 
Jerusalem cricket (Fig. 220). It is found under 
stones or in the soil, has a large smooth head with 
“Dbaby-face,” and is believed to feed on dead plant 
or animal matter. 

The crickets that we know best are the black 
and brown ones of the house and the fields; but 
there are members of the cricket family, the Gryl- 
lide, that live in trees and are pale greenish white, Fy¢. 221. — A common 
and others that burrow into the ground and have “ticket, Gryllus pennsyl- 
broad shovel-like fore feet, and still other curious st Ae er a 

’ ugger; natural size in- 
little wingless pygmies that live as guests in ants’ dicated by line.) 
nests. But the house- and field-crickets represent the more usual or we 
might say normal and typical kind of Gryllid; 
the others are modifications or offshoots of this 
type, both in habit and structure. In all the 
antenne are long and slender (except in the 
burrowing forms, longer than the body), the hind 
legs long and thickened for leaping, and the 
ovipositor, when exserted and visible, long, slender, 
subcylindrical and lance- or spear-like. Well- 
developed wings and wing-covers are present in 
most species, and the males are provided with a 
very effective stridulating organ on the bases of 


-— 


Fic. 222.—Cricket and file the wing-covers. 


(part of the sound-making In the familiar black, bright-eyed, loud-voiced 
apparatus). (Cricket nat- i eae Ree NORRIS 

ural size; the file greatly house- and field-crickets the wing-covers when 
magnified.) folded on the body are flat above and bent down 


sharply at the edge of the body like a box-cover, and the veins in the males 
are curicusly changed in course and specially thickened and roughened 
to make a sound-producing organ. ‘This organ is illustrated in Fig. 222. 


158 Cockroaches, Locusts, Grasshoppers, and Crickets 


To sing, the males lift their wing-covers at an angle of about 45° over the 
back, and strongly rub together the bases. Their chirping is made either 
in the daytime or night, and is a love call or song for their mates. We have 
several common crickets in dweliings, one, Gryllus domesticus (Fig. 223), 
being the European house-cricket, the “cricket on the 
hearth,” which is becoming at home here, being espe- 
cially met With in Canada. It is pale brown and less 
than an inch long. Gryllus luctuosus and G. assimilis 
are two native crickets which are common in houses; 
they are black with brownish-black wing-covers, larger 
and mpre robust than domesticus, and with the folded 
wings projecting backward beyond the wing-covers like 
pointed tails. ‘These house-crickets are most active 
at night, and seem to have a taste for almost any 
food-product in the house. They will eat each other 
when other food is scarce. If they become so nu- 
merous in the house that they need to be got rid of, 
advantage may be taken of their liking for sweet 
liquids by exposing smooth-walled vessels half filled 
Fig) aq he eine with such liquids, into which the crickets will fall and 

pean house -cricket, drown in their attempts to get at the food. The most 

ee ves (Amer ae abundant and wide-spread outdoors cricket is Gryllus 

ger; natural size in- abbreviatus (Fig. 224), the short-winged field-cricket. 

dicated by line.) The wings are sometimes wanting, but more often pres- 
ent and shorter than the wing-covers, which in the females are themselves 
unusually short, reaching but half-way to the end of the abdomen. The 
slender ovipositor is as long as the 
body, and the hind femora are very 
thick and have a red spot at the 
base on either side. The life-history 
of this common insect is not yet fully 
known, some writers stating that the 
eggs laid in autumn do not hatch until 
the following spring, the insect thus 


passing the winter in the egg stage, Fic. 224.—The short-winged cricket, Gryllus 
while others have taken half-grown abbreviatus. (Natural size.) 

young from beneath logs in late autumn and in midwinter. The field- 
cricket is “nocturnal, omnivorous, and a cannibal. Avoiding the light 
of day,” says Blatchley, “he ventures forth as soon as darkness has fallen, 
in search of food, and all appears to be fish which comes to his net. Of 
fruit, vegetables, grass, and carrion he seems equally fond, and does not 


Cockroaches, Locusts, Grasshoppers, and Crickets 159 


hesitate to prey upon a weaker brother when opportunity offers. I have 
often surprised them feasting on the bodies of their com- 
panions; and of about forty imprisoned together in a 
box, at the end of a week but six were living. The 
heads, wings, and legs of their dead companions were all 
that remained to show that the weaker had succumbed 
to the stronger—that the fittest, and in this case the 
fattest, had survived in the deadly struggle for existence.” 

These crickets live in cracks in the soil, or under 
stones or logs, or sometimes make burrows. 

The genus Nemobius contains a number of little 
crickets known as “striped ground-crickets,’’ which are 
less than half an inch long, are dusky brownish with hairy 
head and thorax, and have faint blackish longitudinal 
stripes on the head. ‘Unlike their larger cousins, the 
field-crickets, they do not wait for darkness before seek- 
ing their food, but wherever the grass has been cropped 
short, whether on shaded hillside in the full glare of Se Ue 

striped ground - 
the noonday sun along the beaten roadway, mature speci- cricket, Nemobius 
mens may be seen by hundreds during the days of early arg a 
autumn.” They are powerful jumpers and readily evade Lugger; about 
attempts to capture them. They feed on living vegetation twice natural size.) 
and on all kinds of decaying animal matter, and because of 
their abundance and voracious appetite must do much 
damage at times. Scudder gives the following account of 
the singing of the wingless striped cricket, Nemobius vittatus 
(Fig. 225), our commonest species: “The chirping of the 
striped cricket is very similar to that of the black field-cricket, 
and may be expressed by r-r-r-u, pronounced as though it 
were a French word. ‘The note is trilled forcibly, and lasts 
a variable length of time. One of these insects was once 


Fic. 226.— The observed while singing to its mate. At first the song was 
Snowy tree- 
cricket, Gican- : ; 
thus niveus. forcible, and more prolonged; then it decreased in volume 


(Natural size.) and extent until it became quite soft and feeble. At this 
point the male began to approach 
the female, uttering a series of 
twittering chirps; the female ran 
away, and the male, after a short 
chase, returned to his old haunt, 
singing with the same vigor, but I 


mild and frequently broken; afterwards it grew impetuous, 


2 


7.—CEcanthus fasciatus, female. (After 
uugger; natural size indicated by line.) 


oN 


160 Cockroaches, Locusts, Grasshoppers, and Crickets 


with more frequent pauses. At length finding all persuasions unavailing, he 
brought his serenade to a close.” 

From midsummer till frost comes there is a shrill insistent night-song 
that makes familiar an insect rarely seen except by persistent students. 
T-r-r—r-e-e; t-r-r—r-e-e, repeated without pause or variation about seventy 
times a minute: this is the song of the snowy tree-cricket, or white climbing 
cricket, Ccantheus niveus (Fig. 226), common all through the East and 
Middle West. These crickets differ much from the better known robust, 
black-brown house- and field-crickets in shape and color; the body is 
about one-half inch long, slender, and the long wing-covers are so held, 
when the insect is at rest, that the back (including the wing-covers) is widest 
behind and tapers forward to the 
small narrow head. The body is 
ivory-white tinged with delicate 
green, and the wing-covers and 
wings are clear. The antenne are 
extremely long and thread-like and 
have two slightly elevated black 
dots on the under side, one on the 
first segment and one on the second. 
The females do much harm by 
their habit of cutting slits in the 
tender canes or shoots of raspberry, 
grape, plum, peach, for their eggs. 
The cane or shoot often breaks off 
at the place where the eggs are 
deposited, and by collecting these 
in the late autumn or winter and 
burning them many eggs will be 


Fic. 228. FIG. 229. 
Fic. 228.—(icanthus fasciatus, male. (After 
Lugger; natural size indicated by line.) , 
Fic. 229.—Orocharis saltator, female. (After destroyed. Several other species 


Lugger; natural size indicated by line.) of Gcanthis are) found ano tne 


country; one, O. fasciatus (Figs. 227 and 228), with three black stripes on 
head and prothorax and usually dark body, is common in the Mississippi 
Valley, and a third species, O. angustipennis, with wing-covers just one- 
third as wide in broadest part as their length, is less common. 
Occasionally one finds on the ground, or more likely in digging, a curious 
flattened, light velvety brown insect about an inch and a half long, with 
the fore feet much widened and strangely resembling those of the common 
mole, and altogether having an appearance strange and unlike that of any 
other insect. This is a burrowing, or mole, cricket, which burrows beneath 
the soil in search of such food as the tender roots of plants, earthworms, 
and the larve of various insects. Its eyes are also like those of the mole, 


Cockroaches, Locusts, Grasshoppers, and Crickets 161 


much reduced, being nearly lost, and as this cricket crawls rather than 
leaps, the hind or leaping legs are not so disproportionately larger than the 
others as in the above-ground crickets. The males make a sharp chirping 
loud enough to be heard several rods away. The common species, called 
the northern mole-cricket, Gryllotalpa borealis, has the wing-covers less than 
half the length of the abdomen, while the wings extend 
only about one-sixth of an inch beyond them. A less 
common species, G. columbia, the long-winged mole- 
cricket, has the hind wings extending beyond the 
tip of the abdomen. The mole-crickets like rather 
damp places near ponds or streams, where they make 
channels with raised ridges which resemble miniature 
mole-hills. These ‘‘runs”’ usually end beneath a stone 
or small stick. The insects are infrequently seen, as 
they remain mostly underground, only occasionally 
coming out at night. The female deposits from two 
hundred to three hundred eggs in masses of from 
forty to sixty in underground chambers, and the young 
are about three years in reaching maturity. When 
present in any region in large numbers mole-crickets Fic. 230.—The Porto 
become seriously destructive because of their attacks ae dae 
on plant-roots. In Porto Rico a mole-cricket, Scap- lus. (After Barrett; 
teriscus didactylus (Fig. 230), called “changa,” dam- tural size.) 

ages tobacco, sugar-cane, and small crops to the value of more than 
$100,000 annually and is by far the most serious insect 
pest in the island. 

Much smaller than the true mole-crickets are the 
pygmy, burrowing crickets of the genus Tridactylus, 
of which several species occur in the United States. 
The largest species, 7. apicalis (Fig. 231), is about 
4 inch long. They resemble the mole-crickets in general 
body characters, but are more brightly colored, and the 
fore feet, although broad and flat for digging, differ in 
being curiously armed at the end with three spurs; hence 


eee arte: the generic name. They can leap amazingly, so that 
Lugeer; naturalsize they seem, on jumping, to disappear most mysteriously, 
indicated by line.) _ the eye not being able to follow them in the air. 

The most aberrant of all the crickets are the tiny flat and broad-bodied 
species of the genus Myrmecophila, which live as commensals or mess- 
mates in the nests of ants. They are found only in ants’ nests, have no 
compound eyes, and the hind femora are much swollen and enlarged. 


162 Cockroaches, Locusts, Grasshoppers, and Crickets 


The semi-parasitic life which they lead has resulted in such a change of 
habits that their body is modified very far from the normal cricket type. 
The commonest species is Myrmecophila nebrascensis, about '5 inch long, 
shown in Fig. 232. 

Formerly included in the order Orthoptera, the earwigs are now recog- 
nized as entitled to distinct ordinal rank, and the thirty or more genera in 
the world, of which but six occur in the United States, 
are held to constitute the order Euplexoptera. This 
order is closely related to the Orthoptera, although the 
insects themselves look more like beetles. 

The earwigs are small, brownish or blackish insects, 
readily recognized by the curious forceps-like appendages 
on the tip of the abdomen (Fig. 233). They are either 
winged or wingless, but when winged have small leath- 
ery wing-covers only extending about half-way to the 
= tip of the abdomen, with the well-developed nearly 

IG. 232.—Myrme- ; 3 > ; 5 
cophila nebrascensis, a hemispherical wings compactly folded, both longitudi- 
degenerate cricket nally and transversely, underneath them. Earwigs are 
that inhabits ants A 5 
nests. (Five times NOt often seen because they are nocturnal in habit, 
natural size.) but in some places they are rather abundant. They 
are vegetable feeders, being especially fond of ripe fruit, flower corollas, etc., 
which they bite off and chew with the well-developed jaws and maxille. 
The female lays her small, yellowish oval eggs in 
small masses under fallen leaves or in other con- 
cealed places, and is said to nestle on them as a 
hen on her eggs. She is also said to protect the 
young for some time after they are hatched. The 
young undergo an incomplete metamorphosis, de- 
veloping wings externally, and resembling the 
parents, except in size, from the time of their 


hatching. J , Fic. 233.— An_ earwig, 
The commonest representative of the orderin the Labia minor. (Six times 


northern and eastern states is the little earwig, natural size.) 

Labia minor (Fig. 233), measuring to tip of forceps only about } inch. 
Other American species, as Labidura riparia, a Florida species, brownish 
yellow with a pair of longitudinal black stripes on prothorax and wing- 
covers, with long slender forceps, and Anisolabis annulipes, a black wingless 
California species with short heavy forceps, are larger, these two species 
being a little more and a little less than ? inch respectively. 


CHAPTER X 


THE TRUE BUGS, CICADAS, APHIDS, SCALE- 
INSECTS, ETC. (Order Hemiptera), AND THE 
THRIPS (Order Thysanoptera) 


Z HEN an Englishman says ‘“bug’?—and 
he doesn’t say it in polite society—he 
means that particular sort of bug which 


we more specifically speak of as bedbug; 
when we say “bug” we are likely to mean any insect 
of any order; but when a professed student of insects, 
an entomologist, says or writes bug, he means some 
member of the insect order Hemiptera. It is to this 
order of ‘‘bugs”’ that we have now come in our system- 
atic consideration of insects, and it is in this order that 
we first meet conspicuously the difficulties of treating 
systematically the populous insect class. From now 
on the making of this book useful depends on the discriminating selection 
of the few kinds of insects whose special consideration the limits of 
text and illustration permit, leaving the great majority of species to be 
referred to comprehensively and vaguely as the “others.” 

The Hemiptera, or true bugs, make up a large order compared with any 
of those so far considered, although a smaller one than certain others yet to be 
taken up. As regards popular acquaintanceship and interest also this 
order is still more inferior to the other large ones, namely, the beetles, the 
moths and butterflies, the two-winged flies, and the ants, bees, and wasps. 
Most of the true bugs are small, and obscurely, or at least inconspicuously, 
colored, and few of them attract that attention necessary to gain popular 
interest. 

The order Hemiptera includes over 5000 known species of North 
American insects, representing a large variety and a great economic impor- 
tance; some of the most destructive crop pests and most discomforting insect- 
scourges of man and the domestic animals belong to this order. The 
chinch-bug’s ravages in the corn- and wheat-fields of the Mississippi Valley 
offer effective evidence to the dismayed farmers of the workings of a dis- 
pleased Providence; the tiny sap-sucking aphids and phylloxera and insig- 
163 


164 Bugs, Cicadas, Aphids, and Scale-insects 
nificant-looking scale-insects make the orchardist and vine-grower similar 
believers in supernatural moral correction by means of insect-scourges, 
and the piercing and sucking lice and bugs—in the English meaning—make 
personal and domestic cleanliness a virtue that brings its own immediate 
reward. 

Other not unfamiliar representatives of this order are the loud-singing 
cicadas with their extraordinarily protracted adolescence, the thin-legged 
water-striders and skaters of the surface of pond and quiet trout-pool, the 
oar-legged water-boatmen and back-swimmers of the depths of the same 
pools, the ill-smelling squash-bugs, calico-backs, and stink-bugs of the 
kitchen-gardens, the big, flat-bodied, electric-light or giant water-bugs that 
whirl like bats around the outdoor arc-lights, 
and the assassin- and ‘‘kissing’’-bugs of one- 
time newspaper interest. In structure all the 
Hemiptera agree in having the mouth-parts 
formed into a piercing and sucking beak (Fig. 
234) capable of taking only liquid food. As 
that food is nearly always the blood of living 
animals or the sap of living plants, the nearly 
uniformly injurious or distressing character of 
the food-habits of all the members of the 
order is apparent. This beak is composed 
of the elongate, tubular under-lip (labium) 
acting as sheath for the four slender, needle- 
like piercing stylets (modified mandibles and 
maxilla). The labium is not a perfect tube, 
for it is narrowly open all along its dorso- 
medial line, but the edges of this slit can be 
brought closely together and the slit also 
covered internally by the stylets, so that an 


Fic. 234.—Diagram of section 
through head and basal part 
of beak of a sucking-bug. 
ph., pharynx; m., muscles 
from pharynx to dorsal wall 
of head; v., valve; s., stop- 
per; m., muscle of stopper; 
s.d., salivary duct; Z/r., la- 
brum; 6., one of the stylets 
of beak. To pump fluid up 
through the beak, the mus- 


cle attached to the stopper 
contracts, thus expanding the 
cavity closed by the valve. 
(After Leon.) 


effective tubular sucking proboscis is formed 
(Fig. 14). The name Hemiptera is derived from 
the character of the fore wings shown by most, 


though by no means all, of the members of the 
order; this is the thickening of the basal half of the otherwise thin, 
membranous wing, so that each fore wing is made up of two about equal 
parts of obviously different texture and appearance; hence “‘half-winged’’ 
(Fig. 268). All Hemiptera (excepting the male scale-insects) have an incom- 
plete metamorphosis, the young at birth resembling the parents in most essen- 
By steady growth, 
with repeated moultings and the gradual development of external wing- 
pads, the adult form is reached, without any of the marked changes apparent 


tial characteristics except size and the presence of wings. 


Bugs, Cicadas, Aphids, and Scale-insects 165 


in the insects of complete metamorphosis. With similar mouth-parts the 
young have, in most cases, similar feeding habits, preying on the same kinds 
of plants or animals that give nourishment to the parents. 

The extent of the injuries done by various members of this order to 
farm and orchard crops, to meadows and forests, and to our domestic 
animals is enormous. Of the other insects the order of beetles includes 
numerous crop pests, and the caterpillars of many moths and a few butter- 
flies do much damage; locusts have a healthy appetite for green things, 
and many kinds of flies could be lost to the world to our advantage, but 
perhaps no other order of insects has so large a proportion of its members 
in the category of insect pests. The single Hemipterous species, Blissus 
leucopterus, better known by its vernacular name of chinch-bug, causes 
an annual loss to grain of twenty millions of dollars; the grape phylloxera 
destroyed the vines on 3,000,000 acres of France’s choice vineyards; the 
San José scale has in the last ten years spread from California to every 
other state and territory of the United States and become a menace to the 
whole fruit-growing industry. So, despite their small size and their general 
unfamiliarity to laymen, the Hemiptera are found by economic entomologists, 
in their warfare against the insect-scourges of the country, to be one of the 
most formidable of all the insect orders. 

The classification of the Hemiptera into subgroups is a matter likely 
to prove difficult for the amateur and general collector. The order as repre- 
sented in our country includes thirty-nine families, and the structural char- 
acters separating some of these families are slight and not easily made out by 
untrained students. For the use, however, of readers of this book capable 
of using them, keys or tables of all the families of the Hemiptera are presented. 
For more general use, however, I shall try to arrange the families in groups 
depending on the habits and more obvious appearance and make-up of the 
insects, characteristics which may be readily noted. And this arrange- 
ment will not be less ‘‘scientific’’ than the arrangement in the key com- 
monly used by entomologists, as the latter is confessedly largely artificial 
and convenient rather than natural in its groupings. 

The order is separable into three primary natural groups or sub-orders 
as follows: 


Wingless forms, with a fleshy, unsegmented sucking-beak, living as parasites on 
manjand other mammals. 2... c 2 ese e eee wna wire meine enna = PARASITA. 
Winged, or sometimes wingless, but always with the beak segmented. 

Wings of the same texture throughout and usually held sloping or roof-like 
over the back and sides of the body; sucking-beak arising from the 
hinder part of the lower side of the head; tne head so closely joined 
to the prothorax that the bases of the fore legs touch the sides of the 
HEE! o5- Get ned na cog obese = FEO BOe Es SOOO SOc OOC oS ae HOMOPTERA, 


166 Bugs, Cicadas, Aphids, and Scale-insects 


Fore wings with basal half thickened and parchment-like, apical half thin 
and membranous; the four wings lying flat on the back when folded, 
the membranous tips overlapping; sucking-beak arising from the 
front part of head, and the head usually separated from the pro- 
thorax by a more or less distinct neck................ HETEROPTERA. 


Of these three suborders the Parasita, or sucking-lice, are degenerate 
wingless species and will be considered last. The Heteroptera include 
the so-called ‘‘true bugs” with fore wings thickened at base, and when 
folded lying flat on the back, as the squash-bug, chinch-bugs, and the great 
majority of the species in the order, while the Homoptera include the cicadas, 
the tree- and leaf-hoppers, the aphids or plant-lice, the mealy-winged flies, 
and the degenerate scale-insects. 


SUBORDER HOMOPTERA. 


Key To FAMILIES OF THE HOMOPTERA (INCLUDES BOTH NYMPHS AND ADULTS). 
(ADAPTED FROM WoopwoRTH.) 


Proboscis seeming to rise from the middle of the sternum, or proboscis wanting; insects 
less than } inch long. 
Hind femora much larger than other femora........ (Jumping plant-lice.) Psyiiipz. 
Hind femora not much larger than the others. 


Tegs long, and SlemGe rere reese ate tet etelel atte lteter (Plant-lice.) APHIDIIDA, 
Legs short, or wanting. } 
Feet of one joint, or wanting..........--........---- (Scale-insects.) Coccip&. 
IRA Ko) MAVEN Sos Soo re eadogAsOSehos osone (Mealy wings.) ALEYRODIDZ. 


Proboscis plainly arising from the head. 
With three ocelli, sometimes (nymphs) with large front tibia and no wings. 
(Cicadas.) CICADIDE. 
With two ocelli or none, and the front tibie not enlarged. 
Antenne inserted on head below the eyes.....-.-.- (Lantern-flies.) FULGORIDz. 
Antenne inserted in front of and between the eyes. 
Prothorax extending back over the abdomen. ...(Tree-hoppers.) MEMBRACID2. 
Prothorax not extending back over the abdomen. 
Hind tibia with few spines...............-.- (Spittle-insects.) CERCOPIDA. 
Hind tibe with two rows of spines.........-..--- (Leaf-hoppers.) JASSIDz&. 


Perhaps no other insect-species has any single characteristic of its life- 
history of the same interest as the extraordinarily long duration of the adoles- 
cence of the seventeen-year cicada. That a single one of the 300,000 and 
more known species of insects should have a period of development from 
egg to adult of more than sixteen years, while this period in all other insects 
varies from a few days to not more than three years—comparatively few 
insects live, all told, more than a year—is perhaps the most striking excep- 
tional fact in all insect biology. The other members of the family 
Cicadide, to which this insect belongs, have, as far as known, an immature 


Bugs, Cicadas, Aphids, and Scale-insects 167 


life of but one or two years. But few species of cicadas, dog-day locusts, 
harvest-flies, or lyremen, as they are variously called, occur in this country 
—they are more abundant in subtropic and tropic countries—but their 
large, robust, blunt-headed body, their shrill singing and their wide dis- 
tribution make them familiar insects. : 

In summer and fall the piercing, ' 
rhythmic buzzing of the cicadas comes 
from the trees from early morning 
till twilight. The song, unlike that 
of the katydids and tree-crickets, is 
hushed at night. The sound is made, 
not by a rasping together of wings 
or legs, but by stretching and relaxing 
a pair of corrugated tympana, or 
parchment-like membranes, by means 
of a muscle attached to the center 
of each; much, indeed, as a small 
boy makes music from the bottom of Fic. 235. — The seventeen-year cicada, 

5 : e Were 6 Cicada sepltendecim; specimen at left 

a tin pan with a string fastened to its yowing sound-making organ. .p., 
center. These sound-making organs _ ventral plate; 4, tympanum. (Natural 
of the cicadas, confined to the males— size.) 
“Happy is the cicada, since its wife has no voice,’ says Xenarchos—are 
situated in resonance-cavities or open boxes, furnished with other sym- 
pathetically vibrating membranes, at the base of the abdomen (Figs. 235 
and 236). The sound-chambers are incompletely closed (wholly open in the 
seventeen-year cicada) by a pair of semicircular 
disks, which are opened or shut by move- 
ments of the body so as to give the song a 
peculiar rhythmic increase and decrease of 
loudness. 

The cicada that is most familiar, and on hand 
every summer over most of the country, is the 
large (2 inches in length to tip of closed wings) 
u black and green dog-day harvest-fly, Cicada 
Fic. 236.—Diagram of section (fibicen. The life-history of this species is not 

of body of cicada, showing fully known, but the insect requires, accord- 

attachment of musclestoinner | 

surface of sound-making ing to Comstock, two years to become mature. 

organ. (Enlarged.) The really famous cicada is Cicada septen- 
decim, the seventeen-year locust, or periodical cicada (Fig. 235). It is 
about 1} inches jong, black, banded with red on the abdomen, and with 
bright red eyes and the veins of both wings red at the base and along the 
front margin. The females lay their eggs in early summer in slits which 


168 Bugs, Cicadas, Aphids, and Scale-insects 


they cut with the sharp ovipositor in the twigs of various trees, in this way 
often doing much damage to orchards and nurseries. The young hatch 
in about six weeks and drop to the ground, where they burrow down through 
cracks and begin their long underground life. They feed on the humus 
in the soil and, to some extent, on juiges sucked from the tree-roots. They 
grow slowly, moulting probably four or six times at intervals of from 
two years to four years. In spring or early summer of the seventeenth 
year (thirteenth in a race in the southern states) they come above ground, 
and, after hiding for a while under stones and sticks, crawl up on the trunks 
of trees and there moult for the last time, the winged adult emerging and 
soon flying into the tree-tops. The various broods or swarms in this country, 
about twenty in number, are known, and the territory occupied by each 
has been mapped, so that it is possible for entomologists to predict the 
appearance of a swarm of seventeen-year cicadas in a particular locality 
at a particular time. As all the members of one of these swarms issue in 
the same season, and indeed in the same month or fortnight, they usually 
attract much attention. The broods to issue in the next few years are the 
following: a large one in 1905 in the northern half of Illinois, eastern part 
of Iowa, southern part of Wisconsin, southern edge of Michigan, and northern 
and western edge of Indiana; a scattered one in 1906 ranging, not contin- 
uously, from Massachusetts south and west through Long Island, New 
Jersey, Pennsylvania, Maryland, West Virginia, Ohio, Indiana, Kentucky, 
Tennessee, North and South Carolina, and northern Georgia; and a large 
one in 1907, ranging from central Illinois south and east to the Gulf and 
Atlantic. 

A considerable number of small insects, often seed-like in shape, or 
with the thorax prolonged into odd horns, spines, or crests, are included 
in the families of tree-hoppers (Membracide) and lantern-flies (Fulgoride) 
(Fig. 237). Striking members, large and bright- 
colored, of this latter family are found in the 
South American tropics, but the North American 
‘ species are small, and are rarely seen or collected 
Fic.237.—A fulgorid, Stobera. by amateurs. Among the commonest of our forms 

tricarinata. (After Forbes; are the candle-heads, species of Scolops, small 
natural length + inch.) 3 Fae 
insects living on grass and herbage, with the head 
bearing a long slender upcurving projection. The tree-hoppers (Mem- 
bracidz) almost all suggest small angular brownish seeds or thorns in shape 
and color. The prothorax is sometimes widely expanded, sometimes 
lengthened so as to cover nearly the whole body, sometimes humped or 
crested, sometimes spined or pitted. The unusual form is probably pro- 
tective, making the insects simulate seeds or other plant structures. The 
species of Enchenopa (Fig. 239) are curiously horned. £. binotata is common 


Bugs, Cicadas, Aphids, and Scale-insects 169 


in the east. It is gregarious and is attended by ants which feed on a sweetish 
substance excreted by it. It lays its eggs in little white waxen frothy masses. 
A curiously pees form is Senilia camelas (Fig. 240). The best known 

and most injurious tree-hoppers are those 
of the genus Cerasa, of which the species 
C. bubalus, or buffalo tree-hopper (see initial 
letter of this chapter), injures fruit-trees 
both by piercing and sucking sap from 


Fic. 238. FIG. 239. Fic. 240. 


Fic. 238.—The black-backed tree-hopper, Arthasia galleata. (After Lugger; natural 
length } inch.) 

Fic. 239. wa tree-hopper, Enchenopa gracilis. (Three times natural size.) 

Fic. 240.—A tree-hopper, Senilia camelas. (Three times natural size.) 


them, and by making slits in the twigs to lay eggs in. It is about 4 inch 
long, light grass-green with whitish dots and a pale yellowish streak on 
each side. On the front there are two small sharp processes jutting out one 
on each side from the prothorax, and suggesting a pair of horns, hence 
the name. It is common on apple and many other trees from the middle 
of summer until late in the autumn. The eggs are laid in pairs of nearly 
parallel and slightly curved slits. The young hatch in the spring following 
egg-laying. 

Walking over our lawns or through pastures and meadows we often 
startle from the grass hundreds of small, usually greenish, little insects that 
leap or fly for a short distance, but soon settle again in the herbage. Nearly 
all these smill and active insects are sap-sucking leaf-hoppers, of the family 
Jasside, one of the largest and most injurious of the Hemipterous families. 
It is stated by careful students of these grass-pests that from nearly one- 
fourth to one-half of all the grass springing up annually is destroyed by 
leaf-hoppers. Professor Osborn estimates that over one million leaf-hoppers 
can and often do live on an acre of grass-covered ground. These insects 
are rarely more than 4 inch long, and most of them are nearer half of that. 
The body is more slender than in the tree-hoppers, and is usually widest 
across the prothorax or a little behind it, tapering back to the tip of the 
folded wings. The head is more or less triangular, as seen from above, 
and the face is oblique, sloping back to the base of the fore legs. The 
family is a large one, containing many species, of which several are well 


170 Bugs, Cicadas, Aphids, and Scale-insects 


known to economic entomologists as special pests of grasses, growing grain, 
grapes, roses, etc. The injury is caused by the draining away of the 
sap of the plant by the host of little sucking-beaks thrust into its leaves 
or stem. Among the notorious destructive species are the destructive leaf- 
hopper, Cicadula exitiosa, + inch long, brownish, which often injures 
seriously the winter wheat of the southern states. Also the various 
grape-leaf hoppers, which cause the leaves of grape-vines to wilt and turn 
brown and prevent the formation of full grapes; one 
of these, Erythroneura vitis, is about }¢ inch long, 
crossed by two blood-red bands and a third dusky 
one at the apex. I have seen millions of individuals 
of Erythroneura comes (Fig. 242) in the great 3300- 
acre vineyard of the Vina Ranch in the Sacramento 
Valley of California. These leaf-hoppers hibernate 
in the vineyard or about its edges under fallen 
leaves and rubbish. Probably the best remedy for 
them is to keep the vineyards as clean as possible, 
or at least to burn up in the winter any accumulated 
rubbish. The rose leaf-hop- 
per, Typhlocyba rose, is 
often abundant on _ rose- 
bushes, and also on apple- 
trees. The eggs are laid in 
the summer, and the young 
develop through the summer 


Fic. 241. Fic. 242. and fall, hibernating as 

Fic. 241.—The celery leaf-hopper, Cicadula 4-lineata. adults under leaves or rub- 
(After Lugger; natural size indicated by line.) : 

Fic. 242.—Two vine-hoppers, at left Erythroneura bish. A common leaf-hop- 
vulnerata, on right E. comes. (After Forbes; much per of grass-fields is Diedro- 
entarged.) cephala mollipes, + inch long, 

spindle-shaped, grass-green above, pale yellowish below, with black lines 

across the face and top of head, and the fore wings with bluish veins and 
yellowish edges. 

Occasionally one finds frothy, spittle-like masses adhering to the stems 
of weeds or shrubs in which may be found imbedded one or more odd- 
shaped, squat, slant-faced insects from 34; inch to } inch long (Fig. 243). 
These are the young—they have no wings, only wing-pads or, if very young, 
not even these—of the spittle-insects or frog-hoppers, family Cercopide. 
The spittle is a viscid fluid expelled from the alimentary canal of the insects, 
and beaten up into a froth by thé whisking about of the body. What 
advantage it is to the young insects is hard even to conjecture; it certainly is 
not known, The adult frog-hoppers—this name is derived from a popular 


Bugs, Cicadas, Aphids, and Scale-insects 171 


belief that the spittle is that of tree-frogs—are small flattish, brownish or 
grayish insects about 4 inch long which occasionally occur in sufficient 
numbers to do some injury to grapes, 
cranberries, or pasture grasses. A grape 
frog-hopper, Aphrophora 4-notata, has 
brown wing-covers with three blackish 
spots on each; another found on grapes 
in the east, A. signoreti, is tawny brown 
clouded with dull white and thickly dotted 
with black spots; the cranberry spittle- 
insect, Clastoplera proteus, which occurs 
on cranberries and blueberries in marshes, 
is black, with two yellow bands on top 
of the head, one in the thorax, two 
oblique stripes on the base of the fore 
wings, and a cross-bar near the tip; C. 
pini is a small shining black species with 
pale yellow head with black band at front 
margin, that occurs on the needles of 


pine-trees. 
: oe a : b s 
Looking like miniature cicadas, but Wie ase =sThe Gotlesect al ales 
belonging to a different family, and really phora, showing stages of froth 
more nearly related to the aphids or true production. (After Morse; en- 


plant-ice, are the Psyllide, or jumping larged.) 


plant-lice. They are not more than + inch long, their hind legs are 
enlarged for leaping, some of them exude honey-dew, as the true plant- 
lice and the scale-insects do, and some make galls on the wings of hack- 
berry and other trees. The best-known and most destructive member of 
the family is the pear-tree flea-louse, Psylla pyricola. This is a minute 
insect measuring only ;'; inch long to tip of folded wings, but it often occurs 
in such large numbers in pear-orchards in the northeastern and northern 
states as to destroy extensive orchards. The eggs are orange-yellow and 
laid on the leaves, each egg having a lash-like process projecting from it. 
The young is broad and flat and yellow in color, growing brownish as it 
grows older. The adults hibernate in crevices in the bark and come out 
in spring to lay their eggs. The pests can be killed by spraying the trees 
with kerosene emulsion (see p. 189), immediately after the leaves have 
expanded in the spring. 

A very important and very interesting family is that of the Aphidiide, 
the plant-lice or aphis-flies (Figs. 244 and 245). The species, of which 
there are many, are all small, } inch being a rarely attained maximum 
length. The most familiar representatives of the family are the tiny, 


172 Bugs, Cicadas, Aphids, and Scale-insects 


plump-bodied, pale-green insects, some with two pairs of long, delicate, 
transparent wings, some without wings, common on flowers in conserva- 
tories and gardens and known as ‘‘green fly.’’ Other often-noticed kinds 
are the cockscomb gall-louse of the elm and the “blights” of various foliage 
trees, as alder-blight, beech-blight, elm- 
blight, etc., these ‘‘blight”’ aphids all 
secreting conspicuous white woolly masses 
of wax and most of them also excreting 
honey-dew, which is conspicuous on the 
leaves and on the sidewalks under the 
trees. 
; Of more economic importance are 

Ln Tee ieee some of those plant-lice which infest 

migrant. (After Pergande; much crop-plants, the extraordinarily ruinous 

enlarged.) grape-phylloxera, for example, the apple- 
tree root-louse, and the woolly apple-aphis, the cherry-, plum-, and 
peach-aphids, the corn-root louse, the hop-louse, and the cabbage-aphis, 
turnip-louse, and other aphid pests of garden vegetables. All of these 
insects are minute soft-bodied defenceless creatures, which effect their great 
injuries to their host-plants by virtue 
of great numbers. Fitch, New York’s 
first state entomologist, estimated the 
number of cherry-aphids that were 
living at one time on a small young 
cherry-tree to be 12,000,000. Although 
uncounted millions of the toothsome 
juicy little aphid bodies are being con- Fic. 245.—The southern grain-louse, 
stantly eaten in spring and summer by eee eee eee ie 
eager predaceous insects, such as lady- nymph. (After Pergande; much en- 
bird beetles, certain syrphid-fly larve — !@rsed.) 
and aphis-lions (larva of lace-wing and hemerobius flies), just as constantly 
are new millions being produced by the fecund aphis mothers, most of the 
young being born alive and requiring but a few days to complete their 
growth and development, and to be ready to take up the production of 
young themselves. 

Professor Forbes has made an estimate of the rate of increase of the corn- 
root louse that shows this great fecundity. A single stem-mother of the 
corn-root aphis produces twelve to fifteen young that mature in a fortnight. 
“Supposing that all the plant-lice descending from a single female hatched 
from the egg in spring were to live and reproduce throughout the year, we 
should have coming from the egg the following spring nine and a half tril- 
lion young. As each plant-louse measures about 1.4 mm. in length and .93 


Bugs, Cicadas, Aphids, and Scale-insects 


ays 


mm. in width, an easy calculation shows that these conceivably possible de- 
scendants of a single female would, if closely placed end to end, form a proces- 


sion seven million eight hundred and fifty thousand 
miles in length; or they would make a belt or strip 
ten feet wide and two hundred and thirty miles long.” 

The remarkabie plasticity of the aphids as re- 
gards their possession or lack of wings and, on the 
physiological side, their reproduction agamically or 
sexually, introduces certain unusual conditions into 
their life-history. Although each species is likely 
to present idiosyncrasies of its own, a fair example 
of the course of aphid life through a season may 
be outlined as follows: In spring there hatch, from 
eggs which have been laid the fall before, wingless 
females, called stem-mothers, which produce young 
agamically (ie., from unfertilized eggs) either by 
giving birth to them in active free condition or by 
laying eggs. From these eggs hatch wingless females 
which produce in turn other agamic broods of wing- 
less females. But at any time in the course of these 
successive agamic generations either all or a part of 
the individuals of a brood may be winged, and these 
winged females fly away to other plants and there 
found new colonies which continue the series of 
agamic generation$®. But toward the end of the 
season, when the firstg@ld weather announces the 
approaching winter, broods, still parthenogenetically 
produced, of sexed individuals, both males and fe- 
males appear. “The males may be either winged 
or wingless, but these true females are always wing- 
less.’ These individuals mate, and each female 
produces a single large egg which passes over 
the winter to give birth in the following spring to a 
wingless stem-mother—that one which begins the 
spring series of parthenogenetic generations. 


Fic. 246.—Bodies of 
aphids which have been 
killed by Hymenopter- 
ous parasites, the adult 
parasitic flies having 
emerged from the small 
circular holes. (En- 


larged.) 


The unfertilized eggs, called 


pseud-ova, produced in numbers by the spring and summer agamic mothers 
(from which eggs the young frequently emerge while the eggs are still in the 
body of the mother) should not be confused with the single fertilized egg 


laid in the late fall by the mated females of the sexed generation. 


Although 


these two sorts of eggs are alike in their earliest stages in the ovaries of the 


females, differences very soon occur, the embryo in the pseud-ovum begin- 
ning to develop before the formation of its own egg is properly completed. 


174 Bugs, Cicadas, Aphids, and Scale-insects 


Characteristic variations in the general course are described later in 
connection with the accounts of the few particular aphid species for which 
we have place, but it should be kept in mind that considerable variations 
may occur in the case of a single species. Extrinsic influences, such as 
crowding a host-plant and hence the lessening of food, or an unusual 
humidity or lack of humidity, an early lowering of temperature in autumn, 
etc., seem to be very potent in producing or acting as effective stimuli for 
adaptive variations of the usual course of life. Slingerland reared ninety- 
four successive generations (in 
four years) of an aphid species 
in the insectary at Cornell 
University under such constant 
conditions of food-supply and 
summer temperature that not 
a single winged aphid nor single 
sexual generation was _ pro- 
duced. Even longer series of 
identical wingless agamic gen- 
erations have been obtained by 
certain European experiment- 
ers. Clarke, in California, has 
been able to produce a winged 
generation at will by simply 
changing the chemical constitu- 
tion of the sap of the host- 
plant on which the aphids were 
reared in his laboratory. 

In addition to the interest- 

Fic. 247.—Rose-aphids visited fe ee (Natural ae as regards wees 
size; from life.) and reproductive processes 

among the various individuals 

of a single aphid species, it has been found that of the wingless males some 
have no mouth, while others are furnished with functional mouth-parts 
and opening. An interesting physiological variation also occurs in the 
matter of the food-plant selected. The winged individuals frequently 
migrate to a plant of different species from that on which they were born. 
For instance, the apple-aphids, A phis mali, ‘‘spend the summer upon grasses, 
where they continue breeding until autumn, when they return to the apple and 
the winged females establish colonies of the wingless egg-laying form upon 
the leaves. The males fly in from the summer host-plant; the eggs are 
then laid on the twigs and buds, and the cycle for the year is completed.” 
The common cherry-aphis, Myzus cerasi, has a similar history, described by 


Bugs, Cicadas, Aphids, and Scale-insects 175 


Weed as follows: “It winters over on the twigs in the egg state. Early 
in spring the young aphids hatch and crawl upon the bursting buds, insert- 
ing their tiny sap-sucking beaks into the tissues of the unfolding leaves. 
In a week or ten days they become full-grown and begin giving birth to 
young lice, that also soon develop and repeat the process, increasing very 
rapidly. Most of the early spring forms are wingless, but during June 
great numbers of the winged lice appear, and late in June or early in July 
they generally leave the cherry, migrating to some other plant, although 
we do not yet know what that plant is. Here they continue developing 
throughout the summer, and in autumn a winged brood again appears and 
migrates back to cherry. These migrants give birth to young that develop 
into egg-laying females which deposit small, oval, shining black eggs upon 
the twigs.” 

The point of all this is plainly that in the aphids there must be recog- 
nized an unusual and, to them, very advantageous adaptive plasticity of both 
structure and function. Defenceless as are the aphid individuals as far 
as capacity either to fight or to run away is concerned, the various aphid 
species are, on the contrary, very well defended by their structural and physi- 
ological plasticity and their extraordinary fecundity. 

The two secretions, wax and honey-dew, play an important part in the 
aphid life. The wax secreted or excreted through various small openings 
scattered over the body is, of course, liquid when first produced, but quickly 
hardens; the total waxy secretion appears usually as a mass of felted threads 
or “‘wool,”’ and doubtless is an important protection for the delicate body. 
The honey-dew, long supposed to be secreted through two conspicuous 
tubular processes on the dorsal surface of the posterior end of the abdomen, 
is now known to be an excretion from the intestine, issuing in fine droplets 
or even spray from the anal opening. From the so-called “‘honey-tubes”’ 
issues another secretion, not sweetish, about which little is known. It is 
common knowledge, however, that the aphid honey-dew is a favorite food 
of ants—the Germans call it the ants’ ‘“‘national dish’”—and many accounts 
have been written of the care of plant-lice, the ants’ cattle, by the ants them- 
selves. Without question there is some basis of fact for these stories. No 
more evidence of this is needed than the careful observations of Professor 
Forbes of the extraordinary care of the corn-root louse by the little brown 
ant, Lasius brunneus, of the Mississippi Valley corn-fields (see p. 545 for an 
account of this). The feeding by ants on the fresh honey-dew can be readily 
observed in almost any garden (Fig. 247), and undoubtedly the mere presence 
in the aphid neighborhood of such redoubtable warriors as the ants is a 
strong deterrent of various predaceous insect enemies of the plant-lice. 
But most of the stories of ants and aphids printed in popular natural-history 
books need to be tested by careful observation. 


176 Bugs, Cicadas, Aphids, and Scale-insects 


Of all aphid species the grape-phylloxera, Phylloxera vastatrix (Fig. 248), 
has deservedly the widest notoriety. First made known in 1853 by Fitch from 
specimens found in New York, it was soon discovered to be well scattered on 
wild vines over the eastern United States. “It was introduced into the 
south of France before 1863, upon rooted vines sent from America; 
though the insect itself was not found and described there until 1868. 
The infection commenced at two points: one in the southeast in Gard, 
the other in the southwest near Bordeaux. In 1868, when the nature of 
the pest was understood, it had already invaded considerable areas. The 


Fic. 248.—The grape-phylloxera. In upper left-hand corner an egg from which a male 
has issued, next an egg from which a female has issued; in upper right-hand corner 
winter egg; at left hand of middle row a just-hatched young, next a male (note 
absence of mouth-parts); at right end of middle row, female; lower figure, winged 
form. (After Ritter and Rubsaamen; much enlarged.) 


two areas first attacked gradually enlarged until they touched about the 
year 1880, and the insect began to spread northward. By 1884 about 
2,500,000 acres, more than one-third of all the vineyards of France, had 
been destroyed and nearly all the rest were more or less affected. The 
progress of the disease in parts of southern France was so rapid that in some 
towns vine-stumps became the principal fuel. Since 1884 the pest has 
continued to spread with somewhat less rapidity in France, partly because 
the most densely planted vineyard districts had already been devastated, 
but also because elsewhere its progress was retarded by quarantine and 
other restrictive measures. No remedies yet discovered, however, are 
capable of exterminating the pest; and to-day there is no vine-grow- 


Bugs, Cicadas, Aphids, and Scale-insects 77 


ing region of any importance in France, or elsewhere, exempt from 
phylloxera.” 

Curiously enough this native American pest came to California, in which 
state it has done much more damage than elsewhere in our country, from 
France, introduced on imported cuttings or roots. It was first noticed about 
1874; by 1880 vines had been killed by phylloxera in three counties and 
hundreds of acres had been pulled up in the famous Sonoma Valley. 
Since then the pest has spread, according to Bioletti, to all the important 
grape-growing regions of central and northern California, and probably not 
less than 30,000 acres of vineyards have been destroyed. 

The phylloxera appears normally in four forms: (1) the gall form, living 
in little galls on the leaves, and capable of very rapid multiplication (this 
form rarely appears in California); (2) the root form, which is derived from 
individuals which migrate from the leaves to the roots, and which, by its 
piercing of the roots, sucking the sap, and producing little quickly de- 
caying tubercles on the rootlets, does the serious injury; (3) the winged 
form, which flies to new vines and vineyards and starts new colonies; and 
finally (4) the sexual forms, male and female, which are the regenerat- 
ing individuals, appearing after several agamic generations have been 
produced. 

The life-history of the pest has been described as follows by Bioletti: 
“Some time during the summer, usually in July or August, some of the eggs 
laid by the root-insects develop into insects of slightly different form, called 
nymphs. They are somewhat larger than the normal root form and show 
slight protuberances on the sides, which finally develop into wings. These 
are the winged or colonizing insects, which emerge from the soil and, though 

possessing very weak powers of flight, are capable of sailing a short distance, 
and if a wind is blowing may be taken many rods or even miles. Those 
which reach a vine crawl to the under side of a leaf and deposit from three 
to six eggs. These eggs are of two sizes, the smaller of which produce males 
and the larger females. The female, after fertilization, migrates to the 
rough bark of the two-year-old wood, where she deposits a single egg, called 
the winter egg, which remains upon the vine until the following spring. 
The insect which hatches from this egg in the spring goes either to the young 
leaves and becomes a gall-maker, or descends to the roots and gives rise to 
a new generation of egg-laying root-feeders. The normal and complete 
life-cycle of the phylloxera appears then to be as follows: Male and female 
insects (one generation in autumn); gall-insects (one to five generations 
while the vines are in leaf); root-insects (an unknown number of genera- 
tions throughout the year); nymphs, which become winged insects (one 
generation in midsummer). The gall stage may be omitted, as it generally 
is in California, and the insects which hatch from the fertilized eggs laid by 


178 Bugs, Cicadas, Aphids, and Scale-insects 


the female go directly to the root and produce offspring which are in- 
distinguishable from the root form produced in the normal cycle. For 
how many generations the root form can exist and reproduce without the 
invigoration supposed to come from the production of the sexual form is 
not known, but certainly for four years and probably for more. The 


Fic. 249.—Roots and rootlets of grape-vine infested by the phylloxera. (After Ritter 
and Rubsaamen; enlarged.) 


gall form on American vines can be prevented by spraying the vines in 
winter with liquids to kill the winter eggs; but this treatment has no 
effect on the root forms, which in California hibernate abundantly in the 
soil.” 

All forms of the phylloxera species are very small, about 3'; of an inch 
being an average for fully developed individuals. The root form is light 
greenish yellow in summer, when it can be found by examining the rootlets 
of infested vines, and bronzy purplish in winter, when it can be found in 
little patches under the bark just at the crown of the vine. The newly 


Bugs, Cicadas, Aphids, and Scale-insects 179 


hatched young of the root form moves about freely, but when it reaches 
the egg-laying stage it becomes fixed. 

The chief injury to the vine is not sap-drinking, but the decaying or 
“cancer” of the roots caused by the punctures and tubercle forming (Fig. 
249). It usually takes two or three years for phylloxera to kill a vine, but 
the results of the infestation are shown each season in the increasingly reduced 
growth of the new wood and in the lessened bearing. Suspected vines 
should be dug up and the rootlets carefully examined for tubercles and 
the insects themselves. The remedies, unfortunately, are either expensive, 
difficult, or severe. If a vineyard can be submerged for six weeks under 
at least six inches of water, the insects will be killed (by suffocation). Car- 
bon disulphide can be put into the soil among the roots by an injector at 
a cost of from ten to twenty dollars an acre. ‘‘ This method succeeds only 
in rich, deep, loose soils and cannot be successfully used in soil containing 
much clay or on dry rocky hillsides.” Finally, most severe but most effec- 
tive is the digging up of the whole of an infested vineyard and replanting 
resistant vines. ‘‘A resistant vine is one which is capable of keeping alive 
and growing even when phylloxera are living upon its roots. Its resistance 
depends on two facts: first, that the insects do not increase so rapidly on 
its roots; and second, that the swellings of diseased tissue caused by the 
punctures of the insects do not extend deeper than the bark of the rootlets 
and are sloughed off every year, leaving the roots as healthy as before. 
The wild vines of the Mississippi States have evolved in company with the 
phylloxera, and it is naturally among these that we find the most resistant 
forms. No vine is thoroughly resistant in the sense that phylloxera will not 
attack it at all; but on the most resistant the damage is so slight as to be 
imperceptible. The European vine, Vitis vinijera L., is the most suscep- 
tible of all, and all the grapes cultivated in California, with a few unimportant 
exceptions, belong to this species.” But the preferred French stocks can 
be grafted on to resistant American roots and the vineyard made practically 
immune. This is the method which has rehabilitated the French vine- 
yards and is now rehabilitating the California ones. 

Another very important aphid pest of this country is the woolly 
apple-aphis, called in England and in Europe the American blight. This 
species, like the phylloxera, appears in different forms and lives both above 
ground on the twigs and larger branches and underground on the roots. 
It makes itself conspicuous and readily recognizable by the abundant fluffy 
waxen “wool” which it secretes. Badly attacked trees have the bark of 
their branches badly “‘cankered” and the roots covered with excrescences, 
and may die. The injuries are almost always severe, and the pest is one 
difficult to eradicate. If but few trees in an orchard are attacked, it is best 
to dig them up and burn them. The bark can be thoroughly sprayed or 


180 Bugs, Cicadas, Aphids, and Scale-insects 


scrubbed with a carbolized solution of soft soap (soap 1o parts, carbolic 
acid 2 parts, water 88 parts) and carbon disulphide injected into the soil about 
the base of the tree. 

Of the various aphids which attack foliage trees, the most familiar are 
those which resemble the woolly apple-aphis in their habit of secreting floc- 
culent masses of wax, and thus obtain the name of “ blight,” as elm-blight, 
beech-blight, alder-blight, etc. The alder-blight, or woolly alder-aphis, 
Pemphigus tessellata, gives birth in autumn to vast numbers which crawl 
down the trunks to the ground, where they congregate in the crevices between 
the base of the trunk and larger roots and the soil, or beneath the fallen leaves 
or other rubbish at the surface. They remain in their hiding-place until 
spring, when at the coming of the first warm days they crawl up the tree 
and out to the budding tips of the twigs. Here they begin sucking sap and 
at the same time secreting waxen “wool.” In a week or so they become 
mature and begin giving birth to living young, and hereafter during the 
autumn and summer agamic generation after generation is produced. With 
the oncoming of cold weather the last generation crawls down to the ground 
to seek winter quarters. No sexual forms of this species have yet been 
found. 

Among the gall-forming aphids, one of special interest, because of the 
strange character and abundance of its galls, is the cockscomb gall-louse, 
Colopha ulmicola. Elm-trees infested by this aphis develop on the upper 
side of the leaves narrow, erect, blackish galls irregularly toothed along 
the top, and suggesting a cock’s comb sufficiently to warrant the common 
name. These aphids secrete much honey-dew, noticeable on sidewalks 
under the trees and on the leaves, and in this honey-dew where it covers 
the galls and leaves grows a blackish fungus. 

Of all the families of the Hemiptera, probably the most important from 
the economic entomologist’s point of view is that of the Coccide, or scale- 
insects, and from the point of view of the biological student, also, no other 
is more interesting and suggestive. More nearly on a footing with the 
Coccids than any other Hemiptera are the Aphididae, just studied, but the 
scale-insects are even more specialized in curious and unusual ways, both 
as regards structure and physiology. In the more specialized scale-insects 
the females are quiescent in adult life, as well as in part of the immature 
life, and their fixed bodies are very degenerate, lacking both organs of loco- 
motion and of orientation, viz., eyes, antenna, wings, and legs. The family 
is a large and widely distributed one, numbering about 1450 known species 
in the world, of which 385 occur in the United States, but almost all are 
small and obscure and so foreign in appearance to the usual insect type 
that but few others than professional entomologists and the harassed fruit- 
growers ever recognize them as insects. Most of us have often had oppor- 


Bugs, Cicadas, Aphids, and Scale-insects 181 


tunity to make easy acquaintance with one or two species at our breakfast- 
tables; the flattish, nearly circular little red-brown spots, or the more 
ovate blackish spots, which are occasionally to be seen on carelessly packed 
oranges are scale-insects and excellent examples of the extreme of degen- 
erate, quiescent type. The adult male scale-insects, unlike the females, 
are winged (although possessing but a single pair) and have eyes, an- 
tenn, and legs, but, strangely enough, no mouth-parts nor mouth-opening, 
so that they can take no food and must necessarily have but a few hours or 
perhaps days, at most, of life. And they are much more rarely seen 
than the females. Indeed, of many scale-insect species the males are not 
yet known, it being possible that in some species there is no male sex at 
all. 

The economic importance of the scale-insects has been keenly appre- 
ciated on the Pacific Coast ever since fruit-growing came to be a leading 
industry there, but the rest of the United States had not had to worry itself 
much because of the existence of these insect-scourges until recent years. 
A single Coccid species, however, has 
within ten years called the attention 
of entomologists and orchardmen 
and legislators all over the country to 
itself in a very illuminating manner. 
This species, the ill-named San José 
scale, Aspidiotus perniciosus,—which 
should rather be called ‘‘the perni- 
cious scale,” or, if not that, then the 
Oriental scale, as it is a native of Japan 
or China,—was first made known to 
science,and named, by Prof. J. H. Com- 
stock in 1880. Professor Comstock’s specimens were collected in the Santa 
Clara Valley near San José, California. How much earlier the species 
had been brought to California is not known, but at the time of its naming 
by Professor Comstock it was already recognized by California fruit-growers 
as a serious pest, and Comstock wrote: ‘‘From what I have seen of it I think 
it is the most pernicious scale-insect known in this country.’ In August, 
1893, it was found to have got a footing in the east, and since then no other 
injurious insect—indeed hardly all others together—has received such con- 
stant and excited attention as has this obscure little pest. It is found now 
in every state and territory of the Union, and in Canada as well, and in 
thirty-five states has been the subject of hurried—and only partly well- 
advised—legislation. This legislation has been directed toward restricting 
its spread by (a) quarantining it at the states’ borders, and (b) inspecting 
orchards and nurseries for it within the state and attempting to stamp it 


Fic. 250.—San José scale on bark of fruit- 
tree. (After Slingerland; natural size.) 


182 Bugs, Cicadas, Aphids, and Scale-insects 


out, The structural characteristics and life-history of the insect may be 
briefly described as follows: 

There may be seen on infested branches, leaves, or fruit, small, flat, 
grayish, irregularly circular scales of varying size (Figs. 250 and 251), the 
large stones (about 3's; inch diameter) being the adult females and the smaller 
ones being the immature individuals 
of both sexes. These circles are thin 
waxen plates, bearing one or more (de- 
pending on the age of the individual) 
faintly yellowish concentric inner cir- 
cles or plates (the inner one usually 
blackish and like a tiny nipple) which 
are the moulted exuvie of the scale. 
When the plant is badly infested the 
scales lie thickly together, even overlap- 
ping, and forming a sort of grayish 
scurf over the smooth bark. By rubbing 
or crushing this scurf a yellowish oily 
liquid issues from the injured bodies. 
If a scale be tipped over with a pin- 
point, there will be found underneath 
! it a delicate flattened yellowish sac-like 
Fic. 251.—The San José scale, Aspi- creature, the insect itself (Fig. 252). 

ae sid megane aa aes vine If adult, this degenerate female will be 

specimens; at left, natural size; at seen (by examination with magnifier) 

right, considerably enlarged.) to have no distinct head, no eyes nor 
antenne, no wings nor legs. It does have a long, fine, flexible, thread-like 
process projecting from near the center of its under side; this is the suck- 
ing proboscis, and serves as a means of attachment to the plant as well 
as the organ of feeding. 

Early in the spring, females which have hibernated under their pro- 
tecting armor begin giving birth to living young, and continue doing this 
actively for about six weeks, when they die exhausted. The minute orange- 
yellow young, which have eyes, antenne, and three pairs of legs, crawl out 
from under the scale and run about actively for a few hours over the twigs 
or leaves; then they settle down and each * ‘‘slowly works its long bristle- 
like sucking-beak through the bark, folds its antenne and legs beneath its 
body and contracts to a nearly circular form. The development of the 
scale begins even before the larva becomes fixed. The secretion starts 


* The following long quotation is made from Howard and Marlatt’s “The San José 
Scale ” (Bull. 3, N. S., Div. Ent., U. S. Dept. Agric., 1896). 


Bugs, Cicadas, Aphids, and Scale-insects 183 


in the form of very minute white fibrous waxy filaments, which spring from 
all parts of the body and rapidly become more numerous and dense. At 
first the orange color of the larva shows through the thickening downy white 
envelope, but within two days the insect becomes entirely concealed by the 
white or pale grayish-yellow shell or scale, which now has a prominent central 
nipple, the younger ones often possessing instead a central tuft. The scale 
is formed by the slow matting and melting together of the filaments of wax. 
During the first day the scale appears like a very microscopic downy hemi- 
sphere. The matting of the secretion continues until the appearance of 
down and individual filaments is entirely lost and the surface becomes 
smooth. In the early history of the scale it maintains its pale whitish or 
grayish-yellow color, turning gradually darker gray, the central nipple 
remaining lighter colored, usually throughout development. 

“The male and female scales are exactly similar in size, color, and shape 
until after the first moult, which occurs twelve days after the emergence of 
the larva. With this moult, however, the insects beneath the scale lose all 
resemblance to each other. The males (Fig. 252, @) are rather larger than 
the females, and have large purple eyes, while the females have lost their 
eyes entirely. The legs and antenne have disappeared in both sexes. The 
males are elongate and pyriform, while the females are almost circular, 
amounting practically to a flattened sac with indistinct segmentation, 
and without organs, except a long sucking-bristle springing from near the 
center beneath. The color of both sexes is light lemon-yellow. The 
scales at this time have a decidedly grayish tint, overcast somewhat with 
yellow. 

“Bighteen days from birth the males change to the first pupal condition 
(propupa), and the male scales assume an elongate oval, sometimes slightly 
curved shape, characteristic of the sex, the exuvia or cast larval skin show- 
ing near the anterior end. The male propupe are very pale yellow, with 
the legs and antenne (which have reappeared) together with the two or three 
terminal segments colorless. . . . Prominent wing-pads extend along the side 
of the body. 

“The female undergoes a second moult about twenty days from the 
larva. At each moult the old skin splits around the edge of the body, the 
upper half adhering to the covering scale and the lower forming a sort of 
ventral scale next to the bark. This form of moulting is common to scales 
of this kind. 

“The covering scales at this stage are of a more purplish gray, the por- 
tion covering the exuvie inclining to yellowish. The male scales are more 
yellowish than the female. The effect of the sucking of the insects is now 
quite apparent on the young growth, causing the bark to assume a pur- 
plish hue for some distance around the central portion, contrasting strongly 


My, 


184 Bugs, Cicadas, Aphids, and Scale-insects 


with the natural reddish green of the uninjured bark. With the second 

Le moult the females do not change materially from 
their former appearance, retaining the pale-yellow 
color with a number of transparent spots around 
the edge of the body. The sucking-bristles are 
extremely long, two or three times the length of the 
body of the insect. 

“About twenty days after birth the male insect 
transforms to the true pupa. With the first moult 
the shed larval skin is retained beneath the scale 
as in the case of the female; with the later moult- 
! ings the shed skins are pushed out from beneath 
Fic. 252.—The San the scale. The scale, after the second moult, pre- 

José scale, Aspidiotus sents on the inside two longitudinal ridges run- 

perniciosus. a, male; : Z 

h,adult female, ing from one end to the other, touching the sides 

(Much enlarged.) of the pupa, and which apparently enable the 
insect to move backward or forward and assist the imago in pushing itself 
out. 

“The true pupa is pale yellow, sometimes purplish, darkened about 
the base of the abdomen. The head, antenna, legs, wing-pads, and style 
are well formed, but almost colorless. . . . 

“From four to six days later, or from twenty-four to twenty-six days 
from birth, the males mature and back out from the rear end of their 
scales, having previously, for a day or two, remained practically developed, 
but resting under the scale. They seem to issue chiefly by night or in 
the evening. 

“The mature male (Fig. 252) appears as a delicate two-winged fly-like 
insect with long feelers and a single anal style projecting from the end of 
the body; orange in color, with a faintly dusky shade on the prothorax. 
The head is darker than the rest of the body, the eyes are dark purple, and 
the antennae, legs, and style are smoky. The wings are iridescent with 
yellow and green, very faintly clouded. 

“Thirty days from birth the females are full grown and the embryonic 
young may be seen within their bodies, each enclosed in a delicate mem- 
brane. At from thirty-three to forty days the larvae again begin to make 
their appearance. 


“The adult female, prior to the development of the young, measures 
one millimeter in length and a little less in breadth, and is pale yellow with 
transparent spots near the margin of the body (Fig. 252). 

“The length of a generation is determined by the female, and, as shown 
by the above record, covers a period of from thirty-three to forty days. Suc- 
cessive generations were followed carefully throughout the summer, and 


Bugs, Cicadas, Aphids, and Scale-insects 185 


it was found that at Washington four full generations are regularly developed, 
with the possibility of a partial fifth generation. On a number of potted 
trees a single overwintered female was left to each tree. After the full 
progeny of this individual had gone out over the tree all were removed 
again, except one of the oldest and fertilized females. This method was 
continued for each generation throughout the breeding season. Some 
interesting records . . . were thus obtained, which indicate the fecundity 
of the females as well as the number of generations.” 

From these records it may be fairly estimated that an average of 200 
females (in addition to about as many males) are produced by each female, 
and that there are four generations each year in the latitude of Washington, 
D. C. Thus the product of a single overwintered female in a single year 
amounts to 3,216,080,400 male and female descendants. This total is, 
of course, never reached, because only a part of each generation reaches 
maturity and produces young, but in a favorable season on a tree newly 
infested (and thus providing a plentiful food-supply) a large majority of 
each generation do most probably go through their normal existence. 
“Neither the rapidity with which trees become infested,” add Howard and 
Marlatt, ‘‘nor the fatal effect which so early follows the appearance of this 
scale-insect is therefore to be wondered at.” 

But not all scale-insects are so specialized either structurally or physio- 
logically as the pernicious (or San José) scale. The females of some species 
retain the eyes, antenne, and legs through their whole life and can crawl 
about if need be at any time. Others show a sort of transition between 
these two extremes of activity and quiescence, having the legs present, but 
in adult life much reduced in size and probably functionless, or at best 
capable of carrying the insect but feebly and briefly. In the matter of the 
covering, too, there is much variety; some scales secrete no wax at all, but 
have the body-wall of the back specially thickened and made firm so as 
to act as an effective covering-shield underneath which, somewhat as with 
a turtle, the legs and head can be concealed. Others secrete filaments or 
tufts of soft white wax which form a sort of felted protecting covering for the 
body. In a general way the various scale-insects may be instructively 
gathered into three groups, depending on the characters of the females; 
in the first group the females retain the antenne, eyes, and legs, and the 
segmented condition of the body (typical of normal insects) and are capable 
of locomotion throughout life; they secrete wax usually in the shape of white 
cottony filaments or masses with which they cover the body more or less 
completely, sometimes forming conspicuous waxen egg-sacs at the posterior 
extremity of the body; the females of the second group retain their legs 
and antenne through life, but have them in reduced condition when adult, 
and although capable of feeble motion, usually lie quiescent; they commonly 


186 Bugs, Cicadas, Aphids, and Scale-insects 


secrete no wax, but have the body-wall of the dorsum strongly chitinized, 
and usually very convex, so that it forms 
a strong rigid protecting shell; finally the 
females of the third (and largest) group are 
the so-called armored scales, which in the 
adult stage are degenerate creatures without 
distinct body segmentation, without antenne, 
eyes, and legs, thus being incapable of 
locomotion; they form a flattish or convex 
dorsal scale of secreted wax and of the cast 
skins or exuvie of the body. 

In all the groups the males (Figs. 252 and 
253) are very different in appearance from the 
females, being minute fly-like creatures with 
Fic. 253.—The fluted orcottony 2 Single pair of wings, a pair of long antenne, 

cushion-scale, Icerya purchast, and a plump, soft, little body, usually 
bles enero [eae terminating in a single needle-like process or 
sac (es). (After Jordan and in a pair of long waxen hairs. Males are 
So AEE eet not yet known for some of the species. 

Familiar examples of the first group are the mealy-bugs (Dactylopius sp.) 
of greenhouses and gardens, soft-bodied scales, bearing projecting rods 
and threads of white wax of varying length, and rather prettily arranged. 
A more famous and interesting member of this group is the fluted or cottony 
cushion-scale, Icerya purchasi (Fig. 253) (so called because of the beautiful 
fluted white waxen egg-sac secreted by the female), which once threatened 
to destroy all the orange-groves of California, but was brought to bay by 
a little red and black ladybird-beetle, Vedalia cardinalis (Fig. 254), brought 
from Australia for this very purpose. In 1868 some young orange-trees 
were brought to Menlo Park (near San Francisco) from Australia. These 
trees were undoubtedly infested by the fluted scale, which is a native of 
Australia. These scale immigrants throve in the balmy California climate, 
and particularly well, probably, because they had left all their native enemies 
far behind. By 1880 they had spread to the great orange-growing districts of 
southern California, five hundred miles away, and in the next ten years 
caused enormous loss to the growers. In 1888 the entomologist Kcebele, 
recommended by the government division of entomology, was sent at the 
expense of the California fruit-growers to Australia to try to find and send 
back some effective predaceous or parasitic enemy of the pest. As a result 
of this effort, a few Vedalias were sent to California, where they were zeal- 
ously fed and cared for, and soon, after a few generations, enough of the little 
beetles were on hand to warrant trying to colonize them in the attacked 
orange-groves. With astonishing and gratifying success the Vedalia in a 


Bugs, Cicadas, Aphids, and Scale-insects 187 


very few years had so naturally increased and spread that the ruthless scale 
was definitely checked in its destruction, and from that time to this has 
been able to do only occasionally and in limited localities any injury at all. 


Fic. 254.—The fluted scale, [cerya purchasi, attacked by the Australian ladybird-beetle, 
Vedalia cardinalis. In lower left-hand corner a Vedalia which has just issued from 
its pupal case. (From life; upper figure slightly enlarged; lower figure much 
enlarged.) 


Of the second group, the best-known scales are the various species of the 
genus Lecanium (Fig. 256). Of these, the olive or oleander or black scale, 
L. ole, as it is variously called, is the most widely distributed and abundant 
and hence economically important. It is a long-known species, having 
been described in Europe in 1743, and it was brought to this country in 
early days. The adult females are blackish, almost hemispherical, rough- 
skinned creatures, with no external indication of head or other body divi- 
sions, feet, antennz, etc., all these parts being visible only from the ventral 
aspect, which normally is closely applied to the leaf or twig. On the back 
may be distinguished three ridges forming an H. The young are flatter 
and light brown, but can be recognized by their even more distinct H-mark. 
This scale is found all over the United States and has a wide range of food- 
plants, garden-bushes of all kinds, as well as deciduous and citrus fruits 
being attacked. In California it is one of the worst insect-pests of the olive- 
tree and also one of the worst of the orange enemies. It has certain natural 
enemies in the persons of various ladybird-beetle species, and a few special 
ladybird-beetles have been imported from Australia and elsewhere in the 
hope of repeating the signal Vedalia success. Only a fair measure of suc- 
cess has been achieved. An indirect but serious injury caused to plants 
by the black scale is due to the germination in the honey-dew secreted by 
it of the spores of a fungus, Capnodium sp., which spreads its felted mycelia 


188 Bugs, Cicadas, Aphids, and Scale-insects 


over the leaf-surfaces, closing the breathing-pores (stomata) and thus truly 
suffocating the plant. Although this scale species has been known for a 
century and a half, the males have 
been seen but few times and in but 
few places. Another familiar member 
of this group, which secretes a distinct 
white waxen egg-sac, is the maple- 
scale, Pulvinaria innumerabilis (Fig. 
255), common on maples in the 
eastern states. 

. Of the third group, that of the 
’ most specialized (degenerate) scales, 
the pernicious scale, already fully 
described, may be taken asa shining 
<f example. There is a host of these 
armored scale-insects, and few trees or 


Fic. 255. Fic. 256. 


Fic. 255.—The maple-scale, Pulvinaria innumerabilis. Females with egg-sacs on the 
twig; young scales on under side of leaf, and a single young scale, much enlarged, 
at left. (After Felt; natural size.) 

Fic. 256.—Lecanium scales attacked by the fungus Cordyceps clavulata. (After Pettit; 
much enlarged.) 


shrubs escape their attacks. The various genera are mostly distinguishable 
by the shape of the covering scale, but to determine the species exactly 
requires, for many, careful examination, under high powers of the microscope, 
of the minute chitinous processes which form a fine fringe along the posterior 
margin of the last abdominal segment. To make this examination it is 
necessary to remove the female from under her scale, and mount her cleared 
body flat in balsam or glycerine on a glass slide. An important species 
in this group is the red orange-scale, Aspidiotus aurantii (Fig. 257), common 
in orange-groves of southern California. A species very closely resembling 
it is A. ficus, common in the Florida groves. On pine-needles one may 
often note small, narrow elongate white waxen scales, with the smaller, 
yellowish-brown exuvie at one end; these belong to the widely spread species 
Chionaspis pinijolie. On apple-trees often occurs a roughened shining 


Bugs, Cicadas, Aphids, and Scale-insects 189 


blackish narrow elongate curved scale, resembling a little an oyster-shell 
in miniature; this is the sometimes serious apple-pest, Mytilaspis pomorum. 
But we have no space to list 
even the most important of 
these degenerate but successful 
insect enemies of our fruit- and 
foliage-trees. 

The devising of remedies for 
scale attack has been given much 
attention, and a number of effec- 
tive means have been discovered 
for fighting the pests. Probably 
the most effective of all is the 
fumigation of infested orchard- 
trees by hydrocyanic gas. A 
tent capable of enclosing a whole Fic. 257—The red orange-scale, Aspidiotus 


tree is made, and with this in aurantit, a, females, natural size, on leaf; 6, 
1 hyd 5 4 female, much enlarged, removed from under 
piace hydrocyanic gas 1S gen- waxen scale; c, the scale, composed of wax 


erated under it by pouring and exuvie, much enlarged; d, just hatched 
b wat 26 t ycung, much enlarged; e, male, much enlarged. 
about 50 0Z. of water into 5 02. (After Jordan and Kellogg.) 


of commercial sulphuric acid and 

dropping in 15 oz. of cyanide of potassium, these amounts of acid, water, and 
cyanide being sufficient to fumigate a tree 12 ft. high by ro ft. in foliage diam- 
eter; that is, to fumigate about 1000 cu. ft. of space. For larger or smaller trees 
change the amounts of acid, water, and cyanide proportionally. Of washes 
to be applied in winter, when the leaves are off, the best is one made of lime 
50 Ibs., sulphur so lbs., salt 50 lbs., water 150 gals.; slake the lime with 
water enough to do it thoroughly, and during the process add the sulphur. 
Boil one hour with water enough to prevent burning and until the mixture 
becomes of a deep amber color. Dissolve the salt in water enough to do 
it quickly and add slowly to the boiling mass. When all is thoroughly 
mixed together and has actually boiled at least an hour add water enough 
to make up 150 gals., and apply by spraying or washing while hot. It 
may be safely applied when the foliage is off to any fruit-tree, garden shrub, 
or small fruit, and is a very effective ‘‘scale-killer.” Of sprays for the leaves, 
kerosene emulsion is undoubtedly the safest and best. For use, undiluted 
crude petroleum should be entirely untreated and of specific gravity of 43° 
or over on the Beaumé scale. Smith has used this oil safely on all ordinary 
fruit-trees, but advises not applying it to peach-trees. At time of apply- 
ing, the trees should be dry, the oil of a temperature not below 60° Fahrenheit, 
and the nozzles should throw a perpetual fine spray. Kerosene emulsion is 
made by boiling 4 Ib. of hard soap in 1 gal. of water and then adding 2 gals. 


190 Bugs, Cicadas, Aphids, and Scale-insects 


of kerosene and churning violently until a thick white cream is formed. 
Let this cool and jelly; it is the “‘stock,” and will hold for a few weeks; when 
ready to spray, dilute stock with twelve 
to fifteen times its own bulk of water 
and spray finely over the foliage. The 
spraying should be done when the 
young scales are hatching and crawl- 
ing about. They are then easily killed 
by contact with even a single fine drop 
of kerosene. For peach-trees dilute 
the stock twenty times. 

Some of the scale-insects present 
such unusual conditions of structural 
modification and of habits that they 
Fic. 258.—Female red orange-scale, Aspi- are, when first met with, difficult to 

Cree Otten tamenTSER,y ecognize as insects at all. The 
waxen covering may be so irregular and 
curiously shaped that it gives no clue to the character of the enclosed insect 
(ig. 261), but seems to be simply a secretion of the plant in which the insects 
are found. Or the globular shape and absence of distinct body-parts may 
make the insects with their hardened blackish cuticle look like small plant- 
galls; indeed certain scale-insect species were first described by botanists as 
galls. Some scales live under ground, either in 
ants’ nests or independently; the curious so-called 
“‘ground-pearls,” small spherical shining bodies 
found loosely scattered in the soil in certain tropic 
regions, and really collected to be strung on threads 
or necklaces, are the strangely modified bodies of 
Margarodes formicarum, a scale-insect. Taken alto- 
gether, probably no other family of insects exceeds 
the Coccide in the extremes of strange specializa- 
tions. 

Closely related to the plant-lice and scale- 
insects are the mealy-winged flies, constituting the 
family Aleyrodide. The adults (Fig. 262), except 
of two or three of the most abundant species, are 


Fic. 259.—Female  rose- 
scale, Diaspis rose. 
careful search will reveal in almost any locality the (Photomicrograph b y 


aa : é F «ae . George O. Mitchell; 
US > rlike e ne “Ss , o 

curious little box-like elliptic ul bodies of the YOUNES © irrich eninegedt) 

(Fig. 263), usually shining black, with pure-white 

waxen rods, filaments, or tufts. Examined under a good magnifier, the 

wax-tufted cases are exquisite objects. These young mealy-wing flies look 


rarely seen even by professional entomologists, but 


Bugs, Cicadas, Aphids, and Scale-insects Ig 


much like scale-insects and have the same general habits. Provided with 
a delicate long sucking-beak, each individual remains fixed in one spot on 
a green leaf, sucking up its food, the plant-sap, as it needs it. The adults 
which finally issue from the beautiful little cases have four rounded wings, 
pure white or with small dusky spots and golden yellow, finely beaded 
margins; each wing has but a single vein, and is dusted with a granular 


Fic. 260.—The California live-oak scale, Cerococcus ehrhorni. (Photograph by Rose 
Patterson; natural size.) 


white waxen powder or “bloom.” The tiny white or pale-yellow eggs 
are laid on leaves in a circle or the arc of one, in one or more rows, and 
vary in number from three to thirty; each egg has a minute but noticeable 
curving stem. The young hatch in from ten to thirteen days, and move 
freely about, but never seem to get more than about one inch from the 
deserted shells. This activity lasts for from ten to forty hours; then 
the young attach themselves to the leaf by inserting the sucking proboscis, 


192 Bugs, Cicadas, Aphids, and Scale-insects 


and soon moult, losing at this time the legs and antenne. After a second 
moulting, however, minute new legs and antennz are again to be seen, and 
later the wing-pads appear, and wings, legs, and antennz develop and grow 
apace; at a last moulting the insect leaves the protection of its beautiful little 
case and flies away. Leaving the pupa-case is a slow and toilsome process, 
the imago often struggling for hours before it is free and ready for flight. 


Fic. 261.—The Southern California oak-scale, Cerococcus quercus. 
(Photograph by Rose Patterson; natural size.) 


All of the pup secrete ‘“‘honey-dew,”’ sometimes in such quantities that 
the leaf around the case, and the top of the case itself, are covered with it. 
This honey-dew is emitted from the tip of a little flap-like anal structure called 
the lingula (Fig. 266). The sweet liquid honey-dew, when exposed to the 
air, becomes thick and finally hardens. The spores of fungi often germinate 
in the excreted honey-dew, and numerous ant-species collect it for food. 


Bugs, Cicadas, Aphids, and Scale-insects 193 


To distinguish any of the various species of mealy-winged flies would 
be a difficult matter for the beginning 
entomologist. Two special students of 


FIG. 262. Fic. 263. 


Fic. 262.—A mealy-wing, Aleyroles pruinosa, adult. (After Bemis; much enlarged.) 
Fic. 263.—Pupa of Aleyrodes tentaculatus. (After Bemis; much enlarged.) 


Fic. 264. Fic. 266. 


Fic. 264.—Pupa of Aleyrodes iridescens. 
Fic. 265.—Pupa-case of Aleyrodes merlint. 


(After Bemis; much enlarged.) 
(After Bemis; much enlarged.) 


Fic. 266.—Vasiform orifice and lingula of pupa of Aleyrodes merlini, (After Bemis; much 


enlarged.) 


the American species have published lists and descriptions of all the kinds 
so far known in this country, namely, Quaintance (Bull. 8, Tech. Ser., Div. 
of Ent., U. S. Dept. Agr., 1900), who has studied the eastern species, and 


194 Bugs, Cicadas, Aphids, and Scale-insects 


Bemis (Proc. U. S. Nat. Mus., vol. 27, 1904), who has studied the Pacific 
Coast forms. Mrs. Bemis found twenty hitherto unknown species of mealy- 
winged flies in easy collecting 
range of Stanford University, 
and these twenty kinds added 
to those already known make a 
total of sixty different species so 
far recorded from the United 
States. There are certainly 
many more species yet unde- 
scribed. 

The mealy-winged flies have 
some, though not a large, eco- 
nomic importance. One or two 
species, Aleyrodes vaporariorum, 
Fic. 267.—Pupa of Aleyrodes merlini, showing etc., are recognized as pests in 

long waxen tufts. (After Bemis; much en- greenhouses; one, A. citri, is a 

larged.) pest of oranges, and another, 
A. packardi, injures strawberry-plants. In all these cases probably as much 
injury is done by the suffocating fungus growth that is supported by the 
secreted honey-dew as by the direct sap-sucking of the Aleyrodes themselves. 
Fumigation by hydrocyanic gas (see p. 189) is probably the best remedy 
for the greenhouse and orange mealy-wings, and spraying with kerosene 
emulsion (see p. 189) the best for the strawberry Aleyrodes. 


SUBORDER HETEROPTERA. 


Key To FAMILIES OF THE HETEROPTERA (INCLUDES BOTH NYMPHS AND ADULTs). 
(ADAPTED FROM WoODWORTH, WITH SOME ADDITIONS.) 


Antenne shorter than the head: aquatic or shore insects. 
With two ocellizcccca0 oc coerce cane cee eee eee ee (Toad-bugs.) GALGULIDE. 
With no ocelli. : 
Hind feet without claws; aquatic insects. 
Prothorax overlapping the head above...... (Back-swimmers.) NOTONECTIDE. 
Head overlapping prothorax above.........--.- (Water-boatmen.) CorIsID&. 
Hind feet with claws. 
With two long processes on tip of abdomen which can be held together to form 


@ tubes oi.cicocce wee on cieciesie eet eee ene (Water-scorpions.) NEPIDs&, 
Without abdominal processes, or if any, short flattish retractile ones. 
Hind legs broad and flat.......-.... (Giant water-bugs.) BELOSTOMATID&. 
Hind ‘legs: slender:.-:...).,5 5-2-3 sa tee ee ee NAUCORIDE. 
Antenne at least as long as the head: a few aenatie forms, but mostly terrestrial. 
Head as long as the whole thorax...........-.- (Marsh-treaders.) LIMNOBATIDE. 


Bugs, Cicadas, Aphids, and Scale-insects 195 


Head shorter than thorax. 
Last segment of foot divided and the claws not at the tip. 
Middle and hind legs very long......-.....- (Water-striders.) HyDROBATID#. 
Middle and hind legs not very long..............-----+-e+eeeeeeee VELUDE. 
Last segment of foot not divided, and the claws at the tip. 
Antenne 3- or 4-segmented. 
Proboscis (or beak) with three joints. 


Body very long and slender.......--..- (Thread-legged bugs.) EmeEsip&. 
Body not long and slender. 
Femora of fore legs very wide........ .--(Ambush-bugs.) PHyMATID2. 


Femora of fore legs not very wide. 


Fore wings usually lacking or rudimentary; when s0, ocelli are absent. 
(Bedbugs.) ACANTHIID2. 


Fore wings usually present; when absent, ocelli are always present. 
Hind feet consisting of three joints. 


Beak long and slender. .-...........: (Shore-bugs.) SALDID. 
Beak short and stout............ (Assassin-bugs.) REDUVUDZ. 
Hind feet consisting of two joints.......... (Flatbugs.) ARADID2. 


Proboscis (or beak) with four joints. 
Without ocelli. 

Heavy-bodied insects, membrane of wings (in adults) with two large cells 

at the base from which arise about eight branching veins (Fig. 268, 2). 
(Redbugs.) PyRROCHORID#. 

Light-bodied insects; membrane of wings (in adults) with one or two closed 

cells at the base and with no longitudinal veins (Fig. 268, 1). 
(Leaf- and flower-bugs.) CapsID2&. 
With ocelli. 

Fore legs very different from the others; wings when present in fully de- 
veloped condition with four long veins in the membrane bounding three 
discal cells, which are often open; from these cells diverge veins which 
form several marginal cells (Fig. 268, 5)..-(Damsel-bugs.) Nasipz. 

Fore legs not very different from the others. 

Body very narrow...-.----+-----++++-++-+---- (Stilt-bugs.) BrERryTIp2&. 

Body not very slender. 
Feet of two joints; wing-covers (of adults) resembling lace network. 
(Lace-bugs.) TINGITID2. 

Feet of three joints. 
Antenne inserted below an imaginary line drawn from the eye to the 
beak; membrane of wing (in adults) with four or five simple veins 
arising from its base, the two inner veins sometimes joined to a 
cell near the base (Fig. 268, 3). -(Chinch-bug family.) Lycaip&. 
Antenne inserted above an imaginary line drawn from the eye to the 
beak; membrane of wings (in adults) with many usually forked 

veins, springing from a transverse basal vein (Fig. 268, 4). 
(Squash-bug family.) CorEID&. 
Antenne 5-segmented. 


Body flat above. 
With few or no spines on the tibie.........- (Stink-bugs.) PENTATOMID&. 


With rows of spines on the tibie.....-..---- (Burrower-bugs.) CYDNID&. 
Body strongly convex above. 
Prothorax round in front and nearly straight behind. 
(Negro-bugs.) CORIMELENID, 
Prothorax hexagonal.....-.---.---- (Shield-backed bugs.) SCUTELLERID. 


196 Bugs, Cicadas, Aphids, and Scale-insects 
We come now to the “true bugs,” representing twenty-six families and 
constituting the Heteroptera, the largest of the three suborders of the 
Hemiptera. The classification of the members of this large group into 
families, by the use of the keys commonly used by entomologists, demands 
the recognition of such small and obscure structural characters that I have 
tried to find some easier means for the use of the amateur and general col- 
lector. As collecting and observing in the field imply the discovery of 
insects in their native haunts, we may acceptably make use of constant 
habits for a basis of convenient grouping. About one-third of the Heterop- 
terous families are aquatic in habitat, and of these the members of some 
are to be found on the surface of pools and ponds, of others swimming 


Fic. 268.—Wings of Heteroptera, showing disposition of veins in membrane character- 
istic of various families: 1, Capside; 2, Pyrrhocoride; 3, Lygeide; 4, Coreide: 

5, Nabide; 6, Acanthiide. (After Comstock.) 
or crawling about below the surface, and of two, only partly aquatic, 
on the shore, but always by the water’s edge. Some of these aquatic bugs 
are to be discovered occasionally in flight far from water, as the giant 
water-bugs and others, when circling about electric lights or in search of 
new homes. But the structural signs of the aquatic habitat, legs flattened 
and fringed so as to be fitted for swimming, will betray these estrays. 
Occasionally, too, a strictly terrestrial bug will be found on the surface of 
a pool, but his violent and obviously unaccustomed and awkward attempts 
to swim to shore will betray him. So we may begin an acquaintance with 
the Heteroptera by resorting to the nearest pond or quiet stream-pool. 

On the surface are the familiar water-striders, or skaters. Their long, 
spider-like legs, narrow and black or oval and yellow and black body, 
and swift nervous running distinguish them from all other bugs. They 
are members of the family Hydrobatide, and the commoner species belong 
to the genus Hygrotrechus (Figs. 269 and 270). Upheld by the tense surface- 
film of the water, their feet only make little dimpled depressions in the sur- 
face, the shadows of which may often be seen on the sandy bottom. The 
locomotion is really due to a sort of surface rowing or gliding, and not a 


Bugs, Cicadas, Aphids, and Scale-insects 197 


true running. The water-striders are predaceous, capturing smaller living 
insects by running or leaping, and, with the prey held securely in the grasp- 


Fic. 269. FIG. 270. 


Fic. 269.—Water-strider, Hygrotrechus sp., adult. (Twice natural size.) 
Fic. 270.—Water-strider, Hygrotrechus sp., young. (Twice natural size.) 


ing fore legs, piercing and sucking the blood of the unfortunate victim, yet 
alive. Care should be taken in handling water-striders, as the sharp beak 


Fic. 271. ‘ FIG. 273. 
Fic. 271.—Broad-bodied water-strider, Stephania picta. (After Uhler; natural 
size.) 


Fic. 272.—An ocean water-skater, Halobates willersdorffi, from near Galapagos Islands. 


(Three times natural size.) 5 < ; 
Fic. 273.—A marsh-treader, Limnobates lineata. (One and one-half times natural size.) 


can make a painful puncture. Some of them are winged and some wing- 
less, and both kinds of individuals may belong to the same species. The 


198 Bugs, Cicadas, Aphids, and Scale-insects 


young are usually short-bodied, and of course wholly wingless or with small 
wing-pads only. In late autumn the water-striders conceal themselves 
in the mud beneath leaves or rubbish or at the bottom of the pool under 
roots or stones to hibernate, coming out again with the first warm days of 
spring. The whitish elongate eggs are laid in early spring, being attached 
by a sort of glue to the leaves and stems of aquatic plants. Some species 
have several generations each year. Water-striders are easily kept in 
aquaria if the sides are high enough above water to prevent their leaping 
out. In bringing them in from the pond covered pails should be used, or 
they may be enclosed in any small dry receptacle not air-tight. They are 
easily drowned if shaken about in a covered pail of water. 

A few interesting Hydrobatids, belonging to the genus Halobates (Fig. 
272), live on the surface of the ocean, especially in subtropic and tropic 
latitudes. They are said to feed on the juices of dead animals floating on 
the surface, and probably attach their eggs to floating seaweed (Sargassum). 

Certain stout-bodied insects, widest across the prothorax and with much 
shorter, stouter legs, members of the family Veliide, are sometimes to be 
found, running about on the surface of the water, always near the shore. 
They can also run readily on land, which the true water-skaters cannot 
do. Also certain other slender insects, about 4 inch long, with thin long 
legs and hair-like antenne and long cylindrical head, are to be found on 
top of the water. But they creep slowly about on the surface or on the 
soft mud of the shore, and are found mostly where plants are growing in 
quiet water. These are marsh-treaders, Limnobates lineata (Fig. 273), 
and this species is the only representative of the family Limnobatide known 
in this country. : 

Swimming and diving about beneath the surface are the water-boatmen 
(family Coriside) and back-swimmers (family Notonectide). The water- 
boatmen (Fig. 274) are oval, finely mottled, greenish gray and black, and 
swim with back uppermost. They are all small, some only 4 inch long, 
none over half an inch. ‘The back-swimmers have the back shaped like the 
bottom of a boat, swim with the back always down, and are usually bluish 
black and creamy white in color. Both of these kinds of water-bugs are 
predaceous, feeding on smaller aquatic creatures. But the beak of the back- 
swimmers is much longer and stronger than that of the water-boatmen, 
and can make a painful sting on one’s finger. Both kinds have the hind 
legs long and specially flattened and fringed to serve as oars, and both kinds 
come to the surface for air, although the back-swimmers come up far more 
often than the water-boatmen. The air taken up clings as a silvery bubble 
to a large part of the body both under the folded wings and on the under 
side, being held there by fine hairs which form a pile like that on velvet. 
A supply of air is thus taken down by the bugs, which enables them to remain 


Bugs, Cicadas, Aphids, and Scale-insects 199 


for some time under water. Both kinds are attracted to lights, and may 
often be seen in summer about outdoor electric lamps. The eggs of the 
water-boatmen are attached to the submerged stems of aquatic plants, while 
those of the back-swimmers are inserted in the stems, the female having 
a sharp ovipositor for this purpose. In winter the adults lay dormant in the 
mud at the bottom of ponds or streams. — 

All the species of water-boatmen in the country belong to the genus 
Corisa, while there are three genera of back-swimmers, Notonecta, with 
hind legs longer than the others and fore wings but little longer than the 
abdomen, being the most abundant and : 
wide-spread. Plea is a genus with all the 
legs alike, while Anisops, the third genus, 
has the wing-covers usually much longer 
than the abdomen. The complete life- 
history of no member of either of these 
families of water-bugs is yet known, but it 
ought not to be a difficult matter for some 
persistent observer to add this needed 5, ep cae Als nectemm, (CRUE 
knowledge to entomological science. Both sp. (After Jenkins and Kellogg; 
water-beatmen and back-swimmers live — tWice natural size.) 
readily in aquaria, and make thoroughly interesting creatures to observe 
at leisure. The characteristic habits of obtaining air, swimming, capturing 
prey, etc., can all be learned from the observation of aquarium specimens. 
The capacity of the water-boatmen to remain below the surface in pure 
water for protracted periods, apparently indefinitely long, needs to be better 
understood than it is at present, and should be an interesting problem for 
some observer of aquarium life. 

Creeping or crawling about among the stems and leaves of submerged 
plants in reedy and grassy quiet waters, and feeding on smaller insects, may 
sometimes be found certain small flat-bodied oval insects with front legs 
thickened and fitted for grasping. These are water-creepers, or Naucoride, 
only five species of which are known in this country. The single species 
found in the eastern states is known as Pelocaris femorata, and is about 
4 inch long, broadly oval in shape, and yellowish brown in color. The 
other species belong to the genus Ambrysus and are restricted to the western 
states. The life-history of but one member of this family is known. 

Occasionally there will be seen resting, or swimming slowly about, at the 
bottom of the pool a veritable giant bug, 2? inches long and r} inches wide, 
with heavy strong legs flattened and oar-like and the front ones held out 
arm-like and bent in an expectant grasping position. Again, in the warm 
sultry evenings of midsummer and early autumn, among the swarms of 
insects attracted to the electric lights on the streets, one or two great bugs 


200 Bugs, Cicadas, Aphids, and Scale-insects 
5”? ? ? 


will go whirling around the bright globe of light, casting large fleeting 
shadows on the ground below. ‘The giant in the pool’s depth and the giant 
in the giddy swarm at the light are one and the same, viz., the giant water- 
bug or electric-light bug, a member of the family Belostomatide. Most 
of its life is passed in the water; it hatches from eggs deposited under water, 
lives its whole immature life in the pool, and only comes out for a short flying 
season to find mates or a new pool. Two very large species of this family, 
both common in this country, are Belostoma americana (Fig. 275) and Benacus 
griseus, distinguishable by the fact that 
the former has a groove on each front 
femur for the tibia to fit in when folded. 
A smaller kind, more oval in shape, is the 
commonest form on the Pacific slope. 
This is Serphus dilatatus, the toe-biter, 


FIG. 275. Fic. 276. 


Fic. 275.—The giant water-bug or electric-light bug, Belostoma americana. (Natural 
size.) 

Fic. 276.—The western water-bug, Serphus sp.; male with eggs deposited on its back 
by female. (Natural size.) 


which is 1} to 14 inches long and } to $ inch wide. In the East a still 
smaller form, Zaitha fluminea, is common. This is a little less than 1 
inch long. All these Belostomatids are fiercely predaceous, capturing 
aquatic insects, tadpoles, etc., and are armed with a short, strong, pointed 
beak with which a serious puncture can be made. They secrete themselves 
beneath stones or rubbish, whence they dart out on their victims. A con- 
siderable amount of poisonous saliva enters the wound made by the beak, 
and probably aids in overcoming the prey. The larger species attack 
young fish, seizing them with their strong grasping fore legs and sucking 
their blood. They can do much injury in carp-ponds or in garden-pools 
where fishes are kept for pleasure. The females of the species of the 


Bugs, Cicadas, Aphids, and Scale-insects 201 


smaller genera Serphus and Zaitha have the curious habit of gluing their 
eggs upright, in a single layer, on the back of the unwilling male (Fig. 276), 
For a long time it was believed, and is so stated in most entomological books, 
that the female deposited the eggs on her own back, but it was discovered 
by Snodgrass that the female Serpius had no ovipositor capable of reach- 
ing to her back, and by Miss Slater that the female Zaitha is in similar con- 
dition. Miss Slater observed the egg-laying by aquarium specimens. The 
male struggles against the indignity, but is actually overcome by the female. 

Another small aquatic family of few species is that of the Nepide, or 
water-scorpions. These dirty brown, stick-like insects can be distinguished 
from other aquatic Hemiptera by the long slender respiratory tube, made 
up of separable hatves each grooved on its 
inner face, which projects from the tip of 
the abdomen. Rather sluggish in habit, 
they lie at the bottom of a shallow pool and 
lift this respiratory tube up so that its open 
tip reaches the surface. They are preda- 
ceous and have the fore legs modified for 
seizing prey, the other legs being fitted for 
walking or crawling over the bottom. There 
are two common genera in the family: Nepa, 
with flattened oval body less than three times 
as long (not including respiratory tube) as 


Fic. 277. Fic. 278. 


Fic. 277.—Young water-scorpion, Ranatra sp. (One and one-half times natural size.) 
Fic. 278.—Eggs of the water-scorpion, Ranatra fusca. (After Pettit; enlarged.) 


broad, and Ranatra (Fig. 277), with elongate slender body more than five 
times as long as broad. Like the giant water-bugs the water-scorpions 
lie in wait for their prey, trusting to their inconspicuous color and partial 
concealment in the mud and rubbish of the bottom to hide them from 
approaching victims. 


202 Bugs, Cicadas, Aphids, and Scale-insects 


By the edge of pond or stream may be found representatives of two other 
small families, most striking in appearance and manner, the dark-colored, 
squat, broad, rough bodied, big-eyed, leaping toad-bugs (Galgulide#) and 
the smaller, soft, long-oval, long-legged, running shore-bugs (Saldidz). 
One species of toad-bug, Gelastocoris oculatus (Figs. 279 and 280), is common 
all over the country and may often be found in considerable numbers on 
the muddy .banks of streams and ponds. It lives 
upon other insects, which it catches by creeping 
slowly to within a short distance and then suddenly 
leaping upon and seizing them with its strong front 


Fic. 279. Fic. 280. 


Fic. 279.—The toad-bug, Gelastocoris oculatus. (Three times natural size.) ; 
Fic. 280.—Three toad-bugs, Gelastocoris oculatus, ‘coming on.’’ (From life; three times 
(natural size.) 


legs. Toad-bugs vary in general coloration with the mud or soil they are 
on, so as to harmonize with the ground color and thus be undistinguishable. 
The shores of a small pond, Lagunita, on the campus of Stanford 
University, vary much in ground color, three shades, namely, reddish, slaty 
bluish, and mottled sand color, being the principal 
ones, and toad-bugs collected from the banks of 
this pond -show very noticeably all these distinct 
schemes of color. The shore-bugs (Saldide) are 
represented by but one genus, Salda (Fig. 281), of 
thirty or more species, in our country. The insects are 
about 3, inch long, smooth-bodied, and narrower than 
the toad-bugs, blackish with white or yellow markings, 
Fic. 281.—A shore- 
bug, Salda sp. (Six and have long slender antenne. They prefer stream 
times natural size.) or pond banks which are weedy or grassy and offer 
good hiding-places. They are common also on seabeaches. They feed 
on drowned flies and other insects, from which they suck the blood. They 
thus do some good as scavengers. 

The preceding ten families include all of the aquatic and strictly shore- 
inhabiting Hemiptera. The remaining sixteen families of the suborder 
Heteroptera, as well as all the families in both other suborders, are terres- 
trial, being found for the most part (the Parasita wholly excepted) on vegeta- 
tion, where food, either the juices of the plants, or the blood of other plant- 


Bugs, Cicadas, Aphids, and Scale-insects 203 


feeding insects, is found. This difference in food-habit is accompanied 
by more or less obvious structural differences. In the predaceous forms 
the fore legs are usually spined and fitted for seizing and holding the living 
victims, the other legs fitted for swift running, the beak is stout, firm, and 
sharp-pointed, the eyes are often large, protuberant, and flashing bright, 
and there is a general unmistakable air of ferocity about these miniature 
bloodthirsty dragons of the garden shrubbery. 

Five of the terrestrial families of Heteroptera are predaceous, the remain- 
ing eleven being composed of sap-suckers, although in one or two of these 
families a few species seem to have acquired a taste for blood-sucking. 

The largest predaceous family is that of the assassin-bugs, wheel-bugs, 
and soldier-bugs, the Reduviide. More than fifty genera belonging to 
this family are represented in this country, but so little are the bugs col- 
lected or even noticed by amateurs (or professionals either, for that matter) 
that but few of the species can be said to be at all familiarly known. And 
to use the word ‘‘familiarly” in this connection is to indulge in the figure 
of speech known as hyperbole. 

The Reduviids have an unmistakable look of ferocity, small and insig- 
nificant creatures as they are. The eyes are usually large and protuberant, 
looking like a pair of shining black beads set on the small outstretched head. 
The beak, 3-segmented, is strong, sharp-pointed, and large for the small 
head that carries ?t, and it projects forward in a suggestively eager way. 
While the ground or body color of the bugs is usually black, they are often 
conspicuously marked with blood-red and sometimes with yellow. The 
wingless young are in many species wholly red. A few years ago the news- 
papers were filled with references to a much dreaded “‘kissing-bug” (one 
of the Reduviids), the name being a satire on the stinging and poisoning 
capabilities of the bug’s beak or mouth. The sting, i.e., piercing by the 
beak, of the kissing-bug, and of all other Reduviids, is poisonous because 
of the injection of saliva into the wound, and this poisoning, which makes 
such a wound often very painful and sometimes rather serious to man, must 
be paralyzing and fatal to the more usual insect victims of the assassin-bugs. 
The usual “‘kissing-bug” of the newspapers is the masked bedbug-hunter, 
Opsicoetus personatus, an insect from 4 to ? inch long, blackish brown, 
with prothorax strongly constricted in the middle and _ longitudinally 
grooved along the middle of the upper surface. The entomologists’ 
name for this insect comes from the fact that the young exude a sticky 
substance over the body to which dust, lint, etc., adhere so as to cover or 
mask the body, and that the bugs enter houses and prey on bedbugs, cock- 
roaches, and flies. The bite or sting is unusually poisonous and severe. 

Another assassin-bug which forces its acquaintance on us is the “big 
bedbug,”’ or cone-nose, Conorhinus sanguisugus (Fig. 282), which comes 


204 Bugs, Cicadas, Aphids, and Scale-insects 


into houses primarily to drink human blood. It is about an inch long, 
pitchy brown or black, with long narrow head, and with bright red patches 
on the sides of the body and on the base and apex of the fore wings. These 
insects, whose normal outdoors food consists of various insects, often noxious 
ones, as locusts and potato-beetles, are specially common in the South, where 
Comstock says they not infrequently sting children. The banded soldier- 
bug, Milyas cinctus, is a common 
wide-spread friend of the farmer, 
preying on many kinds of noxious 
insects. It is yellow in all stages of 
development with conspicuous fine 
transverse black bands on legs and 
antenne. It roams about over plants 
F 7 from early summer to late autumn, 
1a eugeraucking, conn: enevolently assimilating. the blood 
and Marlatt; natural size.) of its various insect cousins. It glues 
its eggs to the bark of trees and covers them with a protecting water-proof gum. 
Another fairly well-known member of this family is the wheel-bug, Prionidus 
cristatus, especially common in the South. The full-grown bug is about 
an inch long, black, and has on its thorax a thin convex crest with nine teeth. 
This is the “‘wheel.”” The little jug-shaped eggs are laid in six-sided single- 
layered masses of about seventy, which are glued to the bark of trees, or on 
fence-rails, the sides of houses, etc. The young are blood-red, with black 
on the thorax. The wheel-bugs are specially beneficial because they are 
among the few predaceous insects that prey on the well-protected hairy 
caterpillars that infest our shade and orchard trees. 

Closely related to the Reduviids are the curious and readily recognized 
thread-legged bugs, Emeside. The few known species have the body very 
slender and long, and the legs and antenne simply like jointed threads. 
The fore legs, however, are spined and fitted for seizing prey. The common 
species, Emesa longipes (Fig. 283), has the body a little less than 14 inches 
long, each middle and hind leg a little more than 1} inches long, and the 
wings when folded not reaching the tip of the abdomen. It is clayey brown 
in color with a reddish tinge above. Howard says that one of the thread- 
legged bugs frequents spiders’ webs and robs the spiders of their prey. The 
damsel-bugs (Nabide) are another small family of predaceous insects which 
usually lurk among flowers and foliage where they capture small insects, 
but which in autumn may often be seen running about on sidewalks and 
elsewhere about houses, probably looking for winter hiding-places. One 
of the commonest and most conspicuous damsel-bugs is the shining jet-black, 
yellow-legged species Coriscus subcoleoptratus. The wings and wing-covers 
(in most individuals) are reduced to mere scales, the body is wide and plump 


Bugs, Cicadas, Aphids, and Scale-insects 205 


behind, tapering forward to the narrow prothorax and head. It is about 
3 inch long. The air-bush bug, Phymata wolfii, a rough, horny-bodied, 
yellowish-green insect with brown or blackish band across the abdomen, 
is about 4 inch long or less and the body is 
rather like some scaly seed. The abdomen is 
curiously widened behind into two thin, angular, 
scale-like expansions. It conceals itself in 
flower-cups and captures the. nectar-sucking 
insect visitors. It is very strong and overcomes 


TH~r 


Fic. 283. Fic. 284. 


Fic. 283.—A thread-legged bug, Emesa longipes. (Natural size.) 
Fic. 284.—A damsel-bug, Nabis fusca. (After Bruner; natural size indicated by line.) 


insects, as small butterflies, bees, and wasps, much larger than itself. 
Another small family of blood-sucking bugs is the Acanthiide, of which 
the most familiar is the wingless degenerate pest, the bedbug, Acanthia 
lectularia (Fig. 285), world-wide in distribution and detestation. To the 
fortunate few who have not at one time or other been forced to a personal 
acquaintance with this bug species it may be told that it is, when full-grown 
and fairly nourished, about % inch long, reddish brown in color, and broad 
and flat bodied. Small wing-scales or pads can be seen on close examina- 
tion of specimens. The bugs, both immature and adult, can run quickly 
and, because of their flatness, can conceal themselves in narrow cracks. In 
such crevices in bedsteads, in walls and floors, they hide by day, coming 
out at night to feed. In spring the females lay about two hundred oval 
white eggs in lots of fifty at a time in their haunts in crevices. The eggs 


206 Bugs, Cicadas, Aphids, and Scale-insects 


hatch in about a week and the young become full grown in about three months 
moulting five times during growth, but active and capable of “finding” for 
themselves from birth. In the northern states there is but one generation 
a year. The disagreeable bedbuggy odor is produced by a secretion of 
small glands opening, in the adult, on the under side of the body. Another 
species of Acanthia attacks chickens, pigeons, swallows, and bats, and 
Lugger found this species, A hirundinis, or another similar one, attacking 
in daytime the pupils in a school in western Minnesota. The best remedy 
is the free application with a quill-feather of a saturated solution of corrosive 
sublimate (Poison!) in alcohol to all cracks and crevices in infested bed- 
steads, walls, floors, and ceilings. When bedbugs cannot be found hiding 
in bedsteads in daytime and yet mysteriously appear every night, it is often 
because they drop from the ceiling. 


Fic. 285 Fic. 286. 


Fic. 285.—The bedbug, Acanthia lectularia; young at left and adult at right. (After 
Riley; natural size indicated by line.) 

Fic. 286.—A predaceous leaf-bug, Lyctocoris fitchii, (After Lugger, natural size 
indicated by line.) 


In this family belong several small inconspicuous insects called flower- 
bugs, which do much good by their persistent preying on noxious insects. 
The best-known species is the insidious flower-bug, Triphleps insidiosus, 
which preys on the chinch-bug. Another species 1s Lyctocoris fitch 
(Fig. 286), which preys on the larve of certain destructive wood-boring 
beetles. 

The remaining families, eleven, of American bugs find their food and 
drink, for the most part, in the juices of living plants. Like the blood- 
sucking bugs, they need for their feeding, and have, a well-developed suck- 
ing-beak. From the tip of the sheath (labium) can be thrust out the four 


Bugs, Cicadas, Aphids, and Scale-insects 207 


sharp stylets or lancets (maxilla and mandibles) to lacerate the plant-tissues, 
and then the pharyngeal pump sucks up from the wound the flowing sap. 
When too many pumps are drawing away too much sap, the leaves wilt, 
yellow, and die. When too many leaves wilt, the plant starves to death. 
And if the leaves happen to be the corn-leaves, and the pumpers chinch- 
bugs, we have the result estimated for us (by the official U. S. statistician) in 
millions of dollars of loss, as in 1887, when this particular loss in the Missis- 
sippi Valley states was $60,000,000. 

The eleven plant-feeding families of true bugs (Heteroptera) can be 
distinguished by the following key: 


Antenne 4-segmented. 
Fore wings reticulated and of uniform thin substance throughout ....... TINGITIDE. 
Fore wings of various forms or absent, but not reticulated, and not of uniform. thin 
substance throughout. 
Beak 3-segmented; body greatly flattened.................--0lesceeee ARADIDE. 
Beak 4-seymented; body not greatly flattened. 
Membrane (apical area) of fore wings with one or two closed cells at base, but 
otherwise: without, veins’ (lig) 268))ce- eae tee oes cee eicisies oare CAPSID. 
Membrane of fore wings with four or five simple or anastomosing longitudinal 
veins arising from the base; or with a larger number of veins arising from 
a cross-vein at the base. 
Ocelli wanting; membrane of fore wings with two large cells at the base, and 


from these arise branching veins (Fig. 268).....-....... PYRRHOCORIDE. 
Ocelli present. 
Head with a transverse incision in front of the ocelli.......... BERYTIDA. 


Head without transverse incision. 
Membrane of fore wings with four or five simple veins arising from the 
base of the membrane; the two inner ones sometimes joined to a 


cell near, ithe’ base’ (Wig. 268) /5° <0. sme oie geese LyG 21D, 
Membrane of fore wings with many usually forked veins springing from 
@ transverse: basal’ vein (Fig. 268). <5. con cecw-sccemnccce CoREIDZ. 


Antenne 5-segmented. 
Scutellum nearly flat, narrowed behind. 


‘Tibi unarmed or furnished with very fine short spines.......... PENTATOMIDE. 

Tibiz armed with strong spines in rows...-...........2-2-2---eeeeees CYDNIDZ. 
Scutellum very convex and covering nearly the whole of the abdomen. 

Small, black (sometimes with bluish or greenish tinge)......... CorRIMELEZNIDE. 

INGE SEOK. ope ncoosonnendocodoDEeoaebondoToscoooobsdseHensee SCUTELLERID. 


The first of the families in the above table, the Tingitida, includes the 
curious small lace-bugs (Fig. 287), readily recognized by the delicate gauze- 
or lace-like appearance of the back, due to the uniform thin and reticulated 
character of the fore wings and of the wing-like expansions of the prothorax. 
About twenty-five species are found in this country, all being plant-feeders, 
living mostly on shrubs and trees. Hawthorn-bushes and oak-, sycamore-, 
and butternut-trees all have particular species of lace-bugs on them. In the 


208 Bugs, Cicadas, Aphids, and Scale-insects 


south cotton and beans are also attacked by lace-bugs. The most familiar 
eastern species is the hawthorn lace-bug, Corythuca arcuata, which is com- 
mon on the leaves of hawthorn-bushes. The bugs keep almost exclusively 
on the under side of the leaves. The eggs are laid in small groups on the 
leaves, each egg being imbedded in a little bluntly conical mass of a brown 
sticky substance which hardens soon after egg-laying and looks much like 
a small fungus. The top of the glistening 
white egg can be seen, however, by looking 
down on one of these brown masses. The 
young is broadly oval and flattened in shape, 
brown and spiny, and moults five times in its 
development. The torn, delicate, whitish 
exuvie (cast skins) stick to the leaf. The 
adults hibernate under the fallen leaves 
on the ground beneath the bushes. In 
California a similar lace-bug, Corythuca sp., 
(Fig. 287), infests the Christmas berry, 
_ Heteromeles arbutifolia, a plant whose clusters 
Fic? adpo= The decease of bright ted berries take the place in Cali- 
thuca sp. of the California fornian Christmas-tide decorations of the 
Christmas berry, Heleromeles holly of the East. The eggs (Fig. 287) are 
arbutijolia; at bottom, eggs On Genocited in the same way as the hawthorn 
small tubercles on leaf; above, P e y € 
just-hatched young, intermediate lace-bugs’, and the life-history is practically 
abe nae es (Fight times the same. But because the California winter 
is much less severe and the Christmas berry 
is covered with green leaves all the year, active lace-bugs, young as well 
as adult, can always be found on the bushes. Lace-bugs, small as they 
are, injure any plant on which they gather in numbers, by the continual 
draining away of the sap. Spraying the infested bushes or trees with 
kerosene emulsion (p. 189) will kill the insects. 

The flattest of all the bugs, flatter than the bedbugs even, are the 
curious members of the small family Aradide. They live in the cracks or 
beneath the bark of decaying trees, and their dull brown color and flat leaf- 
like body make them very difficult to distinguish when at rest in their hiding- 
places. The glistening white eggs are laid under the bark. The flatbugs 
are often mistaken for bedbugs, as they are nocturnal and are often found 
in log cabins. But they probably feed exclusively on plant-sap, being 
especially attracted to mills and recently felled trees, where they suck up the 
sap exuding from the cut or sawed logs. Aradus cinnamomeus (Fig. 288) 
is about the same size as a full-grown bedbug and is reddish in tinge, so that 
superficially it does much resemble a bedbug. But most adult flatbugs 
have wings, while all the bedbugs are winoless. 


Bugs, Cicadas, Aphids, and Scale-insects 209 


The flower-bug family, Capside, contains two hundred and fifty known 
North American species, almost all of which, however, are small and incon- 
spicuous. They mostly live in pastures, meadows, gardens, and along 
roadsides, on the grasses, weeds, and herbaceous flowering plants of these 
places, but some infest woody plants and a few species do much damage 
to garden and orchard shrubs and trees. A few species are predaceous, 
and Howard has seen one species sucking the eggs of the imported elm-leaf 
beetle, a great pest of our elm-trees. The structural characteristic by which 
they can most readily be distinguished from other bugs is the presence of 
one or two closed cells and no longitudinal veins in the membrane (apical 
half) of each fore wing (Fig. 268). When examined closely many of these 


Fic. 289. FIG. 290. 


Fic. 288.—A flatbug, Aradus cinnamomeus. (After Lugger; enlarged about six times.) 

FIG. 289.—The tarnished plant-bug, Lygus pratensis. (Five times natural size.) 

Fic. 29¢.—The four-lined leaf-bug, Pecilocapsus lineatus; at right, eggs deposited in 
plant-stem. (Figure of insect original, enlarged three and a half times; of eggs, 
after Slingerland, and much enlarged.) 


little bugs will be seen to be elaborately patterned and beautifully colored, 
and their body outline is trim and graceful. They are active and quick 
to escape from the collecting-net. (The best way to collect them is by sweep- 
ing rankly growing herbage with a short-handled stout net.) Among the 
most abundant and wide-spread Capsids of economic importance is the 
tarnished plant-bug, Lygus’ pratensis (Vig. 289), which attacks many cul- 
tivated plants, as the sugar-beet, strawberry, pear-, plum-, apple-, quince-, 
and other fruit-trees. It is about £ inch long, and ranges from dull dark 
brown to yellowish or greenish brown. A yellowish-white V-shaped mark 
on the scutellum is its most characteristic marking. It hibernates in the 
adult stage, under fallen leaves or in any rubbish, and comes out in the spring 
to pierce and suck sap from tender buds and leaves. The four-lined leaf- 
bug, Pecilocapsus lineatus (Fig. 290), a small bright-yellow bug with head 


210 Bugs, Cicadas, Aphids, and Scale-insects 


and under side of body orange-red, and four black stripes on the back, is 
abundant in the east and north, and is known to attack at least fifty dif- 
ferent kinds of cultivated plants. It is especially familiar as a currant-pest. 
The eggs are deposited in slits cut lengthwise in plant-stems. The best 
general remedy for these bugs is the jarring of branches of the bushes over a 
dish partly filled with kerosene. Comstock says that the most abundant 
flower-bug in the northeastern states is a small greenish-yellow species with 
two longitudinal black stripes extending from the eyes over the prothorax 
and scutellum. It is long (? inch) and narrow (5 inch), is found in the 
grass in meadows, and its name is Leptoterna dolobrata. ‘The injury done 
by all Capsids is by the sucking of sap through small punctures and prob- 
ably also, in some cases, the pouring of poisonous saliva into the plant- 
tissues through the punctures. The attacked leaves or buds wilt, turn yellow, 
and finally wither. One of the beneficial Capsids is the glassy-winged bug, 
Hyaliodes vitripennis, a beautiful small yellowish-white insect with almost 
transparent fore wings, with a dash across the apex of these wings, and pro- 
thorax red. It feeds on other insects, and especially on the grape-phyl- 
loxera in its leaf-inhabiting form. Lopidea media is an abundant yellowish- 
red and black Capsid which has learned to like human blood. When it 
cannot have blood it is content with the sap of wild gooseberries. 

The family Pyrrhocoride is a small family of comparatively large and 
stout bugs, often conspicuous by their colors, of which red and black are 
the most usual. They may be recognized by their 
having the membrane (apical half) of the fore wings 
provided with two large basal cells from which 
several branching veins arise (Fig. 268). They are 
commonly known as ‘‘redbugs,’’ and the twenty- 
five species found in our country belong mostly to 
the south and west. The commonest species in 
the north is Largus succinctus (Fig. 291), a rusty 
blackish-brown bug about half an inch long, with 
yellowish or pinkish-orange margins on the front 
two-thirds of the back, and a transverse stripe of 
similar color across the base of the prothorax. The 
Fic. 291.—Redbug, Lar- young are steel-blue with a small bright-red dash on 

gus succinctus, (Twice 
natural size.) base of the abdomen between the backward-pro- 
jecting wing-pads. This species ranges from New 
Jersey to California and south into Mexico. The commonest species of 
the southern states, and one of great economic importance, is the red- 
bug or cotton-stainer, Dysdercus suturellus, which does much damage 
by piercing the stems and bolls of the cotton-plant and sucking the juices, 
but does even more damage by staining the cotton in the opening bolls 


Bugs, Cicadas, Aphids, and Scale-insects 21/1 


by its reddish-yellow excretions. Howard says that experiments have 
been made with this insect looking towards its use commercially, and that 
the whole substance of the insect can be converted into a rich orange- 
yellow dye which is readily fixed on woolens or silk by the alum mordant 
liquor. The cotton-stainer is a handsome bug, reddish in color with pale 
brown fore wings striped with pale yellow. The young are bright red with 
black legs. Comstock says that this insect also punctures oranges in 
Florida, so that the fruit begins to decay and drops from the tree. The 
insects can be trapped by laying chips of sugar-cane about the cotton-field or 
orange-grove: the bugs will gather about these chips and may be scalded 
to death. 

One of the largest families of true bugs is the Lygeide, made notorious 
by a small and obscure representative of it, which, according to the estimate 
of the United States Entomologist, causes our country an annual loss of 
$20,000,000. This insect is the chinch-bug, the 
worst pest of corn, and one of the worst of wheat 
and other small grains. Nearly two hundred species 
of Lygeids occur in this country, and most of 
them may fairly be called noxious insects. The 
family’s structural characteristic most readily noted 
is the presence of but four or five simple longitudinal 
veins in the membrane (apical half) of the fore wings 
(Fig. 268). The antenne rise rather from the under 
than the upper side of the head, and all of the members 
of the family have ocelli (simple eyes). While most 
of the Lygwids are small and inconspicuous, a few Fig, 292.—Lygeus turci- 
are comparatively large and bright-colored. The «#s-_ (After Lugger; 

- ‘ é much enlarged.) 

milkweed-bug, Oncopeltus fasciatus, about % inch 

long, orange above with most of head and prothorax except the margins 
black, and a broad black band across the middle of the fore wings and 
large black blotch on their tips, is a common showy bug on various 
species of milkweed. An odd-looking, long-necked, common member of 
the family is Myodocha serripes. It is about ~ inch long, with head long 
and narrow, expanding in front, and rising from a bell-shaped prothorax, 
the rest of the body being elongate and narrow. It is black, with the 
margins, sutures, veins, and some spots on the wing-covers yellow. It is 
common in meadows and thin woods, where it keeps half concealed under 
fallen leaves and twigs. In the south a small species, Pamera longula, 4 
inch long, dark brown with lighter brown on prothorax and fore wings, is 
abundant, feeding mostly on meadow plants. 

Among the many smaller species, the chinch-bug, Blissus leucopterus 
(Fig. 293), is the best known and most important. It is found nearly all 


212 Bugs, Cicadas, Aphids, and Scale-insects 


over the United States and in Canada, but the great losses occasioned by 
it occur mostly in the corn-growing states of the Mississippi Valley, where 
it has been known as a pest since 1823. I have seen great corn-fields in 
this valley ruined in less than a week, the little black and white bugs mass- 
ing in such numbers on the growing corn that the stalk and bases of the 
leaves were wholly concealed by the covering of bugs. The chinch-bug 
when adult is about 4 inch long, blackish with the fore wings semi-trans- 
parent white and with a conspicuous small trian- 
gular black dot near the middle of the outer margin. 
The very young are red, but become blackish or gray 
as they grow older. The bug is injurious in all 
stages, young, half grown, and adult. The life- 
history, in Kansas, is as follows: The eggs are laid 
in the spring (from middle of March to middle of 
May) by bugs which have hibernated in the adult 
stage. They are laid a few at a time, perhaps five 
hundred in all by each female. The young “‘red- 
bugs” begin work in the wheat-fields, and usually 
Fic. 293.—The chinch- Temain in the wheat until harvest (last of June to 
bug, Blissus leucopterus. middle of July), when the destructive host moves into 
oi times natural the fields of young and growing corn. It requires 
about six weeks for the maturing of the bugs. 
The adults now pair and the cycle of a new generation begins. The 
perfect insects of this generation are those which pass through the winter 
and lay the eggs the following spring for the next year’s first brood. It 
is highly probable if not certain that a third brood often appears in Kansas. 
The chinch-bug, though winged, uses its powers of flight but little, and its 
migrations from wheat- to corn-fields in July are usually on foot. The wings 
are used to’ some degree at pairing-time. 

The remedies for chinch-bug attacks include the gathering together in 
winter of all rubbish, old corn-leaves, dead leaves, etc., in which the old bugs 
hibernate, and burning it, which will destroy many parent bugs, thereby largely 
lessening the spring brood. Disputing the entrance of the bugs into the 
field, when migrating on foot, by plowing furrows around the field and 
pouring coal-tar or crude petroleum into these moats, is often effective. 
There are several natural remedies, namely, the attacks of predaceous insects, 
as aphis-lions, ladybird-beetles, and others, and the attacks of some birds, 
as the common quail. Most effective of all, however, is the rapid spread 
in a crowded field of a parasitic fungus, Sporotrichum globulijerum, which 
kills the bugs by the wholesale. This fungus cannot grow rapidly except 
in moist warm weather, and the bugs thrive especially in dry weather. So 
the rapid spreading and effective killing by this disease depends on favorable 


Bugs, Cicadas, Aphids, and Scale-insects 213 


meteorological conditions. The “‘chinch-bug cholera” is well established 
all through the Mississippi Valley, but it can be artificially spread by dis- 
tributing dead and infected bugs in fields where it has not begun to develop. 
This method is followed in several of the corn- and wheat-growing states 
whose entomolgists keep on hand a supply of this fungus—it can be artifi- 
cially cultivated on various nutrient media in the laboratory—to send out 
to farmers on request. The work was begun by Professor F. H. Snow of 
the University of Kansas, and though in the beginning its beneficial results 
were overrated, there is no doubt that much good has come from this wide- 
spread attempt to disseminate artificially the ‘‘chinch-bug disease.’’ 

The family Coreide, to which the squash-bug, the box-elder bug, and 
certain other more or less familiar insects belong, is another of the larger true 
bug families, being represented in this country by about two hundred species. 
In this family the membrane (apical half) of the fore wings is furnished 
with many veins, most of which arise from a cross-vein near the base (Fig. 
268), and the antennz arise from the upper side of the head. The squash- 
bug, Anasa tristis (Fig. 294), ill-favored and ill-smelling, is a pest of squashes 
and pumpkins all over the country. 
It is brownish black above, with some 
yellow spots along the edges of the 
body, and dirty yellow below. It hiber- 
nates in the adult stage, comes out in 
early spring, and lays its eggs on the 
young sprouts or leaves of squash- and 
pumpkin-vines. The young hatch in 
about two weeks and at first are green, 
but soon turn brown and _ grayish. 
They suck the sap from the growing Fic. 294. Fic. 295. 
vine, and soon stunt them or even kill Fic. 294.—A squash-bug, Anasa tristis. 

; (Natural size.) 

them. The remedy is to protect the yg. 29< —The box-elder bug, Leptocoris 
young plants by means of frames coy- trivittatus. (Twice natural size.) 

ered with netting. After the plants get well started the bugs cannot injure 
them so easily. The box-elder bug, Leptocoris trivittatus (Fig. 295), a con- 
spicuous black insect with three bright-red broad lines on the prothorax 
and the fore wings, with edges and veins of a more dingy red, has become 
familiar with the increased planting of box-elder trees in gardens and streets. 
In the Mississippi Valley and in the plains states these box-elders are much 
used for shade and ornamental trees because of their hardiness, and with this 
increased supply of trees the box-elder bugs have come to be very abundant. 
In late autumn they gather under sidewalks or, often, in stables and houses 
to pass the winter, and have led many housewives to think a new and 
enlarged kind of bedbug had come to town. The bug lives on the sap of 


214 Bugs, Cicadas, Aphids, and Scale-insects 


the trees until winter, and it does not care for much food while hibernating. 
As its mouth is a sucking-beak, it cannot possibly injure hard and dry house- 
hold substances, as some housewives claim. Another Coreid, not uncom- 
mon, is the cherry-bug, Metapodius femoratus, which punctures cherries to 
suck the juice from them. It is dark brown with a rough upper surface, 
and its hind femora are curved thick and knobby, while the hind tibia have a 
blade-like expansion. The leaf-footed plant-bug, Leptoglossus oppositus, 
is a Coreid destructive to melon-vines, recognizable by the remarkable 
leaf-like expansion of its hind tibiae. A similar leaf-footed species, Lepto- 
glossus phyllopus, occurs in the south, where it attacks oranges and other 
subtropical fruits. 

Allied to the Coreidz is the family Berytide, or stilt-bugs, of which but a 
few species are known in this country. One of these, Jalysus spinosus, 
is common all over the country east of the Sierra Nevadas. It is about 4 
inch long, very slender, and light yellowish brown in color, and is found 
“in the undergrowth of oak woods.” Its life-history is not known. 

The remaining four families of true bugs are distinguished by their 
possession of 5-segmented (instead of 4-segmented) antenne (with a few 
exceptions) and by having the body broad, short, and flatly convex,—shield- 
shaped it may then fairly be called,—or very convex or turtle-shaped. Almost 
all of these bugs are exceptionally ill-smelling and have on this account 
got for themselves the inelegant but expressive popular name of stink-bugs. 
As a matter of fact the giving off of offensive odors is characteristic of most 
of the terrestrial true bugs, the squash-bug, chinch-bug, and others being just 
about as malodorous as the so-called stink-bugs. 

Of these four families of shield-bodied bugs, one, the Pentatomide, is 
represented in this country by numerous species, but the other three con- 
tain but one or two genera each. While most of the Pentatomids, or stink- 
bugs, are plant-feeders, a few are blood-sucking, while some feed indifferently 
on either animal or plant juices. Several of the more common Pentatomids 
are green, as the large green tree-bug, Nezara pennsylvanica, nearly } inch 
long, flattened, with grass-green body margined with a light yellow line, 
occurring in the fall on grape-vines and other plants; and the bound tree- 
bug, Lioderma ligata, much like Nezara, but with broader body edging of 
pale red and with a pale-red spot on the middle of its back, found 
often abundantly on berries and hazel. Other common stink-bugs are 
brown, as the various species of Euchistes. Still others are conspicuously 
colored with red and black, as the abundant small species Cosmopepla car- 
nijex, about 4 inch long, shining black with red and orange spots, most con- 
spicuous of which are a transverse and a longitudinal line in the back of 
the prothorax. The best known and most destructive of these bizarre- 
colored stink-bugs is the harlequin cabbage-bug, or calico-back, Murgantia 


Bugs, Cicadas, Aphids, and Scale-insects 25 


histrionica (Fig. 296), black with red or orange or yellow strips and spots, 
which has gradually spread from its native home in Central America to 
all except the northern states of our country. It feeds on cabbages, radishes, 
turnips, and other garden vegetables, and often does great damage in market- 
gardens. In California it has to be fought vigorously in the large market- 


Fic. 296. FIG. 297. Fic, 298. 


Fic. 296.—The harlequin cabbage-bug, Murgantia histrionica. (Twice natural size.) 

Fic. 297.—The spined tree-bug, Podisus spinosus. (After Lugger; natural length, 
2 inch.) 

Fic. 298.—A stink-bug, Pentatome juniperina. (One and one-half times natural size.) 


and seed-gardens of the Santa Clara Valley. The adults hibernate, and in 
the spring each female lays about twelve eggs in two parallel rows on the 
under surface of the young leaves. The young bugs, which are pale green, 
hatch in three days, and in two or three weeks are full grown, There can 
thus be several generations in a season. 

Among the predaceous or blood-sucking stink-bugs the species of the 
genus Podisus are especially common and effective. They destroy many 
injurious insects. Podisus spinosus (Fig. 297), the most familiar species, 
may be recognized by the prominent spine-like processes projecting from 
the posterior lateral angles of the prothorax. The large gray tree-bugs 
of the genus Brachymena with roughened spiny back and grayish body- 
color may be found resting on the bark of trees, with whose color and rough- 
ness they harmonize so thoroughly as to be nearly indistinguishable. They 
feed indifferently on either plant-sap or the blood of other insects. 

Representatives of the three other families of shield-backed or stink- 
bugs will be rarely found by general collectors. The flea-like negro-bug, 
Corimelena pulicaria (family Corimelenide), is a tiny, very malodorous, 
polished black species often abundant on blackberries and raspberries, 
with which it often goes to market and even farther! The burrower-bugs 


216 Bugs, Cicadas, Aphids, and Scale-insects 


(family Cydnide) have an oval rounded or elliptical blackish body with the 
front legs more or less flattened and fitted for digging. They are found 
burrowing in sandy places or under sticks or stones. They probably suck 
the sap from plant-roots. 


SUBORDER PARASITA. 


The members of the suborder Parasita are the disgusting and discom- 
forting degenerate wingless Hemiptera known as lice. They live parasitic- 
ally on the bodies of various mammals, the ones most familiar being the 
three species found on man, all belonging to the genus Pediculus, and the 
several species of the genus Haematopinus found on domestic animals, as 
dogs, horses, cattle, sheep, etc. Both these genera together with a few 
others found on various wild animals, belong to the Pediculida, the single 
family of the suborder represented in this country. The only other family, 
Polycterride, contains but two species, both found on bats, one in Jamaica 
and the other in China. 

All the Pediculids are wholly wingless, have the mouth-parts fused to 
form a flexible sucking-tube, and the feet provided with a single strong curved 
claw which specially adapts them for clasping and clinging to hairs. The 


FIG. 2099. FIG. 300. 


Fic. 299.—The head-louse of man, Pediculus capitus. (After Lugger; natural size 
indicated by line.) 

Fic. 300.—The body-louse of man, Pediculus vestimenti. (After Lugger; natural size 
indicated by line.) 


sucking-beak has been described by Uhler as “‘a fleshy unjointed rostrum 
capable of great extension by being rolled inside out, this action serving 
to bring forward a chaplet of barbs which imbed themselves in the skin to 


Bugs, Cicadas, Aphids, and Scale-insects 217 


give a firm hold for the penetrating bristles arranged as chitinous strips in 
a long, slender, flexible tube terminated by four very minute lobes which 
probe to the capillary vessels of a sweat-pore.” Of the three species of 
Pediculus infesting unclean persons, P. capitus (Fig. 299), the head-louse, 
is longer than wide, whitish with faint dark markings at the sides of the 
thorax and abdomen; P. vestimenti (Fig. 300), the body-louse, is of the 
same shape and general appearance, but when full grown has _ the 
dorsal surface marked with dark transverse bands; while P. inguinalis 
(Fig. 301), the crab-louse, has the body as wide as long, with strong 
legs spreading out laterally so as to increase the apparent width very 


Fic. 301. FIG. 302. FIG. 303. 


Fic. 301.—The crab-louse of man, Phthirius inguinalis. (After Lugger; much enlarged.) 

Fic. 302.—Egg of crab-louse, Phthirius inguinalis. (After Lugger; much enlarged.) 

Fic. 303.—Sucking dog-louse, Hematopinus piliferus Burm. (After Lugger; natural 
size indicated by line.) 


much. The eggs (Fig. 302), called “‘nits,” of these lice are whitish and are 
glued to the hairs (in the case of P.capitus) or deposited in folds of the 
clothing (P. vestimenti), and the young, when hatched, resemble the parents 
except in size. The whole life is passed on the body of the host. The prime 
remedy for these disgusting pests is cleanliness. Various sulphur and mercu- 
rial ointments will kill the insects. 

The lice of the domestic animals belong to a different genus, Hama- 
topinus, but are very similar in appearance and structure to the head-lice 
of man. H. pilijerus (Fig. 303), of dogs, is about 75 inch long, reddish 
yellow, and with the abdomen thickly covered with fine hairs and minute 
tubercles; Hl. eurysternus (Fig. 304), the short-nosed ox-louse, of cattle, 
is from } inch to } inch long, fully half as wide, with the head bluntly 
rounded in front and nearly as broad as long; H. vituli, long-nosed ox-louse, 


218 Bugs, Cicadas, Aphids, and Scale-insects 


also of cattle, is about $ inch long and not more than } as wide, with long 
slender head, narrow in front; H. urius (Fig. 305), of hogs, is } inch long, 
being one of the largest of the sucking-lice, with broad abdomen and long 
head, and gray in color, with the lateral margins of head, thorax, and abdo- 


Fic. 304. 


Fic. 304.—Short-nosed cattle-louse, Hematopinus eurysternus. (After Lugger; natural 


length 1.5 mm.) 
Fic. 305.—The hog-louse, Hematopinus urius. (After Lugger; natural size indicated 
by line.) 


men black; H. pedalis, the sheep-foot louse, found only on the legs and 
feet of sheep, below the long wool, has a short, wide head and same general 
shape as the short-nosed ox-louse; H. asini, of horses, of about same size 
as the short-nosed ox-louse, but with long and slender head with nearly 
parallel sides; H. spinulosus, of the rat, small, light yellow, and with the 
head projecting very little in front of the antennz and the thorax very short; 
H. acanthopus, of the field-mouse, resembling the rat-louse in color and 
shape, but larger; H. ventricosus, of rabbits and hares, thick-bodied and 
short-legged and with abdomen nearly circular; H. antennatus, of the 
fox-squirrel, with long slender body and curious curved tooth-like process 
on basal segment; H. sciuropteri, of the flying squirrel, with sender light- 
yellow body, and head as broad as long, and with front margin nearly 
straight; HH. suturalis, of the ground-squirrels and chipmunks, with short 
broad golden-yellow body. The eggs of all these forms are glued to the 
hair of the hosts, the young louse escaping by the outer or unattached end 
and immediately beginning an active blood-sucking life. The most effective 


Bugs, Cicadas, Aphids, and Scale-insects 219 


and feasible remedy in the case of thin-haired animals, as swine and horses, 
is the application of a wash of tobacco-water or dilute carbolic acid, or of 
an ointment made of one part sulphur to four parts lard, or kerosene in 
lard, or of a liberal dusting with wood ashes or powdered charcoal; in the 
case of thick-haired animals, as cattle, the best remedy is fumigation by 
enclosing the animal in a sac or tent with the head left free, and burning 
sulphur or tobacco inside the sack. One to two ounces of tobacco and 
exposure of twenty to thirty minutes for each cow have been found effective. 


A BRIEF account of the curious little insects known as thrips may be 
appended here to the chapter on the Hemiptera (Fig. 307). These narrow- 


SS} 


api 


FIG. 306. FIG. 307. 


Fic. 306.—The sheep-louse, Hematopinus ovis, female and egg. (After Lugger; natural 
size of insect indicated by line; egg much enlarged.) 
Fic. 307.—Thrips, Phorithrips sp. (Much enlarged.) 


bodied, fringe-winged, yellowish or reddish brown or blackish little creatures 
can be most readily found in flower-cups, which they frequent for the sake 
of sucking the sap from the pistils and stamens or the delicate sepals 
and petals. Some of them move slowly when disturbed, but others run 
quickly or leap, and nearly all show an odd characteristic bending up of 
the tip of the slender abdomen. This movement is usually preparatory 
to flight (in the case of winged individuals), and is believed to be the means 
of separating and combing out the fringes which border both fore and hind 
margins of each wing. There are fine spines on the sides of the abdomen, 
and the movement of the abdomen seems to draw the fringe-hairs through 
these comb-like rows of spines. The thrips vary in size from 31, to } of 
an inch, and may be certainly known by their narrow fringed wings (when 


220 + Bugs, Cicadas, Aphids, and Scale-insects 


present), which, when the insect is at rest, are laid back along the abdomen 
unfolded, and parallel or slightly overlapping at the tips. Only about forty 
species are yet known in this country, but as practically only one entomol- 
ogist has attempted to make a systematic study of the group and his speci- 
mens were mostly collected in a single locality (Amherst, Massachusetts), 
it is certain that many species are yet to be found and named. This 
entomologist, Hinds, has published in a recent paper (Contrib. to a Mon- 
ograph of the Thysanoptera of N. A., Proc. U. S. Nat. Mus., vol. xxvi, 
1902) practically all that is known of our American species, and I have 
largely drawn on his paper for the present short account. 

Although the thrips used to be classified as a family of the order Hemip- 
tera, they are now, and rightly, assigned to an order of their own, called 
Thysanoptera (fringe-wings). This separation is due te the peculiar charac- 
ters of their mouth-parts and of the feet, and 
to the interesting character of their develop- 
ment, which is apparently of a sort of tran- 
sitional condition between incomplete and 
complete metamorphosis. The food of the 
thrips is either the sap of living plants or 
moist, decaying vegetable matter, especially 
wood and fungi. The mouth-structure in ac- 
cordance with this food habit is of a sucking 
type, with mandibles and maxille modified to 
be needle-like to pierce the plant epidermis. 
But the mouth-parts are curiously asym- 
metrical, the right mandible being wholly 
wanting and the upper lip being more ex- 
panded on one side than the other (Fig. 308). 
The peculiarity in the life-history consists in 
a quiescent, non-food-taking stage like the 
pupal stage in insects of complete metamor- 
Figs 08 leas een amoathe phosis, but before reaching this stage well- 

parts, much enlarged, of developed external wing-pads have appeared, 
thrips. amt, antenna; J. just as happens in the case of immature 
labrum; md., mandible; mx., * F 5 : 
maxilla; mx.p., maxillary pal- Insects of incomplete metamorphosis. Finally, 
pus; /i.p., labial palpus; m.s., the peculiar character of the feet is due to the 
mouth-stylet. (After Uzel; - . “¢ 
much enlarged.) presence of a small protrusile or expansile 
membranous sac or bladder at the tip of the 
tarsus, instead of claws or fixed pads, which seems to play a not well 
understood function in the holding on by the insect to the leaf or 
flower parts which it may have occasion to visit. The bladder seems 


Bugs, Cicadas, Aphids, and Scale-insects 2a 


to be expanded by becoming suddenly filled with blood, and contracted 
by a receding of the blood. 

The eggs are laid either under bark or on the surface of leaves or, in 
the case of certain species which have a sharp little ovipositor, underneath 
the leaf-epidermis. They hatch in from three to fifteen days, varying with the 
different species observed, and the young grow and feed for from five to 
forty days. ‘Then follows the brief, quiet, non-feeding stage, and the insect 
becomes mature. Probably several generations appear in a year. The 
winter is passed in either larval, pupal, or adult stage, under bark, in dry, 
hollow plant-stems, in lichens or moss, or on the ground under fallen leaves. 
A curious variation in the adults of many species has been noted in reference 
to the wings; adult individuals of a single species may have either fully 
developed wings, very short functionless wings, or even none at all; both 
sexes may be winged, or one winged and the other not; one or both sexes 
may be short-winged or both be wingless. There seems to exist a condi- 
tion somewhat like that in the plant-lice (Aphididz), wings being developed 
in accordance with special needs or influences, as scarcity of food, time of 
the year, etc. 

Another peculiarity of the adults is the rarity, and even, apparently, 
the total lack of males in some species. Parthenogenetic development (the 
production of young from unfertilized eggs) is very common throughout 
the order. 

While the food of those thrips most easily found by the beginning student 
' is the sap taken from flower parts, most of the sap-drinking species get their 
supply from the leaves of various plants, and when these plants happen to 
be cultivated ones of field or garden, and the thrips are abundant, these 
tiny insects get the ugly name of “‘pests.” Three species in particular are 
recognized by economic entomologists as pests, viz., the onion-thrips 
(Thrips tabdci), the wheat-thrips (Euthrips tritici), and the grass-thrips 
(Anaphothrips striatus). The first of these is about »'; inch long, about 
one-fourth as wide as long, and of a uniformly light-yellowish to brownish- 
yellow color. It feeds on many different cultivated plants, as apple, aster, 
blue grass, melons, clover, tobacco, tomato, cauliflower, etc., etc., but its 
chief injuries seem to be to onions and cabbages. It occurs all over Europe, 
England, and the United States, and is probably the most injurious species 
in the order. The wheat-thrips, also but »'; inch long, brownish yellow 
with orange-tinged thorax, attacks many plants besides wheat, and is very 
fond of puncturing the pistils and stamens of strawberry-flowers, thus often 
preventing fertilization and consequent development of fruit. The life- 
cycle of this species is very short, requiring only twelve days. Eggs depos- 
ited in the tissues of infested plants hatch in three days, the larve are full- 


222 Bugs, Cicadas, Aphids, and Scale-insects 


grown in five days, and the quiescent pseudo-pupal stage lasts four days. 
The grass-thrips is the cause of the injury or disease of meadow and pasture 
grasses known as ‘“‘silver top”? or “‘white top,’ a common trouble in the 
northeastern states. The male sex seems to be wanting in this species, the 
young all developing parthenogenetically. 


CHAPTER XI 


Ss THE NERVE-WINGED INSECTS 
(Order Neuroptera) SCORPION-FLIES 
(Order Mecoptera), AND CADDIS- 
FLIES (Order Trichoptera). 


INN-ZUS, the first great classifier of animals and 
plants, found in the character of the wings a 
simple basis for grouping insects into orders. 
For the wingless insects he established the order 
Aptera;* the two-winged ones he called Diptera; 
the moths and butterflies, with scale-covered 

wings, he called Lepidoptera; the beetles with their horny sheath-like fore 
wings he termed Coleoptera; the thin- and membranous-winged ants, bees, 
wasps, and ichneumon-flies he named Hymenoptera; to the roaches, crickets, 
locusts, and katydids, with their parchment-like straight-margined fore wings, 
he gave the name Orthoptera; the sucking-bugs with their fore wings 
having the basal half thickened and veinless, the apical half membranous 
and veined, he called Hemiptera; and finally he grouped the heterogeneous 
host of dragon-flies, May-flies, ant-lions, lace-winged flies ef al., with their 
thin netted- or nerve-veined wings, in the order Neuroptera. 

In the light of our present greatly increased knowledge of the structure 
and development (the two bases of classification) of insects, this primary 
Linnean arrangement can no longer be accepted as an exposition of the 
true relationships among the larger groups of insects; that is, it is obviously 
not a natural classification. Its greatest faults are that it groups together 
in the Aptera degenerate wingless members of various unrelated groups with 
the true primitively wingless insects, and places together in the Neuroptera 
a host of insects of somewhat similar superficial appearance, but of radically 
dissimilar fundamental structure and development. With increasing knowl- 
edge of the characteristics of the -various subgroups in the Linnean order 
Neuroptera, the too aberrant ones have been gradually one by one removed, 


* Aptera, from a, without, pleron, a wing; Diptera, from dis, double, pteron, a wing; 
Lepidoptera, from /epis, a scale, pteron, a wing; Coleoptera, from koleos, asheath, pteron, 
a wing; Hymenoptera, from humen, a membrane, pleron, a wing; Orthoptera, from orthos, 
straight, pleron, a wing; Hemiptera, from hemi, half, pleron, a wing; Neuroptera, from 
neuron, a nerve, pleron, a wing. 


223 


224 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


and in most cases given specific ordinal rank. Thus we now consider the 
May-flies to from an order, the stone-flies another, the dragon-flies still 
another, and so on. There are left, grouped together as the order Neu- 
roptera, seven families which possess the common characteristics of netted- 
veined wings (numerous longitudinal and cross veins), mouths with well- 
developed biting or piercing jaws (mandibles), and a development with com- 
plete metamorphosis. Further than this little can be said to characterize 
the order as a whole, and we may proceed at once to a consideration of the 
various distinct families. 


KEY TO THE FAMILIES OF NEUROPTERA. 


A. Prothorax as long as or longer than the mesothorax and the metathorax combined. 
B. Fore legs greatly enlarged and fitted for grasping............ MANTISPIDE. 
BB. Fore legs not enlarged and not fitted for grasping........--...- RAPHIDIID. 
AA. Prothorax not as long as the mesothorax and the metathorax combined. 
B. Hind wings broad at the base, and with that part nearest the abdomen (the 
anal area) folded like a fan when not in use............---..-.- SIALID. 
BB. Hind wings narrow at base, and not folded like a fan when closed. 
C. Wings with very few veins, and covered with: whitish powder. 
CONIOPTE RYGID&: 
CC. Wings with numerous veins, and not covered with powder. 
D. Antenne gradually enlarged towards the end, or filiform with a 
tenn kn Obeee se 6 see ee eee ase eee MyRMELEONID#. 
DD. Antenne without terminal enlargement. 
E. Some of the transverse veins between the costa and subcosta 
forked (in all common forms), wings brownish or smoky. 


HEMEROBIID. 
EE. Transverse veins between the costa and subcosta simple, 
wings) preenish=/.~..cosh ace oreet nn s Peecane CHRYSOPID. 


While most of the Neuroptera are terrestrial in both immature and adult 
life, one family, the Sialide, includes forms whose larve are aquatic. There 
are only three genera in the family, but all are fairly familiar insects to col- 
lectors and field students. The adults of these genera can be distinguished 
by the following key: 

Fourth segment of the tarsus bilobed; no simple eyes (ocelli).........--...---- SIALIsS. 
Fourth segment of the tarsus simple, cylindrical; three simple eyes (ocelli). 

Antennz with segments enlarged at the outer ends; hind corners of the head rounded. 

CHAULIODES. 

Antennz with segments cylindrical; hind corners of the head with a sharp angulation 

Onitoothts se sae ee a) ne eae ee eer Fa ete ae ae ey a ia eee CorRyDALIs. 


The larve can be distinguished by the following key: 
Tip of abdomen bearing a single long, median, laterally fringed tail-like process. .SIALIs. 
Tip of abdomen forked, the two fleshy projections each bearing a pair of hooks. 
Lateral filaments (soft, slender, tapering processes projecting from the sides of the abdom- 
inal segments) with no tuft of short hair-like tracheal gills at base. .. CHAULIODES. 
Lateral filaments each with a tuft of short, hair-like, tracheal gills at base. .CoRYDALIS. 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 225 


Two species of Sialis occur in this country; they are called alder-flies, 
or orl-flies. The smoky orl-fly, Sialis injumata, widely distributed over 
this country, is a dusky brownish in- 
sect about 4 inch long, often seen, with 
wings closely folded, sitting on sedge- 
leaves near quiet waters. The larve 
(Fig. 309), according to Needham, live 
in marshy places filled with aquatic 
plants, on the borders of streams and 
ponds. When full grown they are 
about an inch long, and keep up an 
undulating motion with the abdomen, 
the long tail being intermittently lashed 
up and down. When full grown the ; 
larva crawis out of the water and at Fic. 309.—Larva (at right) and pupa (at 
some litle distance burrows into the MAC amos Salk inima 
moist soil for a few inches or even a 
foot or more. Here it forms an oval cell and pupates within it. Two or 
three weeks after the adult fly issues. 

Of Chauliodes, the fish-flies (Fig. 310), eight North American species 
are known. The adults are from 14 to 2} inches long, and their wings 
expand from 24 to 4 inches. The wings are grayish or brownish with whitish 
spots or bands, and the antenne are curiously feathered or pectinate. The 


Fic. 310.—The saw-horned fish-fly, Chauliodes serricornis, laying eggs. 
(After a photograph from life by Needham; natural size.) 


larve live in wet places at the edge of water or in water close to the surface. 
According to Needham they are perhaps oftenest found clinging to the under 
side of floating longs or crawling beneath the loosened bark. They are 
predaceous, feeding upon other aquatic insects. When ready to transform 
they excavate a cell above the level of the water under a stone or log or layer 


226 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


of moss or in a rotten log, in which they pupate, and from which the adult 
fly issues in about two weeks. 

The genus Corydalis (Fig. 311) is represented by a single species, C. cornuta, 
but it is such a conspicuous and wide-spread insect that it is probably the 
best-known species in the whole order 
Neuroptera. The adult fly is most com- 
monly called ‘‘hellgrammite,’’ while the 
larve (Fig. 312), much used by fisher- 
men as bait, are known as dobsons or 
crawlers. But other names are often 
used. Howard lists the following array 
of names, collected by Professor W. W. 
Bailey, which are applied to the larva 
in Rhode Island alone: dobson, crawler, 
arnly, conniption-bug, clipper, water- 
grampus, gogglegoy, bogart, crock, hell- 
devil, flipflap, alligator, Ho Jack, snake- 


Fic. 311. Fic. 312. 


Fic. 311.—Dobson-fly, Corydalis cornuta, male, with head of female above. (Natural 
size.) 
Fic. 312.—Larva of dobson-fly, Corydalis cornuta. (Natural size.) 


doctor, dragon, and hell-diver. The insect is very common about Ithaca, 
N. Y., and Professor Comstock of Cornell University gives the following 
account of its life-history as observed by him there: “‘ The larve live under 
stones in the beds of streams. They are most abundant where the water 


Nerve-winged Insects ; Scorpion-tlies ; Caddis-flies 227 


flows swiftest. They are carnivorous, feeding upon the nymphs of stone- 
flies, May-flies, and other insects. When about two years and eleven months 


Fic. 313.—Head of larva, pupa, and adult of dobson-fly, Corydalis cornuta, showing 
development of the mouth-parts of the adult within the mouth-parts of the larva. 
A, head of a larva with its cuticle dissected away on the right-hand side, revealing 
the pupal parts; B, head of male pupa with cuticle dissected away on right-hand 
side, revealing developing imaginal parts; C, head of female pupa with cuticle 
wholly removed, showing imaginal parts; D, head of adult male. md., mandible; 
mx., maxilla; /7., labium; 1b., labrum; ant., antenna; L.h., larval head-wall; p.h., 
pupal head-wall; ga., galea; Ji.p., labial palpus; mx-p., maxillary palpus. Any 
of these terms may be prefixed by/, larva; p, pupa; or i, imago. 


old the larva leaves the water, and makes a cell under a stone or some other 
object on or near the bank of the stream. This occurs during the early 


228 Nerve-winged Insects; Scorpion-flies ; Caddis-flies 


part of the summer; here the larva changes to a pupa. In about a month 
after the larva leaves the water the adult insect appears. The eggs are 
then soon laid; these are attached to stones or other objects overhanging 
the water. They are laid in blotch-like masses which are chalky-white 
in color and measure from half an inch to nearly an inch in diameter. A 
single mass contains from two thousand to three thousand eggs. When 
the larvee hatch they at once find their way into the water, where they 
remain until full-grown.” " 

In the Kansas corn-fields I used to find certain wonderfully beautiful, 
frail, gauzy-winged insects resting or walking slowly about on the great 
smooth green leaves. The eyes of these insects shone like burnished copper 
or shining gold, and this with the fresh clear green (tinged sometimes with 
bluish, sometimes with yellowish) of the lace-like wings and soft body made 
me think them the most beautiful of all the insects I could find. But a 
nearer acquaintanceship was always unpleasant; when “‘collected” they 
emitted such a disagreeable odor that admiration changed to disgust. These 
lace-winged or golden-eyed flies are common all over the country and com- 
pose a family of Neuroptera 
called Chrysopide. All except 
two species of the family belong 
to the single genus Chrysopa, 
which includes more than thirty 
species found in the United 
States. In the Chrysopide the 
larve are not aquatic as in the 
family Sialide, but are active 
and fiercely predaceous little 
creatures called aphis-lions, that 
crawl about over herbage and 
shrubbery in search of living 
aphids (plant-lice) and other 
small soft-bodied insects. The 
Fic. 314.—The golden-eyed or lace-winged fly, je Genie AEE 314) = ei 

Chrysopa sp.; adult, eggs, larva, “aphis-lion,” of long, sharp-pointed, slender 
and pupal cocoons on the under side of leaf. jaws which are grooved on the 
(Natural size.) inner face. Having found a 
plant-louse it pierces its body with the sharp jaw-points, and holds it up, so 
that the blood of its victim runs along these grooves into its thirsty throat. 
The Chrysopa larve will bravely attack insects larger than themselves, or will 
quite as readily prey on the defenceless eggs of neighbor insects, or indeed of 
their own kind. Indeed, probably because of this egg-sucking habit the female 
lace-winged fly deposits her eggs each on the tip of a tiny slender stem, about 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 229 


half an inch high, fastened at the base to a leaf or twig (Fig. 314). When 
the first larvee hatch they crawl down the stems and wander around in this 
little forest of egg-trees, but fortunately haven’t wit enough to crawl up to 
the still unhatched eggs of their brothers and sisters. When the aphis-lion 
is full-fed and grown, which, in the studied species, occurs in from ten days 
to two weeks, it crawls into some sheltered place, as in a curled leaf or 
crevice in the plant-stem, and spins a small, spherical, glistening, white, 
silken cocoon, within which it pupates. In another ten days or two weeks 
the delicate lace-winged golden-eyed green imago bites its way out, cutting 
out a neat circular piece. 

In the family Hemerobiide are some insects whose larve are also called 
aphis-lions; these belong to the typical genus Hemerobius. But in two 
rare genera of the family, Sisyra (Fig. 315) and Climacia, the immature 
stages are aquatic, the small larve (about } inch long) living as parasites 


Fic. 3155. FIG. 315¢. Fic. 317. 


Fic. 315.—Sisyra umbrata. a, adult; b, larva; ¢, pupa. (All about five times natural size.) 
Fic. 316.—Polystechotes punctatus. (Natural size.) 
Fic. 317—Hemerobius sp. (Three times natural size.) 


on or in fresh-water sponges (Spongilla). The largest members of the 
family belong to the genus Polystcechotes, of which two species are known. 
The commoner one, P. punctatus (Fig. 316), is about 1} inches long and its 
wings expand 2 to 3 inches. It is nocturnal and is to be collected about 


230 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


lights. Its body is blackish, and the wings are clear but mottled with irreg- 
ular brownish-black spots. When at rest the wings are held steeply roof- 
like over the back. Nothing is known of its life-history. Of the best-known 
genus, Hemerobius (Fig. 317), twenty species have been noted in this country, 
but they are small, dull-colored insects, and are rather rare, or at least 
infrequently seen. Comstock says they occur in forests and especially on 
coniferous trees. The larve are like the Chrysopa larve, predaceous and 
well equipped with big strong head and sharp, curved seizing and blood- 
sucking mouth-parts. The larve (Fig. 318) of some species have the 
curious habit of piling up on their back the empty, shriveled skins of their 
victims, until the aphis-lion is itself almost wholly concealed by this unlovely 
load of relicts. This is true of all the Hemerobius larve I have seen in 
California. Stripped of the covering of skins the aphis-lion is seen to have 
a short, broad, flattened body, with numerous long, spiny hairs arising from 
tubercles. These hairs help to hold the mass of insect skins together. 
Still other Neuroptera with fierce, ever-hungry, carnivorous larve are 
the ant-lions, or Myrmeleonide. The horrible pit of Kipling’s story, into 


Fic. 318. Fic. 319. FIG. 320. 

Fic. 318.—Larva of Hemerobius sp. covered with detritus. (From life; four times natural 
size.) 

Fic. 319.—Larva of ant-lion, Myrmeleon sp. (Three times natural size.) 


Fic. 320.—Pit of ant-lion and, in lower right-hand corner, pupal sand-cocoon, from 
which adult has issued, of ant-lion, Myrmeleon sp. (About natural size.) 


which Morrowbie Jukes rode one night, is paralleled in fact in that lesser 
world of insect life under our feet. The foraging ant, too intent on bringing 
home a rich spoil for the hungry workers in the crowded nest to watch care- 
fully for dangers in its path, finds itself without warning on the crumbling 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 231 


verge of a deep pit (Fig. 320). The loose sand of the pit’s edge slips in and 
down, and the frantic struggles of the unlucky forager only accelerate the 
tiny avalanche of loose soil and sand that carries it down the treacherous 
slope. Projecting from the very bottom of the pit is a pair of long, sickle- 
like, sharp-pointed jaws, adapted most effectively for the swift and sure 
grasping and piercing and blood-letting of the trapped victims. The body 
of the ant-lion (Fig. 319) is almost wholly concealed underneath the sand; 
only the vicious head and jaws protrude above the surface in the pit’s depths. 
Comstock has seen the ant-lion throw sand up from the bottom, using its 
flat head like a shovel in such a way that the flung sand in falling would 
strike an ant slipping on the slope and tend to knock it down the side. Ant- 
lion pits are to be found all over the country, in warm, dry, sandy places. 
The ant-lions can be brought home alive, and kept in a dish of sand, where 
their habits may be observed. 

The adult ant-lion (Fig. 321) is a rather large, slender-bodied insect 
with four long oar-shaped gauzy wings, thickly cross-veined and usually 
more or less spotted with brownish or black. The eggs are laid in the sand 


Fic. 321.—Adult ant-lion, Myrmeleon. (Natural size.) 


and the freshly-hatched larve or ant-lions immediately dig little pits. When 
the larve are full-grown—and just how long this takes is not accurately 
known—each forms a curious protecting hollow ball of sand held together 
by silken threads, lines it inside smoothly with silk, and pupates in this cozy 
and safe nest (Fig. 320). The larva is said to lie for some time, even through 
a whole winter, in this cocoon before pupating. The life-history of no ant- 
lion species is yet thoroughly known. 

The family Myrmeleonide includes eight genera, which are usually 
grouped into two subfamilies as follows: 


Antenna nearly as long as wings. ------- 22-2. seqecewee eee eee eee ened ASCALAPHINE. 
Antenne not one-third as long as wings.......-------------------- MyRMELEONIN. 


The subfamily Myrmeleonine includes the true ant-lions with habits 
in general as already described. The five genera in it may be distinguished 
by the following key: 


232 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


Clans tvery stout, swollence anu comes ee eeeee eee ee eee ACANTHACLISIS. 
Claws slender at base, not swollen. 
Wings with a black band at tip or eye-like spots........-....-.----- DENDROLEON, 
Wings not as above. 
Tibia with no spurs (short but conspicuous spines).........--------- MARACANDA. 
Tibia with spurs. 
Wings with a single row of costal areoles (small cells).......-...--- MyYRMELEON. 
Wings with a double row of costal areoles.. ......--..-------- BRACHYNEMURUS. 


The subfamily Ascalaphine includes but three genera and six species, 
the larve of which do not dig pits (as far as known), but hide under stones 
sometimes with the body partially covered with sand, or even nearly buried 
in it, and wait for prey to come within reach of their long, sickle-like jaws. 
The adults of this subfamily can be readily recognized by their long antenne, 
knobbed at the tip, like the antenne of butterflies. The habits and life- 
history of Ulula hyalina, an Ascalaphid found in the southern states, have 
recently been studied by McClendon in Texas. The adult fly when at 
rest clings, motionless, to some small branch or stalk, head down with wings 
and antennz closely applied to the branch, and abdomen erected and often 
bent so as to resemble a short brown twig or dried branch (Fig. 322). The 


FIG. 322. FIG. 323. 


Fic. 322.—An Ascalaphid, Ulula hyalina, male. (After McClendon; natural size.) 
Fic. 323.—Larva of Ulula hyalina. (After McClendon; natural size, 4 inch.) 


eggs are arranged in two rows along a stalk and fenced in below by little 
rod-like bodies called repagula, placed in circles around the stalk. The 
eggs hatch in nine or ten days, and the larve (Fig. 323) crawl down, after a 
day of resting, and hide under stones or in slight depressions. The body 
is covered with sand and the jaws open widely. When a small insect crawls 
within reach the jaws snap together, pinioning the victim on the curved 
points. The jaws are grooved along the inner or lower side and the maxillz 
fit into these grooves so as to form a pair of ducts or channels through which 
the blood is sucked into the mouth. The larva often changes its hiding-place 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 233 


at night. It lives about sixty days, and then seeks a concealed place and 
forms a spherical cocoon of sand and silk within which it pupates. 

Our three genera of the Ascalaphinee may be determined by the follow- 
ing key: 


IVES GaliiGs \conpedeombegSecUGoCD LEAs Sam ane cou a sAabnnS losses sosonoco suas PTYNX. 
Eyes grooved. 
Eindimarginiof wings entire.) . 2) 8222s. see enna Baro arsancsccuuaons ULULA. 
tana a rp ol Of WAN PS! CXCISEM are ojo mec ey -sele re ele wlinie @/al aie ieee Sete ee COLOBOPTERUS. 


Under the loose hanging strips of bark on the eucalyptus-trees in Cali- 
fornia or on the bark of various Pacific Coast conifers, as pine, spruce, and 
cedar, one may often find certain odd, slender-necked, big-headed, gauzy- 
winged, blackish insects about half an inch long (Fig. 324). A slangy student 
once proposed the name ‘‘rubber-neck”’ for them, and it is a fairly fit one. 
These ‘“‘rubber-necks,” or “‘snake-flies,” belong to the family Raphidiide, 
of which but two genera are known in the world. The species of the genus 
Raphidia have three simple eyes (ocelli), while those of Inocellia have no 
ocelli. Twenty-four species are found scattered over Asia Minor, Syria, 


Fic. 324.—Raphidia sp., adult, larva, and pupa. (Two and a half times natural size.) 


eastern Siberia, Europe, and England, while four species of Raphidia and 
three of Inocellia occur in the western half of the United States. The 
snake-flies are predaceous insects, the larve being notoriously voracious 
insectivores. The larve live in crevices of bark, or under it, where 
there are breaks in it, as is always the case on old trees of most eucalyptus 
species. 

Snake-fly larvee are said to find and eat many larve of the codlin-moth, 
one of the worst pests of apple-trees. Many of the codlin-moth larve crawl 
into crevices in the apple-tree bark to spin their cocoon, and there meet 
the hungry snake-fly larve. 

The pupe (Fig. 324), which are not enclosed in silken cocoons like the 
other terrestrial Neuroptera (ant-lions, lace-winged flies, Hemerobians), lie 


234 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


concealed in sheltered places. They are active, though, when disturbed, and 
look much like the larva, but are more robust-bodied and bear externally 
the developing wings. The head, with eyes and antennz, is more like that 
of the adult. The complete metamorphosis of these insects seems very 
simple compared with that of such other holometabolous insects as house- 
flies and honey-bees. The adult female (Fig. 324) has a long, slender, 
curved, pointed ovipositor, which probably is used to deposit the eggs in 
deep, narrow, and safe cracks in the bark. But the oviposition has not 
yet been seen, and the full life-history of the Raphidians has yet to be worked 
out. 

The extraordinary-looking insect shown in Fig. 325 is one of the few 
members of the Mantispide, the sixth- family of the Neuroptera. Its great 
spiny, grasping fore legs and its long neck make it resemble its namesake, 
the praying-mantis of the order Orthoptera, but its four membranous, net- 
veined wings show its affinities with the Neuroptera. The fore legs are like 
those of the mantis because Mantispa has similar habits of catching live 
prey with them: it is a case of what is called by biologists “parallelism of 
structure,” by which is meant that certain parts of two animals become 
developed or specialized along similar lines, not because of a near relation- 
ship between them, but because o* the 
adoption of similar habits. The wings of 
bats and those of birds show a general 
parallelism of structure, although bats and 
birds belong to two distinct great groups 
of animals. 

Only two genera, viz., Mantispa and 
Symphasis, of Mantispide are known, and 
Wie tsi SS ymaphisis, sienata. (One these include but five American species. 

and one-half times natural size.) Symphasis signata (Fig. 325) is found in 
California, while of the four species of Man- 

tispa three are found in the East and South, while one ranges clear across the 
continent. But they are insects only infrequently seen, and each captured 
specimen is a prize. The life-history of no one of our species has been studied— 
an opportunity for some amateur to make interesting and needed observations 
—but Brauer has traced the life of the European species, Mantispa styriaca, 
and found it of unusual and extremely interesting character. The following 
account of Brauer’s observations is quoted from Sharp (Cambridge Natural 
History, vol. v): ‘‘The eggs are numerous but very small, and are deposited 
in such a manner that each is borne by a long slender stalk, as in the lace- 
wing flies. The larve are hatched in autumn; they then hibernate and 
go for about seven months before they take any food. In the spring, when 


the spiders of the genus Lycosa have formed their bags of eggs, the minute 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 235 


Mantispa larve find them out, tear a hole in the bag, and enter among the 
eggs; here they wait until the eggs have attained a fitting stage of develop- 
ment before they commence to feed. Brauer found that they ate the spiders 
when these were quite young, and then changed their skin for the second 
time, the first moult having taken place when they were hatched from the 
egg. At this second moult the larva undergoes a considerable change of 
form; it becomes unfit for locomotion, and the head loses the compara- 
tively large size and high development it previously possessed. The 
Mantispa larva—only one of which flourishes in one egg-bag of a spider— 
undergoes this change in the midst of a mass of dead young spiders it has 
gathered together in a peculiar manner. It undergoes no further change 
of skin, and is full-fed in a few days; after which it spins a cocoon in the 
interior of the egg-bag of the spider, and changes to a nymph inside its larva- 
skin. Finally the nymph breaks through the barriers—larva-skin, cocoon, 
and egg-bag of the spider—by which it is enclosed, and after creeping about 
for a little appears in its final form as a perfect Mantispa.”’ 

Thus in this insect the larval life consists of two different stages, one 
of which is specially adapted for obtaining access to the creature it is to 
prey on. 

The Coniopterygide include a few tiny, obscure insects, the smallest 
members of the order. They have wings with very few cross-veins, and 
both wings and body are covered with a fine whitish powder, hence the name 
“dusty wings” which entomologists apply to them. Only two species are 
known in this country, of neither of which is the life-history known. In 
Europe the larve of a ‘“‘dusty wing” species have been found feeding on 
scale-insects. When full-fed these larvee spin a silken cocoon, within which 
they transform. 


THE SMALL and little-known order Mecoptera includes certain strange 
little wingless, shining black, leaping insects found on snow, some larger 
net-veined-winged insects with the abdomen of the males ending in a swollen 
curved tip bearing a projecting clasping-organ resembling slightly a scor- 
pion’s sting in miniature, and a number of still larger, slender-bodied, narrow- 
winged insects. The only popular name possessed by any of these insects 
is that of scorpion-flies, which has been given the few species with pseudo- 
stings. For these scorpion-flies are not stinging-insects, although the males 
can pinch hard with the caudal clasping-organ. But little is known of the 
life-history of any members of the order, nor is much known of the habits 
of the imagoes. 

There are but five genera in the order, which may be distinguished by 
the following key: 


236 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


Simple eyes (ocelli) absent. 
Wings well developed; antenne short and thick; body more than 4 inch long. 
MEROPE. 
Wings rudimentary; antennz slender; body less than } inch long........... BoreEvs, 
Simple eyes (ocelli) present. 
Abdomen slender, cylindrical; not ending, in males, in swollen tip with clasping-organ. 
BITTAcus. 
Abdomen more robust, and in males conspicuously swollen and curved at tip, and 
bearing pointed clasping-organ. 
Beak elongate; tarsal’ claws: toothed... -. 2-5-2 fee oo ene ones PANORPA, 
Beak short, triangular; tarsal claws simple................---..-- PANORPODES, 


Boreus is the genus of minute leaping black insects which appear occa- 
sionally in snow. Four species occur in this country, one, B. calijornicus 
on the Pacific coast, two in the northern and northeastern states, and one, 
B. unicolor, found, so far, only in Montana. Of the two eastern species, the 
snow-born Boreus, B. nivoriundus, is shining or brownish black, with the 
rudimentary wings tawny; the other, called the midwinter Boreus, B. 
brumalis, is deep black-green. Comstock says that both species are found 
on the snow in New York throughout the entire winter, and that they also 
occur in moss or tree-trunks. The females have a curved ovipositor nearly 
as long as the tiny body. Neither their feeding-habit nor life-history is 
known. 

The genus Panorpa includes the scorpion-flies, of which fifteen species 
are found in the United States. These insects are from 4 to # inch long, 
with the wings of about the same length. In all, the body is brownish to 
blackish and the wings are clear but weakly colored with yellowish or 
brownish, and have a few darker spots or blotches, which in one or two 
species cover nearly the whole wing-surface. Part of the head projects 
downwards as a short thick beak, the mouth and jaws 
being at the end. The few observations made on the 
feeding-habits seem to show that the scorpion-flies sub- 
sist mainly on animal matter found dead. They have 


Fic. 327. 


FIG. 3 
Fic. 3 


326.—A scorpion-fly, Panorpa rufescens. (Twice natural size.) 
27.—Larva of scorpion-fly, Panorpa sp. (After Felt; three times natural size.) 


been seen to attack living injured and helpless insects. Panorpa rufescens 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 237 


(Fig. 326), the commonest species in the eastern states, lays its eggs, accord- 
ing to Felt, in crevices of the ground; the larve (Fig. 327) hatch in from 
six to seven days and grow rapidly. They burrow in the soil, but not deeply, 
and spend some time wandering about on the surface hunting for food. 
They are full-grown in about one month, probably. The further life-history 
of no American species is yet known, but the larva of a European species, 
when full-fed, burrows deeper ino the ground, excavates an oval cell in 
a small !ump of earth and lies in it for several months before pupating. In 
this condition it shrivels to one-half of its previous length, and the body 
becomes curved backwards. If taken out, it moves slowly and cannot 
walk. 

The species of the genus Bittacus, of which there are nine known in 
our country, are long-legged, slender-bodied, narrow-winged insects (a 
Caliornia species is wingless) which do not resemble the scorpion-flies 
much in general appearance, but havea similar 
beak (although longer and slenderer) on the 
head, and have also a similar venation of the 
wings. All the species as far as known are 
predaceous, capturing and eating various kinds 
of insects and probably taking no food except 
that which they catch alive. Bittacus strigosus 
(Fig. 3 8) is the most familiar form in the East. 
I inhabits shady swamps or moist coverts along 
streams, and may be seen restlessly flitting from 
branch to branch, or resting for short times sus- 
pended from a leaf or twig by its long fore legs, 
sometimes by the middle ones also. Its general 
appearance. thus suspended, is not very unlike 
a bit of dried dangling foliage. The position 
appears restful and one might almost think the 
insect asleep. ‘‘But it is very far from that,” 
says Felt, ‘‘as many a small insect could testify 
were it still alive. The small fly that ventures Fic. 328.— Bitacus strigosus. 
within reach of the long, dangling legs imperils Cece erate asic) 
its life. In a second those well-armed tarsi seize the unfortunate, the fourth 
and fifth segments of the tarsus shutting together like the jaws of a trap 
with teeth upon their opposing surfaces. The struggle is usually short; 
two, three, or four of those long legs lay hold of the captive and soon 
bring it within reach of the sharp beak. It is only a minute’s work 
to pierce a soft part of the body and suck the victim’s blood, when 
the lifeless remains are dropped to the ground and the insatiate insect 
is ready for the next.” The eggs of this species seem to develop and be 


238 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


dropped a few at a time during the adult life. So far as observed, 
egg-laying consists simply of extruding the eggs and letting them drop at 
random. 

The habits of the curious wingless species, Bittacus apterus, common 
in California, have been observed by Miss Rose Patterson, a student of 
Stanford University. These long-legged, thin-bodied creatures are not 
readily distinguished among the drying grass-blades where they live, because 
the color of the body is almost exactly like the yellowish tan of the plants. 
Miss Patterson went into the field one windy day when clouds were scudding 
over the sky. At first not a scorpion-fly was to be seen; then, in a brief 
period of sunshine, one was seen swinging itself deliberately along from 
one grass-blade to another. When the wind blew hard it either held firmly 
to the weeds or dropped down to the ground for protection. Finally it took 
up its position near a flower-cluster and clung by all its tarsi. When a bee- 
fly came passing that way it immediately freed two of its legs and held them 
out in an attitude of expectancy. When the fly had passed it remained 
in that position for a minute or so and then relaxed into what seemed a more 
comfortable attitude, holding on by all tarsi. As it became cloudy again, 
the insect dropped down among the weeds and remained near the ground, 
its legs resting on the grass-stems and its abdomen pointing almost directly 
outwards. Miss Patterson disabled a small skipper butterfly and dropped 
it near the Bittacus, but he seemed to pay no attention. A lady-bug did 
not arouse him. A fly passed over and still he did not move. She touched 
him with a pencil-point and he drew back and began to feign sleep. When 
she continued to disturb him he showed an inclination to fight, but did not 
leave his shelter until she forced him to do so by repeated pokes with the 
pencil-point. Then he ran nimbly to the top of a blade of grass and hung 
there: his tarsi went scarcely around the leaves. He remained in that posi- 
tion, motionless, until a bird twittered overhead; then he promptly found 
a sheltered place in a drooping grass-leaf. 

Near him she discovered another scorpion-fly, with a crane-fly in its 
clutches. The crane-fly was still alive and struggled feebly while the scor- 
pion-fly sucked its blood. She disturbed them, but though the scorpion- 
fly stopped its eating, it held its prey as before and moved slowly off with 
it. The body of the crane-fly was almost cut in two by the grasping tarsi of 
its enemy. 

Finding another of the queer creatures swinging on a weed, its four legs 
held out hungrily, she gave it a crane-fly, which it grasped firmly, winding 
the tarsi around its body. The crane-fly struggled, but its captor soon had 
its head buried almost to the eyes in its body. Finally the mangled crane- 
fly gave out. She caught another crane-fly and held it out to the scorpion- 
fly, which thereupon grasped its first victim firmly in one of its hind tarsi 


Nerve-winged Insects; Scorpion-flies; Caddis-fies 239 


and snatched at the second. Then holding both, it began to suck the blood 
of the fresher* prey. 

Bringing some scorpion-flies into the laboratory, Miss Patterson placed 
a crane-fly in the jar with a pair of them. The male scorpion-fly seemed 
unusually hungry and soon caught its prey and began to eat. The female 
paid no attention until the male had eaten for some time. Then Miss Pat- 
terson observed the male to bend the posterior portion of its abdomen, and 
between the sixth and seventh and seventh and eighth segments on the 
norsal side of the body rounded organs were quickly protruded and with- 
drawn. Shortly after this the female approached and also began to eat 
the crane-fly. Several times she noted the males attracting the females by 
protruding the ‘‘scent-glands.” In every case, when the male began to give 
off the scent, the female gradually approached. 

Eggs were laid by the females in the laboratory jars. These eggs were 
pink in color and spherical, although slightly flattened at opposite sides. 
They are simply dropped by the female loosely and singly to the ground. 


In THE Rocky Mountains of northern Colorado are some of the most 
attractive “‘camping-out”’ places in our land; that is, for “campers” who 
specially like Nature in her larger, more impressive phases. The peaks 
of the Front Range rise to 14,000 feet altitude, and the ice- and water-worn 


canons and ereat sheer cliffs of the flanks of the Range are only equalled 


Fic. 329.—Phryganea cinerea. (After Needham; enlarged.) 


in this country by the similar ones of the Californian Sierra Nevada. The 
mountain-climber in these wild regions cannot but interest himself in the 
animal and plant life which he finds struggling bravely for foothold in even 
the roughest and most exposed places. To the entomologist the few 
hardy butterfly kinds of the mountain-top, the scarce inhabitants of the 


240 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


heavy spruce forests, and the strange aquatic larve desperately clinging 
to the smooth boulders and rock bed of the swift mountain streams are 
among the most interesting and prized of all the insect host. So it was 
that my first summer’s camping and climbing in the Rockies acquired a 
special interest from the slight acquaintanceship I then made with a group 
of insects which, unfortunately, are so little known and studied in this 
country that the amateur has practically no written help at all to enable 


Fic. 330.—Leplocerus resurgens, (After Needham; enlarged.) 


him to become acquainted with their different kinds. These insects are 
the caddis-flies; not limited in their distribution by any means to the Rocky 
Mcuntains, but found all over the country where there are streams. But 
it is in mountain streams that the caddis-flies become conspicuous by their 
own abundance and by the scarcity of other kinds of insects. 

In Europe the caddis-flies have been pretty well studied and more than 
500 kinds are known. In this country about 150 kinds have been deter- 
mined, but these are only a fraction of the species which really occur here. 
Popularly the adults are hardly known at all, the knowledge of the group 
being almost restricted to the aquatic larve, whose cleverly built protecting 
cases or houses made of sand, pebbles, or bits of wood held together with 
silken threads give the insects their common name, i.e., case- or caddis- 
worms. The name of the caddis-fly order is Trichoptera. 

These cases are familiar objects in most clear streams and ponds. 
Figures 331 and 332 show several kinds. There is great variety in tke 
materials used and in the size and shape of the cases, each kind of caddis- 
worm having a particular and constant style of house-building. Grains 
of sand may be fastened together to form tiny, smooth-walled, symmetrical 
cornucopias, or small stones to form larger, rough-walled, irregular cylinders. 
Small bits of twigs or pine-needles may be used; and these chips may be 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 241 


laid longitudinally or transversely and with projecting ends. Small snail- 
shells or bits of leaves and grass may serve for building materials. One kind 
of caddis-worm makes a small, coiled case which so much resembles a snail- 
shell that it has actually been described as a shell by conchologists. Some 
cases in California streams gleam and sparkle in the water like gold; bits 
of mica and iron pyrites were mixed with other bits of mineral picked up 
from the stream-bed to form 
these brilliant houses. An Eng- 
lish student removed a caddis- 
worm from its case, and _pro- 
vided it only with small pieces 
of clear mica, hoping it would 
build a case of transparent walls. 
This it really did, and inside its 
glass house the behavior of the 
caddis- worm at home was ob- 
served. While most of the cases 
are free and are carried about by 


the worm in its ramblings, some FIG. 331. Fic. 3324. 233 
are fastened to the boulders or FIG. 331.—Two cases of caddis-worms. (Natu- 
rock banks or bed of the stream. Seen cases of caddis-worms with the 
These fixed cases are usually com- _ larval insects within showing head and thorax _ 
posed of bits of stone or smooth Projecting. (Natural size.) 

pebbles irregularly tied together with silken threads. In all the cases silk 
spun by the caddis-worm is used to tie or cement together the foreign build- 
ing materials, and often a complete inner silken lining is made. 


Fic. 333.—Halesus indistinctus. (After Needham; enlarged.) 


The larve within the cases are worm- or caterpillar-like, with head and 
thorax usually brown and horny-walled, while the rest of the body is soft 
and whitish. The head with the mouth-parts, and the thorax with the long 
strong legs, are the only parts of the body that project from the protecting 
case, and hence need to be specially hardened. At the posterior tip of the 


242 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


abdomen is a pair of strong hooks pointing outward. These hooks can 
be fastened into the sides of the case and thus hold the larva safely in its 
house. Numerous thread-like tracheal gills are borne on the abdomen 
and by a constant undulatory or squirming motion of the body a stream of 
fresh water is kept circulating through the case, thus enabling the gills to 
effect a satisfactory respiration. The caddis-worm crawls slowly about 
searching for food, which consists of bits of vegetable matter. Those larvae 
which have a fixed case have to leave it in search of food. Some of them 
make occasional foraging expeditions to considerable distances from home. 
Others have the interesting habit of spinning near by a tiny net (Fig. 335), 


Fic. 334.—Hydropsyche scalaris. (After Needham; enlarged.) 


fastened and stretched in such a way that its broad shallow mouth is directed 
up-stream, so that the current may bring into it the small aquatic creatures 
which serve these caddis-fishermen as food. The caddis-flies live several 
months, and according to Howard some pass the winter in the larval stage. 

When the caddis-worms are ready to transform they withdraw wholly 
into the case and close the opening with a loose wall of stones or chips and 
silk. This wall keeps out enemies, but always admits the water which is 
necessary for respiration. The pupa in the well-made cases have no other 
special covering, but in the simple rough pebble houses attached to stones 
in the stream they are enclosed in thin but tough cocoons of brown silk 
spun by the larva. The free cases are also usually attached just before 
pupation to submerged sticks or stones. When ready to issue the pupa 
usually comes out from the submerged case, crawls up on some support 
above water and there moults, the winged imago soon flying away. Some 
kinds, however, emerge in the water. Comstock observed the pupa of one 
of the net-building kinds to swim to the surface of the water (in an aqua- 
rium) by using its long middle legs as oars. The insect was unable to crawl 
up the vertical side of the aquarium, so the observer lifted it from the water 
on a stick. At this time its wings were in the form of pads, but the instant 
the creature was free from the water the wings expanded to their full size 
and flew away several feet. On attempting to catch the specimen Com 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 243 


stock found that it had perfect use of its wings, although they were so recently 
expanded. The time required for the insect to expand its wings and take 
its first flight was scarcely more than one second; certainly less than two. 
As such caddis-flies normally emerge from rapidly flowing streams which 
dash over rocks, it is evident that if much time were required for the wings 
to become fit for use, as is the case with most other insects, the wave succeed- 
ing that which swept one from the water would sweep it back again and 
destroy it. 


FIG. 335. Fic. 336. 


Fic. 335.—Fishing-net of caddis-worm in stream. (After Comstock.) 
Fic. 336.—Goniotaulius dispectus. (After Needham; enlarged.) 


The adult caddis-flies are practically unknown to general students. 
They are mostly obscurely colored, rather small, moth-like creatures, that 
limit their flying to short, uncertain excursions along the stream or pond 
shore, and spend long hours of resting in the close foliage of the bank. 
So far as observed the flies take no food, although in all the specimens I 
have examined there are fairly well-developed mouth-parts fitted for lap- 
ping up liquids. They probably do not live long, and certainly do not live 


Fic. 337.—Trienodes ignita. (After Needham; enlarged.) 


excitingly. In the Colorado mountains numerous small species occur, 
some w.th beautiful snow-white wings and delicate blue-green bodies (Setodes) ; 
other black-winged, brown-bodied kinds (Mystacides); and other light- 
brown winged species (Hydropsyche) in great abundance, but usually the 
adults are comparatively solitary and inconspicuous. They probably fly 


244 Nerve-winged Insects; Scorpion-flies; Caddis-flies 


chiefly at night, as large numbers have been taken in trap lanterns by Betten. 
The eggs are laid, according to this observer, in or directly above the water. 
Many clusters of eggs were found under the bark of submerged trees, which 
would lead to the conclusion that in some cases the female insect goes under 
water to deposit the eggs. A spherical cluster found suspended on a sub- 
merged twig under a log floating in deep water contained 450 eggs. 

Some of the caddis-fly larvae can be readily kept in an aquarium. 
Almost any kinds found in ponds will live in aquariums, where their feed- 
ing-habits and transformation may be cbserved. The caddis-worms that 
build odd cases of small sticks laid crosswise live contentedly in an 
aquarium and are most interesting to watch. The complete life-history 
of no single caddis-fly species has yet been worked out completely, and the 
specific identity of but few of our larve is known. For three California 
species Geo. Coleman, a student of Stanford University, has obtained adults 
by putting wire-screen cages over the larve in the streams. In these cages 
the larve had room enough to hunt food successfully, and they lived, except 
for the circumscribing of their territory, perfectly naturally. Betten has 
similarly reared imagoes from four kinds of larvae in the Adirondack Moun- 
tains. 

The following keys will enable the collector to classify either his caddis- 
worms (larve) or caddis-flies (adults) to families: 


KEY TO FAMILIES (ADULTS). 


Spines on the legs, three simple eyes (ocelli). 
Four spurs on tibie (second long segment) of middle legs.-.-......-- PHRYGANIDE. 
Two or, three Spurs) on middle hibicese- ses oa ee aia em LIMNEPHILID. 
No spines on legs, only hairs or spurs. 
Last two segments of palpi (mouth-feelers) not elongated and flexible. 


Palpi of males 5-segmented; ocelli often present.......-.-.-- RHYACOPHILIDE. 

Palpi of males 4-segmented; ocelli absent. 
No spurs on front legs...--.......-------------------------- HYDROPTILIDE. 
Spurs on front legs...-.-.----------------------+-------- SERICOSTOMATID. 

Last segment of palpi elongate and flexible; palpi hairy. 

Basal segment of antenne long and thick, wings slender, no ocelli- . .. LEPTOCERID. 
Basal segment of antenne shorter, wings broader, last segment of palpi composed 
of numerous subsegments........--------------+--------- HyYDROPSYCHID. 


KEY TO FAMILIES (,ARV4). (Arter BETTEN.) 


Larva with head bent downward at an angle with the body; tubercles generally present 
on the first abdominal segment; lateral fringe generally present; gill filaments, 
when present, usually simple. 

Hind legs more than twice as long as the first pair; cylindrical case of sand and small 
SEONES. 2. 2 Sk ae eee sone Secs ee eta ae = ac\sin'e sian siniajeiaretn ies = LEPTOCERID. 
Hind legs not more than twice as long as first pair. 


Nerve-winged Insects; Scorpion-flies; Caddis-flies 245 


Head elliptical, only pronotum (dorsal wall of prothorax) chitinized (horny and 
dark), abdominal constrictions deep; cases of vegetable matter laid longitudi- 
nally and forming a spiral, widening at front end............-- PHRYGANEID. 

Head oval to circular, pronotum chitinized, mesonotum often, and metanotum some- 
times chitinized, abdominal constrictions slight. 


Lateral fringe well developed; cases various.......--...------- LIMNOPHILID. 
Lateral fringe slightly developed; cylindrical case of sand or small stones. 
SERICOSTOMATIDE. 


Larva with head projecting straight forward in line with the rest of body; tubercles 
and lateral fringe wanting; gill-filaments, when present, branched. 
Abdomen much thicker than the thorax; case kidney-shaped, of small stones, or flat 
ahelel PoC ROA NE 5 oncosentooso sos scosssams Sou so9ooe eee HYDROPTILIDE, 
Abdomen little if any thicker than the thorax. 
Third pair of legs a little longer than the first pair; no larval case.. RHYACOPHILID®. 
Third pair of legs about the same length as first pair; no portable larval case. 
HyYDROPSYCHID&, 


CHAPTER XII 
THE BEETLES (Order Coleoptera) 


==] HE moths and butterflies (Lepidoptera) and the 
beetles (Coleoptera) are the most familiar of the 
insect orders. They are, too, most affected by 
collectors: of all the amateur collectors of insects 
probably nine out of ten collect either Lepi- 
doptera or Coleoptera, or perhaps both. The 
moths and butterflies obviously owe their special 
attractiveness to their beautiful colors and pat- 
terns, and to the interesting metamorphoses 
exhibited in their life-history. A gratifyingly 
increasing number of amateurs and collectors are 
“rearing”? or breeding Lepidoptera, and adding much to our scientific knowl- 
edge of them. The beetles owe their place of honor among collectors largely 
to their abundance of species and individuals, the readiness with which 
they can be collected, and the little special attention necessary to their per- 
fect preservation. They are mostly large enough, too, to be handled and 
examined readily, and not so large as to require much cabinet space for 
their keeping. They also make specially fit specimens for exchange. But 
amateurs give almost no attention to the immature stages of beetles. 
Although, like the Lepidoptera, they undergo a complete metamorphosis, the 
larvee are so obscure and usually so concealed underground or in tree-trunks 
or decaying matter or in the water, or, if seen, are so often unattractive and 
even repulsive in appearance—most beetle-larvee are ‘‘grubs’’—that rearing 
beetles is practically an unknown pastime even with the professed ‘“‘coleop- 
terists.” 
As a matter of fact, the beetles do not begin to present an interest even 
to professional entomologists at all in proportion to the dominant number 


b) 


of species in the order. There is a curious uniformity—with of course the 
startling exceptions which must be mentioned in the same breath with 
almost any generalization about insects—in the general character of the 
structure, development, and habits throughout most of the great order of 
beetles. So that a few life-histories well worked out give us a fair knowledge 
of the principal characteristics of coleopterous development. 

246 


on ae Bes ee 
S 


e 


7. PLATE we 


ne 


wT ATS 
eadTada 
autsilleq auns.0me9C =1 


uapisems aoibigerT = 
_snodil eS =p 


simiddr onal 
ainda silseost =0 Fa 
scototoy, slabaisid =. 1 
a 


PLATE II. 


BEETLES. 


1= Desmocerus palliatus. 
2=Tragidion armatum. 
3=Chalcophora liberta 
4=Chrysochus auratus. 
5=Silpha americana. 
6=Geotrupes splendidus. 
7=Chrysochus cobaltinus. 
8=Buprestis sp. 
9=Calosoma scrutator. 
1o= Tetraopes tetraophthalmus. 
11=Cucujus platipes. 
12= Meloe sp. 
13= Pelidnota punctata. 
14= Parandra brunnea. 
15=Cyllene robini. 
16= Rosalia funebris. 
17=Cicindela genetosa. 


PLATE It 


3 


Beetles 247 
It would be reasonable to expect to find the insects of an order so pursued 
by collectors susceptible of ready classifying and determining. On the 


contrary, no order presents more difficulty to the elementary and even 


mouth-parts 


eee maxillary palpt 
f ‘ ___--head 
labiwm---... i Antenna 


compound eys-—z 


Pf. So 
Cal ‘prothorax 
 —_nesothorax 
metathoraz 


femur” 
tibia-~ 


Fic. 338.—Ventral aspect of male great water-scavenger beetle, Hydrophilus sp. 
(Three times natural size.) 


advanced students of systematic entomology. The tables and keys pre- 
pared by the few specialists really competent to determine accurately the 
different species of beetles are as nearly impossible to the amateur and 
elementary student as any “keys” in al! the field of classific entomology. 


248 Beetles 


The characters made use of in separating species, genera, and even families 
are so slight, obscure, and difficult to understand that the tables and keys 
based on them chiefly result in wholly discouraging any beginner who 
attempts to use them. And this is not so much the fault of the systematic 
specialists as of the beetles themselves. When it is recalled that nearly 


brain_ Sos FF 


oesophagus-~- 


_--- elytron 


ag alimentary 
. canal 
ventral nerve 
chain 


"wing 


>». 
oviduct’. > e9g-lithes_ 7s 
accessory glands rectum 


Malpighian 
tubules 
““sreceptaculum seminalis 
Fic. 339.—Dissection of female great water-scavenger beetle, Hydrophilus sp.; the 
heart and air-tubes (trachew) are cut away. (Three times natural size.) 


™ intestine 


12,000 species of this order are known in North America north of Mexico; 
that they represent nearly 2000 genera, grouped in 80 families; and that 
much general similarity of structure as well as of habits prevails through- 
out the order, it begins to be apparent why difficulties in classification are 
inevitable. To find structural differences among these thousands of beetles, 


Beetles 249 


the specialists have been driven to turn their microscopes on the most obscure 
and insignificant parts of the body, and to take cognizance of the slightest 
appreciable constant differences. The real way in which an entomologist 
gets his beetles classified is to submit specimens to a specialist for determina- 
tion. Then as his authoritatively determined collection gradually increases, 
the collector begins to get acquainted with certain well-marked species, and 
also with the general appearance or habitus of the members of any one family. 
He becomes in time able to classify his new specimens to families, not by 
tables or keys but by general appearance and a certain few characteristic 
structural peculiarities, and to determine some species by comparison with 
the already classified specimens in his collection. The eye thus gradually 
trained becomes more and more discriminating, and the collector may in 
time come to be a recognized “‘coleopterist” both by virtue of his large col- 
lection and the rare forms it contains and by his wide personal ac- 
quaintanceship with beetle species. In the necessarily limited account of 
the Coleoptera given in the following pages I purpose to give keys only to 
tribes and families, and, in order to make even these simple enough to be 
useful, to leave most of the small, rare, and obscure families wholly out of 
consideration. 

The tables thus freed of over half the families of the order still include 
five-sixths of all the North American beetle kinds, and will be found to include 
nine out of every ten beetle species collected. That is, the great proportion, 
ninety per cent. probably, of species at all common enough to be collected 
belong to less than half of the recognized families. These more familiar 
families can also be grouped into a few tribes, each having some simple 
common structural characteristic, thus still further aiding in the work of the 
classifier. The collector will thus first classify his specimen to a tribe by 
means of the table on page 251, and then turning to a discussion of that 
particular tribe find a key to its families.* In the discussion of each of 
these will be found accounts of the life of certain of the more abundant, wide- 
spread, and interesting species of the family. 

The characteristics of the order as a whole are obvious and familiar: 
most beetles are readily known for beetles, and but few insects of other orders 
get mistaken for them. The ‘black beetle” of the house is a cockroach, 
and several of the hard-bodied, blackish sucking-bugs are sometimes mis- 
takenly called beetles, as are also the earwigs. But the horny fore wings, 
elytra, serving as a sheath for the large membranous hind wings, the true 


* Tf the collector wishes a further determination of his specimens, he must do as prac- 
tically all other amateur and most professional entomologists do; that is, send his 
material to a specialist, who has, by the way, the right recognized by custom of keeping 
any of these specimens sent him, to add to his own cabinets. It is well, therefore, to 
send an extra specimen to return in the case of any species likely to interest him. 


250 Beetles 


organs of flight; the firm, thick, usually dark, chitinized cuticle or outer 
body-wall; the strong-jawed biting mouth, and the compact body, usually 
short and robust, are structural characteristics obvious and usually dis- 


Fic. 340.—The different forms of antenne of beetles. 1, serrate; 2, pectinate; 3, cap- 
itate (and also elbowed); 4-7, clavate; 8-9, lamellate; 1o, serrate; 11, irregular 
(Gyrinus); 12, 2-segmented antenne of Adranes cecus. (After LeConte.) 

tinctive. Especially used in classification are the differences in number 

of tarsal segments of the feet, and differences in the character of the antennz. 

To learn the range of these differences in the antenne, and the names applied 

to the various kinds a careful inspection of Fig. 340 will do more than a 


Fic. 341.—Different forms of legs and tarsi of beetles. (After LeConte and Comstock.) 


page of description. Similarly Fig. 341 illustrates the range of the charac- 
ters drawn from the tarsi. 

The development of beetles is ‘‘ with complete metamorphosis s”; that is, 
from the eggs laid underground, or on leaves or twigs, in branches or trunks 
of live trees, in fallen logs, on or in decaying matter, in fresh water, etc., 


Beetles 21 


hatch larve usually called grubs, with three pairs of legs (sometimes want- 
ing), with biting mouth-parts, simple eyes, and inconspicuous antenne. 
These larvee are predaceous, as the water-tigers (larva of water-beetles), 
plant-feeders, as the larve of the long-horns, or carrion-feeders, as those of the 
burying-beetles, and so on. They grow, moult several times, and finally change 
into a pupa either on or in the food, or very often in a rough cell under- 
ground. From the pupa issues the fully developed winged beetle, which 
usually has the same feeding-habits as the larva. The special food-habits 
and characteristics of development are given for numerous common species 
in the accounts (postea) of the various more important families of the order. 

The enonomic status of the order Coleoptera is an important one. So 
- many of the beetles are plant-feeders, and are such voracious eaters in both 
larval and adult stages, that the order must be held to be one of the most 
destructive in the insect class. Such notorious pests as the Colorado potato- 
beetle, the two apple-tree borers, round-headed and flat-headed, the ‘‘ buffalo- 
moth” or carpet-beetle, the wireworms (larve of click-beetles), the white 
grubs (larve of June beetles), rose-chafers, flea-beetles, bark-borers and 
fruit- and grain-weevils, are assuredly enough to give the order a bad name. 
But there are good beetles as well as bad ones. The little ladybirds eat 
unnumbered hosts of plant-lice and scale-insects; the carrion-beetles are 
active scavengers, and the members of the predaceous families, like the 
Carabids and tiger-beetles, undoubtedly kill many noxious insects by their 
general insect-feeding habits. 

The great order Coleoptera is divided into two primary groups, some- 
times called suborders, namely, Coleoptera genuina, the typical or true 
beetles, including those species in which the mouth-parts are all present and 
the front of the head is not elongated into a beak or rostrum, and the 
Rhynchophora, snout-beetles (p. 294), which have the front part of the 
head more or less extended and projecting as a beak or rostrum, and the 
mouth-parts with the labrum (upper lip) so reduced as to be indistinguish- 
able and the palpi reduced to mere stiff jointless small processes. To 
this latter suborder belong those beetles familiarly known as weevils, bill- 
bugs, bark-beetles, and snout-beetles. 


KEY TO SECTIONS AND TRIBES OF COLEOPTERA GENUINA. 
With five tarsal segments in all the feet (with rare exceptions). Section PENTAMERA. (p. 252). 
With the antenne slender, thread-like, with distinct, cylindrical segments. 

(Carnivorous beetles.) Tribe ADEPHAGA (p. 252). 
With the antennz thickened gradually or abruptly toward the tip. 
(Club-horned beetles.) Tribe CLAvicorNIA (p. 258). 
With the antenne serrate or toothed. 
(Saw-horned beetles.) Tribe.SERRICORNIA (p. 265). 
With the antenne composed of a stem-like basal part, and a number of flat blade-like 
segments at the tip. (Blade-horned beetles.) Tribe LAMELLICORNIA (p. 272). 


252 ; Beetles 


With four tarsal segments in each of the feet.......... Section TETRAMERA (p. 277). 

Mostly with slender cylindrical antenne, sometimes very long and _ thread-like, 

sometimes shorter and thickened toward the tip; the fourth and fifth seg- 

ments of the tarsus closely fused, the fourth segment being very small and 
sometimes difficult to distinguish. 

(Plant-eating beetles.) Tribe PHyTOPHAGA (p. 277). 


With three tarsal segments in each of the feet............. Section TRIMERA (p. 286). 
With the front and middle legs with 5-segmented tarsi, and the hind legs with 4-seg- 
mented. tarsivse. Jeet bec meacte ae emtanie a emanate Section HETEROMERA (p. 288) 


SECTION PENTAMERA. 


In the tribe of Adephaga, or carnivorous beetles, are four principal 
families, which may be distinguished by the following key: 
Terrestrial. 
Antenne inserted on front of the head above the base of the mandibles. 
(Tiger-beetles.) CICINDELID#. 
Antenne inserted on side of the head between the base of the jaws and the eyes. 
(Predaceous ground-beetles.) CARABIDZ. 


Aquatic. 
With:-two: eyes <2. 2 saace5 jo 2 eae eee (Predaceous diving-beetles.) Dytiscip#. 
With four eyes, two above and two below........- (Whirligig-beetles.) GyRINID2. 


The attractive tiger-beetles (Cicindelide) are great favorites with col- 
lectors, and deservedly. Their vivid, sharply marked metallic colors, trim 
clean body, and constant alertness and activity, together with their fond- 
ness for warm, bright hunting-grounds and their clever and “gamy”’ 
elusiveness of the collecting-net, combine to give these 
fierce, swift little creatures a high place in the regard of 
the beetle-catching sportsman. ‘There are but four genera 
in the family, but the genus Cicindela contains about 
sixty species, distributed over the whole country. In 
California we are not provided with quite our share of tiger- 
beetles, but then there are not so many Cicindelid-hunters 
as in the East. Look for tiger-beetles on sunny days in 
hot dusty roads or open sandy spots. In cold and cloudy 
weather, and at night, they lie hidden under stones or 
chips or in burrows, although a few species are nocturnal 
in habit. When out and running or flying about they are 
Fic. 342—Larva hunting; their big eyes and long sharp mandibles and the 

eae pee whole seeming of the body some way betray their predatory 
hybrida. (After habits even before one sees the swift pounce on some 
Schiodte; three quyll-witted, slow-footed insect, and the eager blood- 
times natural Bric : 

size.) drinking immediately thereafter. 

The egg-laying habit of the tiger-beetles is not yet known, but the larve 
and their habits are familiar. They are ugly, malformed, strong-jawed 


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PLATE III. 


TIGER BEETLES. (After Leng and Beutenmiiller.) 


Fig. 


1. Tetracha carolina. 
2. Cicindela unipunctata. 
3 ‘ celeripes. 
4 ee dorsalis. 
5. as scutellaris var. rugifrons. 
6. oe longilabris. 
7 “ = var. perviridis. 
8 ia scutellaris var. Lecontei. 
9 s sexguttata. 
10. = St var. patruela. 
II. ws purpurea. 
12. Be ‘evar. limbalis. 
13. > formosa var. generosa. 
14. ne ancocisconensis. 
15. “f vulgaris. 
16. Me repanda. 
t7. bi “« "12. guttata. 
18. Ss hirticollis. 
19. a punctulata. 
20 oi marginata. 
21 - puritana. 
22 be lepida. 
23 5 rufiventris. 
24 ut Hentzii. 
25 se tortuosa. 
26 ‘ abdominalis. 
27 ‘ marginipennis. 


PLATE Ill 


Beetles 2153 


grubs (Fig. 342) which lie in the mouth of a vertical burrow several inches 
* deep, with the dirt-colored head bent at right angles to the rest of the body 
and making a neat plug for the top of the hole. When an unwary insect 
comes in reach of this plug the waiting jaws make a quick grasp, and the 
doomed prey is dragged down into the darkness. On the fifth segment 
of the abdomen of the larva there is a hump, and on it are two small but 
strong hooks curved forward. ‘This is an arrangement by which the little 
rascal can hold back and keep from being jerked out of its hole when it gets 
some large insect by the leg, and by which it can drag its struggling prey 
down into its lair, where it may eat it at leisure. It is interesting to thrust 
a straw down into one of these burrows, and then dig it out with a trowel. 
The chances are that you will find the indignant inhabitant at the remote 
end of the burrow chewing savagely at the end of the intruding straw.” 
Plate III shows the appearance of the body and the character of the mark- 
ings of the tiger-beetles, while the vivid color-effects are illustrated in Plate II. 
In the East occurs, besides Cicindela, the genus Tetracha (PI. III, Fig. 1) 
with two species; on the plains of the middle West the largest member of 
the family, Amblychila cylindriformis, which hunts its prey at twilight, and 
on the Pacific coast the genus Omus with ten species, all nocturnal. 
The family Carabide, the predaceous ground-beetles, is a large one, 
including in North America about 1200 species, representing over a hundred 
genera. They are mostly dark-colored and are nocturnal in habit, hiding 
by day under stones, chips, logs, etc., so not many of them are familiar or 
even often seen. A few, however, are large and brilliantly colored, and 
get discovered by most collectors. Like the tiger-beetles 
they are active and predatory, with long strong mandibles 
and slender running legs. They differ from the tiger-beetles 
in their dislike of daylight, and in having the head in 
most species narrower than the thorax. The larve (Fig. 
343) are “mostly long flattened grubs with a body of almost 
equal breadth throughout. It is usually protected on top 
by horny plates and ends in a pair of conical and bristly 
appendages.” Most of the larve burrow just beneath the 
surface of the earth, feeding on various insects which enter 
the ground to pupate or for other reasons. They destroy aoe. 
large numbers of the destructive leaf-feeding beetles, whose oe Cae 
soft-bodied larvee leave the plants and burrow into the (After Lugger; 
ground when ready to pupate. When full-grown the Carabid enlarged.) 
larve form small rough cells in the soil within which they change to pupe. 
When the adult beetles emerge they push their way up to the surface. 
Plate IV illustrates several species of this family and shows the charac- 
teristic flattened, usually rather broad although trim and compact, shape 


254 Beetles 


of the body. In most of the species the elytra are marked with fine longi- 
tudinal lines or rows of punctures, and in several species the hind wings are 
wanting, so that flight is impossible. There is something characteristic 
and almost unmistakable about the general make-up and appearance of 
these beetles. Their flatness, and smoothness, their shining black, greenish, 
or brownish coloration, and their small head with prominent, projecting, 
slender antenne, pointed mandibles, conspicuous clubbed palpi, and bright 
eyes, together with their equally characteristic haunting of hidden places 
on the ground, their swift alert running, and readiness to bite when caught, 
distinguish them, almost at a glance, from all other beetles. One of the 
largest, most conspicuous and well-known Carabids is the searcher, or cater- 
pillar-hunter, Calosoma scrutator (P1. II, Fig. 9), an inch and a half long, 
with vivid violet-green elytra margined with reddish. It is commonly found 
at twilight and after dark on trees, and is often seen by collectors when 
“sugaring”’ for moths. It is said to make special war on the hairy tent- 
caterpillars, and thus do much good. Two other species of this genus, 
C. frigidum (Fig. 344) and C. calidum (Fig. 345), the latter 
called the fiery hunter from its characteristic rows of reddish 
or copper-colored punctures on the black elytra, are keen 


Fic. 344. Fic. 345. Fic. 346. 
Fic. 344.—Calosoma frigidum, (After Lugger; natural size.) 
Fic. 345.—Calosoma calidum. (After Lugger; natural size.) 


Fic. 346.—Larva of Pterostichus striola. (After Schiodte; two and one-half times natu- 
ral size.) 


hunters of cutworms, canker-worms, etc. At the other extreme of size 
in the family are the tiny Bembediums and Tachys, some species of 
which are but ;4; inch long. The curious bombardiers, or bombarding 
beetles (Brachina), when disturbed, spurt out with popgun sound and puff 
of “smoke” an ill-smelling, reddish, acid fluid from the tip of the 
body. Comstock says that “these beetles have quite a store of ammuni- 
tion, for we have often had one pop at us four or five times in succession 


(medsbiW iA) 21ITAAM 2V0ADAGTAT ni 


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i 


: 
‘ ja 


PLATE ‘IV: 
PREDACEOUS BEETLES. (After Wickham.) 


Fig. 1. Panagzeus fasciatus. 


‘« 2, Patrobus longicornis. 

‘« 3. Pterostichus rostratus. 
‘Shag ss honestus. 

s¢ the. coracinus. 

sea 03 LS sculptus. 

SC ar £e lucublandus. 
[S188 ce tartaricus. 

ee sé mutus. 

oe ato: oa orinomum. 
BY ars 7 erythropus. 


PLATE IV 


ca Uele Wr 
ae ed 7 vaG 
‘ dic < 
Sd eRe 
! 


Beetles 2155 


while we were taking it prisoner.’’ These beetles have a narrow reddish- 
yellow head and prothorax, and blackish-blue elytra. Of similar appear- 
ance is Lebia grandis, the enemy of the Colorado potato-beetle, feeding 
on its egg and larve. Most abundant of the Carabids are the numerous 
dull-black medium-sized species of Pterostichus (Pl. IV), in which the pro- 
thorax has a narrow, flat, projecting margin. Over one hundred species 
of this genus have been found in this country. Harpalus is another large 
genus with some very common species; H. pennsylvanicus is often found 
in orchards eating the larve of the codlin-moth and plum-curculio, ravag- 
ing fruit-pests. A few Carabids are not such good friends, Lugger record- 


Fic. 347.—Predaceous diving-beetles (and back-swimmers, order Hemiptera) in water. 
(From life; slightly less than natural size.) 


ing the fact that Agonoderus pallipes, a species abundant in Minnesota, 
sometimes feeds on sprouting seeds of corn. 

Predaceous beetles of very different habitat are the Dyticide, the carniv- 
orous water- or diving-beetles. Three hundred species occur in this country, 
and some members of the family are to be found wherever there are streams 
and ponds. They vary in size from the large Cybister and Dyticus, an 
inch and a half long, to small species of Hydroporus and other genera less 
than a fifth of an inch long, but all are readily distinguishable from their 
aquatic companions, the whirligigs (family Gyrinide) (p. 257), by having 
but one pair of eyes, and from the water-scavenger beetles (family Hydro- 


256 Beetles 


philide) (p. 258) by having slender thread-like antenne instead of clubbed 
ones. All are oval and flatly convex in shape, with hard smooth body-wall, 
usually brownish or black, and when at rest hang head downward from 
the surface of the water, the characteristic breathing attitude. The females 
sometimes have the elytra furrowed with shallow longitudinal grooves, and the 
males of most species have a curious clinging-organ on the expanded first three 
or four tarsal segments of the front feet (Fig. 349). This organ is com- 
posed of a hundred or more.small capsules on short stems and two or three 
very much larger pads. It is used for holding the females in mating, and 
adheres to their smooth body-wall by the secretion of a gummy fluid insol- 
uble in water. The pads and capsules may also act to some extent as 
“suckers” by atmospheric pressure. The hind legs are long, strong, 
and flattened to form oars or swimming-organs. This beetle regularly and 
perfectly “feathers its oars” by a dexterous twist while swimming. To 
breathe, the beetle comes to the surface—its body being less dense than 
water, it floats up without effort—and projects the tip of its abdomen through 
the surface film. It now lifts the tips of the elytra slightly; air pours in 
and is held there by the fine hairs on the back, where are also the spiracles, 
or breathing-openings. Thus when the beetle goes down 
again it carries with it a supply of air by means of which 
respiration can go on for some time under water. The 
diving beetles can be readily kept in aquaria, as can also 
their larvae (described in the next paragraph), and the 
interesting active life with the characteristic swimming, 
diving, breathing, captur- 
ing of prey, and feeding 
all easily observed. 

The life-history of 
no American species has 
been completely worked 
out, but the eggs of some 
species are dropped ir- 
regularly on the water, 
while those of others are 


Fic. 348. Fic. 349. laid in slits cut by the 

Fic. 348.—Water-tiger, the larva of the predaceous water- sharp ovipositor of the 

beetle, Dyticus sp. (Natural size.) ; female in the stems of 
Fic. 349.—The predaceous water-beetle, Dyticus sp., pupa 


and adult, (Natural size.) aquatic plants. The long, 
slender, semi-transparent, 
predaceous larvee (Fig. 348) are known as water-tigers. They have six slender 
legs and the head is large and flattened. It bears long, slender, curved, 
sharp-pointed, hollow mandibles, each with a small opening at the tip and 


Beetles 257 


another near the base. When a live insect or other aquatic creature is caught 
by the active larva its body is pierced by the mandibles and the blood sucked 
through them into the mouth, the opening at the base just fitting, when the 
mandibles are closed, into the corners of the small silt-like mouth. Both 
larve and adults are fierce and voracious, and the larger species attack and 
kill small fish. In the middle states these beetles actually do much damage 
in qarp-ponds. The larva breathes through a pair of spiracles at the slender 
tip of its body, which is thrust up to the air when it comes to the surface 
of the water. When ready to pupate it leaves the water—breathing now 
also through six pairs of lateral spiracles—and makes a rough cell in the 
ground of the pond or stream bank. ‘The pupa state lasts about three 
weeks in summer; but the larve that transform in autumn remain in the 
pupa state all winter.” 

The larger of our common species belong to Cybister, Dyticus, and 
allied genera. In Cybister the little cups on the under side of the tarsal 
disks of the male are similar, and arranged in four rows. In Dyticus and 
its allies the cups of the tarsal disks vary in 
size. Fig. 349 represents a common species of 
Dyticus. : 

“The most common of the diving-beetles 
that are of medium size belong to the genus 
Acilius. In this genus the elytra are densely 
punctured with very fine punctures, and the 
females usually have four furrows in each wing- 
cover.” 

An interesting account of the habits 
and special structures of the common large 
European diving-beetle, Dyticus marginalis, 
is given in Miall’s Natural History of Aquatic 
Insects, pp. 39-61. 

Smaller than the predaceous diving-beetles, FIG. 350. Fic. 351. 
and readily recognized by their curious spin- Fic. 350. — Whirligig - beetle, 
: Pains R as ehh Dineutes emarginata. (Twice 
ning or circling, in companies, on the surface eee persan 
of ponds or still pools in streams, are the Fic. 351.—Larva of whirligig- 
whirligig-beetles (Gyrinid), common all over (ie Saree Mins 
the country. About forty species of these 
beetles, varying in size from one-sixth to three-fourths inch in length, have 
been found in North America, three-fourths of them belonging to the genus 
Gyrinus. They are all of similar shape and steely blue-black in color, 
and have the compound eye, on each side, wholly divided into an upper 
and a lower part by the sharp lateral margin of the head. Like the 
Dyticids, the whirligig-beetles breathe at the surface and carry air down with 


258 Beetles 


them when diving or swimming below the surface, by having a bubble 
attached to the posterior tip of the body. The hindmost legs are broad 
and paddle-shaped, and fringed with long stiff hairs. The whirligig- 
beetles can fly, but usually have to climb up on some weed or stick pro- 
jecting from the water in order to make a start. They can make a curious 
squeaking noise, probably a call to other whirligigs, by rubbing the under 
side of the wing-covers against the end of the body. When handled, most of 
these beetles emit an ill-smelling whitish liquid. 

In the winter the whirligigs lie torpid in mud among the roots of water- 
plants, coming out by twos and threes in the spring. The eggs are laid 
usually on the leaves of some water-plant, and the curious slender larva 
(Fig. 351) is provided with long tapering lateral gills fringed with fine hairs. 
There is a pair of gills on each abdominal segment. It feeds on water- 
insects and other small aquatic animals, and probably also on the “tender 
parts of submerged plants.” The pupe of but few species are known. 
That of a common English species lies in a grayish silken cocoon spun on 
some water-plant above the water’s surface. 


TRIBE CLAVICORNIA, 


The clavicorn beetles, or those with clubbed antennz, show much variety 
in the character of the terminal thickening of the antenne (Fig. 340, 4-7), 
which is the characteristic structural feature of the members of the group, 
and from which the tribal name is derived. The tribe includes, too, beetles 
of widely different habits, some aquatic, others terrestrial, some predaceous, 
others plant-feeding, others living on dry stored grains, woolens, and still 
others feeding on carrion. They have indeed little in common and the 
grouping is largely a matter of convenience in classifying. The more im- 
portant families of this tribe can be separated by the following key: 
Aquatic; legs fitted for swimming -..--.----- (Water-scavenger beetles.) HyDROPHILIDE. 


Terrestrial; legs not fitted for swimming. 
Antenne moniliform, i.e., with segments bead-like; elytra usually covering only basal 


ihalfiol abdomen aoe-e = cere ae eer eee seer ine (Rove-beetles.) STAPHYLINID. 
Antenne moniliform or sub-moniliform; elytra covering most of the abdomen: brown 
orreddishispectes:)-22 45 se=e se ose eee ae (Grain-beetles, etc.) Cucuyip2. 


Antenne capitate, i.e., ending in a little ball, or clavate. 
Large insects, the smaller not much less than half an inch long (except Catops); 
body usually flattened.......------- (Carrion- or burying-beetles.) SI~pHiD2&. 
Small insects, mostly less than one-half inch long; body thick and convex above. 
(Larder-beetles, etc.) DERMESTIDE. 


In the same ponds and pools with the predaceous diving-beetles and 
whirligigs may be found other water-beetles, black, shining, and often of 
large size, which are readily distinguished by their short concealed clavate 


Beetles 259 


antenne (the long slender palpi may be at first glance mistakenly taken 
for antenne) as members of the family Hydrophilide, the water-scavenger 
beetles. As the popular namie indicates, these beetles feed, for the most 
part, on decaying material, animal or plant, found in the water, although 
they feed also on living water-plants, as Nitella; and living insects are cer- 
tainly taken by some species. They can be distinguished from the Dyticide 
when swimming by their use of the oar-legs alternately, and when at the 
surface getting air by hanging there head upward. The air spreads in a 
thin silvery layer over the ventral side of the body, held there by fine pubes- 
cence. 

The eggs are deposited in a ball-like silken cocoon with a curious handle- 
like tapering curved stem or spike (Fig. 353). The cocoon floats freely 
on the water, or is attached to some floating leaf or grass-blade or stem. 
From fifty to a hundred eggs are enclosed in each sac. The larve (Fig. 
354) are elongate, but thicker and less graceful than 
the water-tigers (larve of the Dyticide), and, unlike 
the adults, feed chiefly on living insects, snails, tad- 


FIG. 352. FIG. 353. Fic. 354. 


Fic. 352.—Great water-scavenger beetle, Hydrophilus triangularis. (Natural size.) 

Fic. 353.—Egg-case of great water-scavenger beetle, Hydrophilus sp. (Twice natural 
size.) 

Fic. 354.—Larva of great water-scavenger beetle, Hydrophilus caraboides. (After 
Schiodte; natural size.) 


poles, etc. They breathe through spiracles at the tip of the body, coming 
occasionally to the surface to get air. In shallow water they simply lie 
with the tip of the tail projected up to the surface. When ready to pupate 
the larve leave the water, and, burrowing a few inches into the ground, form 
a rough cell in which they transform. The adult beetles fly readily, and 
sometimes, with Dyticids, are to be found at night around electric lights. 
When winter comes they burrow into the bottom or bank of the pond or 
stream and lie torpid until spring. 


260 Beetles 


About one hundred and fifty species of Hydrophilide are known in this 
country. The largest species belong to the genus Hydrophilus, are shining 
bluish or greenish black, and measure nearly two inches in length. ‘In the 
genus Hydrocharis the metasternum is prolonged somewhat, but does not 
form a long, sharp spine as in Hydrophilus and Tropisternus, and the sternum 
of the prothorax bears a keel-shaped projection. Our most common species 
is Hydrocharis obtusatus; this measures about five-eighths of an inch in 
length. 

“Some of the smaller species of this family are not aquatic, but live in 
moist earth and in the dung of cattle, where, it is said, they feed on dipterous 
larve.” 

The rove-beetles, Staphylinide, form a large family, numerous in species 
and individuals over the whole country, and one whose members are readily 
reclame by the elongate flattened soft body, narrow and parallel sides, 

with short truncate leathery elytra under which the hind 
wings are compactly folded so as to be wholly concealed. 
They are mostly carrion-feeders and with the Silphide 
(p. 261) are almost sure to be found whenever a mass of 
decaying flesh or excrementitious matter exposed on the 
ground is turned over. They run swiftly when disturbed 
and curve the tip of the flexible abdomen up over the 
body in a sort of threatening way, as if they would sting. 
They cannot; they can simply smell bad. Although the 
more familiar rove-beetles are of fair size, from half an 
inch to nearly an inch long, the majority of the one 
‘thousand or more species found in this country—gooo 
species are known in the world—are very small. In 
Fic. 355.—Larva California great swarms of minute rove-beetles dance in 
of a rove-beetle, aie 5 3 
Xanthalinus the air in April and May, and are a woful nuisance to 
lentus. (After people driving or bicycling. They get into one’s eyes, 
Prateek and when crushed by rubbing, their acrid body-fluids 
both smell bad and burn. Among these smaller Sta- 
phylinids are numerous predaceous species and many which are found in 
flowers, probably feeding on pollen. Others are found on fungi, on mud, 
and in other damp places, and some live in ants’ nests (see Chapter 
XV, p- 552). 

The larve (Fig. 355) are found in the same places as the adults, and 
are elongate, narrow-bodied, and rather like those of the Carabidae, but 
each foot has but a single claw. The pupe of some species are enclosed 
in a sort of exudation that dries into a firm protecting coating rather like 
the horny cuticle of a lepidopterous chrysalid. 

Among the more familiar rove-beetles are species of the genus Creophilus. 


Beetles 261 


C. villosus (Fig. 356), common all over the country, is about } inch long, 
blackish, with an incomplete broad transverse patch of yellowish-gray hairs 
across the elytra and another on the second and third abdominal segments. 
Leistotrophus is a genus with but one American species, L. cingulatus, about 
same size as the preceding, but of grayish-brown color 
indistinctly spotted with brown and with a golden tinge 
on the tip of the abdomen. Staphylinus is a genus of 
twenty species or more; S. maculosus, 1 inch long, is 
dark cinnamon-brown with a row of squarish black 
spots along the middle of the abdomen; S. cinna- 
mopterus, 4% inch long, is cinnamon-colored, with 
blackish abdomen; S. tomentosus, 4 inch long, is deep 
dull black; S. violaceus, 4 inch long, is black with aS Sogn 
e, Creophilus vil- 
thorax and elytra violet. Not uncommon along sandy — /osus. (One and one- 
seashore in California is a curious light-brown wing- ey ess LEE 
less rove-beetle, Thinopinus pictus, with very short 
elytra, each with an open black ring, and with a double row of small black 
dots on the abdomen. Its abdomen is short and rather broad 
Another family of carrion-beetles of comparatively few species, some of 
which, however, are familiar and widely distributed, is that of the Silphide, 
i or burying-beetles. Both adults and larve 
feed almost exclusively on decaying flesh. 
The antenne of most species have the last 
four or five segments expanded and fused 
so as to form a conspicuous little ball or a 
compact club. Two genera include most 
o the familiar species, although the one 
hundred North American species of the 
family represent thirty different genera. 
These two are Silpha (Fig. 357), the roving 
Fic. 357. Fic. 358. carrion-beetles, and Necrophorus (Fig. 


Fic. 357.—Carrion-beetle, Silpha 358), the burying-beetles. The charac- 
noveboracensis. (One and one-half 
times natural size.) 

Fic. 358.—Burying-beetle, Necropho- types are well shown in the figures. The 


ai marginatus. (One and one- species of Silpha are short, broad-bodied, 
alf times natural size.) 

flat, dull blackish, and with the elytra rather 
leathery than horny, and lined longitudinally with shallow grooves. The 
prothorax is subcircular, with thin projecting margins. The larve (Fig. 
359) and adults are found in and underneath putrid flesh. The larve 
are apparently more active than the adults. Silpha lapponica, a common 
dull black form in both Europe and America, is said to enter houses in Lap- 
land to eat the stores of animal provisions. S. americana (PI. II, Fig. 5) has 


teristic shape and appearance of these two 


262 . Beetles 


the large shield-like prothorax yellowish with a black blotch in the center. 
In S. noveboracensis only the margin of the prothorax is yellow. 

The burying-beetles, Necrophorus, are large insects from an inch 
to an inch and a half jong, with the body thick and parallel-sided. The 
commoner species have a pair of dull red transverse blotches on each elytron. 
In some species the prothorax and head are also marked 
with red. The common name comes from the well- 
known habit of these insects of digging underneath small 
dead animals, as mice or birds, until the corpse is ina 
hole; it is then covered over and thus really buried. 
The female lays her eggs on the corpse, and the larve 
hatching from them feed on the decaying matter. These 
Fic. 359.—Larva larve have spiny plates on the back of the body and 

a See oak are otherwise unlike the Silpha larve. Some Necrophorus 
and one-half times larye are predaceous and others feed on decaying vege- 
natural size.) table matter. 

Most of the blind, pale cave-beetles found in caves in this country and 
Europe are Silphide. 

The Cucujide, with a name derived from the Portuguese Cucuyo, a 
large luminous Brazilian snapping-beetle or elater, of entirely different 
family, are a family of small beetles, with flattened reddish or light-brown 
body, whose outdoors haunts are mostly under the bark of trees. Sev- 
eral species, however, have learned that 
life in a granary is just as safe from pre- 
daceous enemies, and a thousand times 
safer from starvation. Of these sophisticated 
Cucujids, Silvanus surinamensis, the saw- 
toothed grain-beetle (Fig. 360), is the most 
familiar and injurious. The adult is about 
4 inch long, flat and chocolate-brown, and 
may be distinguished from the other small 
beetles similarly attacking stored grain by 
the serrated margins of its prothorax. It Fic. 360.—Larva, pupa, and adult of 
infests dried: fruits, nuts, seeds, and dry the saw-toothed grain-beetle, Sil- 

5 pao vanus surinamensis, (After How- 
pantry stores of all sorts, as wellas grainbins ard and Marlatt; much enlarged.) 
and cribs. The larve (Fig. 360) are active 
little six-legged flattened whitish grubs which run about and nibble indus- 
triously. When full-grown the larva attaches itself by a gummy excretion 
to some object, and pupates. When living in light granular substances, 
as oatmeal, etc., a delicate case is constructed of the material in which to 
pupate. In summer the life-cycle from egg to adult requires but twenty- 
four days; in spring from six to ten weeks. Six to seven generations are 


Beetles 263 


produced annually in the latitude of Washington. The insect here hiber- 
nates in the adult state. 

The largest and most familiar of the outdoor Cucujids is a very flat 
bright-red species, Cucujus flavipes (Pl. II, Fig. rr), about half an inch 
long, with black eyes and antenne and the legs with dark tibie and feet. 

The Dermestide constitute only a small family of forty or more North 
American species representing twelve genera, but one which nevertheless 
is of unusual interest and importance to entomologists, for to this family 
belong those insects which eat entomological collections. A depraved taste, 
but one which causes almost constant anxiety and occasional serious 
discouragement on the part of the industrious collector. Dermestids 
are not the bane of collectors and museum curators alone, as larder-beetles, 
“‘buffalo-moths,” and carpet-beetles, various species of this family, help 
make life a burden to the housewife. 

All of the Dermestide are small, oval, and plump-bodied, the largest 
species being about 4 inch long, and most of them are covered with small 
scales, which give them their rather varied colors and markings. The beetles 
themselves mostly feed on pollen, but come into houses to deposit their eggs. 
From the eggs hatch soft-bodied little grubs thickly covered with hairs, 
often very long (Figs. 361 and 362). These larve are the real pests of house- 


Fic. 361. Fic. 362. 


Fic. 361.—Carpet-beetle or ‘“‘buffalo-moth,” Anthrenus scrophularie, larva and adult. 
(After Howard and Marlatt; much enlarged.) 

Fic. 362.—Black carpet-beetle, Attagenus piceus, larva and adult. (After Howard 
and Marlatt; enlarged.) 


hold and museum: they feed industriously on dried insect specimens, 
stuffed birds and mammals, woolen carpets, furs, feathers, or on meat and 
cheese (depending on the particular habits of the various species) until full- 
grown. Then they crawl into a crack or hide in the body of a museum 
specimen and pupate within the larval cuticle, which serves as a sort of thin 
hairy protecting shell. 

The usual museum pests are two species, A. varius and A. museorum, of 
the genus Anthrenus. The adult beetles are tiny, broadly oval, very convex, 
with the black body covered above with scales some of which are yellowish 


264 Beetles 


and some whitish and so arranged as to give the back an irregularly spotted 
appearance. The hairy larvae burrow into the specimens and nibble away 
at the dry bodies. Their presence may be detected by a little pile of dust 
under the pinned-up specimen and by the falling off of its legs, head, etc. 
Pour a teaspoonful of carbon bisulphide into a corner of the case and 
keep it tightly shut for a day. The fumes of the CS, are fatal to the pests. 
The carpet-beetle or ‘‘ buffalo-moth”’ (Fig. 361) is another species, A. scrophu- 
larie, of this same genus. The beetle is about ;3; inch long, marbled black 
and white above with a central reddish line bearing short lateral offshoots 
on each side. The larva is thick, soft, active, and covered with stiff brown 
hairs. It feeds voraciously on carpets, working on the under side, and 
usually making long slits following the floor-cracks. The beetles are common 
outdoors on plants of the family Scrophulariaceze, but come indoors to lay 
their eggs. The remedy for the carpet-beetle is to use rugs instead of 
carpets, and to lift and shake these rugs often. Another member of this 
family attacking carpets is the black carpet-beetle, Altagenus piceus (Fig. 
362). The beetle is black, and the larva is longer, more slender, and lighter 
brown than the buffalo-moth, and has a conspicuous pencil or tuft of long 
hairs at the posterior tip of the body. The larder- or bacon-beetle, Dermestes 
lardarius (Fig. 363), is about 4 inch 
long, dark brown with a pale-yellowish 
band, containing six black dots across 
the upper half of the wing-covers. 
The larva is elongate, sparsely hairy, 


FIG. 363. Fic. 364. 


Fic. 363.—The larder-beetle, Dermestes lardarius, larva, pupa, and adult. (After 
Howard and Marlatt; much enlarged.) ; ¢ 

Fic. 364.—Larva of a water-penny beetle of the Parnide. (Four times natural 
size.) 


brown, and has two short curved spines on top of the last body-segment. 
It feeds on many kinds of animal substance, as ham, bacon, old cheese, 
hoofs, horn, skin, beeswax, feathers, hair, and also attacks museum specimens. 

Another family of Clavicornia which possesses a special interest is the 
Parnide, or ‘‘water-pennies,”’ a family of forty species representing ten genera 
of small brown robust-bodied insects which live in water and yet do not 


Beetles 265 


have their legs fitted for swimming, nor in any other way the body partic- 
ularly modified for an aquatic life. They crawl around on submerged stones, 
sticks, and water-plants, carrying a supply of air with them, held by the 
fine pubescence of the body. The larve are curiously flattened, broadly 
oval to nearly circular small creatures (Fig. 364), which cling to stones and 
give the family its popular name of ‘‘water-pennies.”’ As the legs, mouth- 
parts, eyes, etc., are all on the under side and concealed, the flat, brownish, 
leathery little “penny” is usually not recognized as an insect by the observer 
of brook life. 

The family Platypsyllide has been established to include a single 
species of strangely shaped beetle which lives as a parasite on the bodies 
of beavers. Its name is Platypsylla castoris; it is about 75 inch long, blind 
and wingless, and with the elytra rudimentary. This degenerate condition 
of the body is due of course to the parasitic habit. Other obscure little 
-beetles of curious habits are the Pselaphide and Scydmenide, many of 
which live commensally with ants in their nests. These beetles are rarely 
over an eighth of an inch long, and some of them have bodies strangely 
modified to look like ants. (For a further account of these insects see 
the discussion of myrmecophily in Chapter XV.) 


TRIBE SERRICORNIA. 


In this tribe of beetles, characterized by having the antennz slender, 
with each segment projecting more or less inward so as to give the whole 
antenn a saw-toothed or serrate character (Fig. 340, 10), are included sev- 
eral families certainly not closely related and having widely different habits 
and appearance. The serrate character of the antennz, too, is sometimes 
so slight that it can hardly be distinguished with certainty. The more 
important families of the tribe can b: separated by the following key: 


Head inserted in thorax as far as the eyes; body elongate or elliptical, and with unusually 
hard cuticle. 
Antenne finely serrate, the first two abdominal segments grown together on the ven- 
final Cis as Sete A ee ee eae Sagoo (Metallic wood-borers.) BuPRESTID. 
Antenne often filiform; first two abdominal segments free. 
(Click-beetles.) ELATERIDA. 
Head free, but bent under the thorax. 

Small insects usually less than } inch long......-. (Death-watch beetles.) Prinrip&. 
Head free, but often partly or wholly covered by the thin anterior margin of the thorax. 
Wing-covers flexible; body elongate and flattened; antennz not enlarged at tip. 

(Fireflies.) LAMPyRID#®. 
Wing-covers firm, thorax convex, body not much flattened; antenne often enlarged 
Me Melo coccauccusane wnecuocogce soe seLUsoos (Checkered beetles.) CLERID&. 


The metallic wood-borers, or flat-headed borers, a name suggested by 
the flat broad head of the larva, constitute the large and important family 


266 Beetles 


Buprestide, of which over two hundred species occur in North America. 
The adult beetles have an elongate body, trim and compact, with a rigid 
and armor-plate-like cuticle, and have iridescent metallic coloring. Green, 
violet, reddish, blue, copper, golden they may be, always shining like 
burnished metal and the whole body looking as if cast in bronze. The 
antenne are short and serrate on the inner margin, the head deeply inserted 
in the thorax, and the latter fitting closely against the 
-abdomen and wing-covers; and the second and third 
abdominal segments are rigidly fused. These beetles are 
diurnal, running actively on tree-trunks or resting on 
flowers; seeming to delight in the warm bright sunlight, 
in which their resplendent colors flash and glance like 
jewels. 

The larve are mostly wood-borers, although those of 
some of the smaller species mine in leaves or live in galls. 
The wood-boring Buprestid larve are characterized by the 

eS aa strangely enlarged and flattened, legless, first thoracic 
headed borer, Segment, on which the small head with its powerful jaws 
larva of Rha- sets in front, and the tapering, flattened, legless, meso- 
Peace sey and meta-thoracic segments behind. The abdomen is 
elongate and rather narrow, the segments showing dis- 
tinctly. The whole larva (Fig. 365) is thus a footless whitish tadpole-like 
grub, expressively known as a flat-headed or hammer-headed borer. The 
larvee that do not burrow in wood are cylindrical and have three pairs of legs. 
The most injurious Buprestid is the notorious flat-headed apple-tree 
borer, Chrysobothris femorata (Fig. 366), an obscure bronze or greenish- 
black beetle about half an inch long. The legs and 
under side of the body are of burnished copper, and 
the antenne green. The eggs are glued to the bark 
under scales or in cracks; the young larva on hatching 
eats inward through the bark to the sapwood and 
there burrows about, sometimes quite girdling the tree. 
Later it bores into the solid heart-wood, working up- 
ward and then again out into the bark, where it forms 
a cell in which it pupates, issuing as an adult in just Fic. 366.—Apple-tree 
about one year from the time of its hatching. This borer, Chrysobothris 
pest attacks peach- and plum-trees and several forest- Une ead gi cee ood 
and shade-trees as well as the apple-tree. It ranges 
over the whole country. To prevent the egg-laying on the bark, the lower 
trunk of the tree should be washed with fish-oil soap during June and July. 
When borers are once in the tree, cutting them out is the only remedy. 
The genus Agrilus contains a number of species having the head flatly 


Beetles 267 


truncate in front, as if cut sharply off, and the body rather cylindrical than 
flattened, as with most other Buprestids. A. rujicollis, the red-necked black- 
berry-borer, 3; inch long, with dark bronze head, coppery bronze prothorax, 
and black wing-covers, has a larva that bores into the canes of blackberries and 
raspberries, burrowing spirally about in the sapwood until full-grown, when 
it bores to the pith and there pupates. The eggs are laid in June and July 
on the young canes. Infested canes often show gall-like swellings, and 
should be cut off and burned. 

Our largest Buprestids belong to the genus Chalcophora. C. virginiensis 
is an inch long, dark coppery or blackish with elevated lines and depressed 
spots on the elytra. The larve bore into pines. C. liberta (Pl. II, Fig. 3) is 
a beautiful pink bronze with darker raised lines. Dicerca divaricata, } inch 
long, is copper-colored, with the black-dotted elytra tapering behind and 
separated at the tips. Buprestis (Pl. II, Fig. 8) is a genus of rather large 
brassy-green or brassy-black species often spotted with yellow on the elytra 
and beneath. 

Resembiing the Buprestids much in general shape and appearance, the 
click-beetles, Elateride, are readily distinguished from them by their lack 
of metallic colors, the backward-projecting, sharp-pointed hinder angles 
of the prothorax, and their curious capacity, whence 
their name, of springing into the air with a sharp click 
when laid back downward. When a click-beetle— 
snapping-bugs and skipjacks are other common names 
for them—is disturbed it falls to the ground, lying 
there for a little while as if dead. Then if it has 
alighted, as it usually does, on its back, it suddenly 
gives a spasmodic jerk which throws it several inches 
high and brings it down right side up. This springing 
is accomplished by means of an apparatus consisting 
of a small cavity on the under side of the mesothorax Fc. 367. — Ventral 
. = - eae aspect of a large 
into which the point of a curved projecting process — ¢jjck-beetle, show- 
from the prosternum fits (Fig. 367). When the beetle is ing snapping appa- 
laid on its back it bends in such a way as to bring the aa (eR eeeT 
tip of the curved horn to the edge of the cavity, when, i 
by a sudden release of muscular tension this tip slips and the insect is 
thrown into the air. The Elaterid are a large family, about 350 species 
being known in this country. They are mostly of small or medium size, 
although some are an inch or more long; a very few reach a length of 
nearly two inches. As a rule they are uniform brownish; some blackish 
or grayish and others banded and-marked with brighter colors. In the 
South occur certain luminous click-beetles. In Cuba ladies sometimes use 
these phosporescent species, which are large and emit a strong greenish 


268 Beetles 


light, as ornaments, by keeping them alive in little lace pockets on their 
gowns or attached to delicate golden chains. Two large eye-like spots on 
the prothorax, and the under side of the hinder part of the abdomen, are 
the luminous regions. 

The larve (Fig. 368) are elongate, slender, horny-skinned, brownish 
or yellowish white, living in the ground or in decaying wood, and popularly 
and aptly known as wireworms. ‘They have three pairs of short legs, and 
a stumpy process on the last segment of the body. They feed on the seeds, 
roots, and other underground parts of plants and do much damage to various 
crops. Often whole fields of grain are ruined by the attack of wireworms 
on the planted seeds; meadows often suffer severely, and strawberries lose 
their stolons. The beetles fly about 
in early summer, depositing their 
eggs in the ground in grassy, weedy, 
or plowed land. The larve soon 
hatch, dig down into the soil, and feed 
on roots and seeds for two or three 
years, when they become full-g-own. 
They pupate in the ground in early 
fall and the pupe transform to adults 
before winter, but the beetles do not 
issue from the ground until the fol- 


PVG 


lowing spring. 
Among our largest click-beetles 
BeSHae: ae G5 is the eyed elater, Alaus oculatus 
Fic. 268. —Larva of a click-beetle, Elater (Fig. 369); 18 inch long, blackish 
acerrimus. (After Schiodte; natural with large uneven whitish gray dots, 
size.) oe a pepper-and-salt fellow, Comstock 
Fic. 369.—An eyed elater, Alaus oculatus. : ; £ 
(One and one-half times natural size.) well calls him, with a pair of large 
white-rimmed velvet-black eye-spots 


on the prothorax. The large larva, about 2 inches long, live in decaying 
wood and are often found in the trunks of old apple-trees. Elater rubricollis, 
1 inch long, is black with light-red prothorax; £. sanguinipennis, 
3 inch long, is black with light-red elytra; E. nigricollis, % inch long, is 
black with whitish elytra. Athous scapularis, 3 inch long, is green sh 
black with the base of the elytra and the hind points of the prothorax clay- 
yellow. Several species of Corymbetes have the elytra brownish yellow with 
transverse zigzag black bands; C. hieroglyphicus, 4 inch long, has two 
bands: C. hamatus, rather smaller, has one band near the tip. Melanactes 
piceus, « inch long, is glossy black and its large larva is luminous, 
strong green light being emitted from a narrow transverse region with 


expanded ends on each segment. 


Beetles 269 


The fireflies are familiar insects which are not flies but beetles, although 
their soft body and flexible leathery wing-covers are not of the typical 
coleopterous type. The nocturnal fireflies and their diurnal first cousins, 
the soldier-beetles, compose a coleopterous family, Lampyride, of con- 
siderable size and common distribution over the whole world. The ‘“glow- 
worm” of England and Europe is the wingless female of a common firefly, 
and the railway-beetle of Paraguay, a worm-like creature 3 inches long, 
that emits a strong red light from each end of the body and a green light 
from points along the sides, is also probably the wingless female of a large 
firefly species. In this country over 200 species of Lampyride have been 
ound. Comparatively few of them, however, are luminous. The light- 
giving organ is usually situated just inside of the ventral wall of the last seg- 
ments of the abdomen, and consists of a special mass of adipose tissue richly 
supplied with air-tubes (trachez) and nerves. From a stimulus conveyed 
by these special nerves oxygen brought by the network of trachee is released 
to unite with some substance of the adipose tissue, a slow combustion thus 
taking place. To this the light is due, and the relation of the intensity or 
amount of light to the amount of matter used up to produce it is the most 
nearly perfect known to physicists. 
Not only are the adult fireflies 
luminous, but in some species the 
pupe and larve and even the 
eggs emit light. The combustion 
in the egg is of course accom- 
plished wholly without tracheze 
or controlling nerves. 

The larve (Fig. 370) of Lam- 
pyride mostly burrow  under- 
ground, where they feed on soft- 


: FIG. 371. FIG. 372. 

Fic. 370.—Larva of firefly, Photinus modestus. 

3 oi (Twice natural size.) 

bodied insects, slugs, and other Fig, 371.—Firefly, Photinus scintillans. (Three 

similar food. The adults, too, _ times natural size.) } 

Fic. 372.—Checker-beetle, Tvichodes ornatus. 
(Twice natural size.) 


are carnivorous, the diurnal forms, 
called soldier-beetles, being com- 
monly seen on flowers or tree-trunks hunting prey. 

The commoner luminescent fireflies, or “‘lightning-bugs,”’ belong to the 
genus Photinus. P. pyralis, the common species from Illinois south, is 
$ inch long, blackish, with prothorax with red disk, yellow margin, and black 
spot in center, and the elytra with narrow yellowish border. Farther north 
and east the commonest species is P. scintillans (Fig. 371), similar in mark- 
ing but smaller. P. angulatus, } inch long, is pale, with wide yellow margins 
on elytra and the margin of the prothorax clouded with black. The com- 
moner soldier-beetles belong to the genus Chauliognathus, which is char- 


270 Beetles 


acterized by the possession of a pair of extended fleshy processes belonging 
to the maxilla, which are used in lapping up flower-nectar and pollen. Two 
common species in the East are C. pennsylvanicus, which is yellow with 
a black spot in the middle of the prothorax and one near the tip of each 
wing-cover, and C. marginatus, which has the head and lower part of the 
thighs orange. Telephorus is another common genus without the maxillary 
processes, the species being black with the prothorax partly or wholly reddish 
yellow. The larve of 7. bilineatus, the two-lined soldier-beetle, are velvety 
dark-brown active creatures which are very beneficial in orchards, devour- 
ing ‘immense numbers of such destructive beings as the larve of the plum- 
curculio.”” 

Professor Comstock has given the name checkered beetles to the family 
Cleride; a name apt enough for some of the species which, like the one 
shown in Fig. 372, have the body conspicuously marked with red and white 
or other colored ‘‘checks.” Other species, however, content themselves 
with a monochrome coat. The family is a fairly large one, over a hundred 
species being known in this country. ‘“‘The adults are found on flowers 
and on the trunks of trees running about rapidly, somewhat resembling 
brightly colored ants. Indeed some are decidedly ant-like, the prothorax 
being narrower than the wing-covers and slightly narrower than the head. 
The legs of the Clerids are rather long, the antenne with a marked knob 
at the end, and the body more or less cylindrical, either hairy or not. 

“The larve are usually carnivorous and are most frequently found 
in the burrows of wood-boring insects, chiefly of those that live in sap-wood; 
others are found in the nests of bees, and still others feed on dead animal 
matter.” The slender larve possess short legs and a somewhat prominent 
and pointed head. They are extremely useful in keeping in check such 
destructive beetles as bark-beetles and other borers. 

The species of Clerus are prettily marked and are often found running 
about on logs and trees. C. dubius is 4 inch long, steel-blue with three 
orange bands across the elytra; C. nigrifons is } inch long, tawny yellow 
with smoky markings above and all black below; C. nigripes is similar, 
but all red below; C. sanguineus has the thorax brown and elytra scarlet. 
The species of Trichodes (Fig. 372) are hairy and prettily banded; the larve 
live in nests of bees, and T. apiarius is a pest in beehives in Europe. 
Necrobia violacea, } inch long or less, dark or greenish blue, is an importa- 
tion from Europe and is sometimes found in houses, but more commonly 
on carcasses and especially the bones of dead animals. It has been found 
under the wrappings of Egyptian mummies. Necrobia rujipes, the red- 
legged ham-beetle, a red-legged steel-blue species $ inch long, feeds on hams 
and other stored animal products. The beetles lay their eggs in May and 
June on exposed hams or other meats. The larve hatch in a few days and 


Beetles 271 


are slender white active grubs with a brown head and brownish patches 
above and two small hooks at the end of the body. They feed on the meat 
until full-grown, when they either burrow deeper into the meat or come out 
and bore into the wooden receptacle holding it, and make a glistening paper- 
like cocoon within which they pupate. 

The family Ptinide is composed of small obscure brownish beetles that 
would never attract our attention at all were it not for the injurious food- 
habits of many of the species. The family includes a hundred and fifty 
species, and among them a few notorious pests of rather unusual tastes. 
As the Ptinids mostly live on dead and dry vegetable matter, it was not 
improbable when I began a collecting expedition in a d ug-store that I should 
find a number of specimens of this family. But to find a majority of the 
canisters and jars containing vegetable 
drugs in the condition of roots, stems, 
leaves, etc., infested by beetles of this 
family was unexpected. The most 
abundant species on this collecting- 
ground was Sitrodrepa panicea (Fig. 
373), Which we may well call the “drug- 


Fic. 373.—The drug-store beetle, Sitro- 
store beetle.” It was found to be drepa panicea, larva pupa, and adults. 


attacking blue-flag rhizome, comfrey- (After Howard and Marlatt; much 
: ; : enlarged.) 

root, dogbane-root, ginger-rhizome, 

marshmallow-root, aniseed, aconite-tuber (deadly poison to us!), musk-root, 
Indian-turnip rhizome, belladonna-root, witch-hazel leaves, powdered coffee- 
seed, wormwood stems, flowers and leaves, thorn-apple leaves, cantharides 
(dried bodies of blister-beetles), and thirty other different drugs! Larvae, — 
pupe, and adults were side by side in most of the canisters. Ptinus brun- 
neus, a larger Ptinid, was in half a dozen jars, and the cigarette-beetle, 
Lasiderma serricorne, suggestively named, though it feeds on tobacco in 
almost any form, was living contentedly in a jar of powdered ergot. 

“Death-watch”’ is a name popularly applied to several species of Ptinids 
because of their habit of rapping their heads so sharply against wood in 
which they are burrowing as to make a regular tapping or ticking sound. 
This name is claimed by species of Anobium, tiny, robust, hard-bodied, cin- 
namon-colored beetles, 3%; inch long, and also by Sitrodrepa panicea, our 
drug-store beetle. Comstock records finding this species breeding in 
large numbers in an old book, a copy of Dante’s Divine Comedy, printed 
in 1536. Librarians would call the beetle a “bookworm.” 

Besides the small members of the family which feed on dried foods, 
drugs, etc., there are a few larger species of very different habits, although 
also destructive. The apple-twig borer, Amphicerus bicaudatus, 4 inch 
long, dark chestnut-brown above and black beneath, is the best known of 


272, Beetles 


these. It bores into live apple-twigs in early spring, entering close to a 
bud, and making a burrow several inches long for food and shelter. Twigs 
of pears and cherries are similarly infested. Both sexes bore these tunnels; 
the males have two sharp little horns on the prothorax. The eggs are laid 
in the dead or dying shoots of the greenbrier (Smilax) or in the dead shoots 
of grape. The larve feed on these roots or shoots and pupate in them. 
The remedy is to cut off and burn infested twigs, and to keep greenbrier 
from growing near the orchard. The red-shouldered sinoxylon, Sinoxylon 
basilare, 4 inch long, black with large reddish blotch at the base of each 
wing-cover, has a larva which bores into the stems of grape-vines and into 
twigs of apple and peach. This larva is a much-wrinkled grub, yellowish 
white with swollen anterior segments, three pairs of short legs, a small head, 
and an arched body. The pupa is formed inside the burrow and is of a 
pale-yellowish color. The only remedy is to remove and burn the infested 
canes and twigs. 
TRIBE LAMELLICORNIA. 


In this tribe are only two families, one small but containing strangely 
shaped and interesting beetles, the other very large. In both the terminal 
segments of the antenne have conspicuous lateral prolongations in the shape 
of teeth or plates (lamella) (Fig. 340, 8 and 9). The families may be dis- 
iinguished as follows: 

Antenne elbowed, the club (terminal segments) composed of segments with fixed 

transverse teeth; mandibles of the male often greatly developed. 
(Stag-beetles.) LucaANIpD®. 

Antenne not elbowed, the club composed of segments modified to be large flat 

plates which can be shut together like the leaves of a book; mandibles of 


males not greatly enlarged. 
(Lamellicorn leaf-chafers and scavenger-beetles.) SCARABEID#- 


The stag-beetles, Lucanide, get their name from the extraordinary 
hyper-development and curious branching stag-horn-like processes of the 
males of certain of the larger, more conspicuous species. Only fourteen 
or fifteen North American species of stag-beetles are known, but the abun- 
dance and striking appearance of several of them make the family a well- 
known one. The adult beetles are found on trees, where they presumably live 
on the sap flowing from bruised places, and on honey-dew secreted by aphids 
and scale-insects. In captivity they will take moistened sugar. Comstock 
believes that some species feed on decomposing wood. The large white 
globular eggs are laid in crevices of the bark near the base of the trunk, 
and the white, soft, fat-bodied larve (grubs) burrow into, the tree either in 
rotten or sound wood, and live there for a long time. It is said that the 
larvae of some of the larger species require six years to complete their growth. 


Beetles 272 


The genus Lucanus contains four North American species, three of which 
are familiar. L. elaphus (Fig. 374), the giant stag-beetle, of the southern 
states, varies from 1} to 2 inches in length, not including the mandibles, 
which in the male are 1 inch long and branched; L. dama, the common 
pinching-bug of the East, rich mahogany-brown in color, from 1 inch to 
14 inches long, ‘‘flies by night with a loud 
buzzy sound and is often attracted to lights 
in houses,’ and has a white grub larva 
looking like the white grub of the June-bug, 
but found in partially decayed trunks and 
roots of apple-, cherry-, willow-, and oak- 
trees instead of in the ground; L. placidus, 
not quite an inch long, and black, is a third 
common species. The antelope-beetle, 
Dorcus parallelus, is less than an inch long, 
black, and with longitudinal grooves on the 
elytra. Platycercus quercus, 3 inch long, 
brownish black, is widely distributed. 
Ceruchus piceus, 4 inch long and dark brown, 
is occasionally common in rotten wood. 
The horned Passalus, P. cornutus, large 
and shining black, has a short horn bent 
forward on top of its head. 

The great family Scarabeide, com- Frye, 374.—Stage-beetle, Lucanus 
prising over five hundred species of North elaphus male. (Natural size.) 
American beetles, includes some of our most familiar kinds. Indeed 
sO many common, conspicuous, and interesting Scarabeid beetles are to be 
found by any collector, or observed by any amateur naturalist, that the two 
or three pages of this book which can be devoted to them are confessedly 
miserably inadequate to help any one. The characteristic club of the 
antenne and heavy robust June-bug type of body make most of the members 
of this family readily recognizable. In practically all, too, the anterior 
tibie are broad and flattened and fitted for digging. Depending on their 
habits, the Scarabeids are readily divided into two principal groups, the 


scavengers, of which the tumble-bugs, dung-beetles, etc., are examples, 
and the leaf-chafers, of which the June-bugs, rose-bugs, rhinoceros-beetles, 
fig-eaters, and flower-beetles are examples. Some entomologists divide 
the Scarabzids into several distinct families, but niost do not. The scavenger 
Scarabeids are beneficial to man by their eating or burying of decaying 
matter, but the leaf-chafers are harmful, some of them being serious pests. 
The Scarabeid larve (Fig. 376) are thick, soft-bodied, whitish, six-footed 
grubs, which usually lie curved and often on one side. They are found 


274 Beetles 


in manure, rotten wood, and in the ground. The familiar white grub, larva 
of the June-bug, is a typical example. 

Of the scavenger Scarabeids the tumble-bugs are wide-spread and well 
known. The species common in the East belong to three genera: Copris, 
with middle and posterior tibia dilated at the tip; Canthon, with these tibe 
slender or only slightly dilated; and Phaneus, with the anterior tarsi wanting, 
and the others without claws. The species of Canthon, male and female 
working together, make balls of dung, which are rolled along for some dis- 
tance and finally buried in the ground. The female lays an egg in the ball, 


FIG. 375. Fic. 376. FIG. 377. 


Fic. 375.—Polyphylla crinita. (Natural size.) 
Fic. 376.—Larva of a large Scarabeid beetle. (Natural size.) 
Fic. 377.—Phaneus carnijex. (One and one-half times natural size.) 


and the fat white grub hatching from it feeds on the ball until ready to pupate. 
The adult beetle issues in about two weeks from the time of laying the egg. 
The common Copris carolina does not make a ball, but digs holes close to 
or under manure, and fills the holes with this substance, on which the larve, 
hatched from eggs placed one in each hole, feed. The species of Phaneus 
(Fig. 377) are brilliantly colored with metallic green, rose, and bronze, and 
bear curious projecting horns on the prothorax. The famous Sacred Scara- 
beus of the Egyptians, Ateuchus sacer, was ‘held in high veneration by 
this ancient people. It was placed by them in the tombs with their dead; 
its picture was painted on their sarcophagi, and its image was carved in 
stones and precious gems. These sculptured beetles can be found in almost 
any collection of Egyptian antiquities.” 

Common dung-beetles are the numerous species of Aphodius, ¢ to 4 
inch long, with oblong, convex, or cylindrical body, and with the front 
of the head expanded shield-like over the mouth-parts. ‘‘These insects 
are very abundant in pastures in the dung of horses and cattle, and immense 
numbers of them are often seen flying through the air during warm autumn 
afternoons.” Common species are A. jimetarius, } inch long, with red elytra; 


Beetles 275 


A. oblongus, 4 inch long, wholly black; and A. terminalis, 1 inch long, black 
with reddish legs and tips of elytra. The earth-boring dung-beetles, 
Geotrupes, have 11-segmented antenne, and the upper lip and mandibles 
can be seen from above. ‘‘The females bore holes into the earth either 
beneath dung or near it: this is to serve as food for the larve, an egg being laid 
in each hole.” G. splendidus (Pl. Il, Fig. 6), ? inch long, dark metallic 
green to purple; G. excrementi, 4 inch long, is bronze-black; G. opacus, } inch, 
is deep black. Common on dried decaying animal matter, especially skins, 
and on the hooves and hair of decaying animals are small (4 to 4 inch long) 
rough convex beetles, often with a crest of dirt on their elytra, belonging 
to the genus Trox. They have the thighs of the front legs greatly dilated. 
The Scarabeid leaf-chafers are many and various in color and marking; 
they feed, when adult, on leaves, pollen, and flower-petals. They have the 
abdomen usually projecting beyond the wing-covers. The thick, fat, white, 
horny-headed larvee live either in rotten wood or underground, feeding on 
the roots of grasses and other plants, often doing much damage in this 
way. The June-bugs or May-beetles (Fig. 378), familiar big brown or 
blackish buzzing creatures, belong to the genus 
Lachnosterna, of which sixty or more species are 
found in this country. They are but few, hovrever, 
on the Pacific coast. The larve are familiar white 
grubs that live underground and feed on the roots 
of grasses, strawberries, etc. They often do much 
damage to lawns. They live as larve 
for two or three years, and pupate in 
an underground cell. The adult 
beetles fly and feed at night, often 
injuring the foliage of cherry, plum, 
and other trees. The familiar rose- 
chafer, Macrodactylus subspinosus 
(Fig. 379), % inch long, a slender 
Fic. 378. Wie: 379. yellowish beetle with pale red legs, 

Fic. 378.—The June-beetle, Lachnosterna does great damage to roses and grapes, 
fesca. (One and one-half times natural appearing in early summer and eat- 
Fic. 379.—The rose-beetle, Macrodactylus ing flowers and foliage. The larvee 
subspinosus. (Twice natural size.) live underground, feeding on the roots 
of various plants, but especially grasses. The spotted vine-chafer, Pelidnota 
punctata (P\. II, Fig. 15), 1 inch long, stout, convex, polished reddish or 
yellowish brown, with three large black dots on each elytron, with under 
side of body metallic greenish black, flies during July and August by day, 
feeding on grape-leaves. The larva lives in rotten wood, especially the 
decaying roots of apple, pear, hickory, and other trees. It pupates in a 


276 Beetles 


cell in the wood. The goldsmith-beetle, Cotalpa lanigera, of similar size 
and shape, is glistening, burnished lemon-yellow above with metallic 
greenish, golden, and rose reflections; below it is copper-colored and 
thickly covered with whitish wool, hence the name /anigera, or wool-bearer. 
It appears in May and June, flies by night, and feeds on the foliage of 
various trees. The larva lives in the ground, feeding on plant-roots. It is 
said to require three years to complete its growth. 

The largest beetles in our country are the oddly shaped rhinoceros-beetles, 
Dynastes, found in the south and west. D. tityrus (Fig. 380), 24 inches long, 
is greenish gray with scattered black spots on the elytra; the male has a 
large horn on the head and three horns, one larger than the others, on the 
prothorax; the female has only a tubercle on the head; it is a southern species. 
D. grantii, of the west, has the large prothoracic horn twice as long as in 
tityrus. In the West Indies occurs D. hercules, six inches long! The larve 


Fic. 380.—The rhinoceros-beetle, Dynastes tityrus. (Natural size.) 


(Fig. 381) of these beetles live in the roots of decaying trees. Allied to 
Dynastes is the genus Ligyrus, of which L. rugiceps, the black sugar-cane 
beetle of the southern states, is the best-known species; it burrows into the 
base of sugar-cane and sometimes corn, and is often seriously destructive. 
The larva lives in manure. The flower-beetles are Scarabeids of several 
genera, which are commonly seen flying from flower to flower and feeding 
on pollen. The bumble flower-beetle, or Indian Cetonia, Euphoria inda 
(Fig. 382), a common species, is § inch long, yellowish brown, with the 
elytra irregularly covered with small blackish spots, and with the whole 
body clothed with short -fox-colored hairs, 1t appears early in spring, and 
flies near the ground with a loud humming. It feeds on flower-pollen, the 
tassels and green silk of young corn, and later on ripening fruits of all kinds; 
it often swarms about wounded trees, lapping up the escaping sap. The 
larve feed on decaying substances underground. The fig-eater, or “‘southern 
June-beetle,” Allorhina nitida, } inch to 1 inch long, is rather pointed in 


Beetles 277 


front, velvety green with the sides of thorax and head brownish yellow; the 
under side is not velvety, but metallic green. It flies with a loud buzzing 
sound and feeds on ripe fruit. The larve are found in richly manured 
soil, feeding on decaying matter. They cannot use the short legs for crawling, 
but move along on their backs by means of stiff bristles. “If put on a table 


Fic. 381. Fic. 382 
Fic. 381.—Larva and pupa of the rhinoceros-beetle, Dynastus tityrus. (After Chittenden; 
one-half natural size.) 


Fic. 382. 


Euphoria inda, (One and one-half times natural size.) 


in normal position, they immediately turn upon their backs and by the 
alternate contractions and expansions of their body-segments they wriggle 
away in a straight line.” 


SECTION TETRAMERA. 


In the four families of beetles constituting this section the feet are appar- 
ently composed of four tarsal segments, one of the more usual five being 
so reduced in size and fused with the last segment as to be practically indis- 
tinguishable as a distinct segment (except in the Spondylide). The first 
three tarsal segments are dilated and furnished with brushes of hairs on 
the sole, the third segment being plainly bilobed (Fig. 341, 2). This 
section is sometimes named Phytophaga, because of the voracious plant- 
feeding habits of all its members. The three principal families of the 
section can be separated by the following key: 

Body short and more or less oval; antennz short. 
Front of head not prolonged as a short broad beak; elytra usually covering the tip 
of the abdomen; both larve and adults live on green plants. 
(Leaf-beetles.) CHRYSOMELID®. 
Front of head prolonged as a short, quadrate beak; elytra rather short, so that the 
tip of the abdomen is always exposed; larve live in seeds. 
(Pea- and bean-weevils.) BrucHip. 
Body elongate; antenne almost always long, often longer than the body; larve are 
WOOC-DOLENS et ais8 oc onic o-clorces ciclelawinieme seme (Long-horn beetles.) CERAMBYCID®. 


The leaf-beetles, Chrysomelid, are one of the largest of the beetle fami- 
fies, over 600 North American species being known. They are mostly small, 


278 Beetles 


the familiar Colorado potato-beetle being one of the largest species in the 
family; the body is short, more or less oval in outline, strongly convex above; 
the head small, much narrower than the prothorax, and with the antenne 
inserted widely apart. The adults walk slowly about on the plants on which 
they feed, and when disturbed usually fold up the legs and fall, inert, to the 
ground. However, they sometimes take readily to wing. The eggs are 
usually laid in little groups on the food-plants, and the larva, rather broad, 
thick, and roughened, crawl about, exposed, on the leaves which they eat. 
Sometimes they eat only the soft tissue of the leaf, skeletonizing it; some mine 
inside the leaf, and a few burrow into stems. Most, however, eat ragged 
holes in the leaves, and, if feeding on cultivated plants, do great injury. 
Indeed there are perhaps more beetle enemies of our crops, shade-trees, and 
ornamental plants in this family than in any other in the order. 

The Colorado potato-beetle, Doryphora tro-lineata (Fig. 383), with 
robust; oval, cream-colored body, and elytra with five longitudinal black 
stripes on each, is a notorious Chrysomelid whose gradual extension or 
migration eastward from its native home in Colorado 
created much excitement forty years ago. Its native 
food-plant is the sand-bur, Solanum rostratum, a 
congener of the potato, but after 1850 it began to find 
its way to the potato-plants of the early settlers; by 
1859 it had reached Nebraska, 1861 Iowa, in 1864 
and 1865 it crossed the Mississippi and gradually 
Fic. 383.— The Colo- extended eastward until 1874, when it reached the 

rado potato - beetle, A - = é . 

Doryphora ro-lineata, Atlantic Ocean. Finally it obtained a partial foothold 

(Twice natural size.) jn Europe, creating great consternation there, but it has 
never got to be a serious pest across the ocean. The orange-red eggs are 
laid on the leaves, and the larve are curious humpbacked soft-bodied crea- 
tures with black head and Venetian-red body. They crawl down and bur- 
row into the ground to pupate. There are three generations a year in the 
latitude of St. Louis, the beetles of the last brood crawling underground 
to hibernate. 

The common asparagus-beetle, Crioceris asparagi, red, yellow, and black, 
gnaws holes in young asparagus-heads, and the brown slug-like larvae which 
hatch from oval blackish eggs laid on the heads also eat them. The three- 
lined Lema, Lema trilineata, of similar shape, but yellow with three longi- 
tudinal black stripes on each elytron, is common on ‘‘ground-cherries.” 
Their larvee have the curious habit of covering their backs with their own 
excrement. Elm-trees in the East are often badly infested with the imported 
elm-leaf beetle, Galerucella luteola (Fig. 384), a common European pest. 
It first got to this country in 1834 and is how ‘‘in all probability responsible 
for more ruined elm-trees in the Hudson River valley than all other destruc- 


Beetles 279 


tive agencies combined.” The beetle, 4 inch long, is reddish yellow with 
black spots on head and prothorax, and a thick black stripe on each elytron. 
From orange-yellow eggs laid on the under side of the leaves hatch larve 
which when full grown are 4 inch long, flattened, marked with blackish 
and yellow. They skeletonize the leaves. When ready to pupate they 
crawl down into the ground. The beetles themselves after issuance fly back 
to the tree-tops and eat holes in the leaves. There are two broods a year, 
and the adult beetles of the last brood hibernate in concealed places. 


Fic. 384.—The elm-leaf beetle, Galerucella luteola; eggs, larve, pupa, and adults. (After 
Felt; eggs greatly magnified; larve, pupa, and adults about twice natural size.) 


Four species of the genus Diabrotica are common over the country and 
very injurious: D. vitfata, the striped cucumber-beetle, is greenish yellow 
with two black stripes on each elytron, and feeds on cucumber-, pumpkin-, 
squash-, and melon-vines, the larya also burrowing into the stems and roots 
of the same plants; D. r2-punctata (Fig. 385) is greenish yellow with six 
black spots on each elytron, and feeds on a great variety of plants, the larva 
often being injurious to corn in the South; D. longicornis, the corn-root- 
worm beetle, is grass-green with spots or stripes, and its underground larva 
is very destructive to corn by burrowing into its roots; D. soror (Fig. 386), 
of the Pacific coast, the flower-beetle or “‘diabrotica,” yellowish green with 


280 Beetles 


six black spots on the wing-covers (like 12-punctata), does great damage as 
an adult by eating into the flower-buds of roses, chrysanthemums, and a 
host of others, the larva feeding on the roots of alfalfa, chrysanthemums, 
and many other plants. 


Fic. 38s. Fic. 386. Fic. 387. 


Fic. 385.—The cucumber-beetle, Diabrotica 12-punctata. (Three times natural size.) 
Fic. 386.—The California flower-beetle, Diabrotica soror. (Three times natural size.) 
Fic. 387.—Chrysomela digsbyana, (Twice natural size.) 


Chrysochus auratus (Pl. I, Fig. 4), } inch long, golden green in celor, 
found in the East, and C. cobaltinus (Pl. II, Fig. 7), of same size and shape, 
but brilliant blue, found in the West, are the two most beautiful Chrysomelids. 
Chrysomela (Fig. 387) is a 
genus whose species are often 
curiously marked with short, 
curved lines and _ irregular 
spots. The active little flea- 
beetles, with swollen hind 
femora, and able to leap vigor- 


Fic. 388. 
Fic. 388.—Larve of the grape-vine flea-beetle, Haltica chalybea. (After Slingerland; 


much enlarged.) A ee 
Fic. 389.—A tortoise-beetle, Coptocycla aurichalcea. (Two and one-half times natural 


size.) 


ously, are common pests of grapes, cucumbers, melons, cabbages, turnips, etc., 
numerous species being known. They are small, usually about ;4, to inch 
long, and commonly blackish or steel-blue in color. Haltica chalybea, the steel- 
blue flea-beetle (Fig. 388), is common on grape-vines, where it feeds on the 


Beetles 281 


fruit and leaves; Crepidodera cucumeris, the cucumber flea-beetle, 7's inch 
long, and black, attacks melons, cucumbers, and other vegetables. The 
tortoise-beetles (Fig. 389) are curiously shaped, flat below, convex above, and 
with the prothorax and elytra thinly margined so as to give them a tortvise-like 
appearance from above; they are usually iridescent greenish and golden in color, 
and are often called goldbugs. The colors appear and disappear strangely 
while the insects are alive, but are always lacking in the dead specimen. 
Coptocycla clavata has two projections of the central dark color of each 
elytron looking like the four short broad legs of a tortoise; Cassida bicolor 
is like ‘‘a drop of burnished gold”; Chelymorpha argus, } inch long, brick- 
red with many black spots on prothorax and elytra, is found on milkweeds; 
Physonota unipunctata, 4 inch long, the largest of our tortoise-beetles, yellow 
with whitish margins, is common in midsummer on wild sunflowers. 
The small family Bruchide contains two common and important beetles, 
viz., the pea-weevil, Bruchus pisi (Fig. 390), and the bean-weevil, B. 
obtectus (Fig. 391). The adult pea-weevil is 4 inch long, general color rusty 
or grayish black with a small white spot on the thorax. The eggs are small, 
fusiform, and yellow. The grubs on hatching bore through the pod into 
the peas. The hole made in the growing pea soon closes up, leaving 
the voracious larva within. Here it often comes to an untimely end, 
—which is uncomfortable to think about. If, however, the peas are 
allowed to ripen and are put away for seed, it eats on until there is 


FIG. 390. FIG. 391. 


Fic. 390.—The pea-weevil, Bruchus pisi, and an infested pea. (Natural size of beetle 
indicated by line.) 

Fic. 391.—The bean-weevil, Bruchus obtectus, and an infested bean. (Natural size 
of beetle indicated by line.) 


only a shell left of the pea. Weeviled peas are unfit for food, and, as 
proved by the experiments of Professor Popenoe, should not be used for 
seed. During the fall and winter the larve pupate and finally mature as 
weevils (the adult beetles). Some of the beetles emerge from the peas, 
while others remain in them until they are planted. 


282 Beetles 


““Weevily”’ peas should be put into a tight box or bin, together with a 
small dish of bisulphide of carbon, the fumes of which will kill the insects. 
Or they may be immersed for a minute or two in water heated to 140° F.; 
this will kill all the beetles and larve. 

The bean-weevil is a little larger than the pea-weevil and lacks the 
white spot on the thorax. Its life-history is about the same as that of the 
pea-weevil, the eggs being laid of course on the young bean-pods. Several 
eggs are frequently laid in a single bean. The bean-weevil continues to 
breed also in dry stored beans, and increases its damage materially if the 
stored beans lie long untouched. It is therefore necessary to treat weeviled 
beans with bisulphide of carbon or hot water before storing them away, 


Fic. 392. 


Fic. 392.—Prionus californicus. (Natural size.) 
Fic. 393.—Larva of Ergates spiculatus. (Natural size.) 


The other principal tetramerous family besides the Chrysomelide is the 
Cerambycide, or family of long-horn wood-boring beetles: “long horn” 
because of their long slender antenna, and ‘‘wood-boring” because their 
larvee live in burrows in the trunks of trees. The beetles themselves are 
usually large and strikingly colored and patterned, and whenever seen 
attract attention. Nearly 600 species are known in North America, and 
they are common all over the country. As might be concluded from the 
habits of the larve, the family includes numerous serious pests, such species 
as the round-headed‘apple-tree borer, the oak-pruners, various hickory- 
borers, the twig-girdlers, the giant Prionids ef al., all causing much damage 
to orchards and forests. 


Beetles 283 


The eggs are usually laid on the bark, and the whitish, usually footless, 
soft-bodied but hard-headed and strong-jawed larvae burrow about in the 
tree-trunk for a year or two or even three (varying with the different species), 
feeding on the chewed wood. They pupate in the burrow, in a cell par- 
titioned off with chips, or sometimes specially made just under the bark. 
The beetle has only to gnaw its way through the bark or the loosely plugged 
burrow to escape from the tree. These wood-borers usually select a 
weakened or dying tree for attack. 

The largest Cerambycids belong to the subfamily Prionide (Fig. 392), 
whose members have the sides of the prothorax sharply margined and 
usually toothed. Prionus laticollis, the broad-necked Prionus, varies from 


Fic. 394.—The sugar-maple borer, Plagionotus speciosus, larve and adult beetle. (After 
Felt; natural size.) 


1 inch to 2 inches in length, and is pitchy black or brown, the prothorax 
with three sharp teeth on each lateral margin, and the antenna 12-segmented; 
the larvae, which live three years, are great footless white grubs, 24 to 3 
inches long, which burrow in the roots of oak, poplar, cherry, apple, 
grape-vine, and blackberries. The tile-horned Prionus, P. imbricornis, 
a similar beetle, has nineteen antennal segments in the male and usually 
sixteen in the female; Orthosoma brunnea, is long (14 to 24 inches) and 


284 Beetles 


narrow, with the margins of the body nearly parallel. In the south occurs 
the genus Mallodon, and on the Pacific coast the genus Ergatés (with a 
single species, spiculatus), both 24 inches long, and with the lateral margins 
of the prothorax with many fine sharp teeth. The larve (Fig. 393) of 
Ergates live in the giant sugar and yellow pines of the Sierra Nevada forests. 

The cloaked knotty-horn, Desmocerus palliatus (Pl. Il, Fig. 1), is a 
beautiful species, dark greenish blue with the bases of the elytra orange- 
yellow; the larve bore in elder-pith. Cyllene robinia, the locust-borer (PI. I, 


Fic. 395.—Maple-tree borer, Elaphidion villosum, larva, pupa, and adult beetle. 
(After Felt; natural size.) 


Fig. 15), is black, with striking yellow bands often found on goldenrod; 
its larvee live in locust-trees. A similar species, Cyllene pictus, attacks the 
hickory. The red milkweed-beetle, Yetraopes tetraopthalmus (P1. II, 
Fig. 10), brick-red with black spots, is a common species on milkweeds; 
the larve bore into the lower stems and roots. Two beautiful Cerambycids 
of California are shown in Figs. 2 and 16 of PI. IL 

The sugar-maple borer, Plagionotus speciosus (Fig. 394), is a serious 
pest of sugar-maples in New York and elsewhere in the East. The beetle, 
1 inch long, is black, brilliantly marked with yellow; the eggs are laid in 


Beetles 285 


July or August in the bark, the young borer (a footless, flattened, whitish 
grub) burrowing first into the sap-wood, where it passes the winter. Dur- 
ing the next year it bores vigorously around under the bark, and when about 
sixteen months old makes a final deep burrow into the heart-wood, in the 
end of which it pupates. Fig. 394 shows all the stages of this insect. The 
maple-tree pruner, Elaphidion villosum (Fig. 395), 4 inch long, slender 
grayish brown, lays its eggs on small twigs in maple-trees in July; the larve 
pore into the center of the twig, eat out a large portion of the woody fiber, 
plug the end of the burrow with castings, and wait for a strong wind to break 
off the nearly severed branch. In the fallen twigs thus broken off the 
larve pupates, and the beetles issue, the life-history taking just about a year 
for completion. This pest also “‘prunes” oaks, and apple, pear, plum, and 
other fruit trees. The sawyers, various species of the genus Monohammus, 
are beautiful brown and grayish beetles with extremely long delicate antenna, 
the larve bore in sound pines and firs and do great injury to evergreen 
forests. 

One of the worst and most familiar orchard pests is the round-headed 
apple-tree borer, Saperda candida (Fig. 396). The beetle is } inch long, 
narrow, and subcylindrical, pale brown with 
two broad creamy-white longitudinal stripes. 
The eggs are laid on the bark at the base of 
the tree in June and July. The larva works 
at first in the sap-wood, making a flat shallow 
cavity filled with sawdust and castings; later 
it burrows deeper and works upward. When 
nearly three years old it bores a tunnel from 
the heart-wood out nearly to the bark, partly Fic. 396.—The round - headed 
filling the outer part with sawdust and then  apple-tree borer, Saperda can- 

: } dida, larva and adult beetle. 
retires to the inner end and pupates. Two (After Saunders; natural size.) 
or three weeks after pupation the adult beetle 


issues from the pupal skin, works outward along the tunnel and cuts a 
smooth circular hole in the bark through which it escapes. When several 
larve are working in a tree they may completely girdle it, so that it dies. 
The most effective remedy is to apply a repellent wash of lime or soft soap 
from the base of the trunk up to the first branches several times during the 
egg-laying time, i-e., June and July. 

A small family, Spondylide, called the aberrant long-horned beetles, is 
represented in North America by four species, of which the most common 
is Parandra brunnea (Pl. IL, Fig- 14), a beautiful polished mahogany- 
brown beetle found under the bark of pine-trees. 


286 Beetles 


SECTION TRIMERA. 


Only one family is included in this section of beetles with but three tarsal 
segments in each foot, namely, the familiar little ladybirds or plant-louse 
beetles, the Coccinellide. Their uniformly small size, the semispherical shape, 
and the “polka-dot” pattern distinguish them readily from all other beetles 
except perhaps the Chrysomelide, a few of which are often mistakenly 
called ladybirds. This is a particularly unfortunate confusion because of 
the radically different food-habits and consequent economic relation to 
man of the two families. The Chrysomelide, or leaf-eaters, both as larve 
and adults, attack our crops and trees and flowers; the Coccinellide, or 
ladybirds, both as larve and adults, feed on plant-lice and scale-insects, 
great enemies of our orchards and gardens, and thus are among our best 
insect friends. A friend of mine found that his roses were suffering from 
insect attack; he saw little, convex, black-spotted reddish beetles clamber- 
ing busily up and down the stems, and he set to work to pick these off one 
by one and drop into a tin cup with petroleum in the bottom. When he had 


Fic. 397.—Some Californian ladybird-beetles; beginning at left of upper row the species 
are Megilla vitigera, Coccinella californica, C. oculata, Hippodamia convergens; 
beginning at left of lower row, Coccinella trifasciata, C. sanguinea, C. abdominalis, 
Megilla maculata, (Twice natural size.) 


a full pint he showed them proudly. But the more little round beetles he 
picked off the more rapidly wilted his roses. And for the wholly sufficient 
reason that he was collecting and killing the ladybirds that were making 
a fight—a losing one in the face of my friend’s active part in it—against 
the hosts of tiny inconspicuous green rose-aphids that were sucking the sap 
out of the rose-stems and buds. So be it remembered that not all bugs 
are bad bugs, but that some, like the ladybirds, are most effective helpers 
in waging war against the real pests! 

There are about 150 species of ladybirds known in the United States, 
and almost all are reddish brown with black dots or black with reddish 


Beetles 287 


spots. Their colors and markings make them conspicuous, and yet the 
natural enemies of insects, the birds, obviously let them alone; it is presumed, 
therefore, that these beetles are ill-tasting to birds, and that their bright colors 
are of the nature of readily perceived warning signs (see discussion of 
this subject in Chapter XVII). 

The eggs are laid on the bark, stems, or leaves of the tree or plant on 
which aphids or scale-insects are present. Sometimes they are deposited 
in little patches right in the middle of a colony of plant-lice. The larve 
(Fig. 398) are elongate, widest across the prothorax and tapering back to 
the tip, with the skin usually roughened or punctate, bearing hairs and short 
spines, and marked with blackish, reddish, and yellowish. The larve feed 
steadily on the soft defenceless aphids or young scale-insects, or on the eggs 
and young of other larger insects. When full-grown they pupate, attached 
to the leaves or stems without entirely casting off the last larval exuvia (Fig. 
398). This cuticle often surrounds the pupa “like a tight-fitting overcoat 
with the front not closed by buttons.” In other cases the larval skin is 
forced backwards and remains as a little crumpled pad about the posterior 
end. 

The two-spotted ladybug, Adalia bipunctata, reddish yellow with a 
single black spot on each elytron, +; common in the East, where it often 
enters houses to hibernate. The nine-spotted 
ladybird, Coccinella novemnotata, has yellowish 
elytra with four black spots on each in addition 
to a common spot just. behind the thorax. 
The “twice-stabbed” ladybird, Chilocorus 
bivulnerus, is shining black with a large red 
spot on each elytron. Anatis 15-punctata, the 
fifteen-spotted ladybird, is a large species with 
dark brownish-red elytra bearing seven black 
spots each, and a median common spot just 
behind the thorax. Fic. 398. —A_ladybird-beetle, 

In California the ladybirds are of great Coccinella californica ; larva, 
importance to the fruit-growers, their Steady: )/ Pues S80 eather Lawson's 

3 , : ’ cyprees. (Twice natural size.) 
wholesale destruction of scale-insects being an 
important factor in successful fruit-raising. Fig. 397 illustrates eight species 
found on the Pacific coast. A number of ladybird species have been imported 
from Australia and other countries from which numerous destructive scale- 
insects had been earlier unwittingly brought on nursery stock. Most conspic- 
uously successful of these attempts to introduce and disseminate original home 
enemies of imported pests has been the establishment of the small red-and- 
black ladybird, Vedalia cardinalis, which feeds exclusively on the fluted or cot- 
tony cushion-scale (Jcerya purchasi) (Fig. 254). This Australian scale first 


288 Beetles 


appeared in California near Menlo Park in 1868 on orange-trees, and in a 
few years had become so abundant and widely spread over the state that 
it seriously threatened the extinction of the great orange industry. In 1888 
a few live Vedalias (altogether about 500 specimens in five separate lots) 
were brought from Australia, put on trees infested by the fluted scale, and 
by helpful scattering of the progeny of these original emigrants this lady- 
bird species was soon distributed to all scale-infested localities. In a few 
years it had the pest completely under control, and has ever since remained 
its master. And California continues to grow Washington oranges. 


SECTION HETEROMERA. 


This section includes those beetles which have the front and middle 
feet with five tarsal segments, the hind feet with four. It is a heterogeneous 
assemblage, including, besides two large families of widely differing aspect 
and habits, a number of small ones of obscure, little known, and mostly 
uncommon species of small size, which present a wide variety of structure 
and life-history. The two principal families can be distinguished by the 
following diagnosis: 


Head without distinct neck, narrower than thorax and more or less inserted in it; 
body-wall hard; color usually black. 

(Darkling ground-beetles.) TENEBRIONIDE. 

Head as wide as prothorax, and attached to it by a visible neck; body soft and 

elytra flexible; colors often diversified, frequently metallic blue or green 

(Blister- and oil-beetles.) MrLoID2&. 


The common ground-beetles of the North and East are the swift preda- 
ceous Carabide; any stone or log turned over 
will reveal them. In the dry warm western plains 
and southwestern semi-desert states, however, the 
slower vegetable-feeding Tenebrionidz are the com- 
mon ground-beetles. The most familiar of them on 
the Pacific coast are large, awkwardly moving, shin- 
ing black pinacate bugs, Eleodes (Fig. 399) which, 
when disturbed by the turning over of their covering 
stone, stand on their fore legs and head and emit an 
ill-smelling fluid from the tip of the abdomen. 
Fic. 300.—Pinacate bug, They have no wings, and the thick horny elytra are 

Eleodes sp. (Natural grown fast to the back. All the rest of the body 

=nee) is similarly armor-plated, and the collector has to use 
an awl to make a hole through the body-wall for pinning up his specimens, 


Beetles 289 


The darkling-beetles constitute a large family, more than four hundred species 
being known in this country, although comparatively few of them are at 
all familiar. They are mostly dull or shining black, and feed on dry vege- 
. table matter, often in a state of decay. Some live in grain, flour, meal, or 
sawdust; others in living or dead fungi, and a few are probably predaceous. 
A common species in mills, stables, grocery-stores, and pantries is the meal- 
worm beetle, Tenebrio molitor, 4 to } inch long, flattened, brownish, with 
squarish prothorax and longitudinally ridged elytra. The stout, cylindrical, 
hard-skinned, waxy, yellowish-brown larvae, or meal-worms, infest flour 
and meal. They are often bred by bird-fanciers as winter food for insect- 
eating song-birds. For this purpose they are raised in large numbers in 
warm boxes partly filled with bran, in which they undergo all their metamor- 
phosis. J. obscurus is a darker, almost black, species found also in mills 
and granaries. Both of these species have been spread all over the world 
by commerce. A smaller brown species, Echocerus maxillosus, 4 inch long, 
is common in the southern states in old and neglected flour. 

Uloma impressa, 4 inch long, deep mahogany-brown, is common in the 
east, occurring in decaying logs and stumps. Smaller species of the same 
genus, lighter in color, are also to be found in 
similar places. An odd-looking species called 
by Comstock the forked fungus-beetle, Boleto- 
therus bijurcus, is not uncommon in the north Fig. 40o.—Larva of a Tene- 
and east in and about the large shelf-fungi  brionid, Boletotherus bifurcus. 

5 (Twice natural size.) 
(Polyporus) that grow on the sides of trees. 
The surface of the body and elytra is very rough, and two conspicuous 
knobbed horns project forward from the prothorax. The larve (Fig. 400) 
live in the fungi. 

The other of the two larger heteromerous families, the Meloide, numbering 
about 200 North American species, includes beetles of unusual structural 
character and appearance, of peculiar physiological properties, and of a 
highly specialized and unique kind of metamorphosis. The Meloids are 
known as oil-beetles from the curious oily fluid emitted by many species 
when disturbed, and as blister-beetles from the inflammatory and blistering 
effect of the application of the pulverized dry body substance to the human 
skin. This powdered blister-beetle is known to pharmacists as cantharides, 
and is a recognized therapeutic substance. The beetles are rather long 
and slender-legged and have a soft fleshy body with flexible wing-covers 


which are sometimes rudimentary, being then short and diverging (Fig. 
401). The head is broad and set on a conspicuous neck, and hangs with 
mouth downward. They are to be found crawling slowly about over field- 
flowers, as goldenrod, buttercups, etc., often in companies of a score or more 
individuals. Many of the species are brightly colored, metallic bronze, 


290 Beetles 


green, blue, and steel-black being common colors (PI. II, Fig. 12). Some, 
however, are grayish, dead black, or yellowish and brown. All are leaf-feeders. 
In the development of the blister-beetles an extreme condition known 
as hypermetamorphosis occurs, which is undoubtedly the result of a purpose- 
ful adaptation brought about by long selection, but 
which seems an almost impossible achievement of 
such “‘blind” natural forces. The eggs are deposited 
in the ground; from them hatch minute active strong- 
jawed larve (Fig. 402) with three pairs of long legs, 
each terminating in three claw-like spines. These 
larve are called triungulins. They run about 
seeking food, which, varying with different species, 
consists of the eggs of locusts, or the eggs and 
honey of solitary bees. The triungulin of Epicauta 
Fic. 4or.—The striped vilfafa, one of our common Meloid species, studied 
potato-beetle, Epicauta jy Riley, explores cracks and burrows in the ground 
vittata. (After Pettit; “|. 
twice natural size.) until an egg-pod of a locust (usually of one of the 
destructive Melanoplus species) is found. Into this 
the triungulin burrows and begins to devour the eggs. After a few days 
given to eating a couple of eggs it moults and appears in a very different 


Fic. 402.—Hypermetamorphosis of Epicauta vittata. A, young larva or triungulin; 
B, caraboid larva; C, coarctate larva; D, scarabeoid larva; E, pupa; F, adult. 
(After Riley; natural size indicated by line.) 


larval guise with soft skin, short legs, small eyes, and different body form 
and proportions. One week later a second moult occurs, but without re- 


tt is 


Beetles 2g1 


vealing much of a change in the larva, although it is now more curved, less 
active, and somewhat like a small June-beetle grub; after a third moult it is 
still more helpless and grub-like. It now grows rapidly. When full-grown 
it leaves the ruined egg-pod, makes a little cell in the ground near by in 
which it lies motionless except for a gradual contracting and slow fourth 
moulting, after which it appears as a completely helpless semi-pupa, or 
coarctate larva. In this state it passes the winter. In spring the fifth 
moult takes place, leaving the larva much as before, only smaller and 
whiter. It becomes now rather active and burrows about, but takes no 
food, and after a few days again moults for the sixth time, to appear at last 
as a true pupa. Five or six days later the adult beetle emerges. 

Those blister-beetles which live parasitically on bees’ eggs instead of on 
those of the locust probably follow about the course described by Fabre 
for Sitaris humeralis, a European species, an account cf which I quote 
from Sharp (Cambridge Natural History, vol. vi): “‘The eggs of the Sitaris 
are deposited in the earth in close proximity to the entrances to the bees’ 
nests, about August. They are very numerous, a single female producing, 
it is believed, upward of two thousand eggs. In about a month—towards 
the end of September—they hatch, producing a tiny triungulin of black 
color; the larve do not, however, move away, but, without taking any food, 
hibernate in a heap, remaining in this state till the following April or May, 
when they become active. Although they are close to the abodes of the 
bees, they do not enter them, but seek to attach themselves to any hairy object 
that may come near them, and thus a certain number of them get on to the 
bodies of the Anthophora[the bees] and are carried to its nest. They 
attach themselves with equal readiness to any other hairy insect, and it is 
probable that very large numbers perish in consequence of attaching them- 
selves to the wrong insects. The bee in question is a species that nests in 
the ground and forms cells, in each of which it places honey and lays an 
egg, finally closing the receptacle. It is worthy of remark that in the case 
of the Anthophora observed by M. Fabre the male appears about a month 
before the female, and it is probable that the vast majority of the predatory 
larve attach themselves to the male, but afterwards seize a favorable oppor- 
tunity, transfer themselves to the female, and so get carried to the cells of 
the bee. When she deposits an egg on the honey, the triungulin glides from 
the body of the bee on to the egg, and remains perched thereon as on a raft, 
floating on the honey, and is then shut in by the bee closing the cell. This 
remarkable act of slipping on to the egg cannot be actually witnessed, but 
the experiments and observations of the French naturalist leave little room 
for doubt as to the matter really happening in the way described. The egg 
of the bee forms the first nutriment of the tiny triungulin, which spends 
about eight days in consuming its contents; never quitting it, because con- 


292 Beetles 


tact with the surrounding honey is death to the little creature, which is 
entirely unfitted for living thereon. After this the triungulin undergoes 
a moult and appears as a very different creature, being now a sort of 
vesicle with the spiracles placed near the upper part; so that it is admirably 
fitted for floating on the honey. In about forty days, that is, towards the 
middle of July, the honey is consumed, and the vesicular larva after a few 
days of repose changes to a pseudo-pupa within the larval skin. After 
remaining in this state for about a month some of the specimens go through 
the subsequent changes, and appear as perfect insects in August or Septem- 
ber. The majority delay this subsequent metamorphosis till the following 
spring, wintering as pseudo-pupe and continuing the series of changes in 
June of the following year; at that time the pseudo-pupa returns to a larval 
form, differing comparatively little from the second stage. The skin, 
though detached, is again not shed, so that this ultimate larva is enclosed 
in two dead skins; in this curious envelope it turns round, and in a couple 
of days, having thus reversed its position, becomes lethargic and changes 
to the true pupa, and in about a month subsequent to this appears as a 
perfect insect, at about the same time of the year as it would have done 
had only one year, instead of two, been occupied by its metamorphosis. 
M. Fabre employs the term third larva for the stage designated by Riley 
Scolytoid larva, but this is clearly an inconvenient mode of naming the stage. 
. . - Meloe is also dependent on Anthophora, and its life-history seems 
on the whole to be similar to that of Sitaris; the eggs are, however, not 
necessarily deposited in the neighborhood of the bees’ nests, and the 
triungulins distribute themselves on all sorts of unsuitable insects, so that 
it is possible that not more than one in a thousand succeeds in getting access 
to the Anthophora nest. It would be supposed that it would be a much 
better course for these bee-frequenting triungulins to act like those of Epicauta, 
and hunt for the prey they are to live on; but it must be remembered that 
they cannot live on honey; the one tiny egg is their object, and this appar- 
ently can only be reached by the method indicated by Fabre. The history 
of these insects certainly forms a most remarkably instructive chapter in 
the department of animal instinct, and it is a matter for surprise that it 
should not yet have attracted the attention of comparative psychologists. 
The series of actions to be performed once, and once only, in a lifetime by 
an uninstructed, inexperienced atom is such that we should, a priori, have 
denounced it as an impossible means of existence, were it not shown that 
it is constantly successful. It is no wonder that the female Meloe produces 
five thousand times more eggs than are necessary to continue the species 
without diminution in the number of its individuals, for the first and most 
important act in the complex series of this life-history is accomplished by 
an extremely indiscriminating instinct; the newly hatched Meloe has to 


Beetles 293 


get on to the body of the female of one species of bee; but it has no dis- 
crimination whatever of the kind of object it requires, and, as a matter of 
fact, passes with surprising rapidity on to any hairy object that touches it; 
hence an enormous majority of the young are wasted by getting on to all 
sorts of other insects; these larve have been found in numbers on hairy 
Coleoptera, as well as on flies and bees of wrong kinds; the writer has ascer- 
tained by experiment that a camel’s-hair brush is as eagerly seized, and 
passed on to, by the young Meloe as a living insect is.” 

The commonest Eastern species of blister-beetles belong to the genus 
Epicauta. They feed when adult on the leaves of potato—being therefore 
often called potato-beetles—and on the pollen of goldenrod. E. pennsyl- 
vanica is uniformly black; E. cinerea is grayish black or even ashy, always 
with the margins of the elytra gray; EL. vitlata (Fig. 401) is yellowish or reddish 
above, with head and prothorax marked with black and with two black stripes 
on each elytron. In Meloe the wings are lacking and the elytra short and 
diverging; M. angusticollis, the buttercup oil-beetle, $ to $ inch long, 
of violaceous color, is the commonest eastern species. In the west the 
commonest blister-beetles are metallic green and blue and belong to the 
genus Cantharis. 

Another small family of rarely seen heteromerous beetles, which, how- 
ever, possess an extremely interesting and wonderfully specialized life-history 
and show a marked degenerate structure due to their parasitic habits, is 
the Stylopidz, or wasp parasites. Indeed these 
curiously modified beetles differ so much from 
all the other Coleoptera that some entomolo- 
gists look on them as composing a distinct order 
which these naturalists call Strepsiptera. The 
males are minute with large fan-shaped wings 
and reduced, short, club-like elytra. The 
females are wingless and never develop beyond 
a larval or grub-like condition. They live in Shinn tenia 
the body of a wasp or bee (Fig. 403)—certain (After Jordan and Kellogg; 
foreign species parasitize ants, cockroaches, and slightly enlarged.) 
other insects—while the free-flying males live from only fifteen or twenty minutes 
to a day or two: three days is the longest observed lifetime of active adult 


Fic. 403.—A wasp, Polistes sp., 


existence! The youngest larva of the Stylopids—the egg-laying has not 
been observed—is a minute, active, six-legged creature, not unlike the Meloid 
triungulin, which attaches itself to the larva of a bee or wasp and burrows 
into its body. There it lives parasitically, meanwhile undergoing hypermeta- 
morphosis in that after its first moult it becomes a footless maggot or grub. 
In this state it continues until, if a male, it pupates in the host’s body and 
issues for its brief active adult life. If a female, there is no pupation, but 


294 Beetles 


when the host larva itself pupates the Stylops pushes one end of its own 
body out between two abdominal segments of the host, and there gives birth 
alive to many little triungulins. How the triungulins find their way to 
their bee-larva hosts is not very clear, but they probably lie in wait in flowers 
and when a bee comes along they cling to its leg and are thus carried to 
the nest where the larve are. There are two genera of Stylopide in our 
country, Xenos, which parasitizes the social wasps, Polistes, and Stylops, 
which parasitizes the mining-bees, Andrena. The triungulins of Xenos, 
being born in a community nest, can simply roam about over the brood- 
comb until they they find a wasp-larva to burrow into. 


Rhynchophora. 


In this suborder are included all those beetles known as curculios, wee- 
vils, bill-bugs, and snout-beetles (excepting the pea- and bean weevils, see 
p- 281). They are all characterized by the peculiar prolongation of the 
front of the head into a beak or snout, which may be long, slender and 
curved, or straight, short, thick, and obtuse. The mouth-parts, of which the 
small sharp jaws are the conspicuous feature, are situated at the tip of the 
snout; upper lip (labrum) and palpi are wanting. The antenne arise 
from the sides of the snout and are angularly bent or ‘‘elbowed” in the 
middle and end in a knobbed or clavate tip. The body is solid and compact, 
usually strongly rounded above, and many species are thinly or thickly coy- 
ered with scales. 

Most of the weevils feed, as adults, on fruits, nuts, and various seeds, 
though some attack stems and leaves, and others hard wood. Many 
feign death when disturbed, folding up their legs and head and lying 
inert until danger is past. The larve are soft, wrinkled, white, footless 
grubs which mostly live in fruits, nuts, and seeds. The larve and adults 
of the important family Scolytida, variously called timber-beetles, bark- 
borers, or engraver-beetles, burrow in the bark and wood of trees living or 
dead. 

The principal families of the suborder can be separated by the following 
key: 

The dorsum of the last segment (pygidium) of the male divided transversely, so that 
this sex appears to have one more body-segment, when viewed dorsally, than 
the female. 

Mandibles with a scar on the anterior aspect. 
(Scarred snout-beetles.) OTIORHYNCHID#. 
Mandibles without scar on the anterior aspect........ (Curculios.) CURCULIONIDE. 
Pygidium of both sexes undivided. 
Pygidium vertical; tibie not serrate. 
(Bill-bugs and granary-weevils.) CALANDRIDZ&. 
Pygidium horizontal; tibie usually serrate............ (Bark-beetles.) ScoLyTip&. 


Beetles 295 


The scarred snout-beetles, Otiorhynchide, get their vernacular name 
from the presence of a distinct little scar on the front aspect of each mandible. 
It is made by the falling off of a mandibular appendage present in the pupa. 
Most of these beetles are covered with minute scales, much like those of the 
moths and butterflies, which give them often a bright metallic coloration. 
Several species of the family are injurious to fruits. 

The imbricated snout-beetle, Epicerus imbricatus, $ inch long, dull 
silvery white with darker markings, and with the elytra with longitudinal 
lines of deep pits, has the posterior ends of the elytra very steep and cut off 
almost squarely and ending in a pointed process. It feeds on various culti- 
vated plants, as garden vegetables, strawberries, etc., and gnaws holes in 
the twigs and fruits of apple and cherry. The pitchy-legged weevil, 
Otiorhynchus ovatus, $ inch long, dark brown to black with deeply pitted 
thorax and striated elytra, with deep punctures in the striz, almost egg- 
shaped hind body, and thorax with projecting angle on each side, attacks the 
roots and crowns of strawberry-plants, and also the leaves of apple-trees. 
Fuller’s rose-beetle, Aramiges julleri, is perhaps the most familiar species 
of this family, as it attacks garden and conservatory roses, and in Cali- 
fornia is an orange pest of some note. It is } inch long, oval, smoky-brown, 
and thinly covered with scales; its “‘snout” is short and obtuse. The eggs 
are laid in masses in concealed places on rose-bushes, 
the larve feeding on the roots of the bushes, while the 
adults attack the leaves, buds, and flowers. The beetles 
hide during the day on the under side of the leaves, 
and can readily be collected and destroyed. 

The Curculionide, the typical curculios and weevils, 
compose the largest and most important family of the 
suborder, comprising over 600 species of North Amer- 
ican beetles, and including many seriously destructive 
pests. Such enemies of the fruit-grower as the plum- igs ae ie eck 
curculio, plum-gouger, apple-weevil, and strawberry-  yut-weevil, Balani- 
weevil, and such a destructive pest of cotton as the "us caryatrypes. 
boll-weevil (for the study and combating of which Ce eee ie 
Congress has recently appropriated $250,000), are alone 
sufficient to give this family a high rank in the list of notorious insect 
pests. The eggs of Curculionids are laid singly in holes bored or cut by 
the female with her snout in stems or fruits of the food-plant and pushed 
to the bottom by the snout, which is therefore often very long and slender. 
The nut- and acorn-weevils of the genus Balaninus are characterized by 
their possession of an unusually long, slender, curving beak (Fig. 404); in 
the females this beak may be twice as long as the rest of the body; in the 
males it is usually about the length of the body. These beetles are from 


296 | Beetles 


4 to } inch long, clay-yellow or mottled brownish, and lay their eggs in 
chestnuts, hazelnuts, acorns, walnuts, hickory-nuts, etc. The white, yellow- 
headed, maggot-like larva feeds on the kernel, and is full-grown at the 
time the nuts drop. It either lies in the nut over winter or crawls out and 
into the ground, where it pupates, and transforms into an adult; B. rectus 
and B. quercus are common acorn-weevils, B. caryatrypes (Fig. 404) a 
common chestnut-weevil, and B. nasicus a hickory-nut weevil. 

The genus Anthonomus includes small pear-shaped, modestly colored 
weevils with long slender snouts. A. quadrigibbus, the apple-weevil, + inch 
long, dull brown, with four conspicuous brownish-red humps on the hinder 
part of the body, lays its eggs in little blackish-margined holes drilled into 
apples; the white, footless, wrinkled, brown-headed larva on hatching bur- 
rows into the core, feeds around it, ejecting much rusty-red excrement, and 
finally pupates, the adult weevil gnawing its way out to the surface. A. sig- 
natus, the strawberry-weevil, blackish with gray pubescence, punctures 
the buds, laying an egg in each, and then punctures the flower-pedicel below 
the bud, so that it drops off; the larva feeds on the fallen unopened bud, 
changing to a beetle in midsummer. A. grandis is the notorious boll- 
weevil of the South, which has made its way since 1890 from Mexico into 
this country and is now one of our most serious insect pests; it destroys as 
much as ninety per cent of the cotton-crop in badly infested localities. The 
eggs are deposited in the buds and bolls, and the larve feed on seed and 
shell, pupating inside the wall of the boll, through which the issuing beetle 
gnaws its way. This pest seems to feed only on cotton. 

Next to the codlin-moth and San José scale probably the most notorious 
and destructive fruit-pest is the plum-curculio, Conotrachelus nenuphar 
(Fig. 405), a small beetle, + inch long, brown, 
and with four small elevated excrescences on 
the hard wing-covers. The beetles hibernate 
in rubbish, such as accumulated leaves, about 
the orchard, and come out in early spring to feed 
on the tender buds, leaves, flowers, and even 
Be ocean ___.. green bark. When the plums have set, the 

IG. 405.—The_ plum-curculio, ; A A 
Conotrachelus nenuphar, females begin to deposit their eggs in them by 
(After photograph by Slinger- drilling a tiny hole and pushing an egg into 
land; enlarged.) = A Sas 
each. Then a concentric slit is cut near the 
hole so as to leave the egg in a little flap in which the tissue is so injured 
that the rapid growing of the fruit does not injure the delicate egg buried 
in it. The whitish larva bores in until it reaches the stone around which 
it feeds. (The larva of the plum-gouger, Coccotorus scutellaris, another 
destructive Curculionid pest of the plum, bores into the stone.) When 
the larve are full-grown the infested plums fall to the ground, and the larve 


Beetles 297 


crawl out and into the soil to pupate. The adult beetles soon issue and 
hunt up hibernating quarters. The plum-curculio attacks cherries, and 
also peaches, nectarines, and apricots. In many regions cf this country 
it has nearly stopped the growing of plums. Curiously enough, but 
fortunately, this pest does not seem to be able to maintain itself in California, 
where plum (prune) growing is one of the chief industries. A remedy of 
some effectiveness is to jar each plum-tree, under which a sheet has been 
spread, repeatedly during blossoming and fruit-setting time. The curculios, 
alarmed by the jarring, fold up their legs and snout and fall to the ground 
(sheet), where they feign death. This feigning can be turned into reality 


Fic. 406.—Larva and pupa of the quince-curculio, Conotrachelus crategi. (After photo- 
graphs by Slingerland; at left, larva, natural size and enlarged; at right, pupa much 
enlarged.) 


by any one of various means. Excellent “‘curculio-catchers’”’ consist of 
wheelbarrows on each of which is mounted a large inverted umbrella split 
in front to receive the tree-trunk, against which the barrow (with a padded 
bumper) is driven with force enough to do the jarring. All fallen plums also 
should be promptly gathered and burned or scalded so as to kill the larve 
within. 

The family Calandride includes about eighty North American species 
of weevils, of which several are common and familiar under the names of 
corn bill-bugs and rice- and grain-weevils. To the large genus Sphenophorus 
belong the species known as corn bill-bugs, blackish, brown, or rarely gray 
in color, from } to 4 inch long, with thick and hard elytra which are 
ridged and punctured, as is also the thorax. By day they hide in the soil 


298 | Beetles 


at the base of young corn-plants, and at night bore little round holes into 
their stems. The larve live in the stems of timothy, sedges, or bulb-rooted 
grasses, pupating in fall or early spring. To the genus Calandra belongs 
the destructive rice-weevil, C. orys@, 4 inch long, blackish to pale chestnut, 
which attacks all kinds of stored grains and is especially injurious in the 
southern states to rice, and the granary-weevil, C. granaria, $ inch long, 
dark brown, also common in grain-bins. Both these species have been 
widely distributed by commerce, and by their rapid multiplication and the 
concealment afforded them by the grain often attain such abundance as 
to cause great loss in mills, breweries, 
and elevators. The preventive remedy 
is cleanliness and the rapid removal of 
the stored grain. They prefer dark 
places, therefore a flood of sunlight 
will prevent their rapid increase. In 
bins that can be made nearly air-tight 
these pests may be killed by the fumes 
of carbon bisulphide. 

One may often see in the woods the 
curious hieroglyphics of the engraver- 
beetles (Scolytide). Where bark has 
been torn from a tree-trunk both 
the exposed trunk-wood and the inner 
surface of the stripped-off bark reveal 
the tortuous branching mines or tunnels 
of the Scolytide. A common way of 
Bie ayeaT he quiuee-carealio tOoaee making these tunnels is as follows: The 

trachelus crategi. (After photograph beetles (a male and a female together) 

by Slingerland; natural size and en- hyrrow from the outside through the 

sae thick rough outer bark, usually leaving 
a little betraying splotch of fine sawdust, to the inner live bark or sap- 
wood; here the pair turn, keep to this live sap-filled region, laying their 
eggs in masses or scattered along a tunnel. Soon the larve hatch, where- 
upon each digs a tunnel for itself, all of the new larval mines branching out 
from the original tunnel made by the parent beetles. When full-grown 
the larva digs a cell at the end of its tunnel and pupates in it. The issuing 
beetle burrows its way out from the tunnels and is soon ready to begin a new 
mine. But there is much variation in the mining habits of the various species. 

The beetles are small, often microscopic, the larger ones rarely more than 
4 inch long. They are brown to blackish, with stout, nearly cylindrical 
hard bodies, the hind end of the body usually obliquely or squarely truncate, 
and the head short, bent downward, and so covered by the thorax as to be 


Beetles 299 


almost invisible from above. The larvae are white and footless little grubs 
with very strong jaws. The family includes 150 species in North America, and 
because of the recently awakened interest in forestry is now being given special 
attention by entomologists. The losses, by the death of trees and the rid- 
dling of timber, caused by these obscure little insects are enormous. Pinchot, 
chief of the United States Bureau of Forestry, has recently estimated the 
annual forest losses caused by insects to be $100,000,000, and most of the 
ravages are due to the Scolytide. 

Among the most destructive genera are Dendroctonus and Tomicus, 
each with numerous species. They often work in the same tree. For 
example, the famous Monterey pines of California are attacked by Dendroc- 


—— 
wf iin 


Fic. 408.—Galleries in Monterey pine, with larva, pup, and adults of the engraver- 
beetle, Tomicus plastographus. (Natural size except the single beetle outside, 
which is enlarged three times.) 


tonus valens in the lower three or four feet of the trunk, as many as four 
hundred individuals (larve, pupe, and adults) occurring in this limited 
space in badly infested trees, while above this zone on up to the top of the 
tree are the mines of Tomicus plastographus (Fig. 408), from thirty to forty 
pairs burrowing into each yard of trunk. It is plain that such a combined 
attack on a single tree means death to it. 

The ambrosia-beetles, including half a dozen genera and many species, 


300 . Beetles 


have special habits which make them comparable in some ways with the 
social wasps, bees, and ants, and with the termites. They live in mines— 
the “black holes” often seen in timber—bored into the heart-wood of sick 
or dead trees, in colonies including numerous adults and many larve. Their 
food is not the wood of the tree, but consists of certain minute and succulent 
bodies produced by a fungus which grows on the walls of their burrows. 
This fungus does not grow there by chance, but is ‘‘planted” by the beetles. 
It is started by the female upon a carefully packed bed or layer of chips, 
sometimes near the entrance of a burrow, in the bark, but generally at the 
end of a branch gallery in the wood. It spreads, or is spread, from this 
forcing-bed to the walls of the various galleries and chambers of the mine. 
The young larve nip off the tender tips of the fungus stalks “‘as calves crop the 
heads of clover,” but the older larva and adult beetles eat the whole structure 
down to its base, from which new hyphe soon spring up afresh. The fungus 
is suitable for the insects only when fresh and juicy: if allowed to ripen, the 
tender protoplasm is shut up in spores, and the galleries are soon filled to 
suffocation with these spores and the ramifying mycelial threads. Indeed 
the colony of ambrosia-beetles—ambrosia being the name applied to the 
tender fungus food—is often overwhelmed and destroyed by the quick 
growth of their garden-patch. If anything happens to interrupt the constant 
feeding on and cutting back of the fungus, the colony is almost always 
destroyed, 


CHAPTER XIII 
THE TWO-WINGED FLIES (Order Diptera) 


EXT to the name ‘‘bug” there is no other name so 
popular in point of miscellaneous application to insects 
as “fly.” This looseness of popular nomenclature 
may be largely due to the fact that entomologists them- 
selves apply the term ‘‘fly”” in several compound words, 
as butterfly, alder-fly, caddis-fly, May-fly, saw-fly, and 
the like, to widely differing kinds of insects. Used as 
a simple word, however, by fly an entomologist means 
some species of the order Diptera. The various kinds of 
true flies have of course special names, as mosquitoes, 
midges, punkies, gnats, or as in the compounds 
horse-flies, bee-flies, flower-flies, robber-flies, etc. 

The order Diptera is so large and includes insects of such widely differing 
form and habit that it is difficult to formulate any general account of it. The 
Te name itself is derived from the most censpicuous 

structural condition of flies, namely, their two- 
winged state. All Diptera have but a single 
pair of wings, if any; a few are wingless. The 


FiG. 409. FIG. 410. 

Fic. 409.—Mouth-parts of a female mosquito, Culex sp. /ep., labrum-epipharynx;, md., 
mandible; mx./., maxillary lobe; mx.p., maxillary palpus; /yp., hypopharynx; /i., 
labium; g/., glossa; pg., paraglossa. 

Fic. 410.—Mouth-parts of the house-fly, Musca domestica. 1b., labrum; mx.p., maxil- 
lary palpi; /i., labium; la., labellum. 


hind wings of other forms are replaced by a pair of strange little structures 
301 


302 _ The Two-winged Flies 


called balancers, or halteres, whose use seems to be chiefly that of orienting 
or directing the fly in its flight. The possession of these balancers 
is a certain diagnostic character in distinguishing Diptera from all 
other insects. The wings are membranous and usually clear, and 
supported by a few strong veins. No flies can bite in the sense 
of the chewing or crushing biting common to beetles, grasshoppers, and 
other insects with jaw-like mandibles, but some have mandibles elongate, 
slender, and sharp-pointed, so that they act as needles or stylets to make 
punctures in the flesh of animals or tissues of plants. The great majority 
of flies, however, have no mandibles at all and no piercing beak, but lap up 
liquid food with a curious folding fleshy proboscis, 
which is the highly modified labium or under-lip. 
They feed on flower-nectar, or any exposed sweet- 
ish liquid, or the juices of decaying animal or 
plant substance. To take solid food as the 
Fic. 411.—Head, antenne, house-fly does from a lump of sugar, the solid 
= Saati mosquito, lat- ha; to be rasped off as small particles which are 
either dissolved or mixed in a salivary fluid 

that issues from the fleshy tip of the proboscis. 

All the Diptera have a complete metamorphosis, the young hatching 
from the egg as footless and often headless larva (maggots, grubs), usually 
soft and white, and in many cases ob- 
taining food osmotically through the 
skin. The life-history is usually rapid, 
so that generation after generation suc- 
ceed one another quickly. Thus it may 
be true, as an old proverb says, that 
a single pair of flesh-flies (and their 
progeny) will consume the carcass of 
an ox more rapidly than a lion. The 


pup of the more specialized flies are 
concealed in the thickened and darkened 
last larval moult, the whole puparium 
looking much like a large elliptical brown 


= ie ; hte ioe Fic. 412.—The blow-fly, Calliphora ery- 
The Diptera include the familiar ‘gpyocephala. Larva, pupa, and adult. 

house-flies, flesh-flies, and bluebottles 

of the dwelling and stables; the horse-flies and greenheads, that make 

summer life sometimes a burden for horses and their drivers; the buzzing 

flower- and bee-flies of the gardens; the beautiful little pomace-flies with 

their brilliant colors and mottled wings that swarm like midges about 


the cider-press and fallen and fermenting fruit; the bot-flies, those disgust- 


- 


The Two-winged Flies 303 


ing and injurious pests of horses, cattle, rabbits, rats, etc.; the fierce robber- 
flies that prey on other insects, including their own fly cousins; the midges 
and gnats, that gather in dancing swarms over pastures and streams; the 
black-flies and punkies, dreaded enemies of the trout-fisher and camper; 
and, worst of all, the cosmopolitjan mosquito, probably the most serious insect 
enemy of mankind. Only in recent years have we come to recognize the 
mosquito’s real capacity for mischief. Annoying and vexatious they have 
always everywhere been, by day and night, from tropics to pole, from the 
salt marshes by the sea to the alpine lakes on the shoulders of the mountain- 
peaks. But that the mosquito-bite not only annoys but may kill, by infect- 
ing the punctured tissues with the germs of malaria or yellow fever or filari- 
asis, three of the most wide-spread and fatal diseases of man—this alarming 
fact is a matter which has come to be really recognized only recently, and 
the general recognition of which has given to the practical study of insects 
an importance which years of warning and protesting by economic entomol- 
ogists have been wholly unable to do. 

The Diptera include about 7,000 known species in North America, thus 
ranking among the principal orders of insects in degree of numerical represen- 
tation in this country. About 50,000 species are known in the whole world. 

The order may be separated into certain principal subdivisions by the 
following table: 


Living as external parasites on mammals, birds, or honey-bees; body flattened and 
often wingless; the young born alive as larve nearly ready to pupate. 
Suborder Puprpara (see p. 351). 
Not living on the bodies of other animals; young usually produced as eggs. 
Suborder DreTERA GENUINA (see p. 304). 
Antenne with numerous (more than five) segments. .Section NEMATOCERA (see p. 304). 
Antenne with not more than five segments, usually with three, the third sometimes annu- 
lated, showing it to be a compound segment, i.e., composed of several coalesced 


BEMUNE NUS peeieem ter atate a earcdei svelte ond eee Section BRACHYCERA (see p. 327). 
Third segment of antennz annulated, showing it to be composed of several coalesced 
SERMONS sinc serayesayel ela vavene 0b oi\p%cinehaielel vee eohel Mery etetetete letra, 0's e(aih ales (see p. 327). 
Antenne consisting of four or five distinct segments................-- (see p. 330). 
Antenne with but three segments (rarely less), the third segment with or without a 
stylenorbristles...j5,4</<12 cieiuia stateioveeshe cretepeateecreeieit ala et re ete meets are (see p. 332). 


Of the two suborders the smaller one, the Pupipara, including certain 
strangely specialized and degraded parasitic flies, will be considered last. Of 
he first suborder, the Diptera genuina, the various families of small midge- 
and mosquito-like flies composing the section Nematocera (flies with slender 
several-segmented antennz) will be discussed first, as they are believed by 
entomologists to be the more generalized or simpler flies. 


304 _ The Two-winged Flies 


Of this section the mosquitoes, black flies, and punkies are perhaps best 
known because of the annoyance and irritation caused by their ‘‘bites,” 
that is, the punctures made by the sharp beak of the females in their blood- 
sucking forays. But the swarms of dancing midges and the sprawling long- 
legged crane-flies, or leather-jackets, are not unfamiliar members of this group. 
In addition there belong here a few families of flies little known but possessed 
of most interesting habits and form. 


KEY TO FAMILIES OF NEMATOCERA. 


(The references to the names and character of the veins in the wings which occur in 
this and other keys used in this chapter may be understood by a comparison of the 
venation of the specimen being examined with Fig. 18, and with the figures of the 
venation of various families, as Figs. 425, 436, 444, etc.) 

A. Antenne slender, longer than thorax; usually nearly as long as body or longer; 
legs long and slender, and abdomen usually so. 
B. Very small moth-like flies, with body and wings hairy; wings with 9-11 longi- 
tudinal veins, but no cross-veins except sometimes near the base of the wing. 
(Moth-like flies.) PsycHopip2. 
BB. Not as above. 
G. Wings with a network of fine vein-like lines near the outer and hinder 
margins in addition to the regular (heavier) venation. 
(Net-winged midges.) BLEPHAROCERIDZ. 
CG: The margin of the wings and the veins fringed with scales. 
(Mosquitoes. CuLicip£&. 
CCC. With a distinct V-shaped suture on the back of the thorax. 
(Crane-flies.) TIPULIDz. 
CCCC. Without distinct V-shaped suture on the back of the thorax. 
D. Anal veins entirely wanting; medial vein wanting or at most 
represented by a single unbranched fold. 
(Gall-gnats.) CECIDOMYND2. 
DD. Anal veins present or represented by folds; medial vein present 
or at least represented by a fold which is usually branched. 
E. Ocelli present; legs slender and with greatly elongate 
cexe (basal segment)...(Fungus-gnats.) MYyCETOPHILID. 
EE. Ocelli absent. 
F. Wing-veins well developed in all parts of the wing. 
(Dixa-flies.) Drxip2. 
FF. Wing-veins much stouter near the costal (front) 
margin of the wing than elsewhere. : 
(Midges.) CHIRONOMID2. 
AA, Antenne shorter than the thorax and rather stout. 
B. , Ocelli*present..c )s.cc ove. anlemntots seen eres (March-flies.) BrBIoNID#. 
BB. Ocelli absent; wings very broad............. (Buffalo-gnats.) SmMvuLup#. 


Of the ten families included in the above key the members of five pass 
the young stages, larval and pupal, in fresh water; of the members of two 


The Two-winged Flies 305 


some have aquatic immature stages and some terrestrial; while the larve 
and pup of all the members of the remaining three live in plants or in the 
ground, none being aquatic. 

Best known of the aquatic families, and indeed of the whole suborder, 
is the mosquito family, the 
Culicide. While the different 
kinds of mosquitoes are much 
alike, so much so indeed that 
most of us are quite content if 
we can determine an insect to be 
a mosquito without carrying the 
identification farther, there are 
known in the world at least 300 
different mosquito species, rep- 
resenting two dozen distinct 
genera. In North America 
nearly 60 species are already 
known, representing Io genera, 
and new ones are being found 
constantly. In the family Culi- 
cide are included two distinct 
general types of mosquito, one 
with mouth-parts forming a long, 
slender, sucking proboscis, pro- 
vided with sharp, needle-like 
stylets for piercing (Fig. 411), the 
other with the mouth-parts short 
and better adapted for lapping 
or sucking up freely exposed 
liquids. The latter type of 
mouth is possessed by but two 
genera, all the others being Fic. 413.—The life-history of a mosquito, 
piercers and blood suckers (in Culex sp Asmall raft of eggs is shown on 


: the surface of the water, several larve 
the female sex). Of these pierc- (‘“‘wrigglers’’), long and slender, and one 


i - a Seid »-headed, are shown 
mo A ) ‘ pupa (‘‘tumbler’’), large eaded, ar 
ing genera three are of especial in the water, and an adult in the air above. 


importance and interest to us (From life; much enlarged.) 

because of their abundance and 

their definitely determined relation to the development, incubation, and dis- 
semination of certain serious diseases of man. These three genera are Culex, 
Stegomyia, and Anopheles. To Culex belong the great majority of familiar 
mosquitoes which pursue and harass us with their songs and bites; to Stego- 
myia (and Culex) belong the mosquitoes held responsible for the dissemination 


306 _ The Two-winged Flies 


of yellow fever and filariasis, and to Anopheles belong the malaria breeding 
and distributing mosquitoes. 

All the mosquitoes agree in having strictly aquatic immature stages. The 
eggs are laid on the surface of standing or slowly moving water, usually 
fresh, although several species breed abundantly and probably exclusively 
in brackish water. These eggs are in small one-layered packets or rafts (usual 
in Culex) (Fig. 413) or are scattered singly (in Stegomyia and Anopheles) (Fig. 
414) and hatch in from one to four days, varying with the species, and in 
the same species with the temperature and light 
conditions. The water oviposited on may be, for 
Culex, that of a pond, a pool, or any temporary 
puddle, or even that in an exposed trough, barrel, 
| pail, or can. With Anopheles only natural, usually 
Fic. 414.—The eggs of permanent, pools are selected. I have found the 

Anopheles sp. (After eggs of Culex incidens on the surface of a bubbling 
Giles; much enlarged.) a c “ 5 f Sao 
soda-spring in California, and of Stegomyia in water 
held in slight depressions in a number of ship’s metal parts in Samoa. 
The brackish-water species of Culex usually lay their eggs on the small 
clear pools scattered through the marshes. A few entomologists have 
recorded their belief, based on various indirect observations, that the eggs 
of Anopheles at least may be deposited on the soil, but no direct proof of 
this is yet on record. 

The larve (Figs. 413 and 415) of mosquitoes are the familiar wrigglers of 
ponds and ditches. The long, slender, squirming body, with its forked posterior 
extremity and thick head end, is thoroughly characteristic. The head is 
provided with a pair of vibratile tufts or brushes of fine hairs which are 
kept, most of the time, in rapid motion, creating currents of water setting 
toward the mouth, and thus bringing to it a constant supply of food, which 
consists of organic particles and microscopic animals. Breathing is accom- 
plished by the wrigglers coming to the surface and hanging head downward 
from it with the open tip of the respiratory tube, one of the prongs of the 
posterior forking of the body, projecting just through the surface film. If a 
mosquito wriggler is prevented from coming to the surface, or if, once there, it 
finds some impediment which restrains it from getting its respiratory tube 
into connection with the free air above the surface, it will drown. And 
this fact partly explains the fatal effectiveness of a film of kerosene spread 
over the surface of a pool in which mosquitoes are breeding. The larval 
stage lasts from one to four weeks, varying in different species and also 
varying in the case of each species at different seasons and under different 
conditions of food-supply, temperature, and light. Larvae of Culex have 
lived in breeding-jars in my laboratory for three months. The larve moult 
twice, and on the third casting of the skin appear as active, non-feeding 


/ 


The Two-w inged Flies 307 


pupe (Figs. 413 and 415) with thick, broad head end (the thick part includes 
thorax and head) and slender, curving abdomen, bearing two conspicuous 
swimming-flaps at the tip. The pupa rests at the surface of the water with 
its two short horn-like respiratory tubes, which rise from the dorsum of the 
thorax, extending through the surface film to the air above. When dis- 
turbed it swims swiftly down into the water by quick bendings or flappings 
of the abdomen with its terminal flaps. The pupal stage lasts from two to 
five days, with comparatively little variation beyond these extremes. 

The adults issue through a longitudinal rent in the back of the pupal 
cuticle, and while drying their wings, legs, and body vestiture rest on the 
surface of the water, often partly supported by the floating discarded skin. 
The two wings are long and narrow, the legs long and slender, the thorax 
humped with the small head hanging down in front and the slender sub- 
cylindrical abdomen depending behind. The body is clothed with scales, as 
are the veins of the wings, and on the scales, which are of different shapes 
and sizes on different parts of the body, and vary in different species, depend 
the colors and pattern, often striking and beautiful, just as all the color pat- 
terns of the butterflies and moths are produced by a covering over body and 
wings of similar scales. The males of all mosquitoes differ from the females 
in having the slender, many-segmented antenne provided with many long 
fine hairs arranged in whorls and combining to give the antennz a bushy or 
feathery appearance. These hairs, as has been proved by experiment and 
histologic study, are a part of an elaborate auditory apparatus, their special 
function being to be set into vibration when impinged on by sound-waves of 
certain rates of vibration, and to transmit this vibration to a complex nervous 
organ in the second antennal segment (Figs. 56 and 57). The males, while 
having a long, slender, sucking-proboscis, do not possess the piercing sty- 
lets characteristic of the female, and hence are not blood-suckers, but prob- 
ably feed, if at all, on the nectar of plants or on other exposed liquids. The 
females suck blood when they can get it, but in lieu of this animal fluid 
feed on the sap of plants. In experimental work in the laboratory cut 
pieces of banana are provided the imprisoned adult mosquitoes. 

At this writing about fifty species of Culex, one species of Stegomyia, and 
four species of Anopheles have been found in this country. These three 
genera may be distinguished by the following key: 


Palpi (the mouth-feelers projecting by the side of the proboscis) long in both male and 


female; about.as long‘as the proboscis. --stemcs-ceeeccwevereceacss cal ANOPHELES, 
Palpi as long as proboscis in male, but only one-third as long in female. 

Scales.on) the. head: narrow andi curved) «.  .).'nscc,eestsales cieleie ts Hieastele sere CULEX. 

Scales, on the head fat and! broads. 45 0% srvisicield sin wlenonehaetaatanaiesio eo STEGOMYIA. 


Our particular interest in being able to distinguish these genera lies, as 
already said, in the special relation which their members bear to certain 


308 _ The Two-winged Flies 


wide-spread and serious human diseases. The rdle played by mosquitoes 
in the breeding and dissemination of the microscopic germs of malaria has . 
been so well exploited in newspapers and magazines that, although a matter 
of comparatively recent determination, it is already common knowledge, at 
least in its more general outline. For a somewhat detailed account of the 
etiology of the diseases known to be disseminated by mosquitoes, including 
the exact relation of the mosquito host to the disease-germs, see Chapter 
XVIII of this book. It is sufficient to say here that the malarial germs seem 
to live parasitically in and be disseminated by the various species of Ano- 
pheles only, the yellow-fever germs only by the species Stegomyia fasciata, and 
the minute worms of filariasis by the same species and two or three tropical 
forms of Culex, while the score and more of North American species of 


Fic. 415.—A malaria-carrying mosquito, Anopheles maculipennis; larva at left, in 
middle two eggs below and pupa above, male adult at right. (From life; much 
enlarged.) 

Culex compose most of the hordes of piercing and blood-sucking mosqui- 

toes which in so many localities make life distressful. Stegomyia jasciata is 

found in this country only in the Gulf states. In our colonies, the Hawaiian 
and American Samoan Islands, I have found it to be the most abundant mos- 
quito species, although yellow fever is yet unknown in these islands. But 
it seems not improbable that, with the cutting of a canal through the Isthmus 
of Panama so that ships can sail directly from the West Indies to Hawaii 
continuously within the tropics, Stegomyia individuals infested with yellow- 
fever germs might be readily carried to our tropical Pacific colonies. Such 

a possible contingency should at least be had in mind by those charged with 

the responsibility of public-health affairs in Hawaii and Samoa. Stegomyia 

is already terrible enough in its disease-spreading capacity in unfortunate 

Samoa, as explained in Chapter XVIII, the frightful scourge elephantiasis, 


The Two-winged Flies 309 


an incurable and hideously deforming kind of filariasis, from which quite 
one-third of the natives of Samoa suffer, being disseminated chiefly (so 
far as our present knowledge permits us to affirm) by mosquitoes of the 
species Stegomyia fasciata. 

With a few English investigators and our own government and state 
entomologists in the lead, a great campaign is being waged against mos- 
quitoes. Despite the hosts of the enemy, its great capacity for providing 
new individuals to supply the places of the fallen, its effective means of 
locomotion, and its easily managed de- 
partment of commissary, local foraging 
being exclusively relied on for sustain- 
ing its armies, we are making headway 
against it. Our modes of attack are 
various: by draining swamps, ponds, 


Fic. 416. Fic. 417. 
Fic. 416.—A short-beaked mosquito, Corethra sp. (From life; four times natural size. 


Fic. 417.—Pupa (at left) and larva (at right) of short-beaked mosquito, Corethra sp. 
(From life; six times natural size.) 


and puddles we restrict the multiplication of these pests, and rid particular 
localities of them altogether; by introducing into ponds and pools which 
cannot be drained substances, as kerosene, etc., which are poisonous to mos- 
quitoes, we kill them in their adolescence; by encouraging and disseminating 
their natural enemies, such as dragon-flies, we pursue them in their own 
elements, water and air. Mosquitoes do not fly far; when abundant in a 
locality, breeding-places are to be looked for close at hand. The open rain- 
water barrel, a little puddle by the lawn hydrant, a cistern with unscreened 
openings, all of these are welcome invitations to the mosquito to come and 
rear a large family. Put close screen tops over water in cisterns and barrels; 


310 The Two-winged Flies 


leave no standing puddles in the back yard or decorative lily-pools in the 
front; pour kerosene on the surface of ponds and ditches in the neighbor- 
hood, and the mosquito problem for localities not adjacent to swamps and 
marshes is nearly solved. Where the problem includes swamps larger 
measures must be undertaken, community effort may be necessary, and the 
municipal or county administration called on to take official actions But 
when it is remembered that abolishing the mosquito pest means doing away 
with malaria, and in the subtropic and tropic region with yellow fever and 
filariasis, no pains will seem too troublesome, no expense too large in this 
warfare of man against mosquitoes. 


Fic. 418. FIG. 410. 


Fic. 418.—Scales on the wings of Culex fatigans. (After Theobald; greatly magnified.) 
Fic. 419.—A midge, male, Chironomus sp. (From life; much enlarged.) 


Looking not unlike mosquitoes are the larger species of the family Chiro- 
nomide, whose members are popularly known as midges and punkies, the 
name blood-worm being applied to the reddish aquatic larve of certain 
species. Like the mosquitoes, the males are distinguished from the females by 
their very bushy or feathery antennz, but, unlike the mosquitoes, the females, 
except in the case of the minute punkies or “‘no-see-ums”’ of the New Eng- 
land and Canadian mountains and forests, and their near relatives in the 
western forests, are not blood-suckers. The midges are particularly notice- 
able in “‘dancing-time,”’ that is, when they collect in great swarms and toss up 
and down in the air over meadows, pastures, and stream sides. 

The larve (Fig. 420) of most species are aquatic, some of them forming 
small tubular cases, as caddis-fly larve do, and most of them being distinctly 
reddish in color. They wriggle about in the slime and decaying leaves at 
the bottom of ponds or lakes, feeding on vegetable matter. The pupe 
(Fig. 421) are, like those of the mosquitoes, active, although of course non- 
feeding, and are provided with two bunches of fine hair-like tracheal gills 
on the dorsum of the thorax, or with a pair of short club-shaped processes 


i 


The Two-winged Flies UE 


which have a sort of sieve-like skin. In both cases the pupa breathes the 
oxygen which is mixed with water and is thus not i 

compelled, as are the mosquito pupe, to come to the 
surface for air. The larvae of the genus Ceratopogon 
and its allies, which include the fiercely biting and 
blood-sucking little punkies (Fig. 422), so irritating 
to the fisherman and hunter in the north woods, 


FIG. 420. 
Fic. 420.—Larva of a midge, Chironomus sp. (From life: natural length } inch.) 
Fic. 421.—Pupa of midge, Chironomus sp. (From life; natural length } inch.) 


live, according to Comstock, ‘‘under the bark of decaying branches, under 
fallen leaves, and in sap flowing from wounded trees.” 

Running and half flying about over the spray-wet rocks and on the surface 
of the smaller tide-pools between tide-lines on the ocean shore near Mon- 


Fic. 422. FIG. 423. 

Fic. 422.—Mouth-parts of a female “punkie,” Ceratopogon sp. 1b., labrum; md., 
mandible; mx., maxilla; mx./., maxillary lobe; mx.p., maxillary palpus; /1., labium; 
p-g., paraglossa; hyp., hypothorax. 

Fic. 423.—The tide-rock fly, Eretmoptera browni. (Natural length } inch.) 


terey, California, may be seen in the winter months many small, long-legged, 
spider-like flies (Fig. 423) whose wings are reduced to mere oar-like veinless 
rudiments. The larve and pupe live submerged in the salt water of the 
outer and most exposed tide-pools, where the ocean water is held in shallow 
depressions in the rocks, and is changed many times daily by the dashing 
of the waves. Where the flies go when the tide is in and these rocks are 


212 The Two-winged Flies 


either whouy submerged or at least constantly dashed over by the breaking 
waves, I have not been able to determine; but the larve and pupe cling 


Fic. 424. Fic. 425. 


Fic. 424.—A black-fly, Simulium sp. (Four times natural size.) 
Fic. 425.—Diagram of wing of black-fly, Simulium, showing venation. 


tight and secure in their rock basins to small but strong silken nets spun 
by the larvae. They rest on the under side of these nets, indeed are almost 
enclosed in them as in a cocoon. ‘This little fly is a most interesting insect 
because of its ocean-water habitat—very few insects live in salt water, and 
1/ almost no others have so truly an ocean home, except 
the curious salt-water striders, Halobates (see p. 
197), which live on the surface of the ocean far out 
at sea. It is interesting, too, because of its structu- 
ral modifications, the atrophied wings, rudimentary 
balancers, etc., which set it off widely from all 
other flies. Its tide-pool habitat is undoubtedly the 
result of a slow migration and adaptation in the 
course of many generations on the part of some 
shore-inhabiting fly. There are many small flies 
which frequent ocean beaches and rocks, feeding on 


Fic. 426.—Larve and pup of Simulium sp. on edge of stream, May-fly on projecting 
twig. (After Felt.) 


The Two-winged Flies S03 


decaying seaweed, etc., and from among these this species has no doubt 
gradually worked its way out to the very verge of the shore-line, becoming 
gradually adapted in habit and structure to the conditions of its new 
habitat. 

Besides the mosquitoes and punkies a third kind of fly assails the rod- 
and-line fisherman, the hunter, and the camper in forests and along the streams; 
black, stout-bodied, hump-backed, short-legged, broad-winged flies (Fig. 
424) from one-sixth to one-fourth of an inch long, with short but strong 
piercing proboscis. These are black-flies, buffalo-gnats or turkey-gnats, as 
they are variously called, composing the small family Simuliide, distributed 
all over this country, but especially abundant in the southern states, where 
they attack cattle so fiercely and in such great swarms that the animals are 
driven frantic and sometimes even killed by a violent fever produced by the 
terrible biting. 

The larve (Fig. 426) are odd, squirming, slippery, little black ‘‘worms,” 
which, clinging by the hind tip of the body, occur in dense colonies or patches 
on the smooth rock bed in shallow places Mm 
of swift streams. The lip of a fall is a 
favorite place for them. The swift- 
running water constantly affords them 
an abundant air and food supply. The 
free or head end of the body is provided 


Fic. 428. 

Fic. 427.—Mouth-parts of female black-fly, Simulium sp. lep., labrum; hyp., hypo- 
pharynx; md., mandible; mx., maxilla; mxp., maxillary palpus; /i., labium; pg., 
paraglossa. (Much enlarged.) . 

Fic. 428.—Mouth-parts of larva of black-fly, Simulium sp. Jb., labrum; ep., epipharynx; 
md., mandible; mx., maxilla; mxp., maxillary palpus; mxl., maxillary lobe; Ji., 
labium; /yp., hypopharynx. (Much enlarged.) 


with a conspicuous pair of freely movable brushes which collect food from 
the water. The clinging to the rock is effected by means of silk spun 
from the mouth, and by the skilful use of silken threads the larve can 
move about over the submerged rock bed without being washed away by 
the swift water. When ready to pupate, which is after about a month of 


314 The Two-winged Flies 


larval life (under favorable conditions of temperature and food-supply), the 
larva spins a little silken cornucopia-like cocoon (Fig. 426) fastened to the 
rock by the little end, and often fastened by the sides to adjacent cocoons. 
The large free end is left open. In this cocoon it pupates, and after about 
three weeks the winged fly issues. The eggs are laid in patches on the rocks 


Fic. 429.—Longitudinal section of head of old larva of black-fly, Simulium sp., showing 
adult mouth-parts developing inside of or corresponding with the larval mouth- 
parts. /.md., larval mandible; /.mx., larval maxilla; /./i., larval labium; J.c., larval 
cuticle; /.a., larval antenna; i.md., adult mandible; i.mx., adult maxilla; 7./i., adult 
labium; i.d., adult hypoderm (cell-layer of skin); 7.a., adult antenne; i.e., adult 
eye. (Much enlarged.) 


. 


just below the surface of the water, or on the spray-dashed sides of boulders 
in the stream or on its margin. 

In the same places where the Simulium larve live, that is, on the smooth 
rock faces of stream bed and lip of fall under the thin apron of swift silver 
water of mountain streams, live also the curious flattened larvae (Fig. 430) of 
the net-winged midges or Blepharoceride. This small family of interesting 
flies, comprising only eighteen species in the whole world, of which seven 
belong to this country, is one with which the general collector will hardly 
become acquainted unless he takes particular pains to do so. But the pains 
are well worth while, for they are not pains at all, but pleasures. In the first 
place, the larvae-—and they must be looked for first, the winged flies being very 
rare, very retiring, and hardly distinguishable, until captured, from a number 
of other common and less interesting kinds—live only in the most attractive 
parts of the most attractive mountain brooks. I have found them in a tiny 
swift stream near Quebec, in two or three hillside brooks near Ithaca, 
N. Y., in roaring mountain torrents in the Rocky Mountains, and in similar 
plunging streams in the Sierra Nevada and Coast Range. Clinging by a 
ventral series of six suckers to the smooth shining rock bed, the short broad 


The Two-winged Flies BS 


larve squirm slowly around, feeding on diatoms and other microscopic water 


FIG. 430. FIG. 431. 

Fic. 430.—Larva of net-winged midge, Bibiocephala comstocki. At left, dorsal view; 
at right, ventral view. amt., antenne; J/.p., lateral processes; 4.g., tracheal gills; 
s., sucker. (Natural length, 2 to 4 inch.) 

Fic. 431.—Cross-section of body of larva of net-winged midge, showing anatomical 
details of sucker and other parts. i., heart; a/.c., alimentary canal; 1/.p., lateral 
process; v.c., ventral nerve-cord; r., rim of sucker; s., stopper of sucker; m.s.c., 
muscles for retracting sucker and contracting body; #., tendon at end of muscles. 
(Much enlarged.) 

organisms, and never suffering themselves to get into slow water. Trans- 

planted from the highly aerated swift water of the 

stream’s center to the slow water of eddies or pools 
along the bank, they die very soon. When ready 
to pupate they gather in small patches, still keeping 
in the swift water, and each changes into a curious 
flattened, turtle-shaped, motionless, non-feeding pupa 
(Fig. 432) which is safely glued to the rock face by 
its under surface. The dorsal wall is thick and black, 
and projecting from it at the broad front head end 
is a pair of breathing-organs, each composed of three 
or four thin plate-like gills. When the fly is ready 
to emerge the pupal skin splits longitudinally along the 


: _ Fic. 432.—Pupa, dorsal 
back, and the delicate body pushes up through this aspect, of net-winged 
) ) I § E ne! Be 
slit, and through the shallow swift water until the midees ao ile 
: 5 : S SLOCRI. Note Te- 
wings can be outspread. All this is quickly done, spiratory leaves on 
the fly being enchained by its long legs, which cling dorsum of prothorax. 
M 2 Fes : (Natural length, } inch.) 

to the pupal shell until it can fly away. But the 


316 The Two-winged Flies 


FIG. 433- Fic. 434. 
Fic. 433.—Net-winged midge, Bibiocephala elegantulus, female. (Natural length of 
body, = inch.) 
Fic. 434.—Mouth-parts of female net-winged midge, Bibiocephala doanei. 1.ep., labrum- 
epipharynx; md., mandible; mx., maxilla; mx/., maxillary lobe; mxp., maxillary 
palpus; /i., labium; pg., paraglossa; hyp., hypopharynx. (Much enlarged.) 


Fic. 435.—Heads of female (at left) and of male (at right),of net-winged midge, Bibio- 
cephala comstocki, showing division of eyes into two parts, the upper part with fewer 
and larger facets than the lower part. (Much enlarged.) 


The Two-winged Flies 317 


swift water works great havoc among the weak, soft-bodied emerging creatures. 
I have watched many flies issuing, and a large proportion of them get swept 
away and presumably drowned before they can get their wings unfolded 
and themselves clear of the torrent. It is an extraordinary life-history that 


A 


Fic. 436.—Primary venation of wing of net-winged midge, Bibiocephala comstockt. 
R,, etc., branches of the radial vein. (Much enlarged.) 


p 
these flies have, and the great danger attending the transformation to the 
adult stage probably partly explains why the species are so few. It is an 
unsuccessful type of insect life; the family is probably becoming extinguished. 
Because the few living species are so widely distributed over the world— 


Fic. 437. Fic. 438. . 

Fic. 437-—Diagram of cross-section of head through compound eyes of net-winged 
midge, Blepharocera capitata, female. 0, ocelli; br., brain; o./., optic lobes; /./., large 
facets; s./., small facets. 

Fic. 438.—Mouth-parts of larva of net-winged midge, Bibiocephala doanei. md., man- 
dible; mx., maxilla; /.ep., labrum-epipharynx; /i., labium; /yp., hypophkarynx. 
(Much enlarged.) : . 


they occur in North America, South America, and Europe—entomologists 
believe that in past ages the family was much larger than it now is. 

The flies (Fig. 433) themselves can be distinguished when in hand by 
the curious secondary or pseudo net-veining of the wings. These faint cross 


318 The Two-winged Flies 


and diagonal veins are the marks of the creases made by the compact folding 
of the wings in the pupal shell. The females are provided with long saw- 
edged mandibles (Fig. 434), and are predatory in habit, catching smaller 
flying insects, especially Chironomid midges, lacerating their bodies with 
the mandibular saws and sucking the blood. The males have no mandibles, 
and probably take flower-nectar for food. Both males and females of several 
genera have the compound eyes divided 
into a large-facetted and a small-facetted 
part (Figs. 435 and 437). The egg-laying 
has not yet been observed, although the 
eggs must almost certainly be deposited 
on rocks in the stream or on its edge. 
With the mosquito wrigglers and the 
blood-worms (larve of the Chironomidz) 
may perhaps be found a third kind of fly 
larva (Fig. 440), a slender, pale-colored, 
cylindrical little “‘worm,” about one- 
third of an inch long, which can be 
distinguished from the other aquatic 
larve by its two pairs of short leg-like 
processes borne on the under side of the 


: Fic. 439. FIG. 440. 

Fic. 439.—Diagram of horizontal section through head of old larva of net-winged midge, 
Bibiocephala doanei, showing formation of adult head-parts inside. /.md., larval 
mandible; I.mx., larval maxilla; l.c., larval cuticle; 7.md., adult mandible; i.mx.p., 
adult maxillary palpus; id., hypoderm (cell-layer of adult skin of head); 7.e., adult 

_ eye. (Much enlarged.) 

Fic. 440.—Larva of Dixa sp., with dorsal aspect of head in upper corner. (From life; 
much enlarged.) 


fourth and fifth body segments. It usually keeps the body bent almost double, 
and when feeding near the surface the head is twisted so that the under or 


—— 


~The Two-winged Flies 319 


mouth side faces up although the rest of the body has its ventral aspect facing 
down. This larva belongs to one of the midge-like flies of the genus Dixa 
(Fig. 44¢), which is the only genus in the family Dixide, represented by about 
a dozen North American species. The winged flies (Fig. 442) are found in 
moist places, densely grown over with bushes or rank herbage, in woods. 
Although resembling mosquitoes and 
Chironomid midges in general appear- 
ance, they can be readily distinguished 
from them by the arrangement of 
the wing-veins (Fig. 444). 

An interesting small group of 
readily recognizable flies is the 
family Psychodide, or ‘“moth-fly”’ 
family. The vernacular name comes 
from the slight resemblance to minute 
moths shown by these flies because 
of the hairy broad wings, which are 
held over the back when the fly is at 
rest in the roof-like manner of the Fic. 442. 
moths (Fig. 445). The largest of these Erase of Dixa sp. (Much en~ 
flies are only about one-sixth of an Fic. ee eps (Muchienlareeds) 
inch long, and are rarely distinguished 
except by careful observers. I have found them especially common in gar- 
dens near the seashore in California, and also in the overhanging foliage 


Fic. 443.—Mouth-parts of Dixa sp., female. /l.ep., labrum-epipharynx; md., mandible; 
mx., maxilla; mx.l., maxillary lobe; mx.p., maxillary palpus; /7., labium; pg., para- 
glossa; gl., glossa; hyp., hypopharynx. 


of trees and shrubs bordering the swift little mountain streams of the Coast 
Range. In one of these streams I was fortunate enough to find the 


320 The Two-winged Flies 


immature stages of one moth-fly species, Pericoma californica, which is, so 
far, the only North American member of this family whose life-history is 
known. The larve (Fig. 446), which are little slug-like creatures, one- 
tenth of an inch long, cling by a row of eight suckers on their ventral side 
to stones in or on the margin of the stream, where they are constantly 


FIc. 444. Fic. 445. 
Fic. 444.—Diagram of wing of Dixa sp., showing venation. 
Fic. 445.—A moth-fly, Pericoma californica. (Much enlarged.) 


wetted by the dashing water. When ready to pupate the larve crawl a little 
higher on the stones, where only the spray will reach them, and, fixing them- 
selves to the rock face by a gummy exudation, change to small flattish, 
turtle-backed pupe (Fig. 446), each with a pair of club- or trumpet-shaped 
respiratory horns on the back of the prothorax. They look indeed much 
like dwarf net-winged midge pup. After 
about three weeks the adults issue and fly 


Fic. 446. . Fic. 447. 
Fic. 446.—Larva, ventral surface (at left), and pupa, dorsal surface (at right), of the 


moth-fly, Pericoma californica; also enlarged prothoracic respiratory tube of pupa. 
(Much enlarged.) 

Fic. 447.—Mouth-parts of moth-fly, Psychoda sp. /b., labrum; mx., maxilla; mx.p., 
maxillary palpus; mx.l., maxillary lobe; /i., labium; pg., paraglossa; hyp., hypo- 
pharynx. 


up into the overhanging foliage, where they spend most of their time 
resting on the under side of the leaves. 
The largest family of nematocerous flies in point of number of species, 


The Two-winged Flies 321 


and that one containing the largest flies in the whole order, is the family 
Tipulidae, whose long-legged, narrow-winged members are familiarly known as 
crane-flies, leather-jackets, and “« sranddaddy-long-legs.” The granddaddy- 
long-leg flies, which have wings, should not be confused with the often simi- 
larly named harvestmen, which are allies of the spiders, have no wings, and 
have four instead of three pairs of legs. The Tipulid legs are extremely 
fragile, breaking off at a touch. Most slender-bodied, long- and thin-legged, 
two-winged insects of more than one-half-inch length of body are Tipulids. 
There are some smaller species, 

however, which might be mis- 

taken for midges or mos- 

quitoes, were it not that all 

Tipulids bear a distinct \- 

shaped mark (suture) on the Fic. 448.—Diagram of wing of crane-fly, Sim- 
back of the thorax. More than ERIS EE AS at 

three hundred species of this family are known in the United States, and they 
are common all over the country, in meadows, pastures, along roadsides, 
stream-banks, and in woods. The flight is uneven, slow, and weak, and 
the ungainly flies with their long middle and hind legs training out behind, 
and the front legs held angularly projecting in front, are unmistakable 
when seen in the air. 

The eggs are laid in the ground at the bases of grasses and pasture plants, 
or, by some species, in mud or slime. The footless, worm-like, dirty-white 
larve feed on decaying vegetable matter, fungi, or on the roots or leaves of 
green plants. The root-feeders do some damage to meadows and pastures. 

The largest Tipulid, and the largest species in the whole order of flies, is 
the giant crane-fly, Holorusia rubiginosa (Fig. 449), common in California. 
Its body is nearly two inches long, and its legs are from two to two and one- 
half inches long, so that the spread of legs is four inches. The eggs are 
laid in the ooze of wet banks of little streams where fallen leaves are decay- 
ing and subdrainage water is always slowly trickling out from the soil. The 
larvee (Fig. 450) lie in this slimy bed, in crevices or on narrow ledges of rock, 
with the posterior tip of the body bearing the two breathing-openings (spi- 
racles) held at the surface. The soft ooze, composed of soil and slowly 
decomposing leaves, is swallowed, and, as it passes through the alimentary 
canal, the organic material digested out of it. The footless, worm-like 
larve grow to be two and one-half inches long, but can contract to less than 
an inch. The duration of the larval life is not yet known, but it is at least 
several months. The pup (Fig. 450), which are provided with a pair of 
long, slender respiratory horns on the prothorax, lie motionless in the slime 
for twelve days, when the great flies emerge and fly up into the foliage of 
the stream bank. 


322 The Two-winged Flies 


Next to the mosquitoes, the worst pests among the nematocerous flies are 
various species of the gall-midge family, Cecidomyide, a family in which 
all the stages, larval, pupal, and adult, of all the species are terrestrial. The 
gall-midges are the frailest, 
smallest, and least conspicuous 
of all the flies, but their great 
numbers and vegetable feeding 


Fic. 449. FIG. 450. 


Fic. 449.—The giant crane-fly, Holorusia rubiginosa, male. (Three-fourths natural 
size.) 

Fic. 450.—Larva (at left) and pupa (at right) of giant crane-fly, Holorusia rubiginosa; 
in middle of figure enlarged posterior aspect of larval body, showing spiracles. 
(Larva and pupa three-fourths natural size.) 


and gall-making habits make them formidable enemies of many of our 
cultivated plants. The tremendous aggregate losses suffered by the wheat- 
growers of this country from the ravages of the Hessian fly, the damage 
to clover-fields by the clover-leaf and clover-seed midges, and the injuring 
or killing of thousands of pine-trees from the attacks of the minute 
pine Diplosids, are evidences of the great economic importance of the 
delicate little gall-gnats. About one hundred species are known in this 
country, and of these most are more or less destructive to cultivated herbs, 
shrubs, or trees. 

The tiny bodies of the flies are usually covered with fine hair, easily 
rubbed off, and the antenne bear whorls of larger hairs, which, with some 
species, are attached by both ends, thus making little hair loops. The 
minute eggs, reddish or white, are usually deposited in or on growing plant- 
tissue, and the little footless, headless, maggot-like larvee probably derive 
most of their food by imbibing it through the skin. Lying with the body 


The Two-winged Flies B23 


practically immersed in plant-sap, the thin body-wall acts as an osmotic 
membrane through which an interchange of fluids takes place automati- 
cally. The Cecid larva has to eat whether it will or not, and has to eat 
practically all of the time! These larvae may be distinguished by their 
possession of a strange little chitin plate on the under side of the front part 
of the body, called the breast-bone. What the exact use of this little sclerite 
is has not yet been determined. Perhaps it helps in locomotion, perhaps 
in rasping or lacerating the soft plant-tissue to increase the flow of sap. The 
larvee pupate where they lie, sometimes spinning a thin silken cocoon, some- 
times transforming within the hardened last larval moult, sometimes with 
no special protecting covering at all. 

The most notorious gall-gnat is the wheat-pest, known as the Hessian 
fly, Cecidomyia destructor, and distributed over all the United States east of 
meridian 1oo°, as well as in California. By the ravages of its larve, feeding 
as they do on the sap of growing wheat, this minute fly causes an annual loss 
in this country of approximately ten million dollars. This enormous direct 
tax is paid by those farmers who prefer to farm in the good old way, with a 
strong belief in the dispensations of an erratic Providence, rather than to 
do their farming as modified by modern knowledge and practice. The 
tax-collecting insect, which is a tiny delicate blackish midge about one- 
tenth of an inch long, lays its eggs in the creases or furrows of the upper 
surface of the leaves of young wheat, and the hatching larve wriggle down 
to the sheathing bases of the leaves, where they lie and drain away the sap 
of the growing plant. When full-grown they pupate within the outer hardened 
brown last larval cuticle, and resemble very much a small spindle-shaped 
seed. This is called commonly the “flaxseed” stage. The adult soon 
issues and after a few days of flight and egg-laying dies. There may be as 
many as four or five generations in a year, both spring and winter wheat 
being attacked. The remedies are the late planting of winter wheat, the 
burning or plowing in of the stubble after harvesting, and the early planting 
of strips of decoy wheat about the field, which shall attract the egg-laying 
females and may be afterwards plowed under with the myriad eggs it contains. 
The Hessian fly is a European insect brought unintentionally to this country 
about 1778, but probably not, as often said, with the straw brought by the 
Hessian troopers of the Revolutionary War. It attacks rye and barley as 
well as wheat, and has, in turn, to withstand the combined attacks of half 
a dozen hymenopterous parasites, which are said to destroy nine-tenths 
of all the Hessian-fly larva. Without these natural checks to its increase 
this pest would destroy every wheat-field in this country in a very few 
years. 

In 1896 the Monterey pines, Pinus radiata, much grown, together 
with the famous Monterey cypresses, as ornamental trees on the San Fran- 


324 The Two-winged Flies 


cisco peninsula, showed a peculiar stunting and gall-like swelling of the 
leaves. Since then this deformation has appeared so abundantly and widely 
within the range of this tree that the species is actually threatened with 
extinction, the shortened, swollen needles not being able to perform the 
essential food-assimilating functions of green leaves. This injury is due 
to a single species of Cecid fly known as Diplosis pini-radiata (Fig. 451), 


Fic. 451.—The Monterey-pine midge, Diplosis pini-radiata; eggs in upper left-hand 
corner; pupa, larva, breast-bone of larva, and adult female. (Much enlarged.) 


which lays its eggs at the base of the growing new needles and whose larve 
hatching and lying here use up the sap necessary for the development of 
the needles. Hundreds of Monterey pines have been cut down, and unless 
the natural enemies of this little fly, of which two or three have been dis- 
covered, get the upper hand of the pest, this splendid species of pine may 
be wholly destroyed. A half-dozen other species of Diplosis are known 
in this country and Europe as pests of conifers, but no other pine species 
seems to have suffered quite so severely as this interesting Californian one, 
whose whole geographical range extends over but a thousand square miles, 
and which is thus specially liable to destruction by concentrated insect 
attack. 

If the collector will break up and examine carefully almost any old or 
partially decaying toadstools or shelf fungi from trees, he will find in the 
soft fungous body numerous small translucent white maggot-like larve, the 
larvee of fungus gnats or members of the family Mycetophilide. The gnats 
themselves are slender delicate flies, mostly with clear wings, though some 
common species have dark wings, with the basal segment (coxa) of the legs 
unusually long and the antenne in most cases free from the whorls of long 
hairs so characteristic of the Chironomid, Culicide, and other families of 
flies otherwise much resembling the fungus-gnats. The flies are to be looked 
for on decaying vegetable matter, especially fungi, and in damp places. 

The eggs are laid variously: on fungi, in decaying wood, among decom- 
posing leaves, in animal excrement, and under the bark of trees. The larve 


The Two-winged Flies 200s 


feed on the decomposing substance in which the eggs are .aid, sometimes 
spinning silken webs for protection. They pupate in the food-substance or 
crawl away to some more sheltered spot, often forming a thick cocoon in 


Fic. 452.—A fungus-gnat of the family Mycetophilide; larva, pupa, and adult. 
(Much enlarged.) 


which to transform. Pcrhaps the most singular habits noted in the family 
are those connected with the strong gregarious instinct which leads the 
larvee of many species to live closely together. Some of the species of Sciara, 
known as ‘“‘army-worms,” have “the singular propensity of sticking to- 
gether in dense patches, and will 
form processions sometimes twelve 
or fourteen feet in length and two 
or three inches broad. This phe- 
nomenon has been observed fre- 
quently both in Europe and Amer- 
ica, but the reason therefor is not 
yet well understood, though the 
object of the migration seems to be 
the search for better feeding-grounds.’”’ Various species of this genus live 
in potatoes and other vegetables, while the serious injury to potatoes called 
“scab” is caused by a fungus-gnat known as Epidapus scabies. 

With larger and more robust bodies and relatively shorter and thicker an- 
tenn, the March-flies, Bibionid, serve as a sort of transition family between 
the long-legged, slender-bodied midge type of fly with its thread-like hairy 
antenne, and the compact, heavy-bodied, short-legged type of fly with short 
and club-like three-segmented antennz, characteristic of the many families 
grouped in the section Brachycera. The March-flies (Fig. 454) are from 
one-eighth to one-half inch long, with fairly robust, often hairy, body, black- 


Fic. 453.—Diagram of wing of fungus-gnat, 
Mycetophila sp., showing venation. 


326 The Two-winged Flies 


ish or black and red, strong legs, large clear or smoky wings, and stout an- 
tenn about as long as head and thorax together and composed of nine to 
twelve segments. They may be seen often in large numbers flying heavily 
over gardens and fields or in woods, early in the spring. The eggs are laid 
in the soil or in decaying vegetation or in sewers and excrement, the larve 
feeding usually on decomposing substances. With some species, however, 
the larvee feed on the roots of grains or grasses and in this way may do serious 
damage. Bibio tristis, discovered in Kansas in 1891, appeared in great 
numbers in wheat-fields and frightened many wheat-growers. As a matter 
of fact, little injury seemed to be done. B. femorata, a common species, 
is deep red with black wings; B. albipennis, another abundant and wide- 
spread one, is black-bodied with white wings. A common Californian species 
appears from the ground in damp woods in great numbers in March. I 
have watched these flies issuing in countless numbers 
from the soft rich forest floor in the extensive 
Monterey pine woods near the Bay of Monterey 


FIG. 454. FIG. 455. 


Fic. 454.—March-fly, 3ibio albipennis. (Three times natural size.) 
Fic. 455.—Diagram of wing of Bibio albipennis, showing venation. 


The air danced with them, and the pine-trees and shrubs bore countless 
myriads on their branches. Professor Needham records a similar sight 
in which individuals of B. fraternus formed the hosts, and a woodland pasture 
near Lake Michigan was the scene of their appearance. “I have rarely 
come upon a scene of greater animation than a sheltered hollow in this wood 
presented,”’ writes Professor Needham. ‘‘There was the undulating field 
clad in waving grass and set about with the pale-hued foliage of the white 
oaks; there were the flowering hawthorns; and there were the myriads 
of Bibios floating in the sunshine, streaming here and there like chaff before 
sudden gusts and swirls of air. All the spiders’ webs in the bushes were 
filled with captives; little groups of ants were dragging single flies away to 
their nests, and once I saw overhead a chestnut-sided warbler, perched on 
a bare bough directly in a stream of passing flies, rapidly pecking to right 
and to left, persistently stuffing his already rotund maw. I counted a number 
of flies I could see resting on the grass in several small areas wide apart, and 


The Two-winged Flies 327 


found the counts averaged fifteen Bibios per square foot; and there were 
here in one place forty acres of such Bibio territory.” 

Two families of nematocerous flies are not included in the key, and have 
not heretofore been referred to. They are the Orphnephilid, of which but 
a single species is known in this country, viz., Orphnephila testacea, a small 
reddish-yellow fly without hairs or bristles on its body, and with short antenne 
apparently composed of two segments, but really of ten, the apparent first 
segment being made up of three closely 
opposed segments, and the second of seven. 
The fly itself is found along stream banks, 
but nothing is known of its immature stages. 
The other family, Rhyphide, or false crane- : ; 
flies, is represented in this country by two ve 450 Dean pie winks of 

hyphus sp. 
genera containing several species. The flies 
are small and slender, with broad spotted wings veined in a character- 
istic way (Fig. 456). The larvae of Rhyphus are worm-like, legless, naked, 
more or less transparent, with snake-like movements. They live in water, 
brooks, pools, or puddles, or in rotting wood, hollow trees, or manure. 


SECTION BRACHYCERA. 


” 


The Brachycera, or flies with “short horns,”’ i.e., short thick antenne 
composed of few segments, in contrast with the many-segmented antenne, 
usually slender and long, of the Nematocera, are separable into three groups 
of families, as indicated in the key on page 303, based on a further analysis 
of the structural character of the antenne. These groups are, first, one includ- 
ing flies in which the antennz are composed of more than five segments but 
with all those beyond the second coalesced to form a single compound 
segment, bearing more or less distinct annulations indicating the component 
subsegments; second, one including flies having antenne made of four or 
five distinct segments; and third, and by far the largest, one including flies 
with but three segments in the antenne. 

In the first group are two families and part of a third; this division of a 
family indicating plainly the artificial character of the subdivision into 
groups, the subdivision being merely convenient. The three families may be 
distinguished as follows: 

The branches of the radial vein (see Fig. 460) crowded together near the costal (front) 

THAT PIM OL He WANs fer cr<e/d cis clei cvele/<iavevayelelelsressienel= (Soldier-flies.) STRATIOMYID&. 
Venation normal. 

Alulets, i.e., little whitish wing-like membranous flaps at the base of the true wings, 
IDSs goopbbodods andthe CoOUDS HONS wUoboCUdOn SH0es (Horse-flies.) TABANIDZ. 
WATets' Small’ fara cictayace ciovetarevaravaus) afetetatevetchertacelerserelers (Snipe-flies.) Lrprrp& (in part). 


228 The Two-winged Flies 


The most familiar and interesting flies in this group are the well-known 
horse-flies, gad-flies, or deer-flies, Tabanide. They are all fairly large, 
some indeed being among the largest of our flies. 

The great, black, swift horse-flies that in summer dart suddenly at our 
carriage-horses and with quick shifting flight seem to be fairly carried 
along in the air close to the horses, are the most familiar representatives of 


Fic. 457.—Greenhead, or horse-fly, Tabanus lineola. (After Lugger; natural size 
indicated by line.) 


the order. Many of the smaller horse-flies show gleaming metallic colors, 
especially about the head. Much of this color is in the large compound 
eyes, and almost any horse-fly caught alive or just killed will astonish the 
collector by the brilliant bands and flecks of iridescent green, violet, purple, 


Fic. 458.—Diagram of wing ot Chrysops sp., a horse-fly, showing venation. 


and copper on the eyes. The biting and blood-sucking are done by the 
females alone, the males lacking the sharp dagger-like piercing mandibles 
and contenting themselves with lapping up flower-nectar. 

The brown elongate eggs of horse-flies are laid either on stems or leaves 
of terrestrial plants, or on aquatic plants or submerged stones. The larve, 
whitish, cylindrical, tapering at both ends, and with a series of slightly raised 
roughened ridges running around the body, either live in water, in slimy 
places along pond and brook shores, or in soft rich soil, and are predaceous, 


The Two-winged Flies 329 


feeding on small aquatic or underground creatures, especially insect larvae 
and snails or slugs. 

Nearly 200 species of horse-flies are known in North America. The 
large bluish-black and brownish-black ones, an inch long and with dusty 
wings expanding for two inches or more, belong to the genera Tabanus and 
Therioplectes; the smaller ‘‘greenheads” with banded wings and brilliantly 


Fic. 459.—Mouth-parts of a horse-fly, Therioplectes sp. md., mandible; mx., maxilla; 
mx.l., maxillary lobe; mx.p., maxillary palpus; hyp., hypopharynx; /b., labrum; 
ep., epipharynx; /7., labium; Ja., labellum. 


colored eyes and black or brown and yellow bodies mostly belong to the 
genus Chrysops. Silvius pollinosus is a beautiful small species with a milk- 
white bloom over its body, and with clear whitish wings with a few small 
brown spots. 

The soldier-flies, Stratiomyidz, are unfamiliar insects, although as many 
species of them as of horse-flies occur in this country. Many of the species 
have bright yellow or green markings, and most of them have the abdomen 
curiously broad and flattened. 
They are found about flowers, 
and can readily be classified, 
after capture, by the unusual 
character of the venation (see 
Fig. 460). The eggs are laid 
on the ground or on leaves in or 
near water, some of the larve 
being terrestrial, while others are 
aquatic. ‘The food seems to be mostly vegetable, although the larvee of some 
species are believed to be carnivorous. One or two species live in salt or 
brackish water, and Sharp records that some Stratiomyid larve were found 
in a hot spring in Wyoming with the water temperature only 20° to 30° F. 
below boiling. They pupate within the last larval skin, which is long and 


Fic. 460.— Diagram of wing of Odontomyia 
sp.) Showing venation. 


330 The Two-winged Flies 


tapering at one end. Some species inhabit ants’ nests, and one is suspected 
of living parasitically in bee-hives. 

Stratiomyia is a genus containing rather large conspicuous yellow-banded 
flies with broad flattened abdomen, while Sargus, a genus whose species 
are common, has a subcylindrical abdomen with the whole body metallic 
green. 

- The snipe-flies, Leptide, are a small family represented by about fifty 
North American species, including flies having no habits or structural pecu- 
liarities appealing specially to popular interest. They are rather slender 
and plainly colored, and rather heavy and slow in movement. They are 

apparently all predatory in both larval 
and adult stages. The adults may be 
best found, according to Comstock, in 
low bushes and grass. The larve live 
in the ground, in moss, or in decaying 
wood, sometimes penetrating to the 
Fic. 461.—Diagram of wing of Chryso- burrows of wood-boring insects. The 

phila  thoracica (Leptide), showing 3 : z 

venation: species of the genus Atherix deposit 

their eggs ‘‘in dense masses attached 
to dry branches overhanging water. Not only do numerous females con- 
tribute to the formation of these masses, but they remain there themselves 
and die. The larve on hatching escape into the water.” 

In the second group of Brachycera, including flies which have their anten- 
nz composed of four or five distinct segments, there are two families, the 
Asilide, or robber-flies, and the Midaide, or Midas-flies. These latter resemble 
the robber-flies in size and general appearance, but differ from them by having 
the antenne rather long and clubbed at the tip. They are predaceous, 
catching and devouring other flying insects, and the larvee of the few species 
whose life-history is known are also carnivorous, and seem to have a special 
fancy for the larve of the great wood-boring grubs of the giant Prionus 
beetles. Howard believes that the large species, Mydas luteipennis, found 
in the Southwest, mimics in coloration and general appearance for protection 
or aggression the tarantula-killer wasp found commonly in this country. 

The Asilide, or robber-flies, compose a considerable family—nearly 1000 
species occur in this country—of large, swift, hairy, ferocious-looking flies 
which live wholly by predatory attacks on other insects. The body is usually 
long and slender, tapering behind (Fig. 462), although in a few genera the 
abdomen is flattened and not unusually elongate. The proboscis is strong 
and sharp, the eyes large and keen, and the wings long and narrow and 
capable of carrying this insect hawk swiftly and strongly in pursuit of its 
prey. Some of the robber-flies are very large, an inch and a half or even 
two inches long, and they do not hesitate to attack other large and strong and 


The Two-winged Flies BBN 


well-defended insects, as bumble-bees, dragon-flies, and the fierce and 
active tiger-beetles. The robber-flies usually rest on the ground or on low 


Fic. 462. 


Fic. 462.—A robber-fly, Stenopogon inquinatus. (Natural size.) 
Fic. 463.—A bumble-bee-like robber-fly, Dusyllis soceata. (Natural size.) 


foliage, and fly quickly up with a buzzing sound when disturbed or attracted 
by prey. All the prey is caught on the wing, held in the long spiny feet of 
the robber-fly, and torn and sucked dry by the sharp piercing-beak. 


Fic. 464.—Diagram of wing of robber-fly, Erax cinerascens, showing venation. 


The larve live chiefly in decaying wood or in soil containing decom- 
posing vegetable matter, and are also predatory, feeding on grubs and other 


Y/ 


Be mE 


Fic. 465.—Mouth-parts of robber-fly, Erax cinerascens. li., labium; hyp., hypopharynx; 
1b., labrum; mx., maxilla; mal., maxillary lobe; mxp., maxillary palpus. 
underground or wood-boring insects. The pupe are curiously spiny, the 
spines being used as a sort of pushing or pulling organ when they get ready 

to come to the surface of the ground or dead tree to change into imagines. 
Some of the species of the genera Laphria and Dasyllis (Fig. 463) look 
astonishingly like bumble-bees and wasps, probably a case of protective 


gR2 The Two-winged Flies 


mimicry (see Chap. XVII). Erax is a genus with many common gray and 
black species about an inch long, with sharp-pointed tip of the abdomen. 

The third section or group of Brachycerous families includes many 
families, in all of which the antennz have the first two segments small and 
the third curiously large and club-like, and usually bearing a single con- 
spicuous bristle-like hair. The families of this group can be distinguished 
by the following table: 


A. Antenne composed of three segments, the third usually large and either with or 
without a bristle or style. 
B. Empodium pulvilliform, i.e., feet with three little pads instead of two. 
(Snipe-flies.) Leprip (in part). 
BB. Empodium not pulvilliform, i.e., feet with two little pads and a median bristle 
or nothing. 
C. Radial vein four-branched. 
D. Second branch of cubital vein extending free to the margin of the 
wing or coalesced with the first anal vein for a short distance 
(SeevBig: 466). = chi civic.< twister eres (Bee-flies.) BomByLip2&. 
DD. Second branch of cubital vein joining first anal far from the 
margin of the wing (see Fig. 471). 
(Dance-flies.) EMPIDID& (in part). 
CC. Radial vein with not more than three branches. 
D. Head witha curving suture immediately above the antenne. 
(House-flies and allies.) Muscirp&. 
DD. Head without such suture. 

E. Radial vein with a knot-shaped swelling at the point where 
it forks, with a small cross-vein running back just at or near 
this swelling (Fig. 474). . (Long-legged flies.) DoticHopopip&. 

EE. Wings without such characteristics. 

F. Second branch of cubital vem appearing as a cross- 
vein or curved back towards the base of the wings 
(Fig. 479). 

G. Proboscis rudimentary; mouth-opening small; palpi 
wanting; antenne with dorsal arista. 
(Bot-flies.) CEsTRID&. 
GG. Proboscis not rudimentary; palpi present; antenne 
with terminal style or arista or dorsal arista. 
EMPIDID& (in part). 

FF. Second branch of cubital vein not appearing like a 

cross-vein, 
G. Front with grooves or a depression beneath the 
antennes\...c-cemcioeeasie 6 (Wasp-flies.) Conopip®. 
GG. Front convex beneath the antenne; a spurious 
vein usually present between radius and media 
(CBigr Tayo) eenieeiiata ie (Flower-flies.) SyRPHID#®. 


The families of flies named in the above key contain many hundreds of 
species but few of which are at all popularly known. The bot-flies (Estride), 
house-flies, flesh-flies, bluebottles and stable-flies (Muscide calyptrata), and 


The Two-winged Flies 333 


the cheese-skippers and pomace-flies (Muscidw acalyptrate) are about the 
only names in the list of these hundreds which seem at all familiar. The 
flower-flies (Syrphide) and bee-flies (Bombyliide) are numerous, often 
seen, and, what is more, often definitely noted and admired, but ‘‘beautiful 
flies” is about as specific a name as they ever get. The bristly parasitic 
Tachinid flies are noticed now and then by the nature student, and the 
dancing Empidids interest, in a decided but irritating way, drivers and 
bicyclers in the dance-fly mating-time. But even entomologists, professional 
as well as amateur, unless they are special collectors and students of 
Diptera, recognize but few of the hosts of small flies that fill the air during 
the long summer days. 

In the above key only the larger and more commonly represented families 
are included, so that it will be possible for a collector using this book to 
find himself possessed of a fly which will prove intractable when an atiempt 
is made to classify it into its proper family. But such unfortunate happen- 
ings will be very infrequent, as only small families of obscure or rare species 
are thus omitted. 

Poised almost motionless in the air a few inches above a sunny path or 
roadway, or darting away, when disturbed, with lightning swiftness and 
having all the seeming of bees, hairy, plump-bodied, and amber-colored, certain 
bee-flies (Bombyliide) are rather familiar acquaintances of the summer field 
student. Other bee-flies, as swift 
and as beautiful, are less bee-like 
because of the striking “‘pictures” 
in the wings, blackish or brown 
blotches conspicuous in the thin, 
otherwise clear wing-membrane. 
Some of these bee-flies: have an Fic. 466.—Diagram of wing of Anthrax ful- 
unusually long slender proboscis viana, showing venation. 
held straight out in front of the 
head like a spear at rest (Fig. 467). But this beak has no bloodthirstiness; it 
is used to suck up sweet nectar from flower-cups. The larve of the bee-flies, 
however, are carnivorous, living parasitically in the egg-cases of grasshoppers 
or on the bodies of wild bees and various caterpillars. One of these bee- 
fly larve burrowing into a grasshopper’s egg-pod can do awful harm to the 
embryo grasshoppers, but at the same time much good to us, by the satisfac- 
tion of its egg-eating propensities. Beautiful, velvet-clothed, swift-winged, 
and nectar-feeding as a fly, maggot-like and parasitic as larva, the bee-fly 
is a good example of the great differences in structure and habit which are 
possible between young and old of the specialized insects. 

Bombylius (Fig. 467) is a genus in which the proboscis is very long and 
slender, the body short and plump and covered with a thick soft coat of longish 


334 The Two-winged Flies * 


hair usually light brown cr whitish in color. The wings are blotched with 
brown or blackish. Anthrax contains numerous species with short proboscis, 
and broad flattened body covered with short hair. The wings are either 
clear or partly colored with brown or black. In the species of the genus 
Exoprosopa (Fig. 468) the hair of the body is very short and often in silvery 
bands across the abdomen, the pro- 
boscis is short, and the wings usually 
beautifully ‘‘pictured” with brown and 


Fic. 467. Fic. 468. 


Fic. 467.—A bee-fly, Bombylius major. (Twice natural size.) 
Fic. 468.—A bee-fly, Exoprosopa sp. (One and one-half times natural size.) 


In California the roads and paths, especially along streams and through 
woods and parks, are made almost intolerable in part of the spring for driving 
or bicycling because of hosts of small slender blackish flies 
in swiftly dancing swarms. These are dance - flies, 
Empidide, and their aerial dance is their mating flight. 
I do not know that such hordes of dance-flies occur in 
the East, but some species of 
the family have the same danc- 
ing habit there, and can be dis- 
tinguished by it and by the 
structural characters given in 
the key. The midges, Chirono- 
mide, also dance in swarms in 
the air, but are readily dis- 
tinguished from the Empidids 
by their small fragile body, 
and long many-segmented hairy 


Fic. 469. FIG. 470. . 
Fic. 469.—Mouth-parts of a bee-fly Bombylius sp. ANtenne. All the dance - flies 
(Much enlarged.) are predaceous, sometimes 


Fic. 470.—A dance-fly, Rhamphomyia longicauda. . . : . 
(Three times natural size.) catching their prey in the air, 
sometimes chasing it on the 


ground. The larve, slender cylindrical grubs living in the soil or under leaves 


The Two-winged Flies 335 


or other vegetable matter, are also probably predaceous, feeding on smaller 
jnsects living in the same places. 

The commoner species that dance in large swarms belong to the genera 
Empis and Rhamphomyia (Fig. 470). The males of certain species of Empis 
and Hilara have the odd habit of blowing out bubbles of a whitish viscid sub- 
stance which they carry about with them in the air. Itis believed that these 
toy balloons are attractive to the females. At least, Professor Aldrich, a 
well-known student of flies, has seen a female choose that male among several 
which was carrying the largest balloon! 

An attractive lot of small slender flies, usually of iridescent green or 
greenish-black or blue color, with 
unusually long slender legs, are 
the Dolichopodidz, or long-legged 
flies. They are found especially 
in marshy or low places where 
vegetation grows lush and rank. 
aney at ebout: Seabee Fic. 471.— Diagram of wing of dance-fly, 
lesser insects, which they catch Empis sp., showing venation. 
and devour. They often get their 
prey by swift chasing over leaves or ground or even on the surface of water. 
Like the Empidids the larve are also predaceous, living underground or in 
decaying vegetable matter. Some have been found in the exuding sap of 


Fic. 472. Fic. 473. 
Fic. 472.—Mouth-parts of dance-fly Rhamphomyra sp. 1/b., labrum; mx., maxilla; 
mx.l., maxillary lobe; mx.p., maxillary palpus; /z., labium; hyp., hypopharynx. 
Fic. 473.—Dolichopus lobatus. (Three times natural size.) 


trees and elsewhere on or under bark. The larve of certain species spin 
little thin cocoons when ready to pupate, but with most the pupa is 
naked. 


23 The ‘l'wo-winged Flies 


Dolichopus (Fig. 473) is the largest genus of the family, nearly too species 
occurring in this country. The males are curiously ornamented by special 
outgrowths or expansions on the feet. These make the feet at the end of 
the long legs very conspicuous and are believed to serve the male to help 
attract the female in his courtship of her. These ornaments are not con- 
fined to the males of this genus, other genera of the family showing similar 


Fic. 474.—Diagram of wing of a Dolichopodid, Psilopus ciliatus, showing venation. 


characters. Other ornaments, too, are found in various species, some occur- 
ring on the face, others on the antennz and elsewhere. Aldrich says that 
the males of the flies of this family show more pronounced and various special 
ornamentation than the males of any other single family of animals. He 
has seen the males dangle their tufted feet in the faces of the females during 
courtship. 

Occasionally the general collector or nature observer will find an insect 
that he has taken at first glance for a wasp, but which on examination, after 
capture, is found to have but a single pair of wings, and short, clubbed anten- 
ne like a fly. The puzzle is readily solved with 
these clues: the insect is a fly, not a wasp; it simply 
looks so much like a wasp that it undoubtedly is 
frequently mistaken for a wasp by certain enemies 
which are afraid to attack the well-defended hornet, 
but would make short work of a defenceless fly. 
The wasp-flies, Conopide, thus save their lives by 
i an innocent deception; they are protected by their 
Fic. 475. —A wasp-like curiously close mimicry of wasps. All of them are 
fly, Physocephalaajinis.  ynarrow-waisted, and most have the abdomen spindle- 

Ste tac shaped and tapering like a wasp’s, and often banded 

and colored so as to increase the similitude. All 
of them, too, have robust heads and have been sometimes called “thick- 
head-flies.”” They are all flower-flies, feeding on nectar and pollen, and 
hovering on heavy wing about blossoming shrubs. The oval or pear-shaped 
larve are parasitic, living in the bodies of other insects, especially wasps, 


The-Two-winged Flies 237 
bumble-bees, and locusts. ‘The eggs,” according to Williston, ‘are laid 
directly upon the bodies of the bees or wasps during flight. The young 
larve burrow within the abdominal cavity of their host and there remain, 
the posterior end directed toward the base of the abdomen, feeding upon 
the non-vital portions, until ready to transform into the mature fly, when they 
escape from between the abdominal wings of the insect.” The quiescent 
pupal stage is then passed within the body of the host, a rather unusual 
phenomenon in insect life. 

In the genera Conops and Physocephala (Fig. 475) the abdomen is distinctly 
peduncled as in the thread-waisted wasps, while in Myopa, Zodion, Oncomyia, 
and others the abdomen is sessile or constricted only at the very base. 

Under the name bot-flies (Estrida) some of the most interesting members 
of the order Diptera are widely, but superficially, known. ‘The flies themselves 
are much less familiar than their eggs and larve, the glistening white eggs 
of some species being often seen attached to the flanks, legs, 
or feet of a horse or cow, and the stomach-inhabiting larvae 
being well known to stockmen as the cause of much suffer- 
ing and injury to their animals. In addition to the “‘bots”’ 
which live in the stomach and intestines of horses and 
cattle, several other species live under the skin of the same 
animals, as well as of goats, sheep, antelope, rabbits, rats, Fic. 476. —Larva 
dogs, cats, and even man. The larve of still other species oa Deas 
burrow in the nasal passages of the sheep, the antelope, wood-rat, Neoto- 
the horse, the camel, the buffalo, and various deer species. pen (Natural 
The flies are heavy-bodied, often densely hairy, banded in- 
sects, looking rather like small bumble-bees whose mouth-parts are so atrophied 
that they can probably take no food at all. They lay their eggs on the hairs 
or skin of their special host animal, and the larve on hatching bore directly 
through the skin and into the tissues of the host, or, as in the case of the 
familiar bot-fly of the horse and the heel-fly or warble of cattle, the eggs are 
taken into the mouth of the host by licking, swallowed, and thus introduced 
directly into the stomach, to whose walls the larve either attach themselves or 
through which they burrow into the true body-cavity of the host. 

Less than 100 species of bot-flies are known in the whole world, 
but the parasitic habits and resulting economic importance of these flies 
have resulted in making the family well known. The most widely dis- 
tributed and best known species is probably the horse bot-fly, Gastrophilus 
equi (Fig. 477). ‘This fly, which may be seen in open sunny places along 
the roadways, is about 4 inch long, brownish yellow, with some darker 
markings, but much resembling a honey-bee in appearance. The female 
has the abdomen elongate and bent forward underneath the body. The 
light-yellow eggs are attached by a sticky fluid to the hair of the horse 


338 The Two-winged Flies 


on the shoulders or legs or belly. They are licked off by the horse and 
swallowed, and the larva hatch in the mouth or stomach and attach themselves 
to the stomach lining, living at the expense of the host. When many larve 
thus live in the stomach (and as many as several hundred have been found 
in one animal) the horse suffers serious injury. The larve live in the stomach 


Fic. 477.—Bot-fly of horse, male, Gastrophilus equi, abdomen of female and egg. (After 
Lugger; natural size of fly indicated by line.) 


and intestines through fall and winter, and late in the spring release their 
hold, pass through the intestine with the excretions, and burrow into the 
ground to pupate. The pupal stage lasts about a month, when the flies 
issue and the life-cycle begins again. A smaller species of bot-fly, Gastro- 
philus nasalis, with bright-yellow band across the abdomen, lays its eggs 
in the lips and nostrils of horses. For the rest its life-history is about like 
that of G. equi. 

The bot-flies, warble-flies, or heel-flies of cattle, whose larvee are found in 
small tumors under the skin, also have their eggs swallowed, and the young 
larvee may be found in the mouth and cesophagus. But from here they burrow 
out into the body-tissues of the host, finally coming to rest underneath the 
skin along the back. When the larva or grub is full-grown it gnaws through 
the skin, drops to the ground, pupates, and in from three to six weeks changes 
to the adult fly. The hides of cattle attacked by these flies are rendered 
nearly valueless by the holes, and are known as ‘‘grubby” hides. Osborn 
estimates that these warble-flies, of which we have two species, Hypoderma 
bovis and H. lineata, cause a loss of $50,000,000 annually in this country. 

The genus Cuterebra includes a number of species of which the rabbit 
bot-fly, C. cuniculi, is most familiar. The larve lie in large warbles or tumors 
under the skin of the infested rabbit, and late in the summer the jack-rabbits 
and cottontails are so badly infested in some localities that hardly one can 
be found free from the pest. The adult is a large fly resembling a bumble- 


—————E———— OO 


The Two-winged Flies 339 


bee, with black head, yellow-brown thorax, and the abdomen blue-black 
with yellow base. The full-grown larva is a large black spiny grub. 

One or two species of bot-flies infest man, and also (probably the same 
species) monkeys and dogs and perhaps other animals. Numerous instances 
are recorded in which the larvee of Dermatobia noxialis and D. cyaniventris 
have been found under the skin of persons in tropical America, and a few 
instances of such cases in the United States. The larve are thick and broad 
at one extremity and elongate and tapering at the other. 

The family Syrphide, Syrphus-flies, flower-flies, or hover-flies, as the 
English call them, is one of the largest in the order; including fully 2500 
species in the whole world, of which over 300 are found in this country. 
For so large a family few generalizations regarding the appearance or 
habits of the flies can be made. Many of the Syrphus-flies resemble bees 
and wasps in appearance, and almost all are rather bright and handsome 
insects. They feed on nectar and pollen, and hence are to be found in sun- 
shiny hours at flowers, hovering like tiny humming-birds in front of open 


Fic. 478. FIG. 479. 


Fic. 478.—A flower-fly, Eristalis tenax. (One and one-half times natural size.) 
Fic. 479.—Diagram of wing of Syrphus contumax, showing venation. 


blossoms, or crawling bee-like in and out of deep flower-cups. Some make 
a distinct humming or buzzing as they fly about and thus heighten their 
suggestion of bees. All can be distinguished, after capture, by the so-called 
false vein of the wings (see Fig. 479). The larve live variously in decaying 
wood or other vegetation, or decomposing flesh, or in the stems of green 
plants, or in toadstools, or in water. Some crawl about, slug-like in manner, 
over leaves, preying on aphids and scale-insects. Some live as guests in ants’ 
nests, and others in the underground nests of bumble-bees. 

Those Syrphid larve most often written about are the curious “‘rat-tailed 
maggots” (Fig. 480), larvee which live in stagnant water or slime and have 
the posterior extremity of the body greatly elongate and projecting to serve 
as a breathing-tube. There is a spiracle (breathing-pore) at the tip of this 
‘‘tail,” and the tail projects upward so that its tip reaches the air, while the 
rest of the larva’s body remains underneath the water. The larvae of Micro- 


340 The Two-winged Flies 


don, which live in ants’ nests, look like little mollusks, and when first found 
were actually described as new molluscous genera. Their body is flat, 


Fic. 480. 


Fic. 480.—Rat-tailed larva of a Syrphid. (Twice natural size.) 
Fic. 481.—Larva of Microdon mutabilis, dorsal view. (Four times natural size.) 


broad, unsegmented, and looks like a flat broadly elliptical little shell or 
plant-seed (Fig. 481). 

Among the more common flies of this family which may be taken by the 
collector are various species of Eristalis, with black, yellow, and amber colors, 
heavy-bodied, bee-like forms, and especially E. tenax, the drone-fly, which 
resembles very much a honey-bee drone. _ Its larva is a rat-tailed maggot. 
The species of Syrphus are black with yellow bands, with the abdomen 
not so heavy as in Eristalis. The larvae are predatory, doing great havoc 
in aphid colonies, but being thus of great benefit to florists and gardeners. 


Fic. 482.—Mouth-parts of Eristalis sp. li., labium; hyp., hypopharynx; /b., labrum; 
mx., maxilla; mx.l., maxillary lobe; mx.p., maxillary palpus. 


The species of Volucella are bee-like in appearance and their larve live in 
the nests of bees, but whether as parasites or tolerated guests seems not 
to be yet known. Sharp thinks that they act as scavengers in the nests, 
and thus are helpful rather than harmful to their hosts. Syritta pipiens is 
a common Syrphid fly, with slender, elongate, subcylindrical body, blackish 
with reddish-yellow markings. 


The Two-winged Flies 341 


The abundant house-flies are the most familiar representatives of the 
largest of all the Dipterous families: largest if the great heterogeneous 
group of flies called Muscide is to be looked on as a single family, a point of 
view taken by some entomologists, but not so if this group is called a 
superfamily, composed of a large number, about twenty in all, of distinct 
small families. The group includes, besides the house-flies, the buzzing 
bluebottles, the disgusting flesh-flies and stable-flies, the parasitic Tachina 
flies, the pomace-flies, fruit-flies, grass-stem flies, brackish-water flies, and 
numerous other kinds not familiar enough to have a vernacular name. To 
get acquainted with some of the more abundant and interesting kinds, and 
to enable us to classify them to subfamilies (if the whole group is called 
family), we may scrutinize any fly which our key on page 332 leads us to 
call a Muscid, in the light of the following key- 

(The first posterior cell is the space between the little cross-vein in the middle of 
the wing and the outer margin of the wing. See in Fig. 490.) 


MNES Seeills oo é0ongagasaoodsGbo00 - suaponddC nop oaonceaae!: ACALYPTRATE MUSCID, 
JNWIGIS. JETS. oo bb oossconcmosnosopESbsdonsooonadejadec -CALYPTRATE MuScID#. 
Binstposterior celliwidel ys Opener a-jeferebaleieteid tert rareraernereiare Subfamily ANTHOMYIIN®. 
First posterior cell narrowly open or closed (Fig. 490). 
Antennalibristleswhollysbaxre rs -tereteleetelsirceeiemieiiaeiet tetas Subfamily TACHININ2. 
Antennal bristle with some distinct hairs. 
Antennal) bristle bare neat theltipssr) srr ele))<)s/<11-)2)-1- Subfamily SARCOPHAGINE. 
Antennai bristle plumose or pubescent to the tip. 
Back of abdomen bristly, legs unusually long.............. Subfamily DEXIIN2. 


Back of abdomen not bristly, except sometimes somewhat so near tip. 
Subfamily Muscine&. 


The Acalyptrate Muscide include a host of small, mostly unfamiliar, 
flies, distributed among a score of subfamilies. We shall refer to a few 


Fic. 483. Fic. 484 
Fic. 483.—House-fly, Musca domestica. (After Howard and Marlatt; three times 
natural size.) 


Fic. 484.—Foot of house-fly, showing claws, pulvilli, and clinging hairs. (Greatly 
magnifieds) : c 


of the more interesting kinds in the group after taking up briefly the five 
subfamilies of larger, more noticeable Calyptrate Muscids. 


342 The Two-winged Flies 


Most abundant, most wide-spread, and most important to us of all the 
Muscid flies are the common house-flies. They belong with some other 
similar forms to the subfamily Muscine. A number of species may be 
found in houses, but the true house-fly, Musca domestica (Fig. 483), is by 
far the most numerous. Dr. Howard, government entomologist, who has 
paid special attention to the life of house-flies and mosquitoes, because of 
their dangerous disease-germ carrying habits, says that house-flies undoubtedly 
contribute materially in the dissemination of infectious diseases by carrying 
germs in the dirt and filth on their feet, collected during their pilgrimages 
to the contents of cuspidors, slop-pails, and closets. He advocates a definite 
crusade against the house-fly like the one now being undertaken in this 
country against the mosquito. 


Fic. 486. 


Fic. 485.—Larva of house-fly, Musca domestica. (After Howard and Marlatt; three 
times natural size.) 

Fic. 486.—Pupa, in puparium, of house-fly, Musca domestica. (After Howard and 
Marlatt; three times natural size.) 


The eggs of the house-fly are laid in horse-manure, occasionally in other 
excrementitious or decaying matter. Each female lays about one hundred eggs. 
These eggs hatch in six or seven hours, and the slender pointed white larve 
called maggots (Fig. 485) lie in their plentiful food-supply for the five or six days 
necessary for their full growth. They pupate within the last larval skin, which 
thickens and turns brown at the time of pupation 
(Fig. 486). The pupal stage lasts five days, and 
then the fly issues. Its food is liquid and taken 
up by lapping. The ‘‘house-fly” that bites is 
not the true house-fly, but usually the fiercely 
piercing stable-fly, Stomoxys calcitrans, another 
member of the subfamily, which looks much like 
Musca and which is a not infrequent visitor in 
the house. 

Fic. 487.—A stable-fly, Sto- This stable-fly and another ally of the house- 
moxys calcitrans. (Three fly, called the horn-fly, are great pests of stock. 
Ames natural size.) The horn-fly, Hematobia serrata (Fig. 488), which 

gets its popular name from the habit of clustering, when not feeding, on the 

bases of the horns of cattle, is a European insect that was accidentally brought 

to this country in 1886 or 1887. 

It quickly established itself, and in two years had spread over the eastern 


The Two-winged Flies 343 


states so widely as o cause much alarm. By 1895 it had spread over all 
of the United States east of the Rocky Mountains. The flies pierce the 
skin and suck the blood, thus causing such an irritation and loss of blood 
that the affected animals cease feeding and soon show great loss in milk or 
weight. The eggs are laid in fresh cow-manure, and the larva become full- 
grown and pupate in less than a week. The pupal stage lasts from five 
to ten days. Probably half a dozen generations appear annually. Infested 


Fic. 488.—The horn-fly, Hematobia serrata. (After Lugger; natural size indicated 
by line.) 


cattle may be smeared with a mixture of ‘resh oil and tar, equal parts, which 
repels the flies, and lime, which kills the larvae, may be thrown on the manure. 
The stable-fly, like the house-fly, lays its eggs in horse-manure, and Dr. 
Howard foresees a curious benefit to result from the gradual increase in the 
use of automobiles in cities, and the corresponding decrease in number of 
horses maintained, in the gradual doing away with the breeding-places of 
house-flies and stable-flies. 

Next to house-flies the commonest ones about houses and outbuildings 
are the bluebottles and blow-flies or flesh-flies. These all lay their eggs 
or deposit living larve on meat, and, with some other allied species which, 
however, do not all restrict their egg-laying to animal substances, belong 
to the subfamily Sarcophagin, so named from the flesh-eating habits of the 
larve or maggots of the best-known species The most abundant flesh- 
fly in this country is named Sarcophaga sarraceni@ (Fig. 489), and looks hke 
an extra-large house-fly. It gives birth to larve (hatched from eggs retained 
in the body of the female) which are deposited on fresh meat, sometimes in 
open wounds. The larve (maggots) feed and grow rapidly, attaining their 
full size in three or four days. They pupate within the thickened brown last 


344 The Two-winged Flies 


larval skin, and issue as adults in ten or twelve days after birth. The blow- 
flies and bluebottles, members of this subfamily, have the body steely blue or 
greenish and are great buzzers. The blow-fly, Calliphora erythrocethala, 
has the thorax black and abdomen steely blue. Its eggs are laid on exposed 
meat, fresh or decaying, such egg-infested meat being called ‘“‘blown.” The 


Fic. 489.—A blow-fly or flesh-fly, Sarcophaga sarracenie. (After Lugger; natural size 
indicated by line.) 


larvee feed on the juices of the decaying meat and pupate after a few days. 
The pup enclosed in the thickened brown last larval skin look like 
large smooth shiny brown elliptical seeds, as do indeed the pupe of all 
Calyptrate Muscidae. The commonest bluebottle- or greenbottle-fly is Lucilia 
cesar, which lays its eggs in 
cow-dung as well as on flesh, 
and which often comes into 
houses, particularly before rain. 
A flesh-fly of serious importance 
is the terrible screw-worm fly, 
Compsomyia macellaria, which 


Fic. 490.—Diagram_ of wing of Lucilia cesar, jays its eggs on flesh, manure, in 
showing venation. z es - 


open wounds, and often in the 
nasal passages of domestic animals and human beings, entering the nose for 
this purpose while the unfortunate person or animal is asleep. Numerous 
frightful cases of such attacks on persons are recorded, especially from the 
southern states. The larva fairly eat away the whole inner nose and upper 


The Two-winged Flies 345 


pharynx, causing terrible pain and sometimes death. Indeed, out of twelve 
cases which came to the knowledge of Dr. Richardson, an Iowa physician, 
eleven resulted fatally. As many as three hundred screw-worms were taken 
from the inner nose and region above and behind the soft palate of some 
of the patients. Asa pest of domestic animals the greatest injuries have been 
caused in Texas. The eggs are laid in any open wound or in the nose or mouth, 
and the quickly hatching larva burrow into the adjacent tissues. Cattle and 
hogs are particularly attacked, horses and sheep less often. 

In the states in which sugar-beets are grown some anxiety for the success 
of this new industry—new in this country, that is; sugar has long been made 
from beets in Germany—is felt because of the presence in the beet-fields 
of an obscure little fly, Pegomyia vicina, which may be called the sugar-beet 
midge. The eggs are laid on the leaves, and in three or four days the tiny 
white larva hatch and burrow into the soft leaf-tissue. When many of the 
larvee are at work mining the leaves much injury to the plants results. In the 
great sugar-beet fields along the California coast four or five generations 
of this fly appear annually and occasion great loss to the growers. This 
fly belongs to the subfamily Anthomyiine, to which Muscid group two 
other well-known fly-pests belong, namely, the onion-fly, Phorbia ceparum, 
and the cabbage maggot-fly, Phorbia brassice. Both these insects in the 
adult stage are small light-gray flies, looking rather like small house-flies. 
The onion-fly lays its eggs on the stems of onion-plants, near the soil, and 
the hatching larve burrow into the underground bulb, which they soon 
nearly destroy. This fly appears to live on no other plant. The cabbage 
maggot-fly lays its eggs also on the stem just above or even below the ground, 
and the larvae burrow into the roots. Cauliflowers as well as cabbages 
are attacked, and often tens of thousands of acres of these two vegetables 
are destroyed in a single season by this little fly. The best remedy is the 
use of cards cut from tarred paper and bound, collar-like, around the stems 
of the plants. These protecting collars should be put on when the young 
plants are transplanted from the cold frames into the field- Another familiar 
member of this subfamily is the little house-fly, Homalomyia canicularis, 
smaller, paler, and more conical in shape than the true house-fly. 

Every one who has undertaken to rear butterflies and moths from their 
caterpillars has been compelled to make the acquaintance of certain heavy- 
bodied bristly flies which appear now and then from a cocoon or chrysalid 
in place of the expected moth or butterfly. These are Tachina-flies, and in 
their appearance and parasitic habits are representative of the large sub- 
family of house-fly cousins known as Tachiniine. The females fasten their 
eggs to the skin of young caterpillars, the hatching larve burrow into the 
body of their crawling host and feed on its body-tissues | Sometimes the 
caterpillar is killed before it can pupate, but usually not, spinning its cocoon 


346 The Two-winged Flies 


and pupating with its fatal parasites still feeding inside. But the butterfly 
never issues: in its place buzz out several of these bristly Tachina-flies. 
While their habits arouse our indignation at first acquaintance, and par- 
ticularly if we have set our hearts on rearing a rare moth or butterfly, a 
moment's reflection assures us of the immense good these flies must really 
do. Howard tells of an instance observed by him where the buzzing of 
the swarms of Tachina-flies, hovering over and laying their eggs on the 
hosts of a great army of army-worms, could be heard for a long distance. 


FIG. 491. FIG. 492. 


Fic. 491.—A Tachina-fly, Dejeania corpulenta. (One and one-half times'natural size.) 
Fic. 492.—Tachinid parasite (at left) of the California flower-beetle, and parasitic fungus, 
Sporotrichum sp. (at right) of same beetle. (Slightly enlarged.) 


He says that a great outbreak of army-worms in northern Alabama in 1881, 
when all crops were threatened with total destruction, was completely frus- 
trated by Tachina-flies. These parasites also attack locusts, leaf-eating 
beetles, and many other injurious insects besides caterpillars, and altogether 
do much to keep in check some of our worst insect-pests. A single species 
of Tachina-fly (Fig. 492) is almost the only check on the destructive flower- 
eating Diabrotica (D. soror) of California, which, if allowed to increase 
unhindered, would soon destroy every blossom in this land of flowers. 

Resembling somewhat in appearance the Tachina-flies are the so-called 
nimble-flies, constituting the small subfamily Dexiine. Most of the species 
in this country belong to the single genus Dexia and have been little studied. 
The larve seem to be all parasitic, although the life-history of no species has 
been wholly worked through yet. Beetles and snails seem to be the favorite 
hosts of these flies. 

In the large group of flies, some dingy and obscure in coloration, others 
brightly colored and with beautifully patterned wings, but all small and 
most unfamiliar, called the Acalyptrate Muscide (that is, the house-fly 
allies with small alulets), we shall not attempt to distinguish the vari- 
ous subfamilies as we have for the Calyptrate Muscids.  Dipterologists 


The Two-winged Flies ©! 947 


recognize some twenty distinct subfamilies (or families, if the group 
Muscide be looked on as a super-family) of these small flies, but the distinc- 
tions are quite too fine for the general collector to handle. I shall therefore 
simply refer briefly to a few of the more interesting or abundant or economi- 
cally important species in this group. 


Fic. 493.—Red-tailed Tachina-fly, Winthemia 4-pustuluta, a parasite of the army-worm, 
Leucania unipuncta. a, fly, natural size; 0b, fly, enlarged; c, army-worm, natural 
size, upon which eggs have been laid; d, parasitized army-worms, enlarged. (After 
Slingerland.) 


Of interest because of the extraordinary condition of their eyes are the 
blackish flies called Diopside, which have the eyes on conspicuous elon- 
gate lateral processes of the head. These eye-stalks bear also the antenna. 
Only a single species, Sphyracephala brevicornis, has been found in this 
country, and regarding its life-history nothing is known. The flies are to be 
looked for in woodsy places, and particularly on the leaves of skunk-cabbage. 

In the water and cast up in masses along the shores of Mono Lake and 
certain other similar brackish-water lakes in the desert land just east of 
the Sierra Nevada Mountains in California may be found, at certain seasons 
of the year, innumerable larve of a small predaceous fly of the genus Ephydra. 
These dead-sea waters support hardly any other animal life, but this fly 
finds the water much to its liking and breeds there with extraordinary fecun- 
dity. The Pai Ute Indians of this region, who, like the flies, have a ques- 
tionable palate, gather these larvae by the bushel, dry them in the sun, and 
use them for food under the name koo-chah-bee. Prof. Brewer of Yale, 
who made a ‘trial of koo-chah-bee, says “it does not taste badly, and if one 


348 The Two-winged Flies 


were ignorant of its origin it would make a nice soup.” Other species of 
Ephydridz occur abundantly in salt-water marshes, the flies living a preda- 


Fic. 494.—Scatophaga sp. (Two and one-half times natural size.) 
Fic. 495.—An aquatic muscid, Tetanocera pictipes, larva, pupa, and adult. (After 
Needham; two and one-half times natural size.) 


tory life and doing much to reduce the numbers of brackish-water mos- 
quitoes and other small insect-pests. 

One of the great packing-houses of Kansas City, Missouri, once called in 
an entomologist to aid it in fighting a little fly which was causing the packers 
a loss of many thousand dollars annually. This was 
the cheese-skipper fly, Piophila casei (Fig. 496), which 
might almost as well be called the ham- and bacon- 
skipper fly, for the eggs are laid quite as willingly 
on any smoked meat as on cheese. In the packing- 
house swarms of the flies were buzzing about at 
the mouth of the great smoke-shaft from which the 
hams and pieces of bacon were being constantly 

taken to be wrapped and made ready for shipping. 
Fic. 496.—The cheese-  ,,, A : 
skipper fly, Piophila These flies would dart down and lay their eggs on the 
casez. (Five times smoked meat while actually in the wrapper’s hands, 
natural size.) and thus thousands of egg-blown hams and bacon 
sides would be wrapped and sent out. When the cook a thousand miles 
away tears the wrappings from a ‘‘piophilized”’ ham he quickly sends in 
an indignant report to his local meat-supplier, who in turn makes a protest 
to the packer. In time the packer calls for help from an entomologist. 
The larve of this fly have the odd habit of bending nearly double and 
then with a quick straightening they throw the body some inches into the 
air. Hence the name skipper, commonly applied to it. 


The Two-winged Flies 349 


At cider-making and fruit-gathering time, and in vine-growing districts 
at wine-making time, hosts of tiny yellowish-bodied flies, the pomace-flies or 


fermenting fruit-flies, Drosophilide, may be seen busily lapping up their 


favorite food, the juices of fermenting fruits. 
The most abundantand wide-spread species 
is Drosophila ampelophila, the vine-loving 
pomace-fly. It is a small, clear-winged, 
red-eyed, brownish-yellow, chubby fly 
which lays its eggs on gathered fruits, 
and especially decaying fruit and pomace, 
and also on grapes still hanging on the 
vines if they have been broken somewhat 
by birds The larve or maggots hatch in 


Fic. 497.—Trypeta longipennis. (Two 
and one-half times natural size.) 


from three to five days, live in the fruit four days, and lie in the pupal 
stage three to five days, so that a whole life-cycle is gone through in less 


Fic. 498 —Larva of cherry-fruit fly, Rhagoletis cingulata, dorsal and lateral views. 
(After Slingerland; natural size and much enlarged.) 


350 The Two-winged Flies 


than two weeks. Thus even in the short season of the fruit ripening and 
gathering much injury can be and often is done by these little tipplers. 

A much larger group of fruit-flies is the Trypetida, whose larve burrow 
in fruits or plant-stems, often producing galls on these latter. The familiar 
spherical swelling or gall on goldenrod stems is the hiding and feeding place 


Fig. 499.—Puparia of cherry-fruit fly, Rhagoletis cingulata. (After Slingerland; natural 
size and much enlarged.) 

of the thick white larve of Trypeta solidaginis, a pretty fly with banded 
wings. The longer hollow gall which sometimes occurs on goldenrod 
is made by the caterpillar of a small moth, Gelechia galle-solidaginis. 
Some Trypetid species do much injury by burrowing into fruit, as the apple- 
maggot, and the larva of a black-and-white fly with 
banded wings known as Trypeta ludens, whose 
larve infests Mexican oranges and may sometime 
get a foothold in California or Florida. 

Another group of small flies whose larve are 
responsible for serious injury to growing grain, 
meadows, and pasture grasses are the Oscinide, 
or grass-stem flies. The adults are commonly taken 


by collectors when beating or sweeping in meadows 
Fic. s500.—An aquatic and pastures. The flies are minute but plump, 
muscid, Sepedon fusci- 
pennis, larva, pupa, and : 5 
adult. (After Needham; Sometimes yellowish. They are so small that they 
two and one-half times often get into one’s eyes in their swarming-time, 
natural size.) e 


and are variously colored, sometimes blackish, 


and are said to cause a prevalent disease of the 
eyes in the South. The thick cylindrical little larve of several species of 
Oscinis live in the stems of wheat, barley, oats, rye, and grass. The larva 
of Chlorops similis burrows in the leaves of sugar-beets, and another 


The Two-winged Flies 25E 


species of the genus is the notorious ‘‘frit-fly,” one of the chief grain- 
pests of Europe. 


SUBORDER PUPIPARA. 


Bird-collectors occasionally find on their specimens curious flat-bodied 
insects with leathery skin and a single pair of wings, which are obviously 
parasites on the body of the birds. Owls and swallows seem especially 
infested. Similar parasitic insects, but wingless, are also found on sheep, and 
a winged form is not uncommon on horses. These degraded insects are 
flies of the suborder Pupipara which are commonly known as bird-ticks, 
sheep- and horse-ticks, etc. The animals more rightly entitled to the name 
“ticks”? are really not true insects, but belong with the scorpions, spiders, 
and mites in the class Arachnida. They have four pairs of legs and are always 
wingless. Such true ticks are the leathery-skinned cattle-ticks, dog-ticks, 
and wood-ticks. 

The degraded Diptera belonging to the suborder Pupipara, and also 
called ticks, have of course three pairs of legs and some are winged. Their 
name Pupipara comes from the curious circumstances of their birth. The 
female does not deposit eggs outside her body, but gives birth to young which 
are just ready to assume the pupal stage at the time of their appearance. 
In the case of one species, the sheep-tick (Melophagus), whose development 
has been carefully studied, the female has four egg-tubes each of which 
produces a single germ-cell at a time. Of these four egg-cells three remain 
small, while one becomes large and develops into an embryo. This embryo 
lies in the unpaired wide vagina of the female, soon casts off its egg-envelopes, 
and is nourished as a growing larva by a secretion from two pairs of glands 
opening into the vagina of the mother. Here the headless, footless larva 

-lies and grows until it is about 4 inch long, when it is born and immediately 
pupates. The development of the other Pupipara, as far as studied, is 
similar to that of the sheep-tick. 

The suborder includes three families, as follows: 


With compound eyes; sometimes with wings. 
(Bird-, sheep-, and horse-ticks.) H1ppoposciD&. 
Without compound eyes, always wingless. 
ialteres; presents) on) batSeii-\-j- che piece iele se clalenetoe et (Bat-ticks.) NycCTERIBIIDE. 
iHalteres absent.) ononey=DeeSe re erste irciet--ieistelelelebsterattel alee) = (Bee-lice.) BRAULIDE. 


Of the Hipposcide the sheep-tick, Melophagus ovinus, already referred 
to, is common and familiarly known. It is wingless, and can crawl readily 
about through the wool next to the skin. With its strong proboscis, com- 
posed of two hard pointed flaps, it punctures the skin and sucks blood from 
its host’s body. The horse-tick, Hippobosca equina (Fig. 501), is winged. 
There are several species of this family found on birds. Olfersia americana 


352 The Two-winged Flies 


is a yellowish winged species common on owls, some hawks, and the ruffed 
grouse. Swallows are often infested, and I have taken bird-ticks from half 
a dozen other kinds of birds. A careful search for these curious insects 
will certainly make known numerous new species. 


Fic. sor.—A horse-tick or forest-fly, Hippobosca equina. (After Lugger; natural 
length 4 to 4 inch.) 

The genus Lipoptena includes a few known species found on mammals 
which are winged for awhile, but later cast or bite off the wings. They 
probably fly about in their search for a host, after finding which they remove 
their wings and remain for the rest of their life on this host individual. Lip- 
optena cervi is a species found on deer. 


FIG. 504. 


Fic. 502. FIG. 503. Fic. 503. Bat-tick, Nycteribia sp. 
FIG. 502.—Sheep-tick, Melophagus ovinus. Nat. size } in. 


Fic. 504.—A bee-louse, Braula sp. (After Sharp; much enlarged.) 


The bat-ticks, Nycteribiide (Fig. 503), are curious long-legged, wingless, 
small spider-like creatures about + inch long or less, which look as if the 


The Two-winged Flies else} 


upper were the under surface. The head is narrow and lies back on the 
dorsum of the thorax, and the prothorax rises from the upper instead of 
anterior aspect of the mesothorax. They are found only on bats and are not 
common. 

The strange minute insect, ;'; inch long, found clinging to the thorax 
of queen and drone honey-bees and known as the ‘‘bee-louse,” Braula 
ceca (Fig. 504), is the only species known of the family Braulide. Its legs 
are rather short and stout, and each ends in a pair of comb-like brushes. 


ORDER SIPHONAPTERA. 


The fleas are blood-sucking parasites of mammals and birds which were 
long classified as a family (Pulicide) of the Diptera, being looked on as 
wingless and otherwise degenerate flies. But they are now given by ento- 
mologists the rank of an order, called Siphonaptera, subdivided into three 
families of its own. Neary one hundred and fifty species of fleas are known 
in the world, of which about fifty are recorded from this country. They have 
been taken from the domestic dog, cat, rat, and fowls, and from various wild 
animals, such as several rabbit and squirrel species, the lynx, weasel, mole, 
mountain-rat, shrews and mice, prairie-dog, woodchuck, opossum, etc. 
Rothschild has recently described a new flea species from the grizzly bear 
(British Columbia). But from the great majority of our wild mammals fleas 
have not yet been recorded, although undoubtedly most of them are infested. 
Baker, who has recently published a monograph * of the known North 
American species, suggests that particularly interesting forms will probably 
be found on bats. One flea species, Pulex avium, has been taken from several 
kinds of birds, and two or three other fleas are recorded from bird hosts. 

The peculiar structural characteristics of fleas are their winglessness, 
the extraordinary lateral compression of the body, and the curious modifica- 
tion of their mouth-parts for effective piercing and blood-sucking. The an- 
tenne lie in little half-covered grooves, extending down and back behind 
the eyes; they can be lifted or stretched up whenever needed. Each antenna 
is composed of three segments, the terminal one, however, being spirally or 
transversely lined or grooved and variously shaped, so that it appears to be 
composed of several segments. The mouth-parts consist of a pair of needle- 
like mandibles, a pair of slender grooved labial processes, probably the 
palpi, a pair of short, broad, flattened maxilla, each with a short antenna- 
like palpus at its tip, and an unpaired needle-like hypopharynx. The needle- 
like parts serve for piercing and the grooved labial processes for sucking. 
Regularly arranged over the body are (in most fleas) many series of stiff, 
spine-like hairs, often unusually conspicuous and strong on the head and 

* Baker, C.F. A Revision of American Siphonaptera. Proc. U. S. Nat. Mus., vol. 
XXVii, 1904, pp. 365-469. 


354 The Two-winged Flies 


thorax. The head is ridiculously small and malformed, so that a flea under 
the microscope always suggests an idiotic (microcephalous) creature. But 
if its insidious attack and brilliant tactics in retreat be due to wit, this 


Fic. 505.—Dog- and cat-flea, Ctenocephalus canis. (After Lugger; much enlarged.) 


small-headedness is truly deceptive. However, our modern mechanical 
theories of reflex action, negative phototropism (repulsion by light), etc., 


Fic. 506.—The house-flea, Pulex irritans, A, larva; B, pupa; C, adult. 
(After Beneden; much enlarged.) 


allow us to give the elusive flea little credit for its ingenuity; we must look 
on it as an unusually well-made and smoothly-working organic machine. 


The Two-winged Flies 355 


While the adult fleas are commonly seen, particularly in lands of soft 
climate, like Italy and California, in immature form these insects are wholly 
unfamiliar. The larve (Fig. 506) are small, slender, white, footless, worm- 
like grubs, with the body composed of thirteen segments, the first being the 
small brown head bearing short antenne and biting mouth-parts, but no 
eyes. The larvae seem to live on dry vegetable dust, the excreta of adult 
fleas, and other organic detritus. The larval life varies much in duration 
in different species, and even in the same species under varying conditions. 
In our commonest species, the cat- and dog-flea, Pergande has found the 
larval life to last only one or two weeks, the whole development from egg to 
adult being completed sometimes in a fortnight. When full-grown the 
larva spins (usually) a thin silken cocoon in the dust or litter in which it lies, 
within which it pupates. 

The parasitic habits of fleas vary from a very temporary character to one 
approaching permanence. In such forms as the human flea and the dog- 
flea no stage of the immature life is passed on the body of the host (although 
the eggs of the dog-flea are usually laid on the hairs of the host, but so loosely 
attached that they fall off before the larve emerge), but in the burrowing 
kinds like the “‘chigce” or ‘“‘jigger,” where the females become completely 
encysted in the skin of the host, the young hatch in the tumor, and unless 
carried out by pus probably develop there. But taken altogether the fleas 
are to be considered as belonging to the category of ‘‘temporary external 
parasites.” 

The species known in this country represent two families which may be 
separated by the following key: 


Small fleas with proportionally large head; female a stationary parasite with worm- 
like or spherical abdomen, burrowing into flesh of the host; labial palpi 
I-segmented; no “combs”? of spines on head, thorax, or abdomen. 

SARCOPSYLLID&. 

Larger fleas with proportionally small head; adults active temporary parasites, 
with abdomen always compressed; labial palpi 3- to 5-segmented; head, 
thorax, or abdomen often with “combs” of spines. .......-+-++-- PULICID. 


Of the Sarcopsyllide but two genera are known, one, Sarcopsylla, includ- 
ing the common jigger-flea, infesting various mammals and man in the 
tropics and probably occurring in Florida and southern Texas, and Xes- 
topsylla, the common chicken-flea, being distinguished by having the head 
not angularly produced. 

The jigger-flea, or chigee, Sarcopsylla penetrans (not to be confused with 
a minute red mite, common on lawns, which burrows into the skin and is 
also called “‘jigger’’ or ““chigger”’), was described by Linneus in 1767 and 
has been commonly known as a pest of man in tropical and sub-tropical 
countries ever since. It also infests many domestic animals, as the dog, cat, 


356 The Two-winged Flies 


horse, cow, sheep, etc., as well as birds. The male jigger-fleas hop on or 
off the host as other fleas do, but the females, when ready to lay eggs, burrow 
into the skin, especially that of the feet, and produce a swelling and later 
a distinct ulcer, sometimes so serious as to result fatally. The remedy is 
(as also for the chigger-mite) the pricking out entire, with a needle or knife- 
point, of the pest as soon as its presence is detected. The bursting of the 
body of the female in the skin, with the release of its eggs, is likely to result 
seriously. When domestic animals are attacked it is difficult to fight the 
pest. The liberal use of pyrethrum on the rubbish or dust in which the 
young stages are developing is recommended. The hen-flea, Xestopsylla gal- 
linacea, first described from Ceylon, sometimes becomes a serious pest of 
fowls in warm regions. The females of the hen-flea burrow into the skin of 
the fowl and lay their eggs in the small tumor which forms about them. 
This pest has been known in the Southern United States since about 1890 
and is a common pest from Florida to Texas. 

The second family, Pulicide, includes all the other fleas, none of which 
burrows into the skin. The various species range in size from 4's inch (A nomi- 
opsyllus nudatus, found on a mouse in Arizona) to } inch (Ceratophyllus 
stylosus, taken from Haplodon in Oregon), but all fairly similar in shape 
and appearance to the familiar house-fleas. They are grouped in nine 
genera, of which Pulex is much the largest and includes the human flea 
and the cat- and dog-flea, the two species to which the house-infesting pests 
belong. The human flea, Pulex irritans, was described by Linnzus in 
1746. It is known all over the world, and often becomes a serious pest. 
In this country it is probably not so commonly met with in houses as the 
cat- and dog-flea, Ctenocephalus canis, from which it may be readily dis- 
tinguished by its lack of combs of spines on the back of the head and 
prothorax. The eggs of irritans “‘are deposited in out-of-the-way places, 
in the dust or lint under carpets, and the larve are said to feed upon the 
particles of organic matter which may be found in such localities.” Raillet 
states that each female deposits eight to twelve eggs from which larve hatch, 
in summer, in from four to six days, become pupz eleven days later, and 
after about twelve days in this stage become adult. In winter, in warmed 
houses, the whole development takes about six weeks. The cat- and dog- 
flea lays its eggs on or among the hairs of an infested animal, but the 
eggs drop to the floor or ground as the animal moves about, and the larve 
live in the dust, feeding on whatever bits of organic substance they can find 
there. Larve placed on dust with birds’ feathers mixed with dried blood 
developed perfectly. Others put on the sweepings of a room developed 
as well. These fleas are especially abundant and troublesome in houses 
in the East in damp summers. As flea-larvee will not develop successfully 
in places where they are often disturbed, much sweeping and scrubbing 


The Two-winged Flies Bo 


will keep them down. Mats and places where dogs and cats lie down should 
be kept well dusted with pyrethrum. (Buhach is the trade name for this 
insecticide, which is not injurious to man or domestic animals.) Where 
fleas get a foothold in a neglected room or cellar, the remedy used by Profes- 
sor Gage in the basement of one of Cornell University’s buildings might be 
tried; i.e., tying sheets of sticky fly-paper, sticky side out, around the legs 
from foot to knee of the janitor or a cheap boy and having him tramp for 
several hours around in the room! 

Of the various other flea species, the only ones that come into special 
relation with man are the rat-fleas. The proof that rats are active agents 
in the dissemination of the dreadful bubonic plague, and the belief of some 
pathologists that the disease-germs may be transmitted from rats to man 
by the bites or punctures of rat-fleas, gives this insect a special interest like 
that attaching to the malaria- and yellow-fever-dissminating mosquito and 
the germ-carrying house-fly. Baker pertinently calls attention to the fact 
that the rat-fleas of this country are only remotely related to Pulex irritans 
and Ctenocephalus canis, the two species that bite human beings, while the 
fleas that infest rats in the tropics are, on the contrary, very nearly related to 
the man-infesting kinds. The prevalence of the bubonic plague in tropical 
countries and its rarity with us may be connected with this difference in the 
rat-flea kinds. 


CHAPTER: XT, 
THE MOTHS AND BUTTERFLIES (Order Lepidoptera) 


= SSeS OTHS and butterflies are the insects most 

= NF favored of collectors and nature lovers; a 

German amateur would call them the ‘‘ Lieb- 

lings-insekten.” The beautiful color patterns, 
the graceful flight and dainty flower-haunting habits, and the interesting 
metamorphosis in their life-history make them very attractive, while the com- 
parative ease with which the various species may be determined, and the 
large number of popular as well as more technical accounts of their life 
which are accessible for information, render the moths and butterflies most 
available, among all the insects, for systematic collecting and study by 
amateurs. 

Despite the large number of species in the order (6622 are recorded in 
the latest catalogue of the North American forms) and the great variety in 
size and pattern, the order is an unusually homogeneous one, even a begin- 
ning student rarely mistaking a moth for an insect of any other order, or 
classifying a non-lepidopterous insect in this order. A few aberrant species 
are wingless (females only) and a few (certain “‘clear-winged” species) have 
a superficial likeness to wasps and bumblebees, but the general habitus of 
any Lepidopteron, let alone the readily determinable and absolutely diag- 
nostic character of the scale-covering on the wings, usually indicates unmis- 
takably the affinities of any moth or butterfly. 

The diagnostic structural characters are the (already mentioned) pres- 
ence on upper and lower sides of both wings (as well as over the surface of 
the body) of a covering of small symmetrically formed scales, which are 
modified hairs, and to which all of the color and pattern of the insects are 
due. In Chapter XVII will be found a detailed account of these scales, 
explaining their structure, their origin, and how they produce the color pat- 
terns. The wings themselves are almost always present (in two pairs), the 
fore wings larger than the hind wings, and with a characteristic venation, 
in which the modifications, though small, are yet so constant and definite 
that they are used successfully as the principal basis for the classification 
of the order into families. Another characteristic is the highly modified 
and peculiar condition of the mouth-parts. While in some species the mouth- 
parts are rudimentary (atrophied) and evidently not functional, in most 
there is a well-developed slender flexible sucking proboscis (Fig. 509) com- 
358 


PLATE V. 
BUTTERFLIES. 


1= Junonia ccenia. 
2=Iphidicles ajax. 
3=Epargyreus tityrus. 
4=Cyaniris pseudargiolus. 
5=Ancylosypha numitor. 
6= Papilio turnus. 
7=Nathalis iole. 
8=Parnassius smintheus. 
9= Thecla halesus. 
1o=Zerene czesonia. 


CHAPTER XIV 
‘HS AND BUTTERFLIES (Onder Lei lop era) ) 


: =, fr ae 3) OTHS and butterflies. are- he” insects ost 
<t Pt favored of collectors ae nature jovers; a 
ah aa |. German afuateur would call them the-“Lieb- 
— — —t«és npr nteen.?? = “Thhe beautiful color patterns, : 
} dainty fldwer-hausting habits, and the in cresting 
timc »sis in thelr life-history make them ¥ very attractive, while the coms _ 
parative oo ith FATALF ious species may be determined, and ‘ 
lari be is well.as more. technwat gecemts of their life 
7 ; 9 aa. ‘TUM, render the mothe And Be tierfiles most 
vailable, among for systematic collecting. ‘aad nia A by 
mean -tins99 sinoau| =1 i 
larg ntl, slibidgl =e | in the order (Sb are recorded in 
mui “mri eusrysgdi=gics: 1 forms) and the great variety in 
“2ulofarabysed eitingyDegilly homogeneous ene, even a begin- 
ele decie dese an insect of any other order, or 
a} eyed oiligegT=9 (hs order. A few aberrant species 
, onidlobaiiadiaMey eran “clear winged” species) | have 
| etodainne anizesnie tg bicbees, but the @eneral habitus of 
ic) eweshert tod Tg) eternal s = absolutely diag- 
hesinodersasisNegp te ings, usually indicates. unmis~ 
e af s of any motk or butterfly. f 
tructural characters are the {already mentioned) pre = 
1 lowe des of both wings (as Well ne Over the surtace of 
re in f small symn ically fy d scales, which are 
Oo ich all of the color as witern of ig! insects aire. 
XVII will be found a detailed ac it of these scales, 
ture, t ori d hov duce the color ‘pat 
almost alway nt (in two pairs), the 
| wings d with Tih ncteristic eokaee 
the 1 tion ough smal ; t a constant and definite. 
th al cuceesstulls thre + leisic for the classification: = 
ve istic is the highly imocdified 
hep While in some species the mouth- 
dye vidently not functional, in most 


2 See Sas 7 
1g proboscis (Fig 09) com- 
ri 


PLATE V 


Mary Wellman, dei. 


The Moths and Butterflies 359 


posed of the two greatly elongate maxilla, so apposed that a groove on the 
inner face of one fits against a similar groove on the inner face of the other, 
the two thus forming a perfect tube (Fig. 510). This sucking proboscis, when 
extended, may protrude five or six 
inches, as in some of the sphinx- 
moths, or only a fraction of an inch, 
as in the small moth ‘“‘millers,’’ but 
when not in use it is so compactly 
coiled up, watchspring-like, under 
the head, and so concealed by a 
pair of hairy little tippets (the labial 
palpi) which project up on each 
side of it that it is nearly invisible. 
Of the other mouth-parts, the 
upper lip (labrum) and under lip 
(labium) are greatly reduced and 


N 


are not movable and flap-like as in 


_- 


most insects, while the mandibles 


o ees Se Vy 


are either wholly wanting or, as in 
the sphinx-moths and some others, 
represented only by small immov- 
able functionless rudiments. The 
palpi of the maxilla are also either 
wholly wanting or present as mere 
rudiments. The foregoing descrip- 
tion of the mouth-part conditions 
is true for the great majority of 
Lepidoptera, but among the lowest 
(oldest or most generalized) moths 
some interesting examples of much 
less specialized conditions occur. 


Indeed in one family of minute 


moths, the Eriocephalide, all the F!S- 5°7-—A trio of apple tent -caterpillars, 

XS 5 z larve of the moth Clisiocampa americana. 
usual parts of a typical insect These caterpillars make the large unsightly 
mouth are present and in a condi- Webs or tents in apple-trees, a colony of 


: difor ibis aie = the caterpillars living in each tent. (Photo- 
tion fitted for biting and chewing graph from life by Slingerland; natural size.) 
and in all ways wholly comparable 

with the condition in such biting insects as the locusts and beetles; the 
mandibles are movable and truly jaw-like, the maxilla short and also 
jaw-like and provided with several-segmented palpi, while both labrum 
and labium are truly lip- or flap-like and fully movable, the labium 


bearing 3-segmented palpi. Between this most generalized condition 


360 The Moths and Butterflies 


and the extreme specialization of the butterfly’s mouth an interesting and 


illuminating gradatory series is dis- 
coverable by examining moths of suc- 
cessively more specialized character. 

The development of moths and 
butterflies shows the usual character- 
istics of devel- 
opment with 
complete meta- 
morphosis, the 
larval or cater- 
pillar stage be- 
ing quite dis- 
similar from 
the pupal or 
chrysalid stage, 
and that in 
turn from the 


and butterflies. 


Fic. 509.—Sucking-proboscis of a sphinx- 
moth; at left the proboscis is shown 
coiled up on the under side of the head, 
the normal position when not in use. 
(Small figure, natural size; large figure, 
one-half natural size.) 


ch ahatae Sua 


Fic. 508.—Bit of wing of monarch but- 
terfly, Anosia plexippus, showing scales; 
some scales removed to show the inser- 
tion-pits and their regular arrangement. 
(Greatly magnified.) 


adult or imaginal stage. The immature stages of 
Lepidoptera are more familiar than those of any other 
order; we have all seen, and recognized for what they 
are, the caterpillars and chrysalids of various moths 


The great silken cocoons found on 


orchard-trees in winter-time are known to contain 


the pupe of giant moths, as the 
Cecropia, the Polyphemus, and others, 
while the soft-bodied green tomato- 
worms are as well known to be the 
young (larve) of the hawk-moths. 
As a matter of fact the young stages 
of no other of the insects with com- 
plete metamorphosis are so nearly 
unmistakably characterized by their 
common possession of certain well- 
defined features. The larve or cater- 
pillars, for example, with very few 
exceptions, possess, in addition to 
three pairs of jointed legs on the first 
three segments behind the head, 
from three to five pairs of short 
fleshy unjointed legs or feet called 
prop-legs, on certain abdominal seg- 


The Moths and Butterflies 361 


ments; one of these pairs is on the last segment and four, which is the num- 
ber present in all except the inchworms or loopers (larve of the Geometrid 
moths), are on the sixth, seventh, eighth, and ninth segments behind the 
head. The inchworms have prop-legs only (with a few exceptions) on the 
ninth and last segments. ‘These 
prop-legs, together with the striped 
or hairy body-surface, make a 
moth or butterfly larva almost as 
readily recognizable for what it is 
as the scale-covered wings make 


FIG. 510. Fic. 511. Fic. 512. 

Fic. 510.—Cross-section of sucking-proboscis of milkweed-butterfly, Anosia plexippus; 
see tubular cavity, c., formed by apposition of the two maxille. ¢tr., trachea; 7., nerve; 
m., muscles. (After Burgess; greatly magnified.) 

Fic. 511.—Bit of maxillary proboscis of milkweed-butterfly, Anosia plexippus, showing 
arrangement of muscles in the interior; these muscles serve to coil up or to extend 
the proboscis; see groove on inner face of maxilla. m., muscles; ¢tr., trachea; 
N., N€rve;, c., groove. 

Fic. 512.—Diagram of arrangement of pharynx, cesophagus, etc., in interior of head 
of monarch butterfly, Anosia plexippus, showing means of producing suction in 
the proboscis. oe., esophagus; dm., dorsal muscle; /.m., frontal muscle; c/., clypeus; 
hyp., hypopharynx; s.d., salivary duct; ep., epipharynx; mx., maxilla. 

the adult moth or butterfly distinguishable from any other kind of insect. 

The chrysalids with their hard shell, but with the folded antenne, legs, and 

wings of the enclosed developing adult always indicated, are also hardly to 

be mistaken for the pupz of any other orders, while even the eggs, when ex- 
amined under a magnifier, mostly reveal their lepidopterous parentage by 
the beautiful fine sculpturing of the shell (Fig. 67). As will be noted 
from a perusal of the accounts of the life-history of various familiar and 
representative moths and butterflies given in the following pages, there is 
much variety in the means shown of protecting the defenceless pupe; some 
are subterranean, the leaf-feeding larve crawling down from tree-top or 
weed-stem and burrowing into the ground before pupation; others are 
enclosed in a tough silken cocoon spun by the larva before making its 
last moult; while those which are not protected in one or the other of these 
ways either lie in concealed spots under stones or in cracks of the bark, 
etc., or are so colored and patterned that they blend indistinguishably with 
the object against which they are suspended. The larve have also their 


362 The Moths and Butterflies 


various means of defence; the hairy ones are an uncomfortable mouthful 
for a bird, the naked and brightly marked ones usually contain an acrid 
and distasteful body fluid, while still others find protection in a color pattern 
harmonizing with their habitual environment. 

The food-habits of the larvee make of many of them serious pests of 
our growing crops. Most are leaf-eaters and all are voracious feeders, so 
that an abundance of cutworms or army-worms or maple-worms or tomato- 
worms always means hard times for their favorite food-plants, which are 
too often growing grain and 
vegetables, and leafing or- 
chard and foliage _ trees. 
Others attack fruits, as that 
dire apple pest, the codlin- 
moth larva; while still others 


a) phe 
Fic. 513. 


Fic. 513.—Front of head, with scales removed, of sphinx-moth, showing frontal sclerites 
and mouth-parts. ep.,epicranium; sw., suture; cl., clypeus; ge., gena or cheek; //., 
pilifer of labrum; md., mandible. Between the two pilifers the base of the sucking- 
proboscis composed of the apposed maxillz is seen. (Much enlarged.) 

Fic. 514.—Diagram showing mouth-parts of Lepidoptera. Figure in upper left-hand 
corner, head, with scales removed, of Catocala sp.: cl., clypeus; ge., gena or cheek; 
mx.p., maxillary palpus; p/., pilifer of labrum. In upper right-hand corner, ventral 
aspect of head of Catocala sp.: mx.p., maxillary palpus; ge., gena or cheek; mx.b., 
base of maxilla; gu., gula; /m., labium; /p., basal segment of labial palpus. In 
lower left-hand corner, frontal aspect of head, with scales removed, of sphinx- 
moth, Protoparce carolina: ep., epicranium; cl., clypeus; /b., labrum; }., pilifer 
of labrum; md., mandible; ge., gena or cheek. In lower right-hand corner, front 
of head, with scales removed, of monarch butterfly, Anosia plexippus /b., labrum; 
g.. gena or cheek; /., pilifer of labrum. (Much enlarged.) 


are content with dry organic substances, as the larve of clothes-moths, meal- 
moths, and the like. For all of this kind of feeding very different mouth- 
parts are needed from the delicate sucking-proboscis characteristic of the 
adults, and the lepidopterous larve are all provided with well-formed jaw-like 
mandibles and other parts going to make up a biting mouth structure. The 
larval eyes are simple ones, not compound as in the adults; the antenne 
are short and inconspicuous, not large and feathered as in the moths, or 
long and thread-like, with knobbed tip, as in the butterflies. Altogether the 


The Moths and Butterflies 363 


lepidopterous larva is a well-contrived animal for its especial kind of life, 
which is as different as may be, almost, from that which it will lead after 
it has completed its metamorphosis. Always when one reads or hears of 
injurious moths or butterflies it should be kept clearly in mind that the 
injuries, to crops or fruit or woolen clothing or what not, are caused by the 
moth or butterfly in its larval 
stage and never by the flut- 
tering nectar-sipping adult. 

The sole compensation, 
other than the rather imma- 
terial though perhaps not 
less real one afforded us 
through our esthetic ap- 
preciation of the beauty 
and attractive, apparently 
care-free, flitting about of 


Fic. 515.—Front of head of larva of tussock-moth, Hemerocampa leucostigma. ant., antenna; 
md., mandible; mx., maxilla; mx.p., maxillary palpus; /i., labium. (Much enlarged.) 

Fic. 516.—Front of head of old larva of tussock-moth, Notolophus leucostigma, with 
head-wall dissected away on right-hand side to show forming adult mouth-parts 
underneath. J/.ant., larval antenna; amt., adult antenna; /.md, larval mandible; 
l.mx., larval maxilla; imx., adult maxilla; /b., larval labrum; /./i., larval labium. 
(Much enlarged.) 

Fic. 517.—Developing adult head dissected out from head of larva of tussock-moth, 
Notolophus leucostigma. ant., antenna; mx., maxilla; /i.p., labial palpus. (Much 
enlarged.) 

Fic. 518.—Head of tussock-moth, Notolophus leucostigma; showing adult antenne and 
mouth-parts. mx., maxilla; Ji.p., labial palpus. Note that the two maxille are 
not locked together to form a sucking-proboscis, the mouth-parts of this moth being 
rudimentary and not capable of taking food. (Much enlarged.) 


the butterfly, which the Lepidoptera make for their often disastrous toll on 
our green things, is the prodigal gift of silk made by the moth species known 
as the mulberry or Chinese silkworm. Thoroughly domesticated (the wild 
silkworm species is now not even known), this industrious spinner produces 
each year over one hundred million of dollars’ worth of fine silken thread 


364 The Moths and Butterflies 


ready for the loom. In Italy and Japan nearly every country household has 
its silk-rooms in which thousands of the white “worms” are carefully fed and 
tended by the women and children, and from which comes enough raw silk 
to furnish a good share of the annual income of each of these households. 
The reader who would undertake the collecting of moths and butterflies, 
or the rearing of caterpillars in home ‘‘crawleries,” is referred for some 
specific directions for this work to the appendix of this book, p. 635 et seq. 
The order Lepidoptera may be most conveniently divided into two prin- 
cipal subgroups (suborders they are often called), namely, the Heterocera, 


Fic. 519.—Larva of obsolete-banded strawberry leaf-roller, Cacoecia obsoletana. (Photo- 
graph from life by Slingerland; natural size in lower corner and twice natural size 
above.) 

or moths, and the Rhopalocera, or butterflies. All butterflies have antenne 

which are slender (filiform) for most of their length, but have the tip expanded 

or thickened, forming an elongate spindle-shaped dilation or “club”; the 
moths have their antenne variously formed, as wholly filiform, pectinate, 


The Moths and Butterflies * 365 


Fic. 520.—Pupa of obsolete-banded strawberry leaf-roller, Cacoecia obsoletana. (Photo- 
graph from life by Slingerland; natural size a little more than one-half inch.) 


Fic. 521.—Moths of the obsolete-banded strawberry leaf-roller, Cacoecia obsoletana, 
male above, female below. (Photograph from life by Slingerland; natural size.) 


The Moths and Butterflies 


2.—Larva of the royal walnut-moth, Citheronia regalis. (Photograph from life by Sachse; natural size.) 


The Moths and Butterflies 367 


etc., but never showing the characteristic swollen-tipped or clubbed con- 
dition of the butterflies. The moths, too, are mostly night or twilight flyers, 
while the butterflies go abroad in sunlight only. Scientific students of Lepi- 
doptera do not give the butterflies a classific value equivalent to that of the 
moths taken altogether, but rather rank them as a group more nearly equiva- 
lent to a single superfamily of moths, as, for example, the superfamily Satur- 
niina, which includes all our great silkworm-moths, Cecropia, Luna, Prome- 
thea, Polyphemus, etc., etc. However, the more familiar and readily made 
subdivision of the order into moths and butterflies is more convenient and 


Fic. 523.—Moth and cocoon cut open to show pupa of Samia cecropia. (After Lugger; 


slightly reduced.) 


quite as informing for our purpose, so we shall adopt it, taking up the moths 
first, as including the more generalized members of the order. There are many 
more moth than butterflyfamilies the numbers represented in this country being 
44 to 5. Byreferenceto the following key adapted from Comstock almost any 
North American moth can be traced to its proper family. 


KEY TO THE SUPERFAMILIES AND FAMILIES OF MOTHS. 


This key does not inc lude a few of the smaller families whose members are very few 


and are rarely taken by collectors. Some of these moths are, however, referred to in 


368 The Moths and Butterflies 


the systematic account of the families which follows later. To use the key requires 
an acquaintanceship with the plan of venation in the wings and the nomenclature of 
the veins. This may be got from an inspection of Fig. 525, and by referring to the 
various other figures illustrating the typical venation for the various important families. 
To see clearly the veins, a necessary prerequisite to using the key, a few drops of ether 
should be put on the outstretched wing of a spread specimen and this held so that bight 
light, as from a window or lamp, may pass through the wing to the eye. For a few 
moments (until the evaporation of the ether) the covering-scales will be transparent 
and the number and course of the veins plainly visible. The ether will not injure the 
specimen at all. If duplicate specimens are available, the fore and hind wings of one 
side may be removed and placed in a watch-glass or small saucer containing Eau de 
Labarraque (to be obtained of a druggist), when the scales will be bleached perfectly 
transparent. The wings may be then washed and mounted on glass slides with glycerine 
jelly and thus be made available for inspection at any time. 


A. Moths which have a thin lobe-like process (jugum) projecting backward from the 
base of the fore wing, which holds fore and hind wings together when they are 
outstretched; veins similar in number and arrangement in both wings (Fig. 526). 

(The Jugate.) 

B. Very small moths, not more than one-fifth inch long. 
MicroPpreryGIp# and ERIOCEPHALID#. 
BB. Moths from one-half to one inch long.......... (The Swifts.) HErpIALIp2. 

AA. Moths whose wings are not united by a jugum but by a frenulum (Fig. 533), and 

in which the veins in the hind wing are less in number than in the fore wing. 
(The Frenate.) 
B. Hind wings with fringe on hinder margin as long as the width of the wing; 
hind wings often lanceolate in shape.........Superfamily T1NEINA (part). 
BB. Hind wings with narrow or no fringe, and not lanceolate in shape. 
C. Wings fissured, i.e., divided longitudinally into several narrow parts. 
(Plume-moths.) PrreRopHORID# and ORNEODID=. 
CC. Wings not fissured. 
1 D. Fore wings very narrow; part of the hind wings always, and of 
the fore wings often, clear, i.e., without scaies. 
(Clear-winged moths.) SESIID. 
DD. Wings all covered with scales or, if partly clear, the fore wings broad. 
E. Hind wings with three anal veins. 
F. Subcosta and radius of hind wings close together or fused 
beyond the discal cell (Fig. 533). 
Superfamily PyRALIDINA. 
FF. Subcosta and radius of hind wings widely apart beyond 
the discal cell. 
G. Small; palpi usually prominently projecting; fringe on 
inner angle of hind wings longer than on rest of margin. 
H. Second anal vein of hind wings forked at the 


base (Fig. 539).....Superfamily TORTRICINA. 
HH. Second anal vein of hind wings not forked 
at base.........Superfamily TrverNa (part). 


GG. Medium or large; palpi not conspicuously project- 
ing beyond the head and fringe on inner angle of 
hind wings only slightly or not at all longer than 
on rest of margin. 


The Moths and Butterflies 369 


H.  Subcosta and radius of hind wings fused nearly 
to end of the discal cell (Fig. 553). 
I. Small black moths. 
(Smoky-moths.) PyRoMORPHID# (part). 
II. With long, curling, light-colored or brown 
woolly hairs 
(Flannel-moths.) MErGALOPYGID®. 
HH. Subcosta and radius of hind wings distinct 
or only slightly fused. 
I. Anal veins of fore wings anastomosing so 
as to appear as a branched vein (Fig. 552). 
(Bag-worm moths.) PsycHIp#&. 
II. Anal veins not anastomosing. 
J. Vein m, of fore wings arising from the 
discal cell nearly midway between 
veins m, and m, (Fig. 603). 
(Silkworm-moths.) BomBycip&. 
JJ. Vein m, of fore wings rising from discal 
cell nearer to cubitus than to radius, 
so that cubitus appears four-branched 
(Fig. 548). 
(Carpenter-moths.) Cossrp&. 


EE. Hind wings with less than three anal veins. 


EB: 


iN 


Fore wings with two distinct anal veins or with these two 

veins partly fused so as to appear like a single branched vein. 
G. The two anal veins distinct (Fig. 553). 

PyYROMORPHID (part). 

GG. The two anal veins partly fused and appearing like 

a single branched vein (Fig. 552). PSycCHID# (part). 

Fore wings with but one complete anal vein (rudiments of 


_one or two others sometimes present). 


G.  Frenulum present. 

H. Hind wings with subcosta and _ radius 
apparently distinct, but connected by a strong 
oblique cross-vein; moths mostly with narrow, 
long, strong front wings and small hind wings. 

(Sphinx- or hawk-moths.) SPHINGID®. 

HH. Hind wings with subcosta and radius either 
distinct or fused, but not connected by an 
oblique cross-vein. 

I. Vein m, of fore wings closer to radius than 
cubitus, cubitus being apparently three- 
branched. 

J. Subcosta of hind wings extending 
from base to apex of wing in a regular 
curve (Fig. 560); moths with heavy 
abdomen and rather narrow strong 
fore wings. 

(The prominents.) NoToponT1D&. 

JJ. Subcosta of hind wings with its basal 
part making a prominent bend into the 


370 The Moths and Butterflies 


humeral angle of the wing (Fig. 567); 

moths mostly with slender abdomen 

and rather broad delicate fore wings. 
Superfamily GEOMETRINA. 
II. Vein m, of fore wings more closely joined 
to cubitus than to radius, so that cubitus 

is apparently four-branched. 

J. Subcosta of hind wings distinct from 
radius, or the two fused for a very 
short distance near the base of the 
wing (Fig. 584). 

K.  Day-flying moths that are black 
with large white or yellow patches 
on the wings, or with white front 
wings margined with brown, and 
having the hind wings pale yellow. 

(Wood-nymph moths.) AGARIsTIDA and PERICOPID#. 

KK. Not such moths. 

L. Ocelli absent; antenne pec- 
tinate. 

(Tussock-moths.) LyMANTRIIDA, 
LL. Ocelli present or, if absent, 
with simple antennz. 

(Owlet-moths.) Nocrurp2. 

JJ. Subcosta of the hind wings fused with 
radius for one-fifth or more of the 
length of the discal cell. 

K.  Subcosta and radius of hind wings 
fused entirely or with only the tips 
separate (Fig. 591)... ZyYG#NIDZ 

KK. Subcosta and radius of hind wings 
united for about one-half their 
length, or more, but usually 
separating before the apex of the 
discal cel! (Fig. 597). 

L. Ocelli present. 
(Tiger-moths.) ARcTIIDz, 

LL. Ocelli absent. 
(Footman-moths.) LirHosimpD&. 
GG, Frenulum absent; the humeral angle of the hind 
wings largely expanded and serving as a substitute 

for the frenulum (Fig. 600). 
H. Cubitus of both wings apparently four-branched 
(Fig. 600). (Tent-caterpillar moths et al.) 

LASICOCAMPID&, 
HH. Cubitus of both wings apparently three- 
branched; robust moths with broad wings (Fig. 
603). (Giant silkworm-moths.) SATURNIINA, 


The jugate moths include but two families, the Micropterygide and 
Hepialidz, both represented by but few species and these rarely met with 


The Moths and Butterflies a7 


by collectors and nature students. But these moths are of particular impor- 
tance and interest to entomologists because they are undoubtedly the oldest 
or most generalized of living Lepidoptera; they represent most nearly, among 
present-day existing moths, the ancestral moth type. This is shown most 
conspicuously by the similarity in size, shape, and venation of the fore and 
hind wings, for the primitive winged insects had their two pairs of wings 
equal, while nowadays the various orders show a marked tendency to 
throw the flight function on one pair, either the fore wings, as among the 
flies (Diptera), wasps, bees, etc. (Hymenoptera), and Lepidoptera, or the 
hind wings, as with the locusts, crickets, etc. (Orthoptera), and beetles (Cole- 
optera), the other pair becoming much 
reduced in size, or even, as in the 
Diptera, wholly lost. Quite as impor- 
tant, if not more, although not so con- 
spicuous, as an evidence of the ancient 
character of the jugate moths, is the 
condition of the mouth-parts, certain 
species in the group having true biting 
mouth-parts, with well developed man- 
dibles, short lobe-like maxillz, and short, 
truly liplike labium. All other moths 
and butterflies have the mouth-parts 
specialized for sucking, with the man- 
dibles rudimentary or wanting, the max- 
ill produced and apposed to form the 
long flexible sucking-tube, and the under 
lip (labium) reduced to a mere immovable 
functionless sclerite. The presence of 
the jugum for tying the fore and hind 
wings together, as in the caddis-flies, Fic. 524.—Diagram showing venation 
undoubtedly nearly allied to the moth 0 wings in monarch butterfly, Anosia 
ji <— plexippus. c., costal vein; s¢., sub- 

ancestors, instead of the specialized costal vein; r., radial vein; cu., cubi- 
frenulum as in other moths, is also evi- tal vein; a., anal veins. The base of 
i A ; the medial vein (lying between radius 

dence of the ancestral type displayed by ana cubitus) is obsolete, but its 


the Jugate. branches still persist, lying between 
= branches of radius and cubitus. 
(Natural size.) 


The Micropterygide, represented in 
this country by two genera, Eriocephala, 
with four species, and Epimartyria (Micropteryx), with two species, are among 
the smallest moths we have, the largest not expanding more than one-third 
of an inch and the smallest only one-fifth of an inch, the body being about 
one-tenth of an inch long. They are indeed almost invisible when flying, 
and are only very rarely taken by collectors. They fly in the sunshine, 


372 The Moths and Butterflies 


frequenting flowers, and the different species are so much alike as to be 
nearly indistinguishable to the amateur. The eggs are laid on leaves, or in 
tiny pits in them, and the minute larvee, short and oblong, are either foot- 
less and mine the leaf substance, or have eight pairs of abdominal legs and 
feed exposed on leaves or in moss. The leaf-mining larve burrow into the 
ground to pupate, while the exposed feeders make a slight cocoon of silk and 
debris above ground. The pupe are more like caddis-fly pupe than the 
usual lepidopterous chrysalids (another indication of the primitive char- 
acter of the family), and those of certain species have large mandibles which 
they use to cut their way out of the cocoon. The adults can best be dis- 
tinguished by the venation of the wings (Fig. 525), and if ever found should 
be highly prized by the collector as specimens of the most primitive living 
Lepidoptera. 

The Hepialide, the ghosts or swifts, although an offshoot from the 
Micropterygide, or at least much more nearly related to them than to 
any other moths, are very different in appearance, being from an inch to 
24 inches long (some foreign species have a wing expanse of 6 inches) 
with large broad-ended wings and rather heavy body. They can be recog- 
nized by their venation (Fig. 526), which distinguishes them from all other 
moths of their size. The mouth-parts are rudimentary, but the parts per- 


SC Fs) 62 rapzg 


Fe 


Clk; 
mes SESLL? rsp, 


Fic. 525. Fic. 526. 


Fic. 525.—Diagram of wing venation of Micropteryx sp. cs, costal vein; sc, subcostal 
vein; 7, radial vein; m, medial vein; c, cubital vein; a, anal veins. (After Com- 
stock; enlarged.) 

Fic. 526.—Diagram of wings of Hepialus gracilis, showing jugum (J), and similarity of 
venation in fore and hind wings. (After Comstock.) 


sisting indicate plainly that they are reduced remnants of a very simple set 
of structures. The labium is free and truly lip-hke and of the type of the 
under lip of biting insects. Two genera, Sthenopis, four species, and Hepi- 
alus, nine species, occur in this country. All of these moths are rather sombre 


The Moths and Butterflies B73 


in color, being grayish, yellowish brown, and reddish brown, with a few 
silvery-whitish irregular streaks on the upper 
wing surface. They fly swiftly and are said to 
prefer twilight. The males of some species give 
off a strong scent to attract the females. Others 
seem to show off their silvery spots by hovering 
for some time in the air at twilight, being con- 
spicuous, despite the semi-darkness and the 
Uae Urea ene ee quiet general coloration of the moth, by a pale 
in case, and adult. (After silvery appearance. Females have been seen 
ee Marlatt; twice to fly directly to the ghostly hovering males 
as if strongly attracted. The grub-like larve 
feed in the roots of various plants, as ferns and others, or in the trunk-wood 
of various shrubs and trees, and live for two or three years. Sthenopis 
argenteo-maculatus feeds first in the roots of alder, later going into the 
stems. It either pupates in its burrow or in a loose cocoon in the soil. 
The pupe are provided with certain short spiny teeth, and can wriggle so 
strongly that they are able to move about in the burrows or soil, and when 
ready to transform work their way to the surface of the ground. 

The Jugate are looked on by Comstock as equivalent in ranking to all 
the other moths and all the butterflies combined which are given the sub- 
ordinal name Frenate. That is, this scant dozen of persisting represen- 
tatives of the ancient moth type, or rather 


of immediate offshoots from the ancestral 
type, are to be distinguished subordinally 
from all other living Lepidoptera, however 
more striking may appear the differences 
between some of these, as the obscure 
clothes-moths and the regal Cecropias, or the 
dull moth-millers and the brilliant day-fly- 
ing butterflies. The Frenate Lepidoptera 
include all those forms which have the vena- 
tion of the hind wings reduced (branches 
less in number than in the fore wings) 
and whose wings are tied together by a 
frenulum (Fig. 533) or by the expanded 
humeral angle of the hind wing overlapping 


the base of the fore wing, or by no more Fic. 528.—Larva of the palmer- 
S worm, YVpsolophus pomatellus, 
; : lying under its web spun on a 
of front margin of hind wing and hind leaf (After Lowe; natural length 
4 inch.) 


elaborate means than the simple overlapping 


margin of fore wing, but never by a jugum, 
the caddis-flylike method common to the Micropterygids and Hepialids. 


374 The Moths and Butterflies 

Among the Frenate there is a host of small obscure moths commonly 
lumped by collectors and amateurs under the name Microlepidoptera, which 
are little known because little 
studied, but which professional 
entomologists recognize as in- 
cluding all together eleven moth 
families grouped into three dis- 
tinct superfamilies. Among these 
microlepidoptera are probably the 
most generalized of the frenate 


Fic. 529. FIG. 530. moths. 
Fic. 529.—The palmer-worm moth, Ypsolophus The three microlepidopterous 
pomatellus, (After Fitch; twice natural superfamilies are the Tineina, 


size.) 
Fic 530.—The strawberry root-borer, Anarsia including the clothes-moths, leat- 


lineatella, (After Saunders; moth and larva miners, and others, the Tortri- 
both natural size and enlarged.) E x : d 
cina, including most of the leaf- 


rollers, the notorious codlin-moth and others, and the Pyralidina, including 
certain leaf-rollers and folders, the close-wings, the curious plume-moths, the 
injurious meal-moths, and the bee-moth, principal pest of the bee-keeper. 
The Tineide, only family of the Tineina, are best known by their house- 
hold representatives, the clothes-moths. Of these there are several species, 
the moths themselves looking much alike, although distinguished by some 
differences in marking, but the larve, the stage in which the injury to woolens, 
etc., is done having noticeable differences in habit. The moths lay their 
eggs on garments and stuffs, preferably woolen, hanging in dark closets or 
stored in trunks or dressers, and the smali white larve feed on the dry 
animal fibers of which the cloth is made. The larva of the most familiar 
species, the case-bearing clothes-moth, Tinea pellionella (Fig. 527), makes 
a small free tubular case out of bits of cloth fibers held together by silk spun 
from its mouth; the larva of the tapestry-moth 7. tapetzella, a rarer species, 
attacks thick woolen things, as blankets, carpets, and hangings, burrowing 
into the fabric and forming a long winding tunnel or gallery partially lined 
with silk; the larva of the webbing clothes-moth, Tinea biselliella, a species 
especially common in the Southern States, although not infrequent in the 
North, spins no case or gallery, but makes a cobweb covering over the 
substance it is feeding on. The larvae of all the species, when ready to 
pupate, make a cocoon out of bits of woolen tied together by silken threads 
in which tc transform. The moths, on issuing, rest during the day on the 
garments or stufis, but fly about at night, often coming to the lights in 
rooms. They are all small, pellionella and biselliella expanding about 4 
inch and fapetzella } inch; pellionella has grayish-yellow fore wings with- 
out spots, and ¢apelzelia has the fore wings black at base and creamy- 


The Moths and Butterflies ans 


white with some grayish on the middle and apex. The eggs are laid 
by the moths directly on the woolen garments or other articles favored 
by the larval palate, and several generations may appear each year. The 
remedies for clothes-moths are the admission of light into closets and dressers, 
the fumigation of infested clothes or rugs in tight chests with bisulphide 
of carbon (the fumes will kill every larva and moth in the chest), and the 
keeping of carpets, rugs, hangings, and garments in cold storage during 
summer absences from home. Send the things to a 
cold-storage company with instructions to keep at 
a temperature below 40° F. The insects cannot 
develop in a temperature below this point. Cloth 
covered furniture and cloth-lined carriages, if to be 
left long unused, may be sprayed once each in April, 
June, and August with benzine or naphtha. 

A sometimes serious pest of stored grains, espe- 
cially corn in cribs, is the Angoumois grain-moth, 
Gelechia cerealella. The larve bore into the kernels, 
feeding on the inner starchy matter. I have seen ears 
of corn in Kansas cribs with every kernel attacked. 
The larve feed for about three weeks, then pupate 
inside the kernel, the moth issuing in a few days. 
The kernels of infested ears show from one to 
three little holes from which moths have issued. 
The adult moth, expanding about half an inch, is 
light grayish brown, more or less spotted with black, 
looking much like the case-bearing clothes-moth. 
The eggs are deposited on grain in the field or bin. 

Numerous Tineid species are known as _leaf- 
miners because of the burrows of the larvee. Leaves 
of various trees and shrubs often show whitish blotches 
or lines, which when examined closely are seen to 
be due to the separation of the epidermis of the leaf 
from the inner soft tissue or to the complete dis- Pig, 531.—Pupal cocoons 
appearance of the inner tissue. This is the work of — of the apple bucculatrix, 

7 ; ; ek a F Bucculatrix pomijoliella. 
the tiny burrowing and feeding “‘leaf-miners,” the (Twice natural size.) 
larve of certain Tineid species. Often the miner, 

a small white grub with the usual eight pairs of legs characteristic of Lepi- 
dopterous larva, can be found in his mine, or, perhaps he will have ceased 
feeding and have transformed to a small light-brown pupa. The species of 
these leaf-miners are many, and numerous different types of mines may be 
found; the winding narrow lines called serpentine mines common on wild 
columbine, the spotted and folded tentiform mines on the wild cherry and the 


376 The Moths and Butterflies 


apple, the blotch-mines of the oaks and other forest trees. Even pine- 
needles are mined by certain species, the pine leaf-miner, Gelechia pini- 
foliella, being abundant in the leaves of pitch-pine. 

Inieresting little Tineids are the apple and oak bucculatrix-moths, whose 
larve feed on the leaves and when ready to pupate crawl to a stem or branch 


Tl rears rd 


Fic. 532. Fic. 533- 

Fic. 532.—The apple-leaf bucculatrix, Bucculatrix pomifoliella, pupal cocoons on twig, 
one pupal cocoon removed, and moth. (After Riley; cocoons natural size; 
size of moth indicated by line.) 

Fic. 533. — Venation of a Pyraiid moth, Pyralis farinalis. cs, costal vein; sc, subcostal 
vein; 7, radial vein; m, medial vein; c, cubital vein; a, anal veins. Note the hair- 
like projection, called frenulum, at the base of the anterior margin of the hind wing. 
This fits into a little “frenulum pocket”? on the fore wing. (After Comstock; 
enlarged.) 


and there make long, slender, finely woven little white cocoons, conspicuously 
ribbed or fluted lengthwise, in which they pupate (Figs. 531 and 532). The 
pupz hibernate, the tiny moth issuing the following spring and laying its 
eggs on the leaves. The larve are miners at first, but after the first moulting 
feed on the outer surface of the leaves under thin flat silken webs. 

The Pyralidina include half a dozen families, some of the moths 
hardly properly called microlepidoptera, for they reach a wing expanse of 
14 inches. But most of the species are small and but few are at all 
familiar to collectors. The larve of numerous species are injurious to 
fruits, stored grain, etc., and these species have a particular interest for 
economic entomologists. To collectors and nature students the most attrac- 
tive Pyralids will be the beautiful plume-moths, or feather-wings, small 
moths with the wings split or fissured longitudinally for one-half or more the 
length of the wing. The fore wings are usually thus divided into two parts 
and the hind wings into three (Fig. 534), but on some there are more divisions. 
All the feather-wings excepting one species belong to the family Pteropho- 


The Moths and Butterflies 277, 


ride, the exception being a small moth with both wings deeply cleft into 
six parts. It is called Orneodes hexadactyla and is considered to be the 
sole representative, so far as known, of a distinct family, the Orneodide. 
Of the Pterophoride several species are common in the North and East. 


FIG. 534. FIG. 535- 


Fic. 534. A California plume-moth. (Natural size.) 
Fic. 535.—The raspberry plume-moth, Oxyptilus tenuidactylus, moth and larva. (After 
Saunders; moth natural size; larva much enlarged.) 


Oxyplilus tenuidactylus (Fig. 535), with coppery brownish wings, with the 
plumes deeply fringed, has a pale yellowish-green larva that feeds on rasp- 
berries and blackberries; O. periscelidactylus has wings of a metallic yellow- 
ish brown, with several dull whitish streaks and spots; its greenish-yellow 
caterpillars with scattered small tufts of white hairs feed on grape-leaves 
and often are numerous enough to do much damage. Along the Pacific 
coast the plume-moths are not at all uncommon. 


Fic. 536.—The Mediterranean flour-moth, Ephestia kuehniella; larva, pupal cocoon, 
pupa, and moth. (One and one-half times natural size.) 


The Crambids, or close-wings, are numerous and perhaps more familiar 
than any other family of the Pyralidina. The larve of most of the species 
feed on grass, and the adults fly up before one as one walks through meadow 
or pasture. They may easily be recognized by their characteristic habit of 
closely folding their wings about the body when at rest. The fore wings 
often present pretty designs in silver, gold, yellow, brown, black, and white, 


378 The Moths and Butterflies 


or they may be uniformly dull-colored; the hind wings are white or grayish. 
The palpi are long and project conspicuously, so that snout-moth is a name 
often given to the Crambids. 

Pretty little moths with shining black wings, two-spotted with white on 
the front ones, and one- or two-spotted on the hind wings, are the Desmias, 
of which the species maculalis, the grape-vine leaf-folder, is especially common, 
and often seriously injurious. The larve fold or roll up grape-leaves and 
feed concealed inside the roll, skeletonizing the leaf by eating away all of its 
soft tissues. The larva when full-grown is a little less than an inch long, 
glossy yellowish green, and very active when disturbed. It pupates within 
the folded leaf. It is abundant in the South. 

Among the insects that attack stored grain, flour, meal, etc., are several 
Pyralids. The meal snout-moth, Pyralis farinalis, is a common pest, 
the larve making long tubes of silk in the meal, and taking readily to cereals 


Fic. 537.—A curious hammock and its maker, Coriscum cuculipennellum, a leaf-rolling 
moth, whose larva pupates in the odd little hammock shown in the figure. (After 
photographs by Slingerland; natural size of moth indicated by line; hammcck 
natural size; a rose-leaf enlarged.) 


of all kinds and conditions, in the kernel or in the form of meal, bran, or 
straw. The moth expands one inch, the wings being light brown with red- 
dish reflections and a few wavy transverse lines. The Indian meal-moth, 
Plodia interpunctella, is another familiar pest in mills and stores, its small 
whitish larva, with brownish-yellow head, feeding on dry edibles of almost 
every kind, as meal, flour, bran, grain of all sorts, dried fruits, seeds, and nuts, 
condiments, roots, and herbs. It spins webs of silk with which it fastens 
together particles of the attacked food, making it unfit for our use. The moth 
expands % inch and has the fore wings cream-white at base and reddish 


The Moths and Butterflies 379 


brown with transverse blackish bands on disk and apex. Another and per- 
haps the most formidable of all mill pests is the notorious Mediterranean 
flour-moth, Ephestia kuehniella (Fig. 536). This insect first became seri- 
ously harmful in Germany in 1877, soon invading Belgium and Holland 
and by 1886 having got a foothold in England. Three years later it 
appeared in Canada and since 1892 it has been a pest in the United States. 
The moth, which expands a little less than an inch, with pale leaden-gray 
fore wings, bearing zigzag black and transverse bands and semi-transparent 
dirty-whitish hind wings, lays its eggs where the hatching larvee can feed on 
flour, meal, bran, prepared cereal foods or grain. The caterpillars spin 
silken galleries as they move about, which make the flour lumpy and stringy 
and ruin it for use. In addition to this direct injury, the mill machinery 
often becomes clogged by the silk-filled flour and has to be frequently stopped 
and cleaned, involving in large mills much additional loss. When a mill 
becomes badly infested the whole building has to be thoroughly fumigated 
by carbon bisulphide, an expensive and rather dangerous process. Unin- 
fested mills should be tightly closed at night (if not running continuously) 
and every bushel of grain, every bag or sack brought into the mill, should 
be subjected to disinfection by heat or the fumes of bisulphide of carbon. 

An interesting as well as economically important little Pyralid is the 
bee-moth, Galleria mellonella, whose larve live in beehives, feeding on the 
wax combs. The moths find their way into the hives at night to lay their 
eggs. This has to be done very quickly, however, as bees are alert even at 
night to defend themselves against this insidious enemy. I have intro- 
duced bee-moths into glass-sided observation-hives both by day and night, 
and in each case the moths were almost immediately discovered, stung to 
death and torn to pieces in a wild frenzy of anger. Many must be killed 
where one succeeds in getting its eggs deposited inside the hive. The squirm- 
ing grub-like white larve protect themselves by spinning silken webs and 
feed steadily on the wax, ruining brood- and food-cells and interfering sadly 
with the normal economy of the hive. When ready to pupate they spin 
very tough bee-proof silken cocoons within which they transform to other- 
wise defenceless quiescent pup. Bee-moths often become so numerous 
in a hive as to break up the successful life of the community. I have taken 
thousands of pupae, lying side by side ike mummies in sarcophagi in their 
impervious stiff silken cocoons, from a single hive from which the bees had 
all fled. 

Third of the superfamilies of microlepidoptera is the Tortricina, com- 
prising three families, two of which number many species. The Tortricid 
moths get their name from the habit, common to the larve of many of them, 
of rolling up the edges or the whole of leaves in which to lie protected while 
feeding, and later while in quiescent pupal stage. Not all leaf-rollers are 


380 The Moths and Butterflies 


Tortricids, but the majority of rolled-up leaves so commonly seen on shrubs 
and trees are the homes of these larve. A number of species belonging to 
the genus Cacoecia are among the commonest and most important of these 
because they prefer the leaves of apple, plum, and cherry trees, and currants, 
raspberries, gooseberries, strawberries, cranberries, roses, etc., rather than 
those of trees and shrubs ° 

SC M712 7org 


es EZ whose healthfulness is not 
QL Ws so important to us. The 
larvee of Cacoecia rosaceana, 
the oblique-banded leaf- 
roller, pale yellowish-green 
caterpillars ? inch long, dis- 
figure and injure many kinds 
of fruit-trees, small fruits, 
and garden shrubs. The 
moth expands about one 
inch, and has reddish-brown 
; body, light, cinnamon-brown 
Fic. 538.—The cherry-tree leaf-roller, Cacoecia cera- Ae Kat = age) 

sivorana, (After Lugger; natural size.) fore wings crossed by Wavy 
Fic. 539.—Venation of a Tortricid, Cacoecia cera- dark-brown lines and ochre- 

sivorana, cs, costal vein; sc, subcostal vein; ali landonempeuehol 
r, radial vein; m, medial vein; c, cubital vein; YeHOW Hind wings. 1OKe- 
a, anal vein. (After Comstock; enlarged.) berries, and cultivated cher- 


Fic. 540.—The cranberry leaf-roller, Cacoecia paral- 
lela, (After Lugger; natural size.) 


FIG. 539. Fic. 540. 


ries as well, are often attacked 
by the cherry-tree leaf-folder, 
C. cerasivorana (Fig. 538), whose active yellow larvae “fasten together with 
silken threads all the leaves and twigs of a branch and feed upon them, 
an entire brood occupying a single nest. The larve change to pupe within 
the nest; and the pup when about to transform work their way out and 
hang suspended from the outer portion of the nest.”” The moths expand 
from # to 1} inch, have bright ochre-vellow wings with brownish spots, and 
bands of pale leather-blue on the front ones. 

The oak leaf-roller, C. pervadana, similarly makes ugly nests in oak- 
trees in late summer, each nest consisting of a wad 
of tied-together leaves. Cranberry-plants are sometimes 
attacked by reddish, yellow-headed, warty-backed cater- ; 
pillars, which are the larve of C. parallela (Fig. 540), Fic. 541.— The 
a leaf-roller moth with reddish-orange fore wings crossed phe acing 
diagonally by numerous fine lines of a darker red-brown, Sulfureanal (Af- 


and a pair of broad oblique red-brown bands. The hind _ ter fee nat- 
ural size, 


wings are pale yellow. 
Notwithstanding the apparently sufficient protection afforded the leaf- 
rolling larve by their tightly rolled cylindrical cases and webby nests, birds 


The Moths and Butterflies 381 


may often be seen cleverly engaged in extracting one by one the toothsome 
morsels from their homes. Hovering over a rolled leaf, the bill is carefully 
thrust into the roll for the unseen caterpillar and rarely withdrawn without 
it. Lugger says that the Baltimore oriole is particularly expert at this sort 
of hunting unseen prey. 

A certain Tortricid, accidentally imported many years ago from Europe, has 
become one of our serious grape pests. This is the grape-berry moth, Eu- 
demis botrana, whose small slender whitish-green, black- 
headed larve bore into green and ripening grapes and 
feed there on the pulp and seeds. When full-grown the 
larva becomes olive-green or dark brown and, forsaking 


Fic. 542.—The rus- 
the grape-berry, cuts out of a grape-leaf a little flap which _ set-brown _ tortrix, 
it folds over and fastens with silk, thus forming a small ie eee 
oblong case within which it pupates. The moth expands eae eel size) ate 
2 inch, and has slaty-blue fore wings, marked with dark 
reddish-brown bands and spots, while the hind wings are uniform dull brown. 
Another well-known Tortricid pest is the bud-moth, Tmetocera ocellana 
(Fig. 543), whose larvee burrow into opening fruit- and leaf-buds on apple- 
trees and eat them. The moth expands 3 inch and is 
dark ashen-gray with a large irregular whitish band on 
the fore wing. 
a By far the best known and most feared and hated 
Fic. <43._The eye. Portricid is the codlin-moth, Carpocapsa pomonella (Figs. 
spotted bud-moth, 545 and 546), the most important enemy of the apple- 
ane ere crower. Distributed all over the United States, wherever 
natural size.) apples are grown, minute and obscure so as to be 
easily overlooked until fairly intrenched in the orchard, 
prolific and subject to no very disastrous parasitic attacks, this frail little 
species causes losses to fruit-growers of no less than $10,000,000 annually. 
The moth, which hides by day and is seldom seen, has the fore wings 
marked with alternate irregular transverse wavy streaks of ash-gray and 
brown, with a large tawny spot on the inner 
hind angle, the hind wings and abdomen 
light yellowish brown with a satiny luster. It 
lays its eggs (for the first generation, the species 
being two-brooded over most of the country) 


on the top of the newly forming apple, or 


sometimes, as recently observed in California, F'6- 544-—The cranberry 

é ete : = worm-moth, Rhopobota vac- 

on the side of the tiny fruit. The larva, hatch- ciniana. (After Lugger; 

ing in from three to five days, begin to feed on natural size indicated by 
. 2 Z line.) 


the green fruit, soon burrowing into its center. 
They become full-grown before the apples ripen, burrow out and crawl 


382 The Moths and Butterflies 


away to some crevice in the bark or sheltered place on the ground, and 
there pupate. In two weeks the moths issue and deposit eggs on later 
apples for the second brood. The larve of this brood are tucked away 
in the fall and winter apples when gathered, and are thus carried with 
them into cellars, warerooms, etc. They soon issue from the fruit, and 
finding concealed spots in the cracks of barrels or boxes or elsewhere 
near the stored apples, pupate, the pupe lasting over the winter and 
the moths issuing about apple-blossoming time the following spring. The 
pup are protected by thin papery cocoons of silk spun by the larve. The 
remedies are effective, but must be carefully and regularly used. Spraying 
the young fruit with an arsenical mixture, as Paris green or London purple, 
soon after the blossoms fall and again in about two weeks, will reduce 
immensely the possible loss. Banding the tree with strips of old carpet or 


Fic. 545.—The larva or worm of the codlin-moth, Carpocapsa pomonella, (After 
photograph by Slingerland; three times natural size.) 

sacking at the time the larve are crawling out of the apples and hunting 

for concealed places in which to pupate, will enable the grower to trap and 

destroy thousands of them and thus greatly lessen the numbers in the second 

brood. All fallen fruit should be promptly gathered and destroyed in such 

a way as to kill the larve inside. 

An interesting insect closely allied to the codlin-moth is the Mexican 
jumping bean-moth, Carpocapsa saltitans (Fig. 547), which lays its eggs 
on the green pods of a euphorbiaceous plant of the genus Croton. The 
hatching larve bore into the growing beans in the pod, but do not attain 
their full growth until after the beans are ripe and hard. The ripe beans 
with the squirming larve inside act as if bewitched, twitching and jerking, 
rolling over and leaping slightly clear of the table or desk on which they 


The Moths and Butterflies 383 


may rest. The larve pupate within the beans, first gnawing a circular 
thin place through which the moth may push its way out. Another Tor- 
tricid moth, Grapholitha sebastiane, has similar habits. Most of the jump- 
ing beans come from the Mexican province of Chihuahua. 


Fic. 546.—Pupz, in cocoons, of codlin-moth, Carpocapsa pomonella. (After photograph 
by Slingerland; enlarged.) 


A few moth families, represented in this country by but few species, may 
now be referred to briefly, chiefly for the sake of mentioning certain par- 
ticular forms that are fairly common and wide-spread and hence likely to 
be taken by the collector. 

The flannel-moth family, Megalopygide, includes but five North Ameri- 
can species, of which the crinkled flannel-moth, Lagoa crispata, pale straw- 
yellow, with long, curling, woolly, 
brownish and blackish hairs, with 
wing expanse of about 1 inch, is 
not uncommon in the north Atlantic 
states, while Megalopyge opercularis, 
of about the same size, with yel- 
lowish-white fore wings overspread 
except at the tips by woolly purplish- Fic. 547.—The Mexican jumping bean-moth, 
brown hairs, is not uncommon in Carpocapsa saltitans; pupa, croton-bean 

z from which moth has issued, and moth. 
the southern states. The flannel- (Natural size.) 
moth caterpillars have seven pairs 
of abdominal prop-legs instead of five, the number common to almost all 
other caterpillars, and the cocoons in which the pupe lie have a hinged 
door for the exit of the moth. The larva of M. opercularis looks like an 
animated bit of cotton-wool or lock of white hair. That of L. crispata 
feeds particularly on blackberry, raspberry, and apple; it is nearly oval 
in shape, covered with evenly shorn brownish hairs, which form a ridge 
along the middle of the back. When about } inch long it ceases to feed 


384 The Moths and Butterflies 


and spins a tough oval cocoon fastened securely to the side of a twig. 
The moth issues in the summer of the following year. The cocoon of M. 
opercularis so closely resembles a terminal bud of the Southern live-oak on 
which the caterpillars mostly feed that it is almost impossible to detect it, 
especially as both twigs and cocoons are covered with small bits of lichen. 

Another small family, with thirty-three species, of interest because of 
the odd character of the larvae, is that of the slug-caterpillar moths, the 
Eucleide (or Cochlidiide). The moths themselves are small and stout, 
mostly rather strikingly colored, with brown, apple-green, and cinnamon 
prevailing. The larvee are slug-like, short, thick, nearly oblong and mostly 
spiny and gaudily colored. The spiny oak-slug, formidably armed with 
branching spines and common on oaks and willows in the east, is the larva 
of Euclea delphinii, a small, robust, deep-reddish-brown moth with bright 
green spots on the wings. The saddle-back caterpillar, Sibine (Empretia) 
stimulea, has a striking squarish green blotch on the back, with an oval pur- 
plish spot in the middle. It has branching spiny hairs, which affect some 
persons like nettles, producing severe inflammation. It feeds on many 
plants, on oak and other forest trees in the east, and often on corn in the 
west. The moth is lustrous seal- and chocolate-brown, with a few small 
white dots on the wings. Another slug-caterpillar is the pale apple-green 
larva, with dorsal brown blotch, of Prolimacodes (Eulimacodes) scapha, 
a stout wood-brown moth, expanding one inch, with a curved silvery line 
on each fore wing, behind which the wing surface is paler than in front. 
None of the species of this family has been found west of the Rocky Moun- 
tains except in Texas. Parasa chloris has the fore wings brown at base 
and outer margin and elsewhere apple-green; the hind wings are clayey 
yellow. Its larva is bright scarlet with four blue-black lines along the back 
and with stinging yellow tubercles. It feeds on cherry, apple, and rose. 
Euclea penulata has chocolate-brown fore wings with an irregular bright 
green elongate curving blotch, and the hind wings soft wood-brown. 

The most extraordinary species in this family of moths with strange 
larve is the hag-moth, Phobetron pithecium, whose larva is one of the 
oddest known. It is nearly square, dark brown, and bears eight singular 
fleshy processes projecting from the sides. These processes, which are half 
as long as the larva itself, are covered with feathery brown hairs, among 
which are longer black, stinging hairs. Thus covered, and twisting curi- 
ously up and back, they resemble heavy locks of hair and give the name 
hag-moth to the species. The moth is rarely seen; it is dusky purple- 
brown with ocherous patches on the back and a light yellow tuft on each 
middle leg; the fore wings are variegated with pale yellowish brown, and 
crossed by a narrow wavy curved band of the same color; the hind wings 
are sable, bordered with yellowish in the female. 


The Moths and Butterflies 385 


Much larger moths are the Cosside, or carpenter-moths, with slender, 
smooth, spindle-shaped bodies and long, narrow-pointed, strong wings like 
those of the hawk-moths (Sphingide). The larvae are wood-borers, bur- 
rowing about in the heart-wood of locust- and other shade-trees and also of 
apple-, pear-, and other fruit-trees. The moths are mostly gray, vaguely 
patterned with white and blackish, although a few are conspicuously black- 
and-white spotted. They have no proboscis and hence can take no food. 
The moths fly at night and lay their eggs on the bark of the trees, the hatch- 
ing, grub-like, naked larve burrowing into the hard wood, where they live 
for from two to four years, when they make in their tunnel a thin cocoon 
of silk and chewed wood to ; 
pupate within. When ready 
to transform, the pupa 
wriggles along the tunnel 
to its opening, so that the 
issuing moth finds itself in 
free air. The locust-tree 
carpenter-moth, Prionoxys- 
tus robinie (Fig. 549), or 
goat-moth, so called from 
its curious offensive odor, 
expanding 14 inches (males) 
to 24 inches (females), has 
gray wings with irregular 


black lines and spots in 
the female, and darker @ aa 
fore wings and yellowish Fic. 548.—Venation of a Cossid, Prionoxystus robinie. 
hind wings in the male. cs, costal vein; se, subcostal vein; r, radial vein; 
m, medial vein; ¢, cubital vein; a, anal veins. (After 


Its larve feed on locust- Comstock; enlarged.) 


trees and are often abun- 

dant enough to do much injury. The wood leopard-moth, Zeuzera pyrina, 
is strikingly spotted with black on a white ground color, and is common in 
certain eastern cities, its larvee infesting maples and other shade-trees. On 
the Pacific coast the poplar carpenter-moth, Cossus populi, with whitish 
fore wings shaded all over with blackish and irregular black lines, and hind 
wings yellowish gray, growing darker at the outer margin, is common, its 
larve infesting poplars and cottonwoods. There are only twenty species 
in North America belonging to this family. 

Familiar curiosities of entomology are the moving bags of silk and bits 
of twigs and needles occasionally found in cedars, firs, and arbor vite. The 
“worms” which make these bags and carry them around, with all the body 
inside except the projecting head and thoracic legs, are the larve of the 


286 The Moths and Butterflies 


3 
bag-worm moth, Thyridopteryx ephemereformis (Fig. 550), the females of 
which are wingless, the males with blackish body and clear brown-veined 
wings which expand an inch. This moth is the most common and wide- 
spread of the thirteen moth species which constitute the family Psychide, as 
represented in this country. In the Southern States a common species is 
Abbott’s bag-worm, Oikelicus abbotti, whose larve make bags with the bits 
of twigs fastened regularly transversely, the male moth expanding 14 inches 
and being sable-brown with a clear bar in the middle of each fore wing. 
Smaller bag-worm moths are the three species of the genus Psyche, the males 
expanding from 4 inch to 4 inch, P. confederata, the best known, being all 


2 


moths, young larva and empty pupal case. 
natural size; young larva enlarged.) 


blackish with opaque wings, P. gloveri, a Southern species, dark brown through- 
out, and P. carbonaria, a Texas form, brownish black with subtranslucent 
wings. The females of all the Psychids are wingless. The larvae, after 
moving about over the tree and feeding until full-grown, pupate within their 
bags, and the issuing wingless grub-like females simply remain in the sac 
until found by a flying male, after which they lay their eggs in the bag and 
die. The male Psychids can be readily distinguished from other moths by 
the growing together of the anal veins of the fore wings until they appear 
to be a single branching vein (Fig. 552). 

The smoky-moths, Pyromorphide, of which but fifteen species occur 
in the United States, are small, expanding from 2 inch to 1 inch (a single 
Western species expands 14 inches), and with blackish ground-color on body 


The Moths and Butterflies 387 


and wings, relieved by brilliant patches of red, yellow, and orange. They 
are favorites with collectors and, though few in number, are not at all uncom- 
mon. The larva feed on the leaves of various plants, but grape and Vir- 
ginia creeper seem to be specially liked. Vineyards indeed often suffer 
from the presence in considerable numbers of smoky-moth caterpillars. 
These caterpillars often show a striking gregarious instinct, massing side 
by side in lines while feeding. The small black and yellow larve of Har- 
risina americana, a common Eastern species, may often be found arranged 


Fic. 550.—The bag-worm moth, Thyridopteryx ephemerejormis; eggs, larva, pupa 
bag containing larva, bag containing pupa. male moth. (After Felt; about natural 
size except the eggs.) 


side by side in single line clear across a grape-leaf. Feeding, when young, 
only on the soft tissues of the leaves, they skeletonize them; when older, 
however, they eat everything but the larger veins. When full-grown they 
disperse, each finding a sheltered spot, where it makes a tough, oblong- 
oval cocoon of parchment-like silk, in which it pupates. The moth of this 
species expands one inch, is bluish or greenish black, with orange protho- 
racic collar broad above and narrow below, and narrow subtranslucent 
wings. It flies slowly and unevenly during the warmest, brightest hours 
of the day, frequenting flowers. H. coracina, found in Texas and Arizona, 
expands ¢ inch and is all dull black with a bluish tinge on the abdomen; H. 
metallica, the largest Pyromorphid, found in Texas and Arizona, expands 
12 inches and is lustrous bluish green with orange prothorax. Acoloithus 


388 The Moths and Butterflies 


falsarius, one of the smallest members of the family, expanding # inch, com- 
mon in the East, is black with very narrow reddish collar. Pyromorpha 
dimidiata, expanding 1 inch, common in the Atlantic states, is black with 
translucent wings. The only other genus in the family so far unmentioned 
is Triprocris with eight species, all 
confined to the western states and all 
but two of them marked on body or 
wings with orange or yellowish. 

Of unusual and often very deceptive 
appearance are the clear-wing moths, 
or Sesiida. With their often brightly 
colored black and yellow or red- 
banded tapering or plump bodies and 
partly or wholly clear wings, they 
resemble strongly, at first glance, wasps 
or bees, and are undoubtedly often 
taken to be such and thus left unmo- 
lested by both collectors and birds, two 
of their destructive enemies. For birds 
like almost all moths for food, and 
collectors especially prize the Sesians 
for the sake of their attractiveness 
and the sporting character of their pur- 
suit and capture, for they are among 
the swiftest of the moths. They fly 
in bright sunlight, visiting flowers, 
and thus by their habits further in- 
crease their likeness to wasps and bees. 
There are one hundred species in the 
family in this country, and almost all 
have one or both wings partly or mostly 
clear, i.e., free from scales. A few 
Fic. 551.—Bag-worm; the larvaofa moth moths of other families, as the clear- 

Si aba: BME tte Sk winged sphinges and others, have simi 

whole body except horny head, thorax, larly partly clear wings, but the very 

and legs is concealed. (Natural size-) narrow fore wings and widely expanded 
bases of the hind wings will distinguish the Sesians from the few other 
scattered clear-winged moths. The larve are borers, mining in roots of 
fruit-trees, the canes and roots of small fruits, or in the stems of herbaceous 
plants. They are grub-like and yellowish white, with darker head and legs. 
When abundant they become very injurious, the notorious peach-tree borers 
being probably the most serious insect enemy of the peach-tree. 


The Moths and Butterflies 389 


For one hundred and fifty years the peach, an imported plant, has suffered 
in this country from the ravages of this native pest. One Sesian species, 
Sanninoidea exitiosa (Fig. 554) is 
the peach-tree borer of the eastern 
states, and another, closely related, 
S. pacifica, works equal injury in the 
Pacific states. In both species the 
eggs (Fig. 555) are deposited on 
the trunk of the tree near its base, 
in July and August in the East, in 
April and May in California, and 
the young larve (Fig. 556), hatching 
after a week or ten days, immedi- 
ately bore in through the outer 
bark and begin feeding on the 
live inner bark. | When winter 
comes they cease feeding—in the 
East at least—and hibernate quies- ae Sats Dera showing venation of wings 

: of bag-worm moth, Thyridopteryx ephe- 
cent, being now about half-grown. merajormis. cs, costal vein; sc, subcostal 
In the spring they become active vein; r, radial vein; m, medial vein; ¢, 

: - cubital vein; a, anal veins. 
again, feed and grow rapidly, and 
by summer are ready to pupate. Pacifica begins pupating in California 
in February. For this they leave 
rz their burrows, come out to the 
surface of the bark, spin about 
my, ‘hemselves a thin silken cocoon 
and change (Fig. 557). The 
7 » pupal stage lasts about three 
weeks, when the moths _ issue. 
The clear-winged male moths, 
expanding 1 inch, are deep 
steely-blue, with small golden- 
yellow markings on head and 
thorax and abdomen; the larger, 
heavier-bodied female, expanding 


14 inches, has a broad orange band 
Fic. 553.—Venation of a Pyromorphid, Pyro- across the abdomen in the fourth 
mor pha dimidiata. _&S; costal vein; SC, sub- or fifth segments, and has the 
costal vein; r, radial vein; m, medial vein; R . A 
¢, cubital vein; @, anal veins. (After Com- front wings covered with blackish 
stock; enlarged.) scales (Fig. 554). The remedy 
for this pest is the application, by painting on, of gas tar to the basal 
part of the tree-trunk just before the flying and egg-laying time of the 


390 The Moths and Butterflies 


moths; this prevents the females from ovipositing on the treated trees. Or 
the base of the trunk may have a newspaper tied about it. 


ke 


Fic. 554.—Moths of the peach-tree borer, Sanninoidea exitiosa, the upper one and the 
one at the right being females. (Photograph from life by Slingerland,; natural size.) 


The currant-borer, Sesia tituliformis, expanding three-fourths of an 
inch, has a robust body with a fan-like tuft of scales at the posterior tip, 


+ 


De eer 
a—/ 


. 
=. 


‘ 
- 
Ss onan n 


| 
Fic. 555.—Eggs of peach-tree borer, Sanninoidea exitiosa. (After Slingerland; natural 
ze at n; one egg enlarged at /; micropyle end of egg greatly enlarged at m.) 


dark abdomen ringed with yellow, and yellow lines on the thorax; the eggs 
are laid on currant-canes, and the hatching larve burrow into the center 
and then tunnel longitudinally in the pith. They hibernate in the cane 

larve, not pupating until che following summer, when the moths escape 


The Moths and Butterflies 391 


through holes in the cane thoughtfully made by the strong-jawed larve 
before pupation. The grape-vine-root borer, Memythrus polistiformis, looks 
much like a large Polistes wasp, having a dark body with two bright yellow 


Fic. 556.—Larva of peach-tree borer, Sanninoidea exitiosa. (After Slingerland; natural 
size and much enlarged.) 

narrow bands about the abdomen; the fore wings are brownish black, the 

hind wings clear; the larve bore in the roots of wild and cultivated grapes 

and pupate underground. The raspberry-root borer, Bembecia marginata, 

is also very waspish in appearance, with its black body repeatedly banded 


Fic. 557.—Cocoons and empty pupal skins of the peach-tree borer, Sanninoidea exitiosa. 
(After Slingerland; natural size.)* 

with yellow and transparent fore and hind wings. The eggs are laid on 

raspberry canes, and the larve, first boring into the cane, finally work down 

into the roots. Squashes are often badly injured by having their stems 

tunneled by the larva of the squash-vine borer, Melittia ceto, a Sesian with 

olive-brown fore wings, clear hind wings, and black or bronze abdomen, 


392 The Moths and Butterflies 


marked with red or orange, and with the hind legs fringed with long hairs, 
orange on the outer surface and black on the inner. When full grown the 
larve leave the stems and go into the soil to cocoon and pupate. The genus 


Fic. 558. Fic. 559. 
Fic. 55 .—The ash-tree borer, Trochilium jraxini. (After Lugger; natural size.) 
Fic. 559.—Sesia pictipes, male. (After Lugger; natural size.) 


Sesia (Fig. 563) contains over half (fifty-seven) of the species in this family; 
they are found in all parts of the country. 

The family Notodontide, comprising the puss-moths, handmaid-moths, 
and prominents, is represented in 
this country by about ninety-five 
species, all of medium size, i.e., with 
a wing expanse of from 1} to 2 
inches, and but few of such marked 
patterns as to be particularly con- 
spicuous or attractive to collectors. ° 
The name “ prominents,”’ sometimes 
applied collectively to the moths of 
this family, is based on the occur- 
rence in some of them of an angu- 
lated or tooth-like projection near 
the middle of the hinder margin of 
the fore wings. Probably the most 
familiar species in this family are 
the Datanas, or handmaid-moths; 
Fin. , 560.—Venation fa Notedad gah ny cee certainly their larve are more often 

donta stragula. cs, costal vein; sc, sub- Seen and are better known, under 

costal vein; 1, radial vein; m, medial the names of yellow-necked apple- 
vein; c¢, cubital vein; a, anal veins. A me 

(After Comstock; enlarged.) tree caterpillars and walnut cater- 

pillars, than the larve of any other 

Notodontids. Sometimes there may be seen on the trunk of an apple- or 

other shade-tree an animated bunch or mass of hundreds of caterpillars, 


The Moths and Butterflies 393 


reddish black with conspicuous yellow longitudinal stripes, each caterpillar 
curiously jerking its body or resting quietly with both head and body tip 
held up nearly at right angles to the middle part with its four pairs of clinging 
prop-legs. These are Datana larvae, which : 
have come down from their feeding on the 
leaves of the tree to moult. The jerking 
frightens away in some measure the numerous 
parasitic Tachina flies which are always 
ready to attend on a gathering of this sort 
and lay a few eggs where they will do the py, 56r.—The red-humped cater- 
Tachina species the most good, that is, on pillar-moth, Gidemasia eximia, 
the body of these plump caterpillars, so ‘After Packard; natural size.) 

that the hatching Tachina grub can burrow into this well-nourished body 
and feed on its living tissues. When feeding in the tree-tops, too, the Datana 


Fic. 562.—Larva of red-humped caterpillar-moth, Gidemasia eximia. (After Packard; 
natural size.) 


caterpillars keep closely together, forming rows or files of voracious feeders 
-arranged neatly across each attacked leaf. The common species infesting 
the apple is Datana ministra, and the larve have a distinguishing dull orange 
spot on the back of the first body-ring 
behind the head. The eggs, which are 
white and spherical, are laid, from 70 to 
too by each female, on the leaves, all 
cemented well together in neat patches. 
When the larve are full grown they 
descend from the tree, burrow into the 
soil for two or three inches, and change 
to naked brown chrysalids, which last 
over winter, the moths emerging in the following summer. The moth, 
expanding 14 inches, is reddish or yellowish brown, with the fore wings 
crossed by from three to five darker brown lines, the outer margin and one 


Tic. 563. — Heterocampa  guttivitta. 
(After Packard; natural size ) 


394 The Moths and Butterflies 


or two spots near the middle also being darker; the hind wings are pale 
yellow and not patterned. The species common on walnuts and hickories is 
Datana angusit, with fore wings varying from chocolate to deep smoky 
brown, with transverse lines like those of ministra; the hind wings are 


Fic. 564.—Larva of Heterocampa guttivitta. (After Packard; natural size.) 


paler brown. The caterpillars are black, with dirty-white hairs and with 
three equidistant, very narrow, pale-yellow or whitish stripes on each side 
and three yellow stripes on the under side; when full grown it is a little more 
than 2 inches long. 

Another conspicuous Notodontid larva occurring on apple-trees is a 
greenish-yellow black-striped caterpillar with a coral-red head and promi- 
nent hump on the back of the fourth body-ring. This is the larva (Fig. 562) 
of the red-humped caterpillar-moth, Gédemasia concinna (Fig. 561), a 
darkish-brown moth expanding about 14 inches, the fore wings having a 
darker brown spot near the middle, a spot near each angle, and several 
longitudinal streaks along the hinder margin. 

The puss-moths, Cerura, are readily distinguishable by their characteristic 
black and white wings, white being the ground color, with two broad, not 
sharply defined blackish bars across the fore wing, one across the disk, the 
other, often incomplete posteriorly, across the apex. Along the outer margin 


of each wing there is a row of distinct small black points. The larve (Fig. 


793) of Cerura are extraordinary creatures: short, thick, naked body, tapering 
behind to a kind of forked tail which is held up at an angle with the rest 


of the body. This tail, which is an organ of defence, consists of two tubes, 


within each of which is concealed a long orange-colored extensile thread 
which can be thrust out and drawn in at will. When disturbed, the puss- 
moth caterpillar thrusts out these vivid tails, waving them threateningly, 
at the same time giving off a strong odor. It also telescopes its head and 
front two thoracic segments into the large, humped, third segment, which is 
so shaped and marked as to suggest some formidable large-eyed creature 
quite unlike a soft-bodied toothsome caterpillar. With little doubt this 
elaborate terrifying but actually harmless equipment avails to frighten off 
many of Cerura’s enemies. The larva of a common puss-moth species 
feeds on wild cherry. When ready to pupate the caterpillars gnaw out a 
shallow cavity or depression in the wood which they lie in and over which 
they spin an oval silken net mixed with particles of wood, which makes it 
almost indistinguishable from the rest of the wood surface. These moths 


The Moths and Butterflies 395 


seem to carry very far expedients of Nature for protection by deceit. Other 
common members of the family are the several species of Schizura, moths 
strongly resembling owlet-moths (Noctuide) with their brown and gray 
and gray and blackish finely variegated fore wings and unmarked silky white 
wings. Their brown or greenish larve, which feed on fruit-trees, forest 
trees, small fruits, and other shrubby plants, are distinguished by having 
a prominent horn or spined tubercle on the fourth body-ring behind the 
head. They are said to eat out a notch about the size of the body, in the edge 
of a leaf, fitting themselves along this notch, so that the prominent tubercle 
and other irregularities of the body seem to simulate the rounded edge of 
the leaf; they are thus well concealed. The moths, too, are much given 
to dissimulation. Each moth rests on the trunk or branches of the tree, 


Fic. 565.—Canker-worms, larve of a geometrid moth. (After Slingerland; natural size.) 


head downward, with wings closely folded around the body and’ legs all 
drawn together, the dull-gray tone of the wings with their bits of lichen- 
green and whitish color giving the whole a marvelous resemblance to a bit 
of rough weathered bark. 

Familiar to all observers, although certainly not very often seen and 
rarely found in large numbers, are the inchworms, spanworms, or loopers 


396 The Moths and Butterflies 


as they are variously called, which are the larve (caterpillars) (Fig. 565) 
of the moths of the superfamily Geometrina (earth-measurers). These 
three common names as well as the scientific one refer to the peculiar mode 
of locomotion affected by all the Geometrina. Each loop or step is made by 
the bringing forward of the caudal extremity of the body quite to the thoracic 
feet, the portion of flexible body between 
bending up and out of the way each time 
during the process. The reason for it 
all will be understood when the inch- 
worm is examined. It differs from other 
lepidopterous lary in lacking the front Fre. 566.—Lime-tree inch-worm, larva 
three of the four pairs of prop-legs of sie Se bts ee ae 
normally belonging to the middle part size.) 
of the body, which is thus rendered 
helpless in walking, and the curious looping gait is the outcome of the pos- 
session by a long slender flexible body of only anterior and posterior locomotory 
organs (Fig. 566). Why inchworms are not more often seen, although there 
are hosts of different kinds of them and they 
are well distributed and common all over the 
country, is due to their habit of ‘going 
stiff’ when disturbed, clinging by the hinder 
two pairs of legs to the twig or leaf and 
holding the rest of the body motionless and 
rigid at an angle with the support. As the 
body is always protectively colored and 
marked, so as to harmonize thoroughly with 
the habitual surroundings many an inch- 
worm may be seen but not distinguished 
from the leaf or branch on which it rests. 
Indeed, many of the inchworms are amaz- 
ingly like a short or broken twig, with buds 
or leaf scars and lined or scaly bark, a very 
effective case of protective resemblance. 
Fic. 567.—Venation of a geometrid, The geometer-moths, of which we have 
eee See a ae Ae 800 species in this country, while of course 
radial vein; m, medial vein; Presenting a great variety of coloration and 
¢ cubital vein; a, anal veins. pattern yet possess a likeness of general 
(After Comstock; enlarged.) 
appearance due mostly to the slenderness of 
body compared with the broadness of wings, the impression of fragility or thin- 
ness of wings due to the unusually fineness of the covering scales, and the deli- 
cate and quiet coloration and patterning, which indicate their identity pretty 
effectively. Some are small, i.e., less than 1 inch expanse, and a few large, 


The Moths and Butterflies 397 


i.e., over 2 inches expanse, but most are of medium size, with white, deli- 
cate green, soft yellowish, brownish, grayish, and blackish as predominating 
color tones, and delicate wavy or zigzagging transverse lines, or point-like 
spots as characteristic pattern markings. The superfamily is divided into 
five families based on venational characters rather confusing and appar- 
ently not surely indicative of natural relationships. We may content our- 


Fic. 568.—Male and female lime-tree canker-moths, Hibernia tiliaria. (After Jordan 
and Kellogg; twice natural size.) 


selves with brief reference to some of the more interesting, beautiful, or eco- 
nomically important species. 

The best-known Geometrids of economic importance are the canker- 
worms (Fig. 565), two species in particular, known as the spring canker- 
worm (Paleacrita vernata) and the fall canker-worm (Anisopleryx pometaria), 
being responsible for much damage to orchards, especially apple-orchards. 
The females of the canker-worm moths are wingless and so have to climb 
the trees to lay their eggs on the branches and twigs. 
This fact naturally suggests the most effective remedy 
for them, namely, banding the trees with tar (mixed 
with oil to prevent its drying) so as to make effective 


barriers against them as they crawl upward. Printers’ 5... J6yiDispepieris 
ink, refuse sorghum, or any slow-drying varnish is  gbortivaria. (After 
equally effective. From the eggs laid in the spring by Lugger; natural 
Paleacrita and in the fall by Anisopteryx hatch active aie 

little ‘‘loopers” which feed voraciously in the foliage. The eggs of the fall 
canker-worm do not hatch until the following spring, just when. the young 
apple-leaves begin to unfold. The full-grown canker-worms are about 1 
inch long, greenish brown and striped longitudinally with pale yellow. 
Some of these stripes are broad on the fall canker-worm; all are narrow 
on the other species. When full grown the larve crawl down the tree to the 
ground, burrow into it and pupate ina thin silver cocoon. The males of both 
species are winged delicate moths; Paleacrita has pale ash-colored or brownish- 
gray, silky, almost transparent fore wings with four or five broken transverse 


398 The Moths and Butterflies 


dark lines; Anisopteryx has glossy brownish fore wings crossed by two 
irregular whitish bands. 

Among the Geometrids are numerous species whose wings are green, 
the shades varying, but usually with a strong admixture of whitish and also 


Fic. 570. 
Fic. 570.—The pepper-and-salt currant-moth, Eubyia cognataria. (After Packard; 
natural size.) 
FIG. 571.—Phigalia strigataria, the female wingless. (After Lugger; natural size.) 


usually barred more or less distinctly with narrow or broader whitish lines. 
Geometra iridaria is such a species common in the East in which the green 
is very light in tone; Dyspepteris abortivaria (Fig. 569) is bluish green and 


Fic. 572. Fic. 573. Fic. 574. 
72.—The large blue-striped looper, Biston ypsilon. (After Forbes; natural size.) 
The common Cymatophora, Cymatophora pampinaria. (After Lugger; 


natural size.) 
Fic. 574.—The plum-geometer, Eumacaria brunneraria. (After Lugger; natural size.) 


5 
5 


73- 


has a grape-feeding larva. The raspberry geometer, Synchlora glaucarta, 
has delicate pale-green wings with two transverse whitish lines; its larve 
feed in the fruit and leaves of raspberries and blackberries and cover over 
the body with bits of vegetable matter like minute 

. pieces of flowers, etc., until it seems to be only a 
Pee tiny heap of débris. The snow-white Eugonia, 
Ennonos subsignarius, is pure white, expanding 


Fic. «7<.—The currant fruit- an inch and a half; its larve feed often de- 


575. 
worm moth, Eupithecia in- structively on the foliage of elms, lindens, and 
terruptojasciata. (After i 7 i ‘ = 
Lugger; natural size.) apple-trees. Amngerona crocotaria (Fig. 576) is 

a beautiful sulphur-yellow Geometrid, ex- 
panding 14 inches, with a number of irregular pinkish-brown blotches 


on the wings; its yellowish-green larve feed on currants, gooseberries, 


The Moths and Butterflies 399 


and strawberries, both wild and cultivated. Calocalpe undulata (Fig. 578), 
the scallop-shell moth, has pale yellowish-brown wings crossed by many 
fine zigzag darker lines close together; its larvae feed on wild cherry and 
live gregariously inside of a nest formed of leaves tied together by silken 
threads. A very common little moth in meadows and gardens in summer 
and fall is the chickweed-geometer, Hematopis grataria, with reddish- 


FIG. 577- 


Fic. 576.—The currant-angerona, Angerona crocataria. (After Lugger; natural size.) 
Fic. 577-—The currant-endropia, Endropia armataria. (After Lugger; natural size.) 
FIG. 578.—The scallop-shell geometer, Calocalpe undulata. (After Lugger; natural size.) 


yellow wings and two transverse bands and the outer margins pinkish 
The chain-dotted geometer, Caterva catenaria, expanding 14 inches, with 
white wings dotted with fine black points arranged in two lines and with 
a few extra ones, appears sometimes, according to Lugger, in such very 
great numbers as to look like a snow-storm; its larve are pale straw-yellow 
with two fine lines on the back and two on each side interrupted by two 


Fic. 579.—The diverse-lined geometer, Petrophora diversilineata, (After Lugger; 
natural size.) 


large black dots, a pair on each segment; it feeds on hazel, blackberry, 
raspberry, and other plants. 

A great host of somber-colored moths, blackish, grayish, or brownish, 
with no conspicuous markings and only rarely any bright colors, compose 
for the most part the family Noctuide, the largest of all the families of moths. 
Twenty-one hundred North American species—three times as many as 
there are North American species of birds—belong to the single family 
Noctuidz, and for the most part these two thousand mixed species must be 
as one to the general collector and amateur. Few professional entomologists, 
indeed, lay claim to a systematic knowledge of the group, or even care to 
give to it the time necessary to acquire such a knowledge. Some of the 


400 The Moths and Butterflies 


Noctuids have come into prominence because of the destructive vegetable- 
feeding habits of their larvae; such are the cutworm-moths, the army- 
worm moths, the cotton-worm moths, and others, and these species are 
so often described and pictured that they are fairly well known. Other 
small groups, of which the interesting Catocalas, the red and yellow under- 
wings (Fig. 580), are the most conspicuous, have attracted the attention 
of collectors because of particular habits or patterns, and these are fairly 


Fic. 580.—A group of red and yellow underwings; upper moth, Catocala paleogama; 
lower left-hand corner, Catocala ultronia; lower right-hand corner, Catocala grynea. 
(After Lugger; natural size.) 


well known. Few moth-collectors but have ‘‘sugared” for Catocalas, 
those large night-flyers, somber of fore wing but brilliant of hind wing, 
that can be so readily attracted and taken by a bait of molasses and stale 
beer smeared in patches on the trunks of trees in summer-time. The fore 
wings harmonize in color, shades, and pattern so thoroughly with the bark 
that when the Catocala rests, as it does during the daytime, on tree-trunks 
with its brilliant hind wings, strikingly banded with red, yellow, white, or 
black, covered by the fore wings, it is simply indistinguishable. The 
Catocala larve are curious creatures, with body thick in the middle and 


The Moths and Butterflies 401 


tapering towards both ends. The larve of Catocala ultronia (Fig. 581) 
feed on plum-tree leaves; they are about 14 inches long, grayish brown, 
with two or four small reddish tubercles on each body-segment, a small 
fleshy horn on the back of the ninth segment and on the back of the twelfth 
segment a low fleshy ridge tinted behind with reddish brown. It descends 
to the ground when ready to pupate, making a flimsy cocoon of silk under 
a dead leaf or chip. The pupa inside the cocoon is covered with a bluish 
flour-like dust or ‘‘bloom.”” The moth has the forewings rich amber with 
a broad indefinite ashy band along the middle and several brown and 


Fic. 581.—The plum-tree Catocala, Catocala ultronia, moth and larva. 
(After Lugger; natural size.) 


white transverse lines; the hind wings are deep red with a wide black 
band along the outer margin and a narrower one across the middle. The 
eggs are laid in cracks of the bark in summer. Catocala grynea (Fig. 580), 
with grayish brown forewings marked with zigzag lines of rich brown and 
gray short dark-brown streaks on the front margin and with hind wings 
reddish yellow crossed by two wavy black bands, is called the apple-tree 
Catocala, because the ashen-brown caterpillar feeds on apple-leaves. The 
two front pairs of abdominal prop-legs of all the Catocala caterpillars are 
much smaller than the hinder two pairs, hence the caterpillar has a sort of 
looping gait like that of the Geometrid larvae, the inchworms. Catocala 
relicta has the fore wings grayish white with several indefinite transverse 
black bands, and the hind wings black with one curving white band. 
Catocala epione has blackish-brown fore wings with wavy narrow black and 
lighter brown transverse lines with black hind wings narrowly margined 
with white. 

The largest and most interesting Noctuid, and indeed one of the largest 
of all the moths, is the curious rare species Erebus odora, called the black 
witch; it expands 6 inches and has both wings blackish brown with many 


402 The Moths and Butterflies 


indefinite wavy lines of black and of lighter brown; in the hinder angle 
of the hind wings are two incomplete eye-spots bounded in front by a cury- 
ing velvety black line, and on each fore wing is a single irregular eye-spot 
near the front margin. 

““Cutworm” is the name applied to the smooth, ‘‘greasy,’”’ plump cater- 
pillars of numerous species (representing several genera) of Noctuids. The 
greasy cutworm, dull blackish brown with pale longitudinal lines attacks 
all sorts of garden products and other low-growing plants; it is the larva 


Fic. 582.—Green-fruit worms, Xylina grotei, at left, and Xylina antennata at right. 
(Photograph by Slingerland; natural size.) 


of Agrotis ypsilon, with brownish-gray fore wings bearing an ypsilon- 
shaped mark, the hind wings being silky white. The climbing cutworm, 
Carneades scandens, an active climber and great enemy of nurseries and 
orchards, is light yellowish gray with a dark line along the back and fainter 
ones along the sides; the moth has light bluish-gray fore wings with darker 
markings and pearly-white hind wings. Cutworms mostly hide in cracks 
or burrow in the ground by day, feeding during the night; they will often 
cut off young plants just at the ground, or will ascend tall trees and feed 
on the buds and young leaves. When ready to pupate they burrow into 
the soil and the moths issue in midsummer. 

The members of the large genus Plusia (Pl. VIII, Fig. 7), including some 
of the commonest Noctuids, are recognizable by a small silvery comma-shaped 
spot on the disk of each fore wing. Another large genus is that of Cucul- 
lia, the hooded owlets, in which the thorax bears a prominent tuft of scales 
and the fore wings are marked with irregular blackish dashes. The 


The Moths and Butterflies 4.03 


Fic. 583.—Army-worms, larva of Leucania unipuncta, on corn. (Photograph by 
Slingerland; natural size.) 


404 The Moths and Butterflies 


dagger-moth Acronycta (Figs. 586 and 587), so called from the rather uncer- 
tain small black dagger-like markings of the fore wings, have the larva in 
some species covered with long colored stiff hairs; the familiar caterpillar 
of A. americana is densely clothed with 
yellow hairs, besides bearing a pair of 
long black pencils on the first abdominal 
segment, another pair on the third, and 
a single pencil on the eighth. It feeds on 
the leaves of elm, maple, and other trees, 
and when at rest curls sidewise on a leaf. 
The army-worm (Fig. 583), a black, 
yellow, and green striped caterpillar 
that occurs over nearly all the country 
and often appears in enormous numbers, 
causing great losses to grain-fields, is 
the larva,of a dull-brown moth, Leu- 
‘ f Saad ___ cania unipuncta, marked in the center 
gives Werieigin ae rig of each fore wing with a distinct white 
subcostal vein; 7, radial vein; m, spot. Perhaps as severe a sufferer as 
medial vein; ¢ cubital vein; a, anal any other field product from the attacks 
veins. (After Comstock; enlarged.) & ‘ ; 
of Noctuid larve is cotton. The cotton- 
worm, Aletia argillacea, feeds on the foliage of the cotton-plants and the cotton 
boll-worm, Heliothis armigera, attacks the cotton pods or bolls. These two 
caterpillars cause losses to the cotton-growing states of millions of dollars 


Fic. 585. Fic. 586. 
Fic. 585.—Larve of the gray dagger-moth, Acronycta occidentalis. (After Lugger; 
natural size.) 
Fic. 586.—Gray dagger-moth, Acronycta occidentalis. (After Lugger; natural size.) 


every year. The cotton boll-worm is more or less familiar in states farther 
north, under the name of corn-worm, where it is found feeding on ears of 
green corn and on tomatoes. It is a naked, greenish-brown, dark-striped 
caterpillar. The moth has pale clay-yellow fore wings with a greenish tint, 
the hind wings paler. 

Among the most conspicuous of all the caterpillars are the not unfamiliar 
larve of the tussock-moths, Lymantriide, one common species infesting our 


PLATE vi 


PLATE VI. 
MOTHS. 


1=Catocala parta. 
2=Basilona imperialis. 
3=Apanresis virgo. 

4= Pseudohazis eglanterina. 
5=Automeris io. 


PLATE VI 


a) 
< 
S 
SS 
y 
K 
& 
= 


The Moths and Butterflies 405 


shade-trees in town and country and another, less common, attacking orchards 
and forest-trees. The caterpillars (Fig. 588) of Hemerocampa leucostigma, 
the white-marked tussock-moth, which is the shade-tree species, are about 
1} inches long, very hairy, bright yellow with a blackish stripe along the back 
and one along each side, but chiefly conspicuous by a series of four cream- 
colored dense tufts of vertical hairs on the back, three long black hair pen- 
cils, two on the front part and one on the 
hind part of the body, and by the coral-red 
head and similarly colored two small pro- 
tuberances on the sixth and seventh abdom- 
inal segment which are scent-organs used 
to repel enemies. When full-grown these 
caterpillars pull the hairs from their body 


and mixing them with some silk make a Fic. 587.—The raspberry dagger- 
moth, Acronycta impressa. (After 
Lugger; natural size.) 


grayish cocoon on the tree-trunks. The fe- 
male moth is wingless, light gray in color, 
and unusually long-legged for a moth; when issued she simply crawls out of the 
cocoon and lays her 300 to 500 eggs covered by a frothy-looking but firm sub- 
stance in a grayish mass on the outside of it. The males are ashy gray and 
have broad short wings, expanding r} inches, the fore wings with darker wavy 
transverse bands, a small black spot near the tip, an oblique blackish stripe 
beyond it, and a minute white crescent near the outer hinder angle. The 
antennz are feathery, and the 
fore legs tufted with hairs. The 
best remedy for these pests is 
to gather the egg-masses in the 
winter and put them into a box 
with its top covered by mosquito- 
netting. In the spring the larve 
and the egg parasites which are 
numerous will hatch; the minute parasites will escape through the netting 
to go on with their good work, while the moths will be retained in the box 
and may be killed. 

The orchard and fruit-tree species, Parorgyia parallela, the parallel- 
lined tussock-moth, is winged in both sexes, the moths being dark gray with 
darker-colored wavy lines and spots. The caterpillars are gray with lon- 
gitudinal black stripes; short black tussocks are found on the back of seg- 
ments 4 to 7,a pair of long black pencils is at each end of the body, and on 
the back of each of segments 9 and ro is a small pale-yellow scent-cup. 
The head is shining black. It feeds especially on plum-, crabapple-, and 
oak-trees. 

The most notorious member of the Noctuide is the gypsy-moth, Porthetria 


Fic. 588.—Larva of the tussock-moth, Hemero- 
campa leucostigma. (After Felt, natural size.) 


406 The Moths and Butterflies 


dispar, a European species brought to Massachusetts in 1868, and from 
1890 to 1g00 fought at the public expense. A gentleman living in Med- 
ford, a town of Massachusetts, imported a number of different kinds of Euro- 
pean silk-spinning caterpillars in an attempt to find some species which 
might be bred in this country in place of the mulberry silkworm (Bombyx 
mori). Some of the moths escaped from his breeding-cages, and among 
them some gypsy-moths. In a very few years the species had increased to 
such numbers and spread throughout such an extent of woods that it seri- 
ously threatened the destruction of all the forest- and shade-trees in north- 
eastern Massachusetts. By 1891 it was causing great injury to forest-trees 
over 200 square miles. So far it has been confined because of the whole- 
sale operations against it. The State has employed as many as 570 men 
at a time in spraying, egg-collecting, trunk-banding, etc., in the great fight 


Fic. 589.—The California oak-worm moth, Phryganidia californica. A, eggs on leaf; 
B, just-hatched larva; C, full-grown larva; D, pupa, or chrysalid; 2, moth; F, Pimpla 
behrendsii, parasite of the larva. (B, much enlarged; D and F, twice natural size; 
others natural size.) 


against the pest and up to 1900 had expended over a million dollars in the 
struggle. The caterpillar when full grown is 14 inches long, creamy white, 
thickly sprinkled with black, with dorsal and lateral tufts of long black and 
yellowish hairs. ‘The cocoon is very slight, merely a few silky threads. The 
male moths, expanding 14 to 2 inches, are brownish yellow with smoky fore 
wings bearing darker irregular transverse lines and pale hind wings with 
darker outer margins. The females are large, expanding 24 inches, and 
creamy white in color, with irregular transverse gray or blackish lines. 


The Moths and Butterflies 407 


In California is found a pretty pale-brownish moth that flutters weakly 
about the live-oak trees in early summer and late autumn, which has the 
distinction of being the only North American species in the family Dioptide. 
The larve of this moth feed chiefly on the leaves of the live-oaks and white 
oaks in the California valleys and the species may be called the live-oak 
moth, Phryganidia californica (Fig. 589). ‘The moths expand about 1 inch 
and are uniformly pale brownish, with thinly scaled and hence almost trans- 
lucent wings. The male has a small yellowish-white ill-defined blotch on 
the center of each fore wing. The eggs are laid by the early summer brood 
of moths on the under side of the leaves of the oaks and the naked light- 
yellowish black-striped larvee feed until October 1st on the tough leaves. 
Then they crawl down to the tree-trunks or to near-by fences or logs and 
change to a naked greenish-white or yellowish chrysalid with many black 
lines and blotches. ‘The moths issue in from ten to twelve days after pupa- 
tion and lay their eggs again on the oak-leaves. But here is a curious fact. 
All the eggs laid on white-oak leaves by these autumn moths are doomed 
to death because just at the hatching-time the white-oak leaves fall and dry. 
The live-oak retains its leaves all winter and the larvae hatched on them 
feed and grow slowly through the winter, pupating in May and issuing as 
moths about June rst. Thus each year about one-fourth of the eggs laid 
by this species are wasted. The larvee from the eggs laid on the white oaks 
in the spring live because they have white-oak leaves all summer to feed 
on, but those of the fall brood which hatch on the white oaks all die. In 
some seasons this insect is so abundant as to defoliate the oak-trees in cer- 
tain localities twice during the year, but whenever the caterpillars get so 
numerous a certain small slender ichneumon-fly, Pimpla behrendsii, which 
lives parasitically on them becomes also very abundant (there being plenty 
of food for its young) and soon checks the increase of the moth. Out of 
144 chrysalids of the moth which I once gathered but 11z moths issued, 
99 of the chrysalids giving forth ichneumon-flies and the rest dying from 
other causes. I have found the caterpillar most abundant on the live-oaks 
(Q. agrifolia), but it occurs also on Q. lobata, Q. kelloggii, Q. dumosa, and 
Q. douglassi, Q. chrysolepsis. 

A family represented in this country by only four species is the Peri- 
copide. Three of these species are found only in the western states, the 
fourth in Florida. The single species of the four at all familiar to collectors 
is the beautiful and abundant Gnophela latipennis, with its two or three 
varieties. This moth expands about 2 inches and is black, with two 
large white blotches on the fore wing, each blotch subdivided by the black 
veins running through it and single large blotch on the hind wing. A 
variety common in California has the blotches smaller and pale yellowish. 

The wood-nymph moths, Agaristide, of which about two dozen species 


408 The Moths and Butterflies 


are found in North America, include a few strikingly patterned moths not at 
all uncommon. The moth known as the eight-spotted forester, Alypia octo- 
maculata (Pl. VIII, Fig. 5; also Fig. 590), is common in the Atlantic states; 


itt 


Fic. 590.—Three eight-spotted forest-moths, Alypia 8-maculata, and one beautiful wood- 
nymph, Eudryas grata (the lowest). (After Lugger; natural size.) 


it expands about 1} inches, has deep blue-black wings, with two large sub- 
circular whitish-yellow spots on each wing, the spot nearest the base on 
the hind wing being much larger than the outer one. The patagia (shoulder- 
lappets) are often yellow and the legs marked with orange. The larve, 


The Moths and Butterflies 409 


which are light brown with many fine black lines and one broad orange 
band across each segment and head and cervical shield deep orange with 
black dots, feed on the Virginia creeper, sometimes on the grape, and often 
are so abundant as to injure the plants seriously. The caterpillar is nearly 
14 inches long when full-grown, and burrows into soft or rotten wood to 
pupate, or failing this pupates on or just below the surface of the ground. 

The beautiful wood-nymph, Eudryas grata (Fig. 590) (classed by 
some entomologists with the Noctuide), is very different in color and 
pattern, having milk-white fore wings broadly bordered and marked with 
brownish purple and with two indistinct brownish spots in the center. 
The under surface of these wings is reddish yellow. The hind wings are 
yellow with a pale purplish-brown border. The head is black and there 
is a wide black stripe along the back of the thorax, breaking up into a 
series of spots along the abdomen. The caterpillar is much like that of 
the eight-spotted forester and feeds on the same plants. ‘The moth, which 
is active at night and sometimes attracted to electric lights in large numbers, 
is very often discovered during the day upon the surface of the leaves of its 
food-plants. Its closed wings form a steep roof over its back, and its four 
legs, which have a curious muff-like tuft of white hairs, are protruded and 
give the insect a very peculiar appearance.” 

The grape-vine Epimenis, Psychomorpha epimenis, is a small velvety 
black Agaristid moth with a broad, irregularly lunate, white patch across 
the outer third of the fore wing and a somewhat larger and more regular 
patch of orange-red or brick-red on the hind wings. Its bluish caterpillar 
feeds on grape-leaves. 

Delicate and pretty are the little footman-moths, Lithosiide, in their 
liveries of drab or slate, yellow or scarlet, and with their slender bodies 
and trimly narrow fore wings. The larve of but few species are known; 
they mostly feed on lichens and have the body covered with short stiff 
hairs. Because these caterpillars are not injurious but little attention 
has been given to the life-history of the footman-moths, and the amateur 
has here an opportunity to add to our knowledge of insects in an order 
popularly supposed to be pretty well “‘worked out.” 

The moths themselves although few in number of species are well dis- 
tributed over the country, although the southwestern and Pacific states 
have really more than their share. Two common eastern species are 
the striped footman, Hypoprepia miniata, and the painted footman, 
H. juscosa, each expanding about 1 inch. The first is brick-scarlet, with 
two longitudinal broad plumbeous bars and the distal half of a third on 
the fore wing and a broad outer slaty border on the hind wings. The 
latter has almost the same pattern, but the ground color is distinctly yellowish 
red in place of scarlet or brown-red. Another common eastern Lithosiid 


410 The Moths and Buttertlies 


is the pale footman, Crambidia pallida, expanding nearly 1 inch and 
drab all over; C. cephalica, found in Colorado and Arizona, expanding 
not quite an inch, has both wings and the whole body of a delicate shining 
silvery white. The banded footman, Cisthene (Ozonadia) unifascia, found 
all along the Atlantic and Gulf coasts, expands 3 inch and has the fore 
wings dark with a narrow curving yellow band and the hind wings with 
the base and disk pink or yellowish, the apex being dark. Lithosia (Lexis) 
bicolor, found in the northern states and Canada, expands nearly 1} inches 
and is slate-colored, with yellow on the front margin of the fore wings, the 
tip of the abdomen, the prothorax, and the palpi. The several Rocky 
Mountain and desert species mostly have brick-red or drab or slaty ground 
color, some unmarked and some with dark border on the hind wings if 
red is the ground color, and smoky-whitish hind wings if body and fore 
wings are drab or slaty. 

Another family of moths expanding about an inch, and with a charac- 
teristic habitus due to the long narrow fore wings, the small size of the 
hind wings, and the contrasting colors of the wing-pattern, are the Zygenide, 
or Syntomide, as the newer nomenclature names them. In the hind wing, 
veins subcosta and radius are fused, usually for the whole length. About 
twenty species of the family are found in this country, and because, as 
with the Lithosiide, the larve are not of much economic importance the 
life-history of but few of the species is known. The majority of the species, 
besides, live in the western and southwestern states, and like other 
mountain, plain, and desert insects are hardly known except in their flying 
stage. The larve of some species feed on grasses, of others on lichens. 

One of the most striking species is Cosmosoma auge, found in the 
extreme south, which has both fore and hind wings clear of scales over 
the base and disk only, a border all around the veins, and a small black 
patch at the tip of the discal cell of the fore wing covered with black scales. 
The plump body is scarlet, with the end of the abdomen and a dorsal 
longitudinal band on it metallic blue-black. The wings expand 1 inch. 
Lycomorpha is a genus of small Zygenids characterized by having the 
wings colored in two strongly contrasting shades, black and brick-red or 
black and reddish yellow. In L. pholus the basal two-fifths of each 
wing is yellow and all the rest black; in L. miniata the basal two- 
thirds is red, the rest black; in L. grotei all of the fore wing is red 
except a narrow black border on the outer margin, while the anterior 
half of the hind wings is red, the posterior half black. Ctenucha is a 
genus of larger species which have smoky-brown wings unmarked, as 
in C. virginica, a northeastern species, which has a yellow head 
and metallic bluish-black body, C. multijaria and C. ruberoscapus, 
Pacific coast species which have a coral-red head and shoulder-lappets 


The Moths and Butterflies 


4II 


and metallic deep-bluish body, or which have the fore wings marked 


by a few conspicuous longitudinal 
yellowish lines as in C. venosa, found 
in Colorado, New Mexico, and 
Texas. Scepsis fulvicollis, found in 
the eastern and Mississippi Valley 
states, has subtranslucent smoky 
wings with a region clear of scales 
in the middle of the hind wings; its 
prothoracic collar is yellow and its 
abdomen metallic blue-black. 

The ‘‘woolly-bear” caterpillars 
(Fig. 592) and the tiger-moths, which 
are the same insects in different 
growth stages, are among the most 
familiar of caterpillar and moth 
acquaintances. They belong to the 
family Arctiidae, represented in this 
country by a hundred and twenty 
species of which surprisingly many 


are pretty well known to any ardent collector. 


@ a 


Fic. 591.—Venation of a Zygenid, Ctenucha 


virginica. cs, costal vein; sc, subcostal 
vein; yr, radial vein; m, medial vein; c, 
cubital vein; a, anal veins. (After Com- 
stock; enlarged.) 


The strikingly colored, 


spotted, and banded wings of the stout and hairy-bodied moths and the 
dense clothing of long strongly colored hairs characteristic of most of the 


Fic. 592.—Woolly-bear caterpillars, Halisidota sp., all three of the same species but 
showing variations in extent of the black markings. 


larve are the recognition-marks of the family. 


The moths, too, are 


mostly fairly large and are readily attracted by lights, while the cater- 


412 The Moths and Butterflies 


pillars, trusting to the uncomfortable mouthful of hairs they offer their 
bird enemies, travel conspicuously about in the open with a characteristic 
nervously hurrying gait. Thus the Arctians become familiar to collector 
and observer. 

The woolliest woolly bear is the larva, sometimes called ‘‘hedgehog,” of the 
Isabella tiger-moth, Pyrrharctia (Isia) isabella (Pl. VII, Fig. 3), common all 
over the United States; it is covered with a stiff furry evenly shorn coat black at 
either end and red-brown in the middle, and is commonly seen in the autumn 
traveling rapidly about in open places. It hibernates in larval stage under 
loose bark or logs or sidewalks, and, after a brief activity in the spring, pupates 
within a slight cocoon made up of silk and its own brown and black hairs. 
The moth which issues soon is dull orange with the front wings variegated 
with dusky and spotted with black; the hind wings are lighter and also 
black-spotted; it expands 2 inches. The caterpillars feed on various plants, 
sometimes becoming destructive, when in sufficient numbers, to black- 
berry and raspberry bushes and to nursery stock. Lugger says that they 
are especially susceptible to attack by muscardine, a parasitic fungus disease 
much feared by silkworm-growers. ‘“‘Hedgehogs”’ killed by muscardine are 
found stiffly attached to their food-plants with a whitish powder over the 
body at the base of the dense hair covering. 

The yellow bears, common caterpillars on the leaves of vegetables, 
flowering plants, and fruits, distinguished by their dense but uneven coat 
of long creamy-yellow, light or even dark brown hairs, are the larvae of the 
beautiful snowy-white miller-moth, Spilosoma virginica. The wings bear a 
few (two to four) small black dots, and the abdomen is orange-colored 
with three rows of black spots. The larvae pupate in the fall in cocoons 
composed almost wholly of their own long barbed hairs, and the moths issue 
in the spring. There is usually a second brood each year. This moth is 
kept in check by many parasites, few other insects having to contend with 
so many of these insidious enemies of their own animal class. 

The most destructive member of the family is the fall web-worm, /7yphan- 
tria cunea, which makes the large unsightly silken “‘nests”’ in various trees, 
both wild and cultivated, so familiar in latesummerand autumn. The eggs 
are deposited in regular clusters of 400 or more on the plum-leaves, and the 
hatching pale-yellow larve spin small silky web-nests close together which 
finally get included in one large one. ‘The full-grown larve are pale yellow- 
ish or greenish with a broad dusky stripe along each side; they are covered 
with whitish hairs which rise from black and orange-yellow warts. They 
often hang from the nest or branches by a long silken thread. They pupate 
in crevices of the bark and other sheltered places on the ground, passing 
the winter in this stage. The milk-white moths, sometimes with small 
black spots on the wings, sometimes unspotted, issue in late spring or early 


The Moths and Butterflies 413 


summer. They expand 1} inches. There is much variation in color and 
pattern in both moths and caterpillars, many varieties being found in a 
single tree. 

Among the most strikingly colored and patterned Arctians are the numerous 
species of Apanresis (Arctia). A. virgo (Pl. VI, Fig. 3), a common species 
in the Atlantic states, whose larva feeds on pigweed and other uncultivated 
plants, expands 24 inches, has black fore wings with the veins broadly marked 
with pinkish yellow, and red hind wings with large angularly irregular black 
blotches. The thorax is colored like the fore wings, the abdomen like the 
hind wings. Sharply angled black spots on a ground of reddish, pinkish, 
salmon, and yellowish characterize almost all the many species in this genus. 


Fic. 593.—Caterpillar of Halisidota tesselata. (After Lugger; natural size.) 


Striking moths are Arachnis picta (Pl. VIII, Fig. 4), with whitish fore wings 
marked with wavy band-like blotches of pearl-gray, and red hind wings with 
three uneven gray bands; Ecpantheria deflorata, the leopard-moth of the south 
Atlantic states, and E. muzina, of the southwestern states, both creamy white 
with circular or elliptical black spots or rings thickly scattered over the fore 
wings, but only ina single submarginal series on the hind wings; and Utethe- 
isa bella (Pl. VII, Fig. 7), a familiar little moth of the Atlantic states with 


414 The Moths and Butterflies 


its pinkish-red hind wings with black branching border and yellowish-red 
fore wings crossed by six bending white bands containing small black spots. 

Attractive and familiar moths are the various species of Halesidota, whose 
larvee feed on the leaves of hickory, oak, and several kinds of orchard trees. 
These caterpillars (Fig. 593) are covered with short spreading tufts of hairs 
white and black or yellow, and bear, too, a single pair of long hair pencils 
usually black or orange. They are often called tussock-caterpillars and 
are not unlike the true tussock-moth larve (see p. 404). The moths 
(Fig. 594) have long narrow fore 
wings, and hind wings only about 
half as long; in H. tessellata the 
hind wings are almost transparent 
yellowish (while the fore wings have 
faint darker short transverse lines 
or blotches); H. maculata (Fig. 595) 
has yellowish fore wings thickly 


Fic. 594. FIG. 595. 


Fic. 594.—Halisidota carye, above, and H. tesselata, below. (After Lugger; natural size.) 
Fic. 595.—Halisidota maculata. (After Lugger; natural size.) 


sprinkled with brown and blotched with creamy-white spots, the pale hind 
wings being unmarked; H. lobecula has the wings nearly transparent, the fore 
wings dusted with dark scales, and a regular check pattern on the front and 
hind margins, the hind wings unmarked, and the abdomen of a beautiful 
rose color; H. argentata has the fore wings blackish brown with distinct 
white spots all over the surface, white hind wings bearing a single irregular 
brown spot near the apex. The Callimorphas (Fig. 596) are pretty, slender- 
bodied Arctians with snow-white, creamy, or soft warm yellow-brown wings, 
banded with dark brown or blackish; they belong to the genus Hap‘oa, 
whose larve are blackish studded with blue spots, and covered with short 
stiff hairs. All the species of Haploa are found in the Atlantic states. H. 
clymene (Pl. VII, Fig. 5) has the wings brownish yellow, paler on the fore wings, 
which are incompletely bordered with blackish brown, a curious blunt arm 
of this color projecting in from the hinder margin; the hind wings have a 
subcircular dark spot; H. lecontei has white hind wings, and brown fore 


, 


5 
Be 
ae 
e. 


a14 The Mothe ond Vutrer@ies 
tye pink) h-red hind we inagh vith bheck lwanching border and yellowish-tod 
here wings cross t by a tema vabiue bands containing small black is. 

Attractive aud taaear vanities tS the various species of Halesidots, 
od on the 4 tacbery, oak, and several kinds of enchard 
These catert . Poe egy are covered with short spreading tufts of hairs 
white and back of sey teor, too, » Saghe pair of long Bait TORE 
vieck ot ams ‘“Tcy. are often called nyvsock-caterpilars- and 
at antiee oe, aee tussock-moth larvae (see p. 404): The moths 
(Fig. soe) fave long narrow fore 
wingy, amb hind wings only about | 
half as lomg; i H. tessellata the 


Po. 504- : 
i i alibdetacarye, above, ant 1 lersetata, below- (Atrer Muggers natural sian.) . 
Fic, 99 Tkaituba macwions, (After Luggets natural Stee.) 


i 
sprink al brow and blotched with creamy-white Spots, the pale hind 
wings ter ‘womarked; 2 ober ula has the Wings nearly the bet 
wings & ¢ with dark scales, and « requiat check patiern on tie insut and 
hind we the hind wings unmarked, ard the abdomen of a 
Jor, Hf argentata has the fore wings blackéah brows with fistine 
: ower the surface, white hind wings bearing & single irregular 


te & 
v4 spol Dee the apex. The Callimorphas Pig, 69%) are pretty, alender- 
Arctians with snow white, creamy, OF soit warm yellow brown WINGS) 
: eith dark brawn oF blackish; they belong ta the genus Hap, 
are binckish studded with blue spots, and covered with shart 
’ AM the species 0! Haploa are found in the Atlantic state. H 
acne 12). WEL Fig: §) is the wings brownish yellow, paler on the fore Wi 
hich art tebe bordered with blackish brown, 4 curious hele sen 
this color » ia from the hiacet marin; the hind winge Nave ® 


i teconter bus white hind Wings, an orn fore 


PLATE VII 


The Moths and Butterflies ALS 


wings with six large white blotches; H. fulvicosta has all the wings pure 
white with the front margin of the fore wings weakly fulvous. A familiar 
Arctian is the salt-marsh-caterpillar moth Eustigme acrea, expanse 1 
inches, with creamy-white fore wings and soft yellow-brown hind wings, all 
the wings sparsely dotted with black. 

A small family which includes a few widely distributed and well-known 
moths is the Lasiocampid, of which the tent-caterpillar moths are the most 
familiar. All the Lasiocampid moths, which are robust, hairy, and fairly 
large, lack the frenulum, having, however, the humeral angle of the hind 
wing expanded so as to overlap the inner hind angle of the fore wing. In 
this humeral angle are one or two short supporting veins or vein-spurs. 


Fic. 596.——Haploa fulvicosta (above) and H. contigua (in the middle and below). 
(After Lugger; natural size.) 


The best-known eastern species is the apple-tree tent-caterpillar, the 
forest tent-caterpillar being also familiar; on the Pacific coast also occur 
two common species, one specially affecting orchard trees. These four 
species belong to the genus Clisiocampa (Figs. 598, 599); the moths expand 
about 1} inches and are all brown, varying in shade from yellowish to walnut 
to chocolate-brown, with a pair of pale or distinct light or darker oblique lines 
on the fore wings. C. americana, the apple-tree tent caterpillar, lays its 
three hundred eggs in the summer in a band or ring glued around a small 


416 The Moths and Butterflies 


twig of an apple or wild-cherry tree; the eggs do not hatch until the follow- 
ing spring, when the young larve feed on the buds and young leaves of the 
tree. The social larve build a little web or nest in the fork of a branch, 
going out of it only to feed. As the 
caterpillars grow they enlarge the web 
until it becomes a bulky ugly affair 
perhaps two feet long, partly filled with 
excrement and cast skins. The full- 
grown caterpillars are blackish with 
yellow and bluish spots, white striped 
along the back, and covered with fine 
yellowish hairs. ‘‘They feed on the 
young and tender leaves, and eating 
on an average two leaves a day the 
young of one pair of moths consume 
from ten to twelve hundred leaves, and 
Fic. 597.—Venation of Halesidota tessel- 4S it is not uncommon to find from six 
lata. cs, costal vein; sc, subcostal to eight nests on a single tree not less 
vein; r, radial vei; m, medial vein; 
c cubital vein; a; anal veins) J(ASex than seventy-five thousand leaves are 
Comstock; enlarged.) devoured, a loss which no tree can long 
endure.”’ In about forty days the larve 
are ready to pupate, when they scatter from the nest, find sheltered places 
under eaves, fence-rails, etc., and spin spindle-shaped cocoons of white, 
almost transparent silk, within which they change. After twenty to twenty- 
five days of pupal life the winged moths issue and soon after lay their 
eggs for next year’s brood. /The life-history of the various other species 
is similar to this although other trees are chosen for feeding-grounds. 

The lappet-moths, so-called from the curious lobes or lappets arranged 
along the sides of their caterpillars, are of several species. Tolype velleda, 
expanding 14 to 1} inches, has a white body with a black spot and dusky- 
gray wings crossed by white lines; its caterpillar feeds on the foliage of 
apple-, cherry-, and plum-trees, and is hair-fringed and protectively colored so 
that it looks much like an excrescence of the bark on which it habitually 
lies when not feeding. Gastropacha americana (Fig. 601), the American 
lappet-moth, expanding 14 inches, is so like a dead leaf in appearance that 
it can hardly be distinguished when at rest; it varies somewhat in color, 
but most individuals are reddish brown with a broad interrupted whitish 
band across both wings; the hinder and outer edges of the fore wings and 
the outer edges of the hind wings are deeply notched. The caterpillar feeds 
on apple, cherry, and oak, hiding during the day but becoming active at 
night. It is broad, convex above and flat beneath, ash-gray with fringes 
of blackish or gray hairs, and when at rest it is almost impossible to recognize. 


oe 


The Moths and Butterflies 417 


It grows to be 2 inches long and spins a peculiar gray cocoon which looks 
very much like a slight swelling of the twig to which it is fastened. The 
pupa hibernates, the moth issuing in June of the next year. 


Fic. 598. 


Fic. 598.—A family of young forest tent-caterpillars, Clisiocampa disstria, resting during 
the day on the bark. (Photograph from life by Slingerland; one-third natural size.) 


Fic. 599.—The forest tent-caterpillar moth, Clisiocampa disstria, in its various stages. 


m, male moth; /, female moth; ~, pupa; ¢, egss in a ring about twig; g, eggs after 
hatching; ¢, larva or caterpillar. (After Slingerland; moths and caterpillar natural 
size, eggs and pupa slightly enlarged.) 


Including the largest, the most beautiful—in popular eyes at least— 
and the favorite moths for rearing in “crawleries,” the superfamily Saturniina 
includes as well one of the only two insects that have been domesticated 
by man and reared for the sake of their useful products. The honey-bee 
and the silkworm moth are fairly to be called domesticated animals. To 
the Saturniina belong the great cecropias, the marvelous lunas, the regal 
and imperial walnut-moths, and the soft-tinted rosy dryocampas. Although 
the whole group, divided commonly into four families, includes but forty- 
two North American species, almost every one of these is more or less 


418 The Moths and Butterflies 


familiarly known to the amateur collector and crawlery owner. And popular 
books like Dickerson’s ‘‘Moths and Butterflies,” Eliot and Soule’s “Cater- 
pillars and Their Moths,” etc., which tell in 
detail of the life-history and habits of various 
Lepidoptera, mean by “‘moths,” first Saturnians, 
then Sphingids, and finally a scant sprinkling 
of ‘‘others.” The giant vividly colored cater- 
pillars, the great silken cocoons safely enclosing 
their mystery until that day when a marvel of 


Fic. 600. Fic. 601. 

Fic. 600.—Venation of Clisiocampa americana. cs, costal vein; sc, subcostal vein; 
r, radial vein; m, medial vein; c, cubital vein; a@, anal veins. (After Comstock; 
enlarged.) 

Fic. 601.—The American lappet-moth, Gastropacha americana, (After Lugger; natural 
size.) 


living color and pattern slowly crawls out and unfolds and takes on the 
seeming of the perfect cecropia or polyphemus, it is little wonder that the 
giant silkworm-moths are—always never overlooking the swift and masterful 
Sphingids—the moths of popular fancy. 

Just because these moths are so well known and so well and fully written 
of elsewhere I may limit my account of them to a brief descriptive catalogue 
of adults and larve with the particular aim of making the more common 
species determinable by amateurs. The particular species in hand once 
safely identified, details of life-history and habits can be looked for in the 
many popular or technical accounts of the various kinds. In all, the males 
can be distinguished from the females by their large antenne and smaller 
bodies. In some species the sexes are very different in color and pattern. 

Of the genus Samia, the real giant silkworms, four species occur in 
this country. S. cecropia, the great cecropia-moth of the eastern states, 
expands 5 to 6 inches, has red thorax with white collar, red abdomen 
banded with white and black lines, wings with grizzled gray ground, and 
markings, as shown in Fig. 602, of reddish white and blackish with clay- 
colored outer margins. The large discal spots on the wings are whitish in 
the center, surrounded and encroached on by reddish, and margined with a 
narrow black line. The full-grown larva (Fig. 604) is nearly 4 inches 
long, pale limpid green, and bears on its back conspicuous tubercles, coral- 


The Moths and Butterflies 419 


red on the second and third thoracic segments, blue on the first thoracic and 
last abdominal, and yellow on the others; smaller blue lateral tubercles are 
present. It feeds on many kinds of orchard- and forest-trees, most small fruits, 
and some herbaceous plants. The winter is passed in the pupal stage 
enclosed in a great pod-shaped rusty-gray or brownish silken cocoon about 
3 inches long and 1 inch wide in the middle, composed of two layers, 
an outer strong ‘‘brown-paper”’ layer and an inner loose fibrous one. The 
pup may be easily found on trees when the leaves are off and brought 


Fic. 602.—Cecropia-moth, Samia cecropia. (Photograph by author; natural size.) 


into the house. The moths will issue in early summer through an opening 
which is left by the larva in one end of the cocoon. S. columbia of the north- 
eastern states and Canada is smaller than cecropia, the angulated discal 
wing-spots have hardly any reddish border and the transverse outer wing- 
border of white has no red outer margin as in cecropia, the abdomen is dark- 
red brown rather than red, and the basal half of the front wings is tinged 
with reddish brown. .S. gloveri, found in the Rocky Mountains and west 
to Arizona, is like columbia, but as large as cecropia. S. ceanothi of the 
Pacific coast has the ground color of the wings strongly reddish, the outer 


420 The Moths and Butterflies 


markings weak to wanting, the white transverse wing-band narrow and 
with no reddish border, the discal spots also without reddish margin. 


Fic. 603.—Venation of a Saturniid, 
Bombyx mori. cs, costal vein; sc, 
subcostal vein; r, radial vein; m, 
medial vein; c, cubital vein; a, 
anal veins. (After Comstock; en- 
larged.) 


The polyphemus-moth, Telea polyphe- 
mus (Fig. 605), expanse 4 to 5 inches, 
common in the whole country, is ocherous 
brown with a pinkish margined blackish 
outer transverse band across each wing 
and a discal spot on each wing with 
unscaled clear center; this latter char- 
acter makes the species at once unmistak- 
able; the hind wing-spots are in the center 
of a large blackish blotch with bluish 
scales by the inner margin of the clear 
spot. The larva (Fig. 606), which feeds 
on various forest-, shade-, and orchard- 
trees, reaches a length of 3 inches or 
more, is light green with seven oblique 
pale-yellowish lines on each side of the 
body, and bears numerous little black 
wart-like processes provided with small 
stiff bristles, and each body segment has 
a small silvery spot on the middle. The 
dense oval, completely closed cocoon is 
made of silk and a few leaves closely 
wrapped and tied together. It usually 


falls to the ground in autumn, but sometimes remains on the tree. The 
moth secretes a fluid from its mouth which softens and partly dissolves one 
end of the cocoon for its emergence. 


Fic. 604.—Larva of Samia cecropia. (After Dickerson; natural size.) 


In Plate VII, Fig. 4, is shown in color the luna-moth, or pale empress 
of the night, Tropea luna (Fig. 607), a marvel of delicate green tinting 


The Moths and Butterflies Aa 


and exquisite symmetry of curving outlines. It expands 44 inches, and 
ranges over the whole country. The larva is rather like that of the polyphe- 
mus-moth, being clear, pale bluish green with a pale-yellowish stripe on 


Fic. 605.—The polyphemus-moth, Telea polyphemus, and cocoon. 
(After Lugger; reduced about one-fourth.) 


each side of the body; each segment bears about six small purplish or rosy- 
tinged pearl tubercles; at the tip of the body are three brown spots edged 
with yellow. It feeds on hickory and walnut, on other forest-trees, and 


Fic. 606.—Larva of polyphemus-moth, Telea polyphemus. 
(After Dickerson; natural size.) 


makes a rather thin but compact cocoon of silk and leaves. 
In the eastern states the Asiatic ailanthus-worm moth, Philosamia 
cynthia, expanse 5 inches, with angulated wings, olive-brown ground-color 


422 The Moths and Butterflies 


on body and wings, a whitish lunate discal spot and a white and purplish 
transverse bar on each wing, and body with longitudinal series of white 
tufted spots, has become common near several cities. 

The promethea-moth, Callosamia promethea, expanse 3 to 4 inches, light 
reddish brown in female, and blackish and clay color in male, with mark- 
ings as shown in Fig. 609, is perhaps the most abundant of all these giant 
moths. Its larva when full-grown is 2 inches or more in length; it is bluish 
green and the body bears longitudinal series of black polished tubercles, 
two of these tubercles on each of the second and third thoracic segments 


Fic. 607.—The luna-moth, or pale empress of the night, Trope@a luna, 
(After Lugger; reduced about one-fourth.) 


being larger and red instead of black. It feeds on many kinds of trees, but 
Comstock has found it more frequently on ash and wild cherry than on 
others. ‘The cocoon is long and slender and enclosed in a dead leaf whose 
petiole has been fastened to the branch with silk by the larva. “At the 
upper end of the cocoon there is a conical valve-like arrangement which 
allows the adult to emerge without the necessity of making a hole.” C. 
angulifera is a moth slightly larger than promethea, but otherwise hardly 
distinguishable from it except that the shape and markings of the wings, 


Fic. 608.—Cocoons: 1, 
of Callosamia promethea. (After Laurent; somewhat reduced.) 


The Moths and Butterflies | 423 


2 


, 3, of Tropea luna; 4, 5, 6, of Callosamia angulifera; 7, 8, 9, 10, 


424 The Moths and Butterflies 


which vary a little in male and female of promethea, are identical in this. It 
is found also only in the Atlantic states. 

The Io emperor-moth, Auwlomeris io (Pl. VI, Fig. 5; also Fig. 610), ex- 
panse 24 to 3 inches, is the most familiar and the only eastern species of 
the four members of this genus. It can be recognized by the large blue 
and black eye-spots in hind wings and by its unmarked fore wings. The 
female has rich purplish-brown fore wings, the markedly smaller male yellow 
fore wings. The larva (Fig. 611), which feeds on trees, small fruits, corn, 
clover, etc., when full-grown is 24 inches long, and is pale green with a 


Fic. 609.—The promethea-moth, Callosamia promethea, male. 
(After Jordan and Kellogg; natural size.) 


broad brown stripe edged with white and reddish lilac on each side, and 
has the body covered with clusters of black-tipped green branching spiny 
hairs which are very sharp and strongly stinging. The thin, irregular 
parchment-like cocoon made of tough gummy brown silk is spun under 
dead leaves or other rubbish on the ground. In Texas is found A. zelleri, 
expanse 5 inches, reddish brown, without any yellow color in hind wings; 
in Arizona A. pamina, expanse 24 to 3 inches, with yellow around the white- 
centered black eye-spots of the hind wings; and in New Mexico A. sephyria, 
expanse 2} to 3 inches, with brown-black fore wings and pale-brown abdomen 
broadly banded with red. 

With a single species, the maia moth, in the eastern states, and but half 
a dozen in the Rocky Mountains, desert and Pacific slope states, the genus 
Hemileuca presents a striking difference from the other Saturnians so far 


The Moths and Butterflies 425 


described in the thinly scaled, not hairy, condition of the wings and the 
prevalence of black and white in the pattern instead of warmer colors. HH. 
maida, expanding 24 inches, is subtransparent black with a broad middle 
transverse band of white on each wing; in this band is a small blackish blotch 


Fic. 610.—The Io emperor-moth, Automeris io, and cocoon; female moth above; 
male below. (After Lugger; natural size.) 


isolated in the hind wings, but connected with the black of the base in the 
fore wings. This species occurs in the eastern states; a similar species, 7. 
nevadensis, being found from the Rocky Mountains to the Pacific; H. electra, 
found in southern California, has the hind wings blackish red; other species, 
found in New Mexico and Arizona, are mostly black and white with a red- 


426 The Moths and Butterflies 


dish or pinkish tinge here and there. The larva of H. maia feeds on oak; 
it is brownish black with a lateral yellow stripe, and has large branching 
spines over the body which sting severely. 

In Plate VI, Fig. 4, is shown in proper color and pattern a bizarre 
moth, Pseudohazis eglanterina, not uncommon in the Rocky Mountains, which 


Fic. 611.—Larva of Io emperor-moth, Automeris io. (After Dickerson; natural size.) 


we may call the clown. An allied species, P. shastaensis, similarly marked 
and colored, is found on the Pacific slope, and a third species, P. hera, with 
pale yellowish-white ground-color in the wings instead of purplish red, occurs 
in the region between the Rocky Mountains and the Sierra Nevada. 
Two great moths, the imperial (PI. VI, Fig. 2) and the regal walnut- 
moth (Fig. 612), are the most impressive of a subgroup of the Saturniina 
called the Ceratocampide. They are all short-bodied and hairy and show 
for colors exclusively rich warm browns and soft yellows, light purple and 
rose. A curious structural characteristic of the family is the limiting of the 
pectinations on the antenne of the male to the basal half of the antenna. 
The regal walnut-moth, Citheronia regalis (Fig. 612), expands fully 5 inches, 
has a rich brown ground-color on body and hind wings, with the fore wings 
slaty gray with yellow blotches, and veins broadly marked out in red-brown. 
The larva (Fig. 613), 4 to 54 inches long, and yellowish brown, reddish 
brown, or greenish, is distinguished from all other caterpillars by the great, 
threatening, but harmless blue-black horns of the body; it feeds on butter- 
nut, walnut, ash, pines, and other trees. Basilona imperialis, the imperial 
moth, is as large as the regal walnut, but with ground-color of rich yellow, 
overspread on base and outer part of fore wings and as a spot and band 
on hind wings with soft brownish purple. The larve when full-grown are 
3 inches long, brown or greenish, thinly clothed with long whitish hairs, 
and bear conspicuous spiny horns on the second and third thoracic segments. 
They feed on hickory, oak, elm, maple, and other deciduous forest-trees, 
as well as on spruce, pine, juniper, and hemlock. The larve of both these 


The Moths and Butterflies 427 


great moths burrow into the ground to pupate, the rough brown naked 
chrysalids wintering over. 


Fic. 612.—The regal walnut-moth, Citheroniaregalis. (Photograph by author; natural size.) 


Anisota is a genus of smaller moths containing five species limited to 
the eastern states, four of which are brown and one, A. rubicunda, rosy and 


Fic. 613.—Larva of regal walnut-moth, Citheronia regalis. 
(Photograph by author; natural size.) 


yellow. This latter, called the rosy dryocampa, is shown in color in Plate 
VII, Fig. 1. Its larva, sometimes called the green-striped maple-worm, 


428 The Moths and Butterflies 


is pale yellowish green and is striped with many fine longitudinal lines 
alternating lighter and darker than the ground-color. There are two horns 
on the second thoracic segment, and dorsal spines on the eighth and ninth 
abdominal segments. 

A. virginiensis is purplish red or brown, and the wings are nearly trans- 


Fic. 614. Fic. 615. 
Fic. 614.—The orange-striped oak-worm moth, Anisota senatoria, male. (After Lugger; 
natural size.) 
Fic. 615.—The orange-striped oak-worm moth, Anisota senatoria, female. (After 
Lugger; natural size.) 


parent in the center; the larva, found on oak, is grayish or greenish with 
brownish-yellow or rosy stripes and with small white warty processes all over 


Fic. 616.—Mulberry silkworms, larve of Bombyx mori. (From life; natural size.) 


the skin; A. stigma, expanse 2 inches, is light ocherous brown with many 
blackish dots; its bright tawny or orange caterpillar has long spines on 


The Moths and Butterflies 429 


the back; A. senatoria (Figs. 614 and 615) is like A. virginiensis, but lacks 
the transparent place in the middle of the wing; the caterpillar is black with 
four stripes. All these Anisota larvee feed on oaks, and that of A. senatoria 
also on blackberries and raspberries. Sphingicampa (Adelocephala) bicolor 
is a beautiful moth with brown fore wings and dark-pink hind wings with 
dusky dots, which is not uncommon in the Mississippi Valley and southern 
states; its larvae feed on the locusts and the Kentucky coffee-bean. In the 
southwest are two or three species of the genus Syssphinx resembling Sphingi- 
campa bicolor, but one, S. heiligbrodti, in Arizona, has iron-gray fore wings. 

Now unknown in wild condition, the long-cultivated Chinese or mulberry 
silkworm, Bombyx mori, is spread over most of the world, living exclusively, 
however, under the personal care of man. Indeed it is often said that the 
worm is so degenerate, so susceptible to unfavorable circumstances, that 
it could not live out of doors uncared for. As a matter of fact, however, I 
have bred moths from silkworms placed 
exposed on mulberry-trees in California 
immediately after the first moult. And 
these individuals experienced consider- 
able hardship in the way of low temper- 
atures and dashing rains. The heavy 
creamy-white moths, with wing expanse 
of 1} inches, take no food at all, and 
most of them cannot even fly despite 


Fic. 617.—Mulberry silkworm, show- 
their possession of well-developed wings, ing front view of head and thorax. 


so degenerate are the flight-muscles from  (FTo™ Ife; natural size.) 


generations of disuse. The eggs, about 300, are laid by the female on any 
bit of cloth or paper provided her by the silkworm-growers. They are yellow 
at first, but soon change to a slaty color due to the beginning development 
of the embryo. In the annual race of silkworms, i.e., the variety which 
produces but one generation a year as compared with those others which 
produce two (bivoltins), three (trivoltins), and even five or six (multivoltins), 
the development of the eggs soon ceases, and they go over the winter, hatching 
in the following spring at the time the mulberry-trees begin leafing out. 
The larve (Figs. 616 and 617) must be well fed with fresh mulberry or osage- 
orange leaves (they may at a pinch be carried through on lettuce) from which 
all rain- or dew-drops should be wiped off. The worms moult every nine 
or ten days, ceasing to feed for a day before each moulting, during the forty- 
five days of larval life, spinning before the last moult (pupation) the dense 
white or golden silken cocoon which is, to man, the silkworm’s raison d’éire. 
In this spinning the thread is at first attached irregularly to near-by objects, 
but after a sort of loose net or web has been made the spinning becomes 
more regular, and by the end of three days a thick firm symmetrical closed 


430 The Moths and Butterflies 


cocoon, composed of a single continuous silken thread averaging Over 1000 feet 
long, is completed. Inside this cocoon the larva pupates, and if undisturbed 
the chrysalid gives up its damp and crumpled moth after from twelve to fourteen 


ee a4 
t o. 


soy ¥ 


Note particularly the large silk-glands, one on 


(Three times natural size.) 


al 
F 
! 


alimentary can 
each side, which open into the mouth. 


Malpighian tubule 


Fic. 618.—A silkworm dissected to show its internal organs, 


days or longer. A fluid secreted by the moth softens one end of the cocoon 
so that the delicate creature can force its way out. But this is not the usual 
fate of a silkworm pupa. The professional grower must save the cocoon 


The Moths and Butterflies 431 


from injury by the moth, so he kills his thousands of pupe by dropping 
the cocoons into boiling water or by putting them into a hot oven. Then, 
after cleaning away the loose fluffy silk of the outside, he finds the beginning 
of the long thread which makes the cocoon, and with a clever little reeling- 
machine he unwinds, unbroken, its hundreds of feet of merchantable silk floss. 
From here to the silk-dress stage is a story not entomological, but one of 
elaborate machines and processes of human devising. 

Hovering, humming-bird-like, in the early dusk over the deep flower- 
cup of a petunia or honeysuckle or great jimson-weed, with its long flexible 
proboscis thrust deep down to the nectaries, and the swift wings making a 


Fic. 619.—Larva of the achemon sphinx-moth, Philampelus achemon. 
(After Lugger; natural size.) 


faint haze on either side of the trim body, the sphinx-moth, or hawk-moth, 
or humming-bird moth, as variously called, is a familiar garden acquaintance. 
But that he is but one of a hundred different American species; that he has 
cousins red and cousins green, somber cousins and harlequin cousins; that, 
strong-winged, clean-bodied, exquisitely painted, and honey-fine in his taste 
as he is now, his earliest youth was passed as a “‘disgusting,”’ soft, fat, green 
tomato-worm or tobacco-worm or grape-vine dresser, and that at a later 
adolescent period he lay buried in the ground, cased, mummy-like, in a dark- 
brown sarcophagus—all this may not be as familiar. Still, excepting the 
giant silkworm-moths, the Saturnians, no other moth group is so much 
affected by collectors and crawlery proprietors as the Sphingide. Thus 
the various adolescent stages of several hawk-moth species are known to 


432 The Moths and Butterflies 


many amateurs, and numerous differen: sphingid species will be found in 
any collection of Lepidoptera. The uniformity of structural character in 
farvee and adults of the various species, and the general similarity of habits 
and life-history, make the family a coherent one, and one readily distinguish- 
able from other moths. These moths, with few excepticns, have leng, nar- 


Fic. 620.,—Larva of the sphinx-moth, Phlegethontius carolina, (After Jordan and 
Kellogg; one-half natural size.) 


row, pointed fore wings, very small hind wings, a smooth-coated, compact, 
cleanly tapering body, and a long proboscis, coiled when not in use, like 
a watch-spring, on the front of the head (Fig. 5c9). The cclors and pat- 
terns are extremely varied, but uniformly quietly beautiful and harmonious. 


TN 
1 \ 


ey 
<i 


nan 


Fic. 621.—Larva of Phlegethontius celeus. (After Soule; somewhat reduced.) 


The larve (Fig. 619) are naked, usually green, often with repeated oblique 
whitish lines on the sides, and bear a conspicuous sharp-pointed horn, 
or, in fewer instances, a flattish, button-like shining tubercle, on the back 
of the eighth abdominal segment. The caterpillars, or “worms,” feed on 


The Moths and Butterflies 433 


the foliage of various plants, and when full-grown most of them descend 
and burrow into the ground to pupate. The chrysalid is naked, with firm, 
dark-brown wall, and is distinguished by the odd jug-handle-like sheath 
for the developing long imaginal proboscis. A few larvae pupate on the 


Fic. 622.—Pholus achemon, above, and Pholus pandorus, below. 
(After Lugger; natural size.) 


ground in a slight cocoon made of silk and a few leaves tied together. The 
insects hibernate in the pupal stage; a few are said to be double-brooded. 
The name sphinx, applied to these moths by Linneus a century and a half 
ago, is suggested by the curious attitude assumed by the larve when dis- 
turbed; the front part of the body is lifted (Fig. 620) clear of the object 
on which the insect is resting, and the head is bent forward on the thoracic 
feet. This position may be held rigidly for hours. 

Of the many species found in this country we can refer to but a few cf 
the more familiar or beautiful or interesting ones, and these references may 
be made brief because of the colored figures which are grouped in our frontis- 
piece. These figures render descriptions unnecessary. 


434 The Moths and Butterflies 


Best known of all the hawk-moths, both in larval and adult stage, are 
the five-spotted sphinges, the tomato- and tobacco-worm moths, Phlege- 
thontius quinquemaculata (celeus) and P. sexta (carolina) (Pl. VIII, Fig. 3). 


Fic. 623.—Larva of Pholus achemon. (After Soule; natural size.) 


Quinquemaculata is the commoner in the north, sexfa in the south; in both 
the larva (Figs. 620 and 621) is green with oblique white stripes on the side 
and a long sharp caudal horn, and feeds on tomato-, tobacco-, and potato- 


Fic. 624. — Grape - vine 
sphinx - moth, Ampelo- 
phaga myron. (Natural 
size.) 


leaves or jimson-weed. The horn of sexta is red, 
that of guinquemaculata green or blue-black. 
The pupe are long and slender and dark 
brown (green at first), and are often found when 
plowing or digging up fields in which these plants 
have been grown. The moth of P. guinquemaculata 
has ashy-gray wings, with zigzag markings, while 
the wings of sexta are not thus marked. . The 
great pandorus sphinx, Pkolus (Philampelus) 
pandorus (Pl. I, Fig. 1), found in the eastern 
and central states, is one of the most beautiful 
of all moths. The larve feed on grape-vines 
and Virginia creeper, and, measuring four inches 
long when full-grown, are rich reddish brown 
with five conspicuous cream-colored spots along 
each side; a shining black eye-like tubercle takes 
the place of a caudal horn. It pupates under- 
ground. P. achemon (Fig. 622), with markings 
much like pandorus, but with strong rosy color- 


ation instead of greenish, has a larva which also feeds on grape and Vir- 
gina creeper and may be recognized by its six (instead of five) lateral 


cream-colored blotches. 


a OY 


INV ATAIT 
.CHTOM 


sioonil slidqoliod =r 
a1 sgmss01s) =s 
stxse auiinoniogoldd =¢ 
eioig eindostA =p 
stsluosmoioo siqylA =~ 
story eimlotanA = 


zalqmie sievIT=y 


4 
= 
§ 
% 
= 
e 
q 
‘ 
<, hi 
7 I 
‘ , ' 
} d 
i 
- ' 


PLATE VIII. 
MOTHS. 


t= Deilephila lineata. 
2=Cherocampa tersa. 


3= Phlegethontius sexta. 


4= Arachnis picta. 


5=Alypia octomaculata. 


6=Anatolmis grotei. 
7=Plusia simplex. 


PLATE Vill 


del. 


Mary Wellman, 


The Moths and Butterflies 435 


The beautiful little Ampelophaga myron, with soft red-brown hind wings 
and brownish-gray fore wings, patterned as shown in Fig. 624, has a pea- 
green, cream-banded, and yellow and lilac spotted larva known as the hog- 
caterpillar of the vine, so named from its form—the third and fourth seg- 
ments being greatly swollen, the head and first two segments small—and 
its destructiveness to grape-vines. When ready to pupate it spins a brown 
silken open-meshed cocoon on the ground under leaves or other rubbish. 


Fic. 625.—The double-eyed sphinx, Smerinthus geminatus, above; Paonias excecatus, 
in middle; and P. myops, below. (After Lugger; natural size.) 


A. versicolor (Pl. I, Fig. 3) is a beautiful cousin of myron with greenish 
oyerlaid on the brown. An extremely slim, slender-bodied, and slender- 
winged sphinx is Cherocampa (Theretra) fersa (Pl. VIL, Fig. 2), found in the 
northern states. Itis very swift. Anabundant and familiar hawk-moth found 
all over the United States is the white-lined sphinx, Deilephila lineata (Pl. VIII, 
Fig. 1). Its caterpillar feeds on various plants, as grape, apple, watermelon, 
buckwheat, turnip, and purslane; the latter seems to be the preferred plant. 


436 The Moths and Butterflies 


Exceedingly variable in color and pattern, it is usually yellow-green with a 
conspicuous longitudinal row of elliptical spots on each side of the back, 


Fic. 626.—Larva of Smerinthus geminatus. (After Lugger; natural size.) 


each spot consisting of two curved black lines enclosing a bright crimson 
blotch and a pale-yellow line; all the spots are connected by a pale-yellow 


Fic. 627.—Sphinx gordius. (After Lugger; natural size.) 


line edged aboye with black. Sometimes the larvae are black, with a 
narrow yellow line along the back and a series of paler- and darker-yellow 


The Moths and Butterflies 437 


spots. The double-eyed sphinx, Smerinthus geminatus (P1. I, Fig. 2; also 
Fig. 625), isa common species whose larvee feed on apple, plum, ash, willow, 
birch, and other trees; the full-grown caterpillar (Fig. 626) is 2} inches 
long, apple-green, with seven oblique yellow stripes on each side of the 
body and a violet caudal horn. The genus Sphinx (Fig. 627) contains 
nearly twenty species, all of them soberly patterned with grayish, brownish, 
and blackish, and most ef them expanding more than three inches. 


Fic. 628.—Larva of the abbott-sphinx, Thyreus abbotti. (After Soule; natural size.) 


While most hawk-moths have narrow tapering fore wings and a slender 
tapering smooth-coated body, structural conditions indicating a well-de- 
veloped flight power, a familiar species, the modest sphinx, Marumba modesta 
(Pl. I, Fig. 4), found all over the country, is hairy, heavy-bodied, and 


SVT TIT 


Fic. 629.—Larva of abbott-sphinx, Thyreus abbotti; note difference in pattern from 
larva shown in Fig. 628. (After Soule; natural size.) 


broad-winged. The full-grown larve are 3 inches and more long, whitish, 
yellowish, and bluish green, with fine white dots all over the skin; the cau- 
dal horn is short. They feed on “‘balm-of-Gilead,” poplar, and other trees. 
Another species of unusual shape is the beautiful dark-brown and canary- 
yellow small tufted-bodied abbott-sphinx, Thyreus (Sphecodina) abbotti 
(PI. I, Fig. 6), found in the Atlantic and Mississippi Valley states. Its 
larve (Figs. 628 and 629) feed on woodbine and grape. They are ‘‘ashes- 
of-rose’’ color, finely transversely lined with dark brown and with longitu- 
dinal series of brown blotches. They have a large circular, eye-like tubercle 
in place of a caudal horn. They may appear in two different patterns as 


438 The Moths and Butterflies 


shown in Figs. 628 and 629. The pupa is found under dead leaves or other 
rubbish. Very similar in appearance and habits is the grape-vine amphion, 
Amphion nessus (Fig. 630), of the same size and shape and colors and found 


Fic. 630. Fic. 631. 


Fic. 630.—The grape-vine amphion, Amphion nessus. (After Beutenmiiller; natural 
size, 13-2 inches expanse of wings.) 
Fic. 631.—Larva of clear-winged sphinx, Hemaris diffinis. (After Soule; natural size.) 


in the same states; it may be distinguished, however, by a pair of conspicu- 
ous narrow, bright-yellow bands across the abdomen. The larve are pale 
yellowish green or chocolate-brown with various obscure darkish stripes. 


Fic. 632.—The death’s-head sphinx-moth; note skull-like markings on thorax between 
f ae: I oe 8 
wings. This moth is looked on with superstitious dread by many people. (Photo- 
graph by author; natural size.) 


A few sphinx-moths have the wings partly clear. These are called the 
clear-winged sphinxes and belong to the genus Hemaris. H. thysbe (Pi. I, 


The Moths and Butterflies 439 


Fig. 5) is the most abundant Eastern species, although H. diffinis, with 
bright-yellow hairs in place of brownish yellow on thorax and abdomen, is 
common. In Colorado and Utah is found a smaller species, H. brucei, 
with yellowish thorax and abdominal band, and in California are one or two 
varieties of H1. diffints. The larva of H. diffinis (Fig. 631) feeds on honey- 
suckle and snowberry-bush and is pale green above, darker green on the 
sides, with three brown stripes on the under side; the caudal horn is yellow 
with blue-black tip; some of the caterpillars, as is common among the larve 
of this family, are brown instead of green. It is two-brooded. Moths just 
issued from the chrysalid have scales over all of the wing surface, but these 
scales are so loosely attached on the discal area that the first few flights 
dislodge them, so that the “‘clear-wing’” comes about. The larve of 
H. thysbe feed on viburnum, snowberry, and hawthorn. 


BUTTERFLIES. 


Taken all in all the butterflies are the most familiar and attractive insects 
to people in general; their size, beautiful color-patterns, and daytime flight 


Fic. 633.—The Parnassian butterfly, Parnassius smintheus, which lives in the Rocky 
Mountains and Sierra Nevada at an altitude of 5000 feet and more. (Natural size.) 


chiefly account for this. Six hundred and fifty butterfly species (compare 
with the six thousand species of moths) are accredited to this country in 
the latest authoritative catalogue of North American Lepidoptera. These 
represent, according to this catalogue, thirteen families; a more usual classi- 
fication, however, groups all these species into six families. As this latter 
arrangement is in use in most of the insect manuals, it will be adopted in this. 
Comstock, who has given the classification of the Lepidoptera much attention, 
gives the following key to families: 


440 The Moths and Butterflies 


Fic. 638. Fic. 637. 


Fic. 634.—Venation of a Hesperid, Epargyreus tityrus. (After Comstock; enlarged.) 
Fic. 635.—Venation of a Papilionid, Papilio polyxenes. (After Comstock.) 
Fic. 636.—Venation of a Nymphalid, Basilarchia astyanax. (After Comstock; enlarged.) 
Fic. 637.—Venation of a Lycenid, Chrysophanus thoe. (After Comstock; enlarged.) 
Fic. 638.—Venation of a Pierid, Pontia protodice. (After Comstock; enlarged.) 
For all: cs, costal vein; sc, subcostal vein; r, radial vein; m, medial vein; ¢, cubital 
vein; a, anal veins. 


The Moths and Butterflies 441 


KEY TO FAMILIES OF BUTTERFLIES (LEPIDOPTERA WITH THE 
ANTENN4 FILIFORM, WITH A CLUB, OR KNOB, AT THE TIP). 


A. With the radius of the fore wings five-branched and with all of these branches 
arising from the discal cell (Fig. 634); club of antennz usually terminated by a 
FECUTVEO MOOR am. werspersia Gearate alalobaat yaaa ts (Skippers.) Superfamily HEsSPERIINA. 
B. Head of moderate size; club of antennz large, neither drawn out at the tip 

nor recurved. Large skippers with wing expanse of 2 inches or more. 
MEGATHYMID& (p. 441). 
BB. Head very large; club of antenne usually drawn out at the tip and with a 
distinct recurved apical crook. If the crook is wanting, the species expand 
Jesspithan may INCHES} eit oss oneal oo 2 Sie cattle noe cies HESPERIID (p. 442). 

AA. With some of the branches of radius of the fore wings coalesced beyond the apex 

of the discal cell (Fig. 635); club of antenne not terminated by a recurved hook. 
(The butterflies.) Superfamily Papmronrna. 
B. Cubital vein of the fore wings apparently four-branched (Fig. 635); most of 
the species with tails on the hind wings. 

(The swallow-tails and parnassians.) PAPILIONID® (p. 446). 

BB. Cubital vein of fore wings apparently three-branched (Fig. 636). 
C. With only four well-developed legs, the fore legs being unused, much 
shorter than the others, and folded on the breast like a tippet, except 

in the female of Hypatus; radius of fore wings five-branched (Fig. 636). 

(The brush-footed butterflies.) NympHaLip (p. 450). 
CC. With six well-developed legs; radius of fore wings, with rare exceptions, 

only three- or four-branched (Fig. 637). 

D. Medial vein of the fore wings arising at or near the apex of the 
discal cell (Fig. 637), except in Feniseca tarquinius,in which the 
wings are dark brown with a large fulvous spot on each. 

(The blues and coppers.) LycaNrbD2 (p. 443). 

DD. Medial vein of the fore wings united with last branch of radius 
for a considerable distance beyond the apex of the discal cell (Fig. 
638); ground color white, yellow, or orange. 

(The whites and sulphurs.) Prertp@ (p. 444). 


The family Megathymide, or giant-skippers, contains but one genus, 
Megathyma, represented by but five species, of which none is found outside 
of the southern and southwestern states. The best-known and most widely 
distributed species is the yucca-borer, MM. yucce, whose larve live as bur- 
rowers in the roots of several species of yucca, and are from 4 to 6 inches 
long. The eggs are laid on the leaves and the young larve spend a short 
time above ground in a cylinder made of a rolled leaf tied across with silk. 
Later they tunnel into the stem and downwards into the root, sometimes to 
a distance of 2 feet or more. When ready to pupate they crawl up to 
the chimney-like funnel at the top of the burrow and transform there. The 
moth expands 2} inches, is deep umber-brown with a notched ferruginous 
band and other smaller blotches on the fore wings, and the hind wings with 
a ferruginous border. The other giant-skippers are of similar size and 


442 The Moths and Butterflies 


markings, and all of them are more moth-like than butterfly-like in general 
appearance. They may be looked on, indeed, as a sort of ee link 
between the moths and the true butterflies. 

The Hesperide, or skipper-butterflies (Pl. IX), are a great family of small, 
big-headed, robust-bodied butterflies of obscure patterning in browns and 
blackish (a few forms white and dark gray). Nearly two hundred species 
are known in this country, but few of them are at all familiarly recognized 
as distinct species; general collectors and amateurs know them better 
grouped into generic units, as Erynnis, Amblyscirtes, Eudamus, Thorybes, 
Pholisora, etc. Indeed, but few professional entomologists feel competent 
to undertake the identification of Hesperid species. A few well-marked or 
specially numerous and wide-spread forms are, however, fairly well known. 
The caterpillars of all have large heads, constricted necks, and bodies thick 
in the middle and tapering both ways, and often make protecting nests of 
leaves and silk. The silver-spotted skipper, Epargyreus tityrus (Pl. V 
Fig. 3), is abundant over all the country and is readily recognizable by 
its large size and distinctive pattern; the broad, irregular, silver spot is on 
the under side of the hind wing. The caterpillar feeds on various Legu- 
minose, especially wistaria and locust, and when full-grown is 14 inches 
long, with large, ferruginous head bearing two large orange spots, and lemon- 
green body transversely banded with darker green; it builds a nest or case 
of leaves, in which it remains when not feeding; it pupates either in this 
larval nest or makes a loose cocoon somewhere on the ground, hibernating 
in this stage. Another of the larger species is the curious long-tailed skipper, 
Eudamus proteus, found in the south Atlantic states (ranging as far north 
as New York City) and distinguished by the tailed hind wings and iridescent 
green-brown color. The genus Hesperia includes a dozen or more species 
which are thickly white-spotted on a blackish-brown ground, giving them 
a checkered gray appearance; most of these checkered skippers are limited 
to the western states, but one, H. fessellata, is found commonly all over 
the country. It expands 14 inches, and has even more white than dark on 
the wings; it flies rapidly about close to the ground and lays its eggs on 
various mallows; the larva is green with a dark interrupted dorsal line, dark 
lateral bands, and a pale band below the spiracles. 

A whole host of skippers are the “sooty-wings,’’ members of several 
genera, but almost impossible to be distinguished by means of written 
descriptions. They vary in size from an expanse of 1 inch to nearly 2 inches, 
and have the wings grayish brown to blackish brown to truly sooty, usually 
with obscure indications of markings on both wings and almost always 
with a few small distinct white spots near the apex of the fore wings. The 
small sooty-wing, Pholisora catullus, common in the east, expands 1 inch 
and has uniformly nearly black wings with a few distinct white dots on 


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PLATE IX. 


SKIPPER BUTTERFLIES. (After Skinner.) 


4 


to 


Pamphila hobomok, male, upper side. 


ce 


ce 


fe “* under side. 


ss female, under side. 


ae ae 


upper side. 


zabulon, male, upper side. 


oY “« “under side. 


‘« female, under side. 


os “* upper side. 
scudderi, male, upper side (type). 
‘* female, upper side (type). 
bellus, male, upper side. 
+ ** under side. 
panoquin, male, upper side. 
a “© under side. = 
stigma, male, upper side (co-type). 
a «« under side. 
pittacus, male, upper side. 
es “* under side. 
rhesus, male, upper side. 
a “* under side. 
nemorum, male, upper side. 
massasoit var. suffusa, male, under side 
draco, female, under side. 
loammi, male, under side. 
alcina, male, upper side (type) 


panoquinoides, male, upper side (type) 


¥giale streckeri, male, upper side. 


Neophasia terlooti, upper side. 


PLATE IX 


The Moths and Butterflies 443 


the fore wings. Several large species, known as dusty-wings, expanding 
1% to 1$ inches, with grayish-brown to blackish-brown wings, belonging to 
the genus Thanaos, are common. Another large group of nearly indis- 
tinguishable species is that of the Pamphilas (Pl. IX). These skippers are 
mostly tawny and are specially recognizable by a discal black patch in male 
specimens, which appears like an oblique scorched streak near the center 
of each fore wing. This patch contains certain peculiar scales which give 
off scent presumably attractive to the females. Erynnis sassacus (Pl. X, 
Fig. 5), common in the Atlantic states, is a good example of the group. 
The least skipper, Ancyloxypha nuwmitor (Pl. V, Fig. 5), is the smallest 
commonly seen and differs from other skippers in lacking the recurved 
hook at the tip of the antenne and in having a slender body. The 
pale-yellow pilose larva feeds on grasses, especially those that grow in wet 
places. 

The small butterflies popularly known as blues, coppers, and_hair- 
streaks compose the family of Lycaenidae, or gossamer-winged butterflies, of 
which a hundred and twenty-five species are recorded from the United States, 
mostly the western half. The popular names express well the colors and 
pattern characteristic of the group. They are delicate, light-winged, slender- 
bodied butterflies rarely expanding more than an inch and a half and either 
bluish (pale whitish blue to brilliant metallic dark blue) or coppery or reddish 
or dark brown, often with small blackish spots, or marked with short fine 
little lines, hair-streaks, on the under side of the wings, and often with delicate 
little tail-like processes projecting from the hinder margin of the hind wings. 
The larve are flattened, short, broad, small, forked, slug-like caterpillars 
with small retractile heads; those of a few species distinguish themselves 
from all other butterfly larvae by feeding on other insects, especially aphids. 
The chrysalid is naked, suspended from the posterior tip and supported by 
a. silken line, or “bridle,” about its middle. 

Often to be seen fluttering or clustered about wet spots in the roadway 
are numbers of delicate little pale-blue butterflies with under side of wings 
almost white and conspicuously dotted with small black spots and with 
white-ringed slender antenna; these are “blues,’’ some species of the old 
genus Lycena now broken up by modern systematists into a half dozen or 
more different genera. The spring azure, Cyaniris pseudargiolus (Pl. V, 
Fig. 4), is a wide-spread and common example of the group; with its several 
varieties it ranges over the whole continent, and it is one of the few ‘“ blues”’ 
whose young stages are known. The larvae, which curiously secrete honey- 
dew from little openings on the seventh and eighth abdominal segments, feed 
on the “buds and flowers of various plants, especially those of dogwood 
(Cornus), Cimifuga, and Actinomeris.”” As many as three broods appear 
in a year. The various species of blues differ slightly in size, in shade of 


444 The Moths and Butterflies 


coloring, as grayish blue, lilac-blue, purple-blue, etc., in number and distinct- 
ness of the small black spots, but only an expert can determine the 
species. 

Less in number of species and perhaps not quite so familiar are the 
“coppers”? with orange, red-brown or dark-brown wings conspicuously 
spotted with black. Fig. 4 of Pl. X shows the color, markings, and size 
of a typical “copper,” IZeodes hypophleas, “one of the commonest butter- 
flies in the United States.’’ Most of the other coppers have, however, hardly 
as bright-red a ground color on the fore wings, some being really somber. 
Most of them, too, are a little larger than hypophleas. A species patterned 
and colored much like hypophleas, but a half larger, is Chrysophanus thoe, 
found in the Atlantic states and west to the Rocky Mountains. The har- 
vester, [eniseca tarquinius, small, with bright orange-yellow above spotted 
with black and mottled gray and brown underneath, is a common species 
all through the eastern states west to the Mississippi River; its larva feeds 
on the woolly plant-lice like the alder blight, apple-tree aphid, etc. 

The hair-streaks, mostly belonging to the genus Thecla, have short narrow 
lines or streaks on the under sides of the wings, and are usually provided 
with one or more delicate little “tails” on the hind wings. They vary in 
color from a dull brown to a splendid glancing blue or blue-green. They 
usually have one or more reddish spots at the base of the “tails” and the 
under sides of the hind wings are often greenish or parti-colored. Thecla 
halesus, the “great purple hair-streak” (Pl. V, Fig. 9), is our largest 
species, and is found in the southern half of the country. Like the blues 
the hair-streaks are very difficult to classify to species; indeed professional 
entomologists are not at all satisfied with our present systematic knowledge 
of the Lycenide. 

In the extreme southwest are found rather rarely the few species of 
“metal-marks,’’ Lemonias and Calephelis, black and reddish checkered 
Lycenids, which occur in this country. Sometimes, as in L. virgulti, the 
wings are spotted with white. The vernacular name is derived from a few 
small lead-colored or pearly-white spots near the outer margin of the wings. 
The tiny metal-mark, Calephilis cenius, expanding only } inch, and with 
the reddish-brown wings spotted with small steely-blue markings, comes 
as far north as Virginia. 

A smaller family than the Hesperide or Lycenide, but with numerous 
better-known members, is the Pieridae, the whites, yellows, and orange- 
tips. Because the larve of several species feed on cabbage and other 
cruciferous plants, the unhappy name of cabbage-butterflies is sometimes 
applied to them. The common whites and yellows are the most familiar 
of roadside butterflies, but of the sixty species composing the family in this 
country, only half a dozen occur in the northeastern states, the south and 


The Moths and Butterflies 445 


west being the favored regions of distribution. All the species except two or 
three are of medium size, that is, have an expanse of 1} to 2 inches, and 
have white or yellow, from light sulphur to orange, as ground color, with 
markings of black. The larve are mostly green, longitudinally striped, 
with more or less distinct lines usually paler, and harmonize so thoroughly 
in coloration and appearance with the green foliage on which they feed that 
they are not often seen. The chrysalids are naked, supported at the pos- 
terior tip and also by a loose silken bridle, and distinguished from other 
butterfly pupe by a conspicuous median-pointed process on the head end. 
The males of many Pierids give off a pleasing aromatic odor which comes 
from certain scent-scales (androconia) scattered about over the wing-surface. 
If the fore wings of a freshly caught male cabbage-butterfly be rubbed 
between thumb and finger, this scent can be readily smelled on the fingers. 
It is used to attract or excite the females. 

The three most abundant whites in the eastern and northern states are 
Pontia protodice, P. napi, and P. rape, the larve of all three species being 
voracious cabbage-eaters. P. rape, the European cabbage-butterfly, is a 
European butterfly which got to Quebec about 1860 and since then has 
spread over the whole country and is the most serious pest among all the 
butterflies; it expands from 12 inches (male) to nearly 2 inches (female), 
has faintly, yellowish-white wings with the base and apex of fore wings 
blackish and with two circular black dots on fore wings of the female and 
one in the male; there is a single black spot (in male very faint) on front 
margin of hind wings; under sides of hind wings and tip of fore wings lemon- 
yellow. P. protodice, the southern cabbage-butterfly, or checkered-white, 
has at least three black spots besides a blackish apical border on the fore- 
wings of the male, while both the wings of the female are much checkered 
with blackish brown; the under side of the hind wings is white in the male. 
P. napi, the northern cabbage-butterfly, or mustard-white, appears in eleven 
or twelve appreciably different patterns, but characterized through all this 
variety by the pale or distinct grayish bordering of the veins; there is but 
little blackish on the wings of the male, at most one or two circular spots 
and a blackish apical border. In the western states the species of Pontia 
which will be found by most collectors are beckeri, distinguished by green 
markings on the under side of the hind wings; occidentalis, much like pro- 
todice, and sisymbri, a small species with the veins of the hind wings widely 
bordered with blackish brown on the under side. A beautiful Pierid is 
the pine-white, Neophasia menapia, of the Pacific states and Colorado; in 
both male and female the black color above is limited to the fore wings; 
there is a border along the costal margin from base to beyond the middle, 
where it bends in along the outer margin of the discal cell as a swollen club- 
like blotch; in addition the apex is broadly bordered with black in which 


446 The Moths and Butterflies 


three or four white spots appear; in some specimens the hind wings have 
a narrow broken border of scarlet on the under side. 

Of the yellows, or sulphurs, the most familiar in the eastern states is 
Eurymus philodice, the clouded sulphur, expanding 14 to 2 inches; the 
wings are pale sulphur-yellow with black outer borders and with a discal 
black spot on each fore wing and orange spot on each hind wing; in the 
female the black border of the fore wings is very broad and contains five or 
six irregular yellow spots. Similar in pattern, but with the ground color of the 
wings bright orange instead of pale yellow, is the orange-sulphur, EF. eury- 
theme, common through all the West. Both of these species are polychro- 
matic and polymorphic, that is, show marked variation in ground color and 
in size, some individuals called albinos being white, some called negros 
being suffused with blackish; some are very small, others unusually large. 
A variety of names has been given to some of these aberrations because 
of their regular appearance under certain seasonal conditions. The longi- 
tudinally striped green larvee of both species feed on clover. Another com- 
mon sulphur in the southern and western states is the dog-face, large with 
pointed-tipped front wings and the yellow color of these wings so outlined 
by the black base and broad border as to produce a rough likeness to a dog’s 
head seen in profile; a small discal black spot serves as the eye. The south- 
ern species is Zerene cesonia (Pl. V, Fig. ro), the Pacific coast species Z. eury- 
dice. The caterpillars, which are green with a whitish longitudinal stripe and 
a transverse dark line on each segment, feed on various Leguminose. Another 
common southern and western species is Terias nicippe, the black-bordered 
orange (Pl. XI, Fig. 2), whose larvae feed on cassia. A striking species 
is the cloudless sulphur, Catopsila eubule, the largest of the Pierids, expand- 
ing 24 inches; it occurs in the southern and southwestern states, its larva 
feeding on cassia. At the other extreme in size is the dainty sulphur, 
Nathalis iole, (Pl. V, Fig. 7), the smallest member of the family, expanding 
but 1 inch; it has the same range and food habits as the cloudless sulphur. 

In the western states occur seven or eight species of the pretty little 
Pierids known as orange-tips; only one species, Synchloé genutia (Pl. XI, 
Fig. 3), is found in the east. All are small and most of them are readily 
distinguished by the characteristic orange-colored apex of the fore wings 
as shown in the colored figure of genutia. S. sara, with two named varie- 
ties, reakirtii and sfella, is the commonest western species. The larve of 
the orange-tips, so far as known, feed on Cruciferz. 

Perhaps the most striking and admired of all familiar insects are the 
great swallowtail butterflies. They have an easy, half-fluttering, half-soar- 
ing flight; their unusual size and their black and yellow (or greenish-white) 
tiger-like markings make them so conspicuous that they are fascinatingly 
apparent to the most casual observers. Twenty-one different swallowtail 


The Moths and Butterflies 447 


butterflies are found in the United States. Combined with them in the 
family Papilionide are two species of curious thinly scaled black- and red- 
spotted white butterflies called parnassians, which live exclusively in high 


Fic. 639.—Swallow-tailed butterflies, Papilio rutulus. (From life; one-half 
natural size.) 
altitudes in the Rocky and Sierra Nevada Mountains. Two more species 
are found in high latitudes on this continent, namely in Alaska. Parnas- 
sius smintheus (Pl. V, Fig. 8; also Fig. 633) with four varieties is found 
in both the Colorado Rockies and Sierra Nevada, while P. clodius, a larger 


448 The Moths and Butterflies 


species with more translucent fore wings, is found only on the Pacific coast 
and in the Wyoming mountains. I have seen P. smintheus in great numbers 
in the beautiful flower-dotted glacial parks of Colorado from an altitude 
of 6000 feet upward. The wings are so thinly scaled that they are nearly 
translucent, and the scales themselves are narrow and club-like, so different 
indeed from those of other butterflies that they probably have some special 
function not yet understood. The larve are ‘‘flattened,”’ having a some- 
what leech-like appearance; they are black or dark brown in color, marked 
with numerous light spots. The chrysalis is short and rounded at the head, 
and pupation takes place on the surface of the ground, among leaves and 
rubbish, a few loose threads of silk being spun about the spot in which trans- 
formation occurs. 

The swallowtails (Fig. 639), all except five of which belong to the genus 
Papilio (a name given them a century and a half ago by Linnzus, the first great 
classifier of animals and plants), are readily 
distinguished by the longer or shorter ‘‘ tails,” 
one to three, which project backward from 
the hind wings. The ground color is black, 
sometimes suffused with metallic bluish or 
greenish, and the markings consist of yellow 
or greenish-white bands and blotches together 
with a few red, orange, and blue eye-spots on 
the upper and under sides of the hind wings. 
The larve are large, cylindrical, fleshy, naked 
Fic. bio Caan aan caterpillars usually conspicuously banded or 

low-tailed butterfly, Papilio sp. Spotted with green, black, yellow, orange, 

(Natural size.) and white. They are provided with a pair 
of fleshy and flexible colored “‘horns” (osmateria) which can be protruded 
from, or withdrawn into, the front thoracic segment and which give off a 
strong musky scent sufficiently disagreeable to repel many threatening 
enemies of the caterpillar. The chrysalids (Fig. 640) are naked, sus- 
pended by the tail from a silken button and supported by a silken girdle 
or “bridle.” They often mimic very closely the coloration and surface 
configuration of the tree-trunk or other object to which they are attached 
(Fig. 640). Poulton, an English naturalist, has been able to obtain chrys- 
alids of a single swallowtail species of many different colors by enclosing 
the larve just before pupation in separate boxes lined with paper of different 
colors. The color-tone of the chrysalid tended strongly toward that of the 
environing paper. Such a color plasticity is certainly of much advantage 
to the insect in rendering the exposed and defenceless chrysalid indistin- 
guishable. (See Chapter XVII for a discussion of ‘color and its uses.” 

One of the best-known butterflies of .the east is the zebra swallowtail, 


bras 


x GPAIF 


AALITART PU, 


ogols cinoyo19 =r 
siosisis saeamnsV =s 
zainonqesr oiliqad =¢ 

zenidqoged esbooH =5 


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aimadins sirlorsliasd =O 
sqoijos seonsyvud =y - 


PLATE X. 


; BUTTERFLIES. Ls 
¥ 1=Cercyonis alope. 
- ‘ 2= Vanessa atalanta : 
; 3= Papilio cresphontes 
7 _ 4=Heodes hypophleeas. 
5=Erynnis sassacus. 
6=Basilarchia arthemis. 
7= Euvanessa antiopa 
. —_ 
‘ ‘ 


PLATE X 


The Moths and Butterflies 449 


Iphidicles ajax (Pl. V, Fig. 2), which is distinguished from all other 
swallowtails by its black and greenish-white wings and its long tails; it 
appears in three forms, one, marcellus, emerging in early spring with tails 
% inch long and tipped with white; another, felamonides, appearing in 
late spring, a little larger, with tails + inch long and bordered with white 
on each side for half the length or more, and the third the typical ajax, still 
larger, appearing in late summer and autumn. Both of the first two forms 
may come from a single brood, some of the hibernating chrysalids producing 
butterflies earlier than others. It seems to depend wholly on the time of 
issuance and not at all on the character of the parent whether an individual 
shall be of the marcellus or of the telamonides form. The ajax individuals 
are those that are produced from eggs laid in the spring by either marcellus 
or telamonides individuals. Also some few chrysalids in every brood delay 
disclosing butterflies until the next spring. “ Marcellus and telamonides thus 
produce ajax the same season, or either marcellus or telamonides in the follow- 
ing spring; ajax produces itself the same season or one of the others in the 
spring; but neither marcellus nor telamonides is produced the same season 
by any of the forms” (Scudder). The larvee of this species are pea-green, 
naked, thickest in the thorax, with transverse markings consisting of black 
dots and lines and slender yellow stripes besides a yellow-edged, broad, vel- 
vety b'ack stripe on the thorax. They feed on papaw. 

Papilio turnus, the tiger swallowtail, or Turnus butterfly (Pl. V, Fig. 6), 
is another common species, with a striking “negro” form called glaucus. 
In glaucus the disk of the wing is wholly dusted over with black scales so 
that the bands can be hardly seen. It is found only in regions where there 
are two or more broods a year, and is represented by females alone. The 
tiger swallowtail ranges clear across the continent, and sometimes occurs 
in great numbers; Scudder says that on a cluster of lilacs 69 specimens were 
captured at one time by closing the two hands over them. The larvae, which 
feed on many plants but particularly like wild-cherry, are naked and leaf- 
green, with the front part of the body much enlarged and bearing a double 
stripe of yellow and black across the back, as well as a pair of yellow-black 
and turquoise eye-spots in front of this band and several rows of turquoise 
dots behind it. On the Pacific coast occur P. rutulus (Fig. 639) and P. 
eurymedon of the same general pattern of fwrnus, the first being black 
and yellow as ¢urnus is, but the second being black and pale greenish or 
yellowish white. In the Rocky Mountains is found the splendid Daunus 
swallowtail, P. daunus, larger than Turnus and with two tails on the hind 
wings and a third tail-like lobe at the inner angle. The larva of rutulus 
feeds on alder and willow, of eurymedon on Rhamnus and other plants, 
and of daunus mostly on rosaceous plants. 

Of different pattern is the fine giant swallowtail, P. cresphontes (Pl. X, 


450 The Moths and Butterflies 


Fig. 3), native in the south, but now gradually spreading north. The 
caterpillar, sometimes called “orange-puppy”’ in Florida, feeds on orange- 
and lemon-trees, besides other plants, and is swollen in front of the middle, 
with the anterior part of the body rusty brown with lateral stripe, the hinder 
end of which, including two or three segments and a broad saddle in the 
middle, is cream-yellow flecked with brown. 

A smaller widely distributed and well-known Papilio is the common 
Eastern black swallowtail, P. polyxenes, represented by five named varie- 
ties besides the type form. The black wings are crossed by two rows of 
yellow spots, the inner ones the larger, and there is a series of yellow mar- 
ginal lunules; incomplete bluish spots lie between the two yellow rows of 
spots on the hind wings, specially distinct and large in the female. The 
larva feeds on parsnips, caraway, etc., and is green-ringed with black and 
spotted with yellow. P. troilus, the spice-bush swallowtail of the eastern 
and middle states, has a single row of well-separated yellow spots near the 
outer margin of each wing, with indications of a bluish or greenish row inside 
this, specially distinct on the hind wings; there is an orange spot at each 
end of this row on the hind wings. ‘The larva lives on spicewood and sassa- 
fras and makes a protecting nest by tying the edges of a leaf together. The 
pipe-vine swallowtail, Laertias philenor, has no band of yellow spots, but only 
a few indicated lilac-colored remnants of spots, and has the hind wings suf- 
fused with beautiful glossy blue-green, especially beyond the base; its cater- 
pillar feeds on Dutchmen’s pipe and a wild species of Aristolochia, common 
in the Appalachian forests. There are two Papilionids without tails, viz., 
Ithobalus acauda, found in New Mexico, and J. polydamas, found in 
Florida; both are beautiful butterflies, much like P. philenor in color and 
marking. 

The largest family of Rhopalocera is that of the Nymphalidz, or brush- 
footed butterflies, the vernacular name partly describing their most dis- 
tinctive structural peculiarity, namely the marked reduction (atrophy) of 
the fore legs to be functionless little hairy brush-like processes without tar- 
sal claws on the feet; in both sexes these fore feet lie folded on the thorax, 
“like a tippet,” as Comstock has said. This and the possession of an always 
five-branched radial vein in the fore wing are about the only structural 
characteristics common to all the butterflies of this large family. The species 
range from small to large, present a bewildering variety of coloring and pattern 
and an equal variety of larval habit and appearance. All the chrysalids 
are naked, usually angular, and are suspended head downward by the tail 
without other support. Nearly 250 species of Nymphalids are recorded 
from this country, and the majority of the best-known and most abundant 
butterflies in any locality belong to the group. Some systematists consider 
the brush-footed butterflies to form several distinct families—this is the 


“= 


The Moths and Butterflies 451 


point of view taken by the author of the latest catalogue of North American 
Lepidoptera—while those who believe in the fantily unity of the group sub- 
divide it into a number of subfamilies. 

In the face of the large number of beautiful, interesting, and familiar 
species of Nymphalide we can only select, for description in our limited 
space, a few of the most familiar and interesting. The special collector 
and student of butterflies will find awaiting him a large literature mostly 
readily available, and to this he must refer for anything like a comprehensive 
account of the species of this family. 

The all-conquering American butterfly is the monarch, Anosia plexip- 
pus (Pl. XI, Fig. 4; also Fig. 641), sometimes called the milkweed-butter- 


Fic. 641.—The monarch butterfly, Anosia plexippus (above), distasteful to birds, and 
the viceroy, Basilarchia archippus (below), which mimics it. (Three-fourths natural 
size.) 

fly because of the food-plant of its larva. This great red-brown butterfly 

king ranges over all of North and South America, and has begun its invasion 

of other countries by getting a foothold on the west coast of Europe and 
in almost all of the Pacific islands and in Australia. I have found the mon- 

arch the most abundant butterfly through all of the Hawaiian Islands 2000 

miles distant from the Californian coast, and still 2000 miles farther into the 

great Pacific in the Samoan Islands it is also the dominant butterfly species. 

Its success is due to its hardiness, its strong flight power, the abundance and 


452 The Moths and Butterflies 


cosmopolitan distribution of its food-plant, and finally and most important 
its inedibility—to birds. It secretes in its body an ill-tasting acrid fluid, 
and birds soon learn to let these disagreeable butterfly morsels alone. For 
the sake of this immunity another butterfly species, the viceroy, Basilarchia 
archippus (Pl. XI, Fig. 1; also Fig. 641), which is not ill-tasting, mimics in 
extraordinary degree the color pattern of the monarch, so that it must be 
constantly mistaken for the disagreeable monarch and is passed unmolested 
by experienced birds. The monarch in the eastern states has a migratory 
habit not unlike that oft birds, great swarms flying south in the autumn to the’ 
Gulf states and West Indies, returning north again in the spring, not in swarms, 
however, but singly. It ranges as far north as Canada. It has, too, a curious 
habit of assembling in great numbers in a few trees, like blackbirds or crows 
in a “roost,” and hanging there quietly in masses and festoons, many indi- 
viduals clinging only to each other and not to the branches at all. On cer- 
tain great pine trees near the Bay of Monterey on the Californian coast I 
have seen myriads of monarchs thus “sembled.” The eggs are laid singly 
on the leaves of various milkweed species, Asclepias cornuti the favored 
kind, and hatch in about four days. The larva (Fig. 791) attains its full 
growth in two or three weeks and is a conspicuous object with its greenish- 
white body regularly banded with narrow black and yellow stripes; it has 
two pairs of slender black filaments, one on the second thoracic and the other 
on the eighth abdominal segment. The beautiful plump chrysalid is pea- 
green, smooth, and rounded with a few black and gilt spots and bands. The 
pupal stage lasts from nine to fifteen days. There is but one generation a 
year in the north, but two appear in the south. The winter is passed by 
the adult butterfly in the warm region of the subtropics. 

Although the viceroy, Basilarchia archippus, closely resembles the 
monarch in its red-brown ground-color, black-bordered veins, and small 
white spots, only one of the half-dozen other species of the same genus is 
at all like it. This one is B. floridensis found in the southern states. The 
others have a blackish ground-color with the hind wings suffused with 
greenish blue and a few conspicuous reddish blotches on the under side 
of both wings, as in the red-spotted purple, B. astyanax, common in the East, 
or broadly banded with white, as in the banded purple, B. arthemis (Pl. X, 
Fig. 6), of the northeastern states, or have a blackish-brown ground with 
broad white band and red-brown apex of the fore wings, as in Lorquins 
Admiral, B. lorquini, of the Pacific states. The larve of Basilarchia 
feed on oaks, birches, willows, currants, and various other trees and shrubs, 
and are odd-appearing caterpillars with numerous prominent tubercles or 
bosses on the back. 

Beautiful and abundant Nymphalids are the angle-wings, tawny above 
with black markings, dead-leaf-like below and often with a little silvery 


The Moths and Butterflies 453 


comma-spot. The comma-butterfly, Polygonia comma (Pl. XI, Fig. 6; 
also Fig. 642), is a familiar eastern representative of the angle-wings. On the 


under side of each hind wing is a small but distinct silver comma or C spot. 


Fic. 642.—The comma-butterfly, Polygonia comma; two butterflies, a c: erpillar, and 
empty chrysalid on gooseberry branch. (After Lugger; natural size.) 


The spiny greenish-brown larve feed on hops, nettles, and elms. The pale 
wood-brown chrysalids with metallic golden or silver spots are commonly 


454 The Moths and Butterflies 


known as hop-merchants. If the spots are golden, hops are to bring high 
prices; if silvery, low prices! The violet-tip, P. imterrogationis, is another 
common eastern angle-wing and has on the under side of the hind wings a 
double silver spot a little like a question-mark but more like a semicolon. 


Fic. 643.—The larva of the violet-tipped butterfly, Polygonia interrogationis, making its 
last moult, i.e., pupating. (Photograph from life by author; slightly enlarged.) 


Its chestnut-colored, pale-spotted, spiny larva feeds on hops, elms, and 
linden. Fig. 643 shows a caterpillar just pupating, and Fig. 644 shows 
the formed chrysalid. There are eight other species of Polygonia in the 
United States. 

The Vanessas are among the best known of our butterflies. Three 
species, V. atalanta (Pl. X, Fig. 2), the red admiral, V. huntera, the painted 
beauty, and V. cardui, the thistle-butterfly, are found all over the United 
States, and in addition a fourth, V. cary@, the west-coast lady, occurs on the 
Pacific coast. The latter three species are but little like atalanta, having 
the wings blackish brown, plentifully and irregularly marked with orange 
and whitish; underneath there are true eye-spots; /iuntera may be dis- 
tinguished from cardui by having but two complete eye-spots instead of 
several, and carye differs from cardui by the absence of the rosy tint peculiar 
to that species, the tawnier ground-color of the upper surfaces, and the com- 
plete black band which crosses the discal cell of the fore wings. Atalanta 


> 


1k ATAIL 


».. 
2a ITAATTUS 


engine sirlowsliesl =1 
1asiioT =s 

. sina goldanye=g 
if Iq sizont. =p 


_ PLATE XI. 


BUTTERFLIES. 


PLATE X\ 


The Moths and Butterflies 455 


and cardui occur also in Europe, and cardui is held to be the most nearly 
cosmopolitan of all butterflies, ranging over nearly the whole earth outside 
the arctic and antarctic regions. Its larve feed on thistles by preference, 
but on almost any composite if necessary: those of huntera on everlasting 
and other Gnaphaliee; those of atalanta on nettles; while those of carye 
feed on Lavatera assurgentiflora. All these larvee are spiny. 

Two striking, widely distributed, and abundant butterflies are the mourn- 
ing-cloak, Euvanessa antiopa (Pl. X, Fig. 7), and the peacock-butterfly, 
or buckeye, Junonia cenia (Pl. V, Fig. 1). Both are found over nearly 
all of our country, and the mourning-cloak is common in Europe. The 


Fic. 644.—Chrysalid or pupa of the. violet-tipped butterfly, Polygonia interrogationis. 
(Photograph from life by author; slightly enlarged.) 


larva of the buckeye is black-gray marked with minute black-edged orange 
dashes and dots transversely arranged, and has long spines all over its body; 
it feeds on Scrophulariacex, especially Gerardia. The larva of the mourning- 
cloak is velvety black sprinkled with white papilla and with a row of large 
medio-dorsal orange spots, and has spines much longer than the body seg- 
ments. A curious butterfly of the Mississippi Valley and Great Plains 
is Anea andria, the goatweed-butterfly (Pl. XI, Fig. 5). The larva, 
which is naked, gray-green, and studded with numerous paler points, feeds 
on species of Croton, the goatweeds. The American tortoise-shell, A glais 


456 The Moths and Butterflies 


milberti, which occurs commonly in the North, has brownish-black wings 
with a broad orange fulvous band between the middle and outer margin; 
there are also two fulvous spots in the discal cell of the fore wing. The 
larva, which feeds on nettles, is spiny, velvety black above, greenish yellow 
below, and profusely dotted with whitish spots or points. Another northern 
butterfly is the Compton tortoise, Eugonia j-album, which resembles in 
general color and pattern the angle-wings (Polygonia), but has the hinder 
margin of the fore wings straight, the markings on these wings heavier, 
and a whitish spot on both fore and hind wings near the apex; there is also a 
small L-shaped silver spot on the under side of the hind wings. Eugonia 
californica, the California sister, is a beautiful butterfly common on the 
Pacific coast and found occasionally in the Rocky Mountains; it is velvety 
blackish brown with a broad white transverse bar across each wing, inter- 
rupted on the fore wings and tapering out on the hind wings, and with a 
conspicuous large orange-brown patch nearly filling the apex of the fore 
wings. Its larva feeds on oaks. 

Two large groups of brush-footed butterflies, some of whose species 
occur in every locality, are the fritillaries, or silver-spots (genus Argynnis 
and allies) and the checker-spots (genus Melitaea and allies). The 
fritillaries, mostly medium-sized to large butterflies, are usually red-brown 
with numerous black spots scattered over the upper surface of both wings; 
the hind wings usually bear on the under side a number of striking silvery 
blotches, which give these butterflies their name of silver-spots. The regal 
fritillary, Speyeria idalia, of the Atlantic states, expands 2} to 4 inches and 
has the fore wings bright fulvous above spotted with black, and the hind 
wings blue-black with a marginal row of fulvous and submarginal row 
of cream-colored spots; both fore and hind wings have silver blotches on 
the under sides. The black, ocher, and red-banded caterpillars have six 
rows of fleshy black and white spines; they feed on violets and are nocturnal. 
The spangled fritillary, Argynnis cybele, is a good example of the more 
usual coloring and pattern of the group. It expands from 3 to 4 inches, 
has both wings fulvous above and thickly spotted with black; the under 
side of the hind wings is silver-blotched; in the female the basal half of 
the fore and hind wings above is dark chocolate-brown. The caterpillar 
is black with six rows of shining black branching spines, and feeds on violets. 
Numerous other smaller Argynnids are like cybele in color and pattern: 
it is difficult to distinguish the various species. 

The checker-spots, small to medium size, blackish with red and yellowish 
spots, are represented by numerous species in the western mountain states, 
but by only two species in the east. The Baltimore, Euphydryas phaeton, 
expanding 1} to 24 inches, is the most familiar eastern checker-spot; it is 
black above with a marginal row of red spots followed by three rows of pale- 


The Moths and Butterflies 457 


yellow spots on the fore wings and two on the hind wings; besides there 
are some scattered red spots and some other yellow ones. The caterpillar 
is black, spiny, and banded with orange-red; it feeds chiefly on Chelone 
glabera, a kind of snakehead. On the Pacific coast the chalcedon, 
Melitaea chalcedon, is the most abundant checker-spot, although several 
other species are common. It has black wings spotted with red and 
ocher-yellow; the spiny black caterpillar feeds chiefly on Mimulus and 
Castilleja. 

The satyrs or meadow-browns are a group of fifty or more beautiful velvet- 
brown butterflies whose markings consist chiefly of eye-spots, large and small, 
on both upper and under wing surfaces. A number of species are abundant 
and familiar, but a majority live exclusively in mountain states, and especially 
in the west. The common wood-nymph, or eyed grayling, Cercyonis alo pe, 
(Pl. X, Fig. 1), is the most familiar eastern and middle state species. 
A larger similarly patterned form, C. pegala, is common in the south. The 
larvee of the meadow-browns feed on grasses, are pale green or light brown, 
and have the last abdominal segment forked. On the Pacific coast one 
of the most abundant autumn butterflies is the California ringlet, Cano- 
nympha californica, a small buffy-white member of this group with small 
eye-spots only on the under side of the wings. A number of interesting 
butterflies related to the meadow-browns are found only on mountain-tops 
or in high latitudes (arctic region) the equivalent in life conditions of high 
altitudes. In the Rocky Mountains on the peaks of the Front Range (13,000 
feet altitude) I have struggled, gasping in the thin air, after beautiful frail 
little brown and grayish butterflies, @neis and Erebia. Far above timber- 
line on bleak mountain-tops, masses of broken granite overspread for great 
spaces with lasting snow, these hardy little flutterers live successfully. At 
the edges of the great snow-fields are patches of alpine flowers, fragrant 
dwarf forget-me-nots and buttercups, which furnish food and interest for 
them in the solitude of the high peaks. 

The mountain-top butterflies of the White Mountains, of the Rocky 
Mountains, and of the Sierra Nevada are closely allied; indeed individuals 
of the same species are found on the summit of Mt. Washington and on 
the crest of the Rockies, and nowhere between these two widely separated 
localities. The question as to how this interesting condition of things came 
about would be answered (by the student of distribution) as follows: In 
glacial times the species probably ranged clear across the continent. With 
the retreat of the great continental ice-sheet, while most of the butterflies 
followed it closely north, or became in successive generations slowly adapted 
to the temperate life conditions, some few probably followed up the slowly 
retreating local mountain glaciers. In time, therefore, the descendants 
of these arctic-loving species found themselves still under truly arctic con- 


458 The Moths and Butterflies 


ditions on the snow-covered mountain-tops, but isolated by the temperate 
lowlands from the rest of their kind on other mountain-tops or in arctic 
latitudes. 

There are several excellent books about American butterflies which will 
help the nature student classify his specimens, and tell him of the distribution 
and habits of the various species. Among the best are Comstock’s “ How 
to Know the Butterflies,’ Holland’s ‘‘The Butterfly Book,” and Scudder’s 
‘* Everyday Butterflies.” 


CHAPTER. XV 


THE SAW - FLIES, 


GALL - FLIES, 


ICHNEUMONS, WASPS, BEES, 
AND ANTS (Order Hymenoptera) 


“=. EES, ants, and wasps are the familiar Hymenoptera. 


“ant and bee people.”’ 
specialization of instinct 
and behavior the perform- 
ances of the solitary wasps 
and bees are little less wonderful than those of 
the social kinds, and the amazing character of the 
life-history of many of the obscure and unfamiliar 
parasitic and gall-making Hymenoptera ought to 
incite as much interest and scientific curiosity as the 
marvels of the bee community. The Hymenoptera 
constitute a large order, 7500 species in this coun- 
try, and one of endless variety of habit and struc- 
ture. Few generalizations indeed can be made that 
will apply to all the members of the order, although 
there is no question concerning the true relationship 
of all the kinds of insects included in the order. 
the structural characteristics common to the Hymen- 
optera the clear, membranous condition of the two 
pairs of wings gives the name to the order (/rymen, 
membrane; pteron, wing). The front wings are 
larger than the hind ones, and all are provided with 
comparatively few branched veins, whose homologies 
have not been fully worked out. The workers 
(infertile females) of all the ant species are wingless, 


They are the “intelligent” and the “social” in- 
sects, and therefore seem, of all the insect hosts, 
those living the most specialized or “highest” kind 
of life. As intelligence and social life are precisely 
those characteristics of our own which most dis- 
tinctly set us off from other animals, we are quick 
to appreciate the worth of similar attributes in the 
But in actual degree of 


Te 
U 


Of Fis. 645.—Mouth-parts of a 


honey-bee with maxilla 
and mandible of right side 
removed. md., mandible; 
mx., maxilla; mx.p., max- 
illary palpus; mo./., max- 
illary lobe; st., stipes of 
maxilla; cd., cardo of max- 
illa; /7., labium; sm., sub- 
mentum of labium; m., 
mentum of labium; pg., 
paraglossa; gi/.,  glossa; 
li.p., labial palpus. 

459 


460 Saw-fies, Gall-flies, Ichneumons, 


as are also the females of the Mutillid wasps and a few other exceptional 
_— forms. In many Hymenoptera (shown 
well in the honey-bee) the fore 
(costal) margin of the hind wings 
bears a series of small but strong 
recurved hooks which, when the 
wings are outspread, fit snugly over 
a ridge along the hind margin of the 
fore wing, the two wings of each side 
being thus fastened together so as to 
move synchronously. <A_ structural 
characteristic not readily made out 
but of much morphological impor- 
tance is the complete fusion of the 
Fic. 646.—Lateral aspect of head of full- true first abdominal segment with 
grown larva of honey-bee which has been the thoracic mass, so that the small 
cleared so as to show the forming adult head é e ¢ 
within. ih., head of adult; 7.e., compound articulating segment between what t 
eye of adult; /c., body-wall of larval head; are called thorax and abdomen is 
jam, antenna of adits Ld. mandible of reany the second abdominal seg- 
maxilla of larva; i.mx., maxilla of adult; ment. 
/.1i., labium of larva; 7./i., labium of adult. The mouth-parts ae variously 
modified, but usually are fitted for both biting and sucking (or lapping). 
This is arranged for by having the maxilla and 
labium more or less elongate and forming a sort 
of proboscis for taking up liquids, while the man- 
dibles always retain their short, strong, toothed, 
jaw-like character. The mandibles of the honey- 
bee are modified into admirable little “trowels” 
for moulding wax and propolis. The females 
throughout the order are provided either with a 
saw-like or boring or pricking ovipositor, or with 
the same parts modified to be asting. The sting 
is possessed by the wasps, bees, and ants (rudi- 
mentary in many ants), on which account these 


Fic. 647.—Mouth-parts of 


groups are often referred to collectively as the 
aculeate Hymenoptera. The sting of the honey- 
bee is shown in Fig. 650 and is a well-developed 
example of this characteristic hymenopterous 
weapon of defence and offence. The barb-tipped 
darts (d) extend down through the sheath (s) and 
are controlled by the chitinous bars called levers 
(). The poison produced in the poison-gland 


mud-wasp, with mandible 
and maxilla of right side 
removed. md., mandible; 
mx., maxilla; mx.l., max- 
illary lobe; mx.p., maxil- 
lary palpus; /i., labium; 
m., mentum of labium; 
pg., paraglossa; gi., glossa; 
li.p., labial palpus. 


(p-g/.) and stored in the 


atbomign asia =8 
insorisy BqeIV =e 


eusintoliles eudmoll =er 


-soiliosq stodgodinA=1 
zierstivelt sido =er 


PLATE XII. 
WASPS AND BEES. 


1=Sphzrophthalmus californicus. 

2= Polistes aurifer. 

3=Elis sp. 

4= Psithyrus elatus. 

5=Bombus vagans. 

6=Agapostemon radiata. 

7= Xylocopa sp. 

8= Bembex spinole. 

g= Vespa germanica. 
10= Bombus californicus. 
11=Anthophora pacifica. 
12= Polybia flavitarsis. 
13=Chalybion cceruleum. 
14=Sphex ichneumonea. 
15= Pelopeus servilla. 


PLATE XIl 


Wasps, Bees, and Ants 


461 


sac (p.s.) flows from this into lesser reservoirs in the expanded base of the 


sheath and escapes through the valve (v) along the darts 
into the wound. The tactile (and perhaps olfactory) palpi 
(p) are used to explore the surface of the object to be 
stung. The modifications of the various appendage-like 
parts which compose the sting to form an egg-depositing 
organ (ovipositor) are extremely various and are described 
later in connection with various special groups. The 
number of separate parts or processes which compose 
the ovipositor or sting and which arise from the two ab- 
dominal segments next in front of the terminal one is 
six, and some entomologists consider these parts to be true 
appendages, homologous with the legs and mouth-parts. 

In the development of all Hymenoptera the meta- 
morphosis is complete, and the larve are, more than 
in any other order, helpless and dependent for their 


Fic. 648.—Frontal as- 
pect of head of larva 
of mud-wasp. md., 
mandible; mx., max- 
illa; mo.l., maxillary 
lobe; Ji., labium; 
li.p., labial palpus. 


food and safety on the provision or care of the parents. With many 


Fic. 649. 

Fic. 649.—Lateral aspect of head of full-grown larva of mud-wasp cleared so as to 
show forming adult head within. 7.4., head of adult; 7.e., compound eye of adult; 
1.c., body-wall of larval head; iant., antenne of adult; /.md., mandible of larva; 
i.md., mandible of adult; /.mx., maxilla of larva; imx., maxilla of adult; imx.p., 
maxillary palpus of adult; /./7., labium of larva; 7.Ji., labium of adult; /i./ip., labial 
palpus of adult. 


Fic. 650. 
1., levers; v., valve; s., sheath; ., palpus. 


Fic. 650. 


Sting of the worker honey-'ee. .g/., poison-gland; p.s., poison-sac; d., dart; 


species, as the solitary wasps and bees, food is stored up in the cell in which 


462 Saw-flies, Gall-flies, Ichneumons, 


the egg is deposited, so that the larva on hatching will find it ready to hand. 
With the social wasps and bees and all the ants, the workers bring food to 
the larva during its whole life. With the lower forms, the parasitic and 
gall-making kinds, the egg is deposited on or in a special and sufficient food- 
supply. All these unusual conditions are described in the discussion of 
the various groups. Indeed this whole chapter on the Hymenoptera is writ- 
ten especially with the aim of illustrating the biology, the special life con- 
ditions and relations of the various larger groups of these insects, rather 
than with the aim which determined the character of the chapters on the 
beetles (Coleoptera) and moths and butterflies (Lepidoptera), namely, that 
of presenting a systematic survey of the classification and individual habits 
of those members of the order most likely to be seen or captured by the col- 
lector. The beetles and the moths and the butterflies are the insects which 
fill the cabinets of the amateur and beginning student, and names and facts 
concerning particular species are likely to be the particular desiderata in 
connection with them. But it is the extraordinary and “wonderful” char- 
acter of the ecological relations and physiological adaptations of the Hymen- 
optera which make these insects of such interest to nature-lovers, and which, 
indeed, is the subject that can most profitably be given special attention 
by any student of the order. Without, therefore, making any further attempt 
to formulate generalizations concerning this great complex of variously 
mannered insects, we may begin our study of its members arranged in sub- 
ordinate groups, this grouping depending rather upon general biologic char- 
acteristics than strictly classific ones. 

The classification of the Hymenoptera is a matter that interests but few 
amateurs; only a few families are at all well represented in general collec- 
tions. Distinction among the more familiar larger groups, as the ants, bees, 
wasps, saw-flies, horn-tails, and ichneumons, is usually pretty well marked 
in the general habitus or tout ensemble of appearance. Certain other of the 
larger groups, composed of minute parasitic species, are almost unknown 
to the general collector; indeed but two or three American professional 
entomologists would attempt to distinguish species in these groups. In the 
following table, therefore, and in the later discussion of the various groups, 
I have lumped these little-known families together on a basis of common- 
ness of habit, namely, of parasitic life, and devoted the Space to a general 
account of the extraordinary life-history and habits which these parasitic 
Hymenoptera have adopted, with some reference to the special habits of 
certain particular species. Their classification into smaller groups is left 
undiscussed. 


Wasps, Bees, and Ants 463 


KEY TO GROUPS OF HYMENOPTERA. 


A. Trochanters (segment between the rounded basal coxa and the long femur) of 
the hind legs divided in two, i.e., two-segmented; female with a saw or borer at 
tip of body for depositing the eggs. 

B. Abdomen joined broadly to the thorax. 
C. Tibie of fore legs with two apical spurs; female with a pair of saw-like 
egg-depositing processes at tip of abdomen. 
(Saw-flies.) Family TENTHREDINID (p. 464). 
CC. Tibie of fore legs with one apical spur; female with elongate borer 
stead of: SAW)rere ole ciec/eleleiel enero (Horn-tails.) Family Srricipa (p. 466). 
BB. Base of abdomen constricted, so that it joins the thorax as if by a stem. 
C. Abdomen joined to the dorsum of the metathorax. 
(Ensign-flies.) Family EvANnODz&. 
CC. Abdomen joined to posterior aspect of metathorax. 
D. Fore wings with few veins and no closed cells (a few exceptions) ; 
very small parasitic Hymenoptera. 
Families CHALCIDID2 and PRocTOTRYPID (p. 476). 
DD. Fore wings with one or more closed cells (a few exceptions). 
E. Fore wings without a stigma (Fig. 655). 
(Gall-flies.) Family Cynrpmp& (p. 467). 
EE. Fore wings with a stigma (Fig. 671); parasitic Hymenop- 
tera, from very small to large. 
(The Ichneumons and other parasites.) Families Braco- 
NID&, STEPHANID, ICHNEUMONID#, and TRIGONALID& (p. 476). 
AA. Trochanters of hind legs not divided, i.e., consisting of a single segment; female 
often with a sting. 
B. Fore wings with no closed submarginal cells (Fig. 683). 
C. Abdomen long and slender, and antennz also long and filiform. 
Family PELECINID (p. 484). 
CC. Abdomen short, but little longer than head and thorax; antenne short 
and elbowed............ (Cuckoo-flies.) Family CHrysiprp& (p. 498). 
BB. Fore wings with at least one closed submarginal cell. 
C. First abdominal segment and sometimes the second segment in the shape of 
a small disk-like piece (Fig. 743). 
(Ants.) Superfamily Formicrna (p. 533). 
CC. Basal segment (or segments) of abdomen normal or elongated to form 
a peduncle. 
D. First segment of tarsus of hind legs cylindrical and naked or with 
but little hair. 
E. Wings not folded longitudinally when at rest. 
(Digger-wasps.) Superfamily SPHECINA (p. 490). 
EE. Wings folded longitudinally when at rest. 
(True wasps.) Superfamily VESPINA (p. 503). 
DD. First segment of tarsus of hind legs expanded and flattened and 
furnished with numerous hairs, some rather long. 
(Bees.) Superfamily Aprva (p 510). 


According to Ashmead our foremost American student of the classification 
of Hymenoptera, the above table gives in some respects false indications of 


464 Saw-tlies, Gall-flies, Ichneumons, 


relationship. For example, the Proctotrypide are held by Ashmead to be 
more nearly truly related to the wasps and to the gall-flies (Cynipid) than to 
the other parasitic Hymenoptera, as the Chalcidide, Braconid, and Ichneu- 
monide, with which this table groups them. The families composing the 
superfamilies Sphecina and Vespina, as separated by the character used 
in the key, are differently divided in Ashmead’s superfamilies Sphecoidea 
and Vespoidea, and the families Tenthredinide and Siricide are replaced 
by the superfamilies Tenthredinidoidea and Siricicoidea, each containing 
several families. I only need to repeat what I have often said before, namely, 
that at best the keys and tables used in this book, as in most other insect manu- 
als, to assist the student in his work of classifying insects are primarily things 
of convenience, taking advantage of obvious but often superficial and adapt- 
ively acquired likenesses and differences, rather than attempts to offer a 
true genealogical arrangement of the various groups. 

The saw-flies, Tenthredinide, are the simplest Hymenoptera; they show 
no such extreme specialization in habit or structure as that possessed 
by the host of parasitic species, or by the “‘intelligent’”’ groups, the ants, 
bees, and wasps. They compose a large family, 600 species being known 
in this country, but one of singular unity. The adults are much alike in 
appearance, and the larve all agree in their salient characters of structure 
and habit. Despite the large number of our species, comparatively few 
are known to the general observer, and these almost solely because of the 
injurious habits of their larva. These larve 
are the familiar rose-, currant-, pear-, larch-, 
and willow-slugs. They are soft bodied, 
naked, slug-like or caterpillar-like creatures, 
usually with six to eight pairs of prop-legs 
besides the three pairs of true thoracic legs, 
and are voracious devourers of green leaves. 
They may be distinguished from lepidopterous 
larve by their usual possession of more than 
five pairs of prop-legs and by their having 
but a single ocellus on each side of the head 
Fic. 65r.—A_ saw-fly, Allantus instead of several. The eggs are laid by the 
basillaris. (Twice natural size.) females in little pockets cut in tender stems or 
in the leaf-tissue, usually on the under side, by means of the famous ‘“‘saws” 
which have given the insects their vernacular name. These saws are a pair 
of small slightly chitinous pieces, finely serrate on the outer margins, which 
are carried by the last abdominal segment and can be thrust out and moved, 
saw-like, up and down. The larve, or slugs as they are often called 
because of their shape and the slimy secretion which covers the body of some 
kinds, usually “skeletonize” the leaves, i.e., eat away only the soft tissues, 


Wasps, Bees, and Ants 465 


leaving the skeleton of tough, fibrous veins; often only the upper surface 
of the leaf is fed on. Some of them cover the body with a white, waxy secre- 
tion, and some, when disturbed, emit a 
malodorous fluid from the mouth or from 
pores in the skin. When full-grown, they 
crawl down to the ground, burrow into it, and 


pupate within a little cell sometimes lined 
with a thin silken cocoon. Some of the larve 
Fic. 652.—The currant-slug, larva 

of the currant saw-fly, Nematus 


such species is common on willows. The  ventricosus. (Two and one-half 
times natural size.) 


live in gall which develop about them; one 


adults mostly have rather broad somewhat 
flattened bodies and head, are quietly colored, blackish, reddish, brownish, 
and usually quietly mannered, but fluttering about in the trees at egg-lay- 
ing time. 

It has been noted that numerous species of saw-flies can produce young 


1a 


Fic. 653.—The currant-stem girdler, Janus integer, a saw-fly at work girdling a stem 
after having deposited an egg in the stem half an inch lower down. (Photograph 
by Slingerland; natural size.) 


from unfertilized eggs (parthenogenetic reproduction), and in some species 


466 Saw-flies, Gall-flies, Ichneumons, 


no males have yet been discovered. It is indeed a general rule in the family 
that the females greatly outnumber the males. 

Probably our most familiar saw-fly, at least in its larval stage, is the 
rose-slug, Monostegia rose, a soft-bodied, greenish-yellow, nocturnal larva 
that skeletonizes rose-leaves and often occurs in such numbers as practically 
to defoliate the bushes. The adult fly is black with sooty wings and whitish 
fore and middle legs. There are two generations a year. Two currant- 
slugs are common: one the imported currant-worm, Nematus ventricosus 
(Fig. 652), green with many small black spots (in its last stage only the head 
is black-spotted); the other the native currant-worm, Pristophora grossu- 
lari@, all pale green except the blackish head, which becomes partly green 
just before pupation. Both of these slugs make slight cocoons of silk and 
leaves in which to pupate, the first-named one in or on the ground, the second 
one attached to the twigs or leaves of the currant-bush. 

The pear-tree slug, Eviocampa cerasi, is half an inch long when full-grown, 
with the body expanded in front so as to be almost tadpole-shaped; it is 
greenish with a gummy slime over it. It feeds in May and June on the 
upper surfaces of the leaves, and when full-grown crawls down to the ground 
and makes a little cell just below the surface in which to pupate. The 
winged saw-fly is glossy black, about $ inch long. The eggs are laid in 
slits cut on the under side of the leaves. The larchis often seriously attacked 
by the larva of the saw-fly Nematus erichsonii; it is a glaucous green slug 
with jet-black head and two double rows of tiny black points around the 
abdomen; it is 3 inch long and has seven pairs of prop-legs. The adult, 
¢ inch long, is thick-bodied, blackish with a broad bright resin-red band on 
the abdomen. The eggs are laid in the young shoots in June or July, the 
larve feeding until late in July or early in August. In California one of 
the most abundant saw-flies is a species of Lyda, which lays its eggs in the 
summer on the new growth of needles on pines. The larve hatch out 
in fifteen days and feed on the needles for four months; then they trans- 
form to another larval stage, migrate to the tops of the trees, and just 
before winter spin a silken cocoon in which they pupate. The adult flies 
issue in the spring. 

A much smaller family than that of the saw-flies is the nearly related 
one of the horntails, the Siricide. About fifty species are known in this 
country. The females are provided with a boring ovipositor, which appears 
as a conspicuous, strong, long “horn,” projecting from the tip of the abdo- 
men; Comstock describes this ovipositor as composed of five long slender 
pieces; the two outside pieces are grouped on the inner surface, and when 
joined make a sheath containing the other three pieces, two of which are 
furnished at the tip with fine transverse ridgés like the teeth of a file. With 
this boring ovipositor the female can drill holes into the solid wood of a tree 


Wasps, Bees, and Ants 407 


and place an egg at the bottom of each. One of the best-known horntails 
is the pigeon-tremex, Tremex columba (Fig. 654), 14 inches long, with reddish 
head and thorax and black abdomen with yellow bands and spots along 
the sides. The females bore holes 4 
inch deep into elms, oaks, sycamore- 
or maple-trees, the ovipositor, in boring, 
being held bent at right angles with 
the abdomen. The larve hatching 
from the eggs laid, one in each hole, 
burrow into the heart-wood of the 
tree, and grow to be cylindrical, blunt- 
ended, whitish grubs, 13 inches long, 
with short thoracic legs and a short anal 
horn. They pupate in their burrows 
within a cocoon made of silk and tiny Fic. 654.—The_pigeon-tremex, Tremex 
chips. The issuing winged adult gnaws eee ee Jordan and Kellogg; 
its way out through the bark. In 

some allied species (Sirex) the pupa may remain in the tree for several 
years. Tremex is parasitized by an extraordinary ichneumon-fly, Thalessa, 
which has a slender, flexible ovipositor, four to five inches long, with which 
it bores into trees infested by Tremex and deposits its eggs in the Tremex- 
burrows. The young Thalessa-grub (larva) moves along the burrow until 
it finds a Tremex-larva, to which it attaches itself, living parasitically. (See 
account of Thalessa, p. 483.) A small horntail sometimes abundant and 
injurious is the European grain-cephus, Cephus pygmaeus, whose larve 
bore into wheat-stems. The adult is 2 inch long, shining-black-banded and 
spotted with yellow. It lays its eggs in tiny holes bored in the stems just 
about the time of the forming of the heads; the larve tunnel down through 
the stem, reaching the lowest part of the straw about harvest-time. This 
part is left by the reaper, and in it the larva makes a silken cocoon within 
which it hibernates. In March or April it pupates, and the adult issues 
in May. 

Indications of the work of certain hymenopterous insects are familiar to 
even the most casual observers in the variously shaped “galls” that occur 
on many kinds of trees and smaller plants, especially abundantly, however, 
on oaks and rose-bushes. Not all galls on plants are produced by insects, 
certain kinds of fungi giving rise to gall-like malformations on plants, nor 
are all the insect galls produced by members of that family of small hymen- 
opterous insects called the Cynipide, or gall-flies. But most of the closed 
plant-galls, and particularly those conspicuous, variously shaped, and most 
familiar ones found abundantly on oak-trees and rose-bushes, are abnormal 
growths due to the irritation of the plant-tissue by the minute larve of the 


468 Saw-flies, Gall-flies, Ichneumons, 


Cynipid gall-flies. These flies (Fig. 655) are all very small, the largest 
species not being more than 4 inch long; 
they are short-bodied and have in most 
cases four clear wings with few veins. 
The females—and in numerous species 
there seem to be no males—have a long, 
slender, and flexible but strong, sharp- 
pointed ovipositor (Fig. 656), composed of 
several needle- or awl-like pieces, which 
is used to prick (pierce) the soft tissue of 
leaf or tender twig so that an egg may be 
deposited in this succulent growing plant- 
tissue. 

Each female thus inserts into leaves or 
twigs many eggs, perhaps but two or three 
in one leaf or stem if the galls are going 
to be large ones, or perhaps a score or so if 
the galls will be so small as to draw but little on the plant-stores and 
be capable of crowding. In two or three weeks the egg gives birth to 
a tiny footless maggot-like white larva which feeds, undoubtedly largely 
through the skin, on the sap abundantly flowing to the growing tissue in 
which it lies. With the birth of the larva begins the development of the 


Fic. 655.—A gall-fly, species unde- 
termined. (Much enlarged.) 


Fic. 656.—Ovipositor of a gall-fly, dorsal and lateral views; the long tapering part is 
the piercing portion; the other parts constitute levers and supports (After Lacaze- 
Duthiers; greatly magnified.) 


gall, which is an abnormal or hypertrophied growth of tissue about the point 
at which the larva lies. The excitation or stimulus for the growth undoubtedly 
comes from the larva and probably consists of irritating special salivary 
excretions and perhaps also of physical irritation caused by the presence 


Wasps, Bees, and Ants 469 


of the wriggling body. In some species the gall grows around and includes 
but a single larva, in others around several to many. The larva reaches its 
full development about coincidently with the 
full growth or end of the vitality of the gall, 
this period varying much with different galls. 
In the galls on deciduous leaves the vitality 
is shortest, ending in autumn; in twig-galls 
it may not end until winter or even until the 
following or indeed the second winter. When 
“dead” the gall dries and hardens, thus form- 
ing a firm protecting chamber in which the larva 
or larve pupate. The pupa undergoes its non- 
food-taking life securely housed in the dry gall, 
which may fall with the autumn leaves or cling 
to the bare twigs. From the galls the fully 
developed flies gnaw their way out when new 
leaves and tender shoots are appearing, ready 
to prick in new eggs for another life cycle. 

But, strange to say, with some species 
the new eggs may be deposited on plants of 
another kind and the hatching larve stimulate 
the growth of entirely different-shaped galls, 
and they themselves develop into gall-flies 
of markedly different appearance from their 
mothers. These new gall-flies in their turn lay 
eggs on the first host-plant; the forming galls 
are like those of the grandparent generation Comal cana (tate 
and the fully developed flies are of the grand- size.) 
parent kind. This alternation of generations— 
a condition in which a single species appears in two forms and produces 
two kinds of galls, usually on different host-plants—has been long known, 
but still remains a problem which interferes sadly with a number of popular 
biological generalizations. One of these generations appears exclusively in 
only one sex, the female, so that the other generation, composed of both 
males and females, is produced uniformly from unfertilized eggs. The 
adults and galls of the two generations were formerly described as belong- 
ing to two different Cynipid species. Not all gall-flies, however, show this 
dimorphic condition; some appear habitually in but one form and pro- 
duce but one kind of gall; in most if not all of these cases the species is 
represented only by female individuals. 

The great variety of the galls, the extraordinary instinct which leads the 
adult flies to the right selection of plant and position on twig or leaf for ovi- 


470 Saw-tles, Gall-flies, Ichneumons, 


position, and the interesting response or reaction of the plant to the growth- 
stimulating irritation of the gall-fly larva are subjects which have attracted 
much attention and study, but concerning which much remains to be dis- 
covered. In size and shape the galls present amazing variety; some are irreg- 
ular little swellings on the leaves, others are like small trumpets, others like 
rosettes or star-like with radiating 
points; on the twigs some are spherical, 
some elongate, and some large and 
reniform. Figs. 657 to 665 show 
something of 
this variety. 
In their interior 
make-up they 
also differ 
much; some 
have a large 
hollow central 
space; some 


Fic. 658. Fic. 659. 
Fic. 658.—Galls on leaf of California white oak. (Natural * 
size.) ; ‘ ; 
Fic. 659.—Trumpet-galls on leaves of California white oak. 
(Natural size.) 


are filled with open, spongy tissue, and some are 
solid except for the cells and tunnels of the larve. 
In some but a single larva lives; in others are three 
or four or a dozen. Externally some are smooth, 
some roughened, some hairy. They occur on leaves, 
branches, and roots in both oak and rose. Only Fic. 660.—Galls on leaf 
a few Cynipid galls are known on other plants frre ae of 
than these. In the face of the host of species of Cyni- 

pide found in this country—over 200 gall-making kinds are known, besides 
a score of parasitic species—and their small size and generally similar appear- 
ance, we shall not undertake to describe any of the various species. Com- 
stock describes in his Manual several of the more common eastern galls, or 


Wasps, Bees, and Ants 471 


“oak-apples.” One of these is the fibrous oak-apple of the scarlet oak, 
1 to 2 inches in diameter, produced by the gall-fly Amphibolips coccinee. 


Fic. 661.—Galls on leaf of California white oak. (Natural size.) 


This gall is distinguished by having a small hollow kernel in the center of 
the gall, in which 
the single larva lives, 
the space between 
the kernel and the 
dense outer layer of 
the gall being filled 
with fibers radiating 
out to the surface 
from the kernel. The 
spongy gall of the red 
and black oak, made 
by Amphibolips 
Spongifica, has the 
space between kernel 
and outer wall filled 
by a porous, spongy 
mass. Inthe “‘emp- 
ty oak-apples,” the 
larger one of the 
scarlet and red oaks, 
Holcaspis inanis, 2 
inches or more in 
diameter, and the 
smaller, of the post- 


oak, Jahe centricola, rs 663. ina 
inch or less in diam- Fy, 662,—Galls on twigs of California white oak; upper figure, 
eter, the space be- a gall split open longitudinally. (Natural size.) 

Fic. 663.—Galls on leaf. (After Jordan and Kellogg; natural 


tween kernel and 
outer wall contains 
only a few slender silky filaments which suspend the kernel in place. The 


size.) 


472 Saw-flies, Gall-flies, Ichneumons, 


common bullet gall, 7. globulus, of the small twigs, 4 to # inch in diam- 
eter, has the kernel surrounded by a hard woody substance. 


Fic. 664.—An oak-apple, or fibrous gall of the California live-oak; in upper figure the 
gall shown in position on the oak-twig; in lower, a gall cut open to show the inside, 
(Upper figure slightly reduced; lower figure natural size.) 


In California the white or valley oaks bear very commonly conspicuous 
large white spherical to kidney-shaped galls (Fig. 665) which are attached 
to the branches, and often occur in such abundance as to make the injured 
tree look like some new kind of fruit-tree in heavy bearing. This gall is 
caused by the gall-fly Andricus californicus, one of the largest of the Cyni- 
pide, and the gall itself attains a larger size than any other known to me. 
It begins as an elongate swelling underneath the bark of the fresh twigs, 
but soon breaks through as a shining, smooth excrescence rapidly increasing 
in size. A single gall is inhabited by from six to a dozen larve. A curious 
oak-leaf gall is the jumping seed-gall (Fig. 666), a small and shot-like gall which 


Wasps, Bees, and Ants 473 


develops on the leaf, but which after reaching full growth falls off, when the 


Fic. 665.—The giant gall of the California white oak, produced by Andricus californicus; 


at right a gall cut open to show inside structure. (After Jordan and Kellogg; one- 
half natural size.) 


wriggling of the still active larva within causes it to roll about or even spring 
a quarter of an inch or more into the air. 

Of the rose-galls Comstock mentions 
the mossy rose-gall, produced by Rhodites 
ros@, aS a very common one on the sweet- 
brier. It consists of a large number of 
hard kernels surrounding the branch and 
covered with reddish or green mossy 
filaments. In each kernel is a larva. 
The pith blackberry-gall, Diéastrophus 
nebulosus, is a common, many-chambered, 
large, woody gall that occurs on_black- 
berry-canes. It attains a length of 3 
inches and a width of 1 inch to 14 inches. 

Regarding the wonderful instinct of 
the gall-fly, I quote the following from 
Stratton, an English student of galls: 

“Tt is impossible that intelligence or 
memory can be of any use in guiding the 
Cynipide; no Cynips ever sees its young, 
and none ever pricks buds a second season, 
or lives to know the results that follow F%6- 666.—Jumping galls of the oak 

i produced by Cynips quercus-sal- 
the act. Natural selection alone has pre- javix. (Galls on leaf of natural 
served an impulse which is released by size; at left a single gall much 
seasonally recurring feelings, sights, or enletee) 
smells, and by the simultaneous ripening of the eggs within the fly. 


474 Saw-flies, Gall-flies, Ichneumons, 


These set the whole physiological apparatus in motion, and secure the 
insertion of eggs at the right time and in the right place. The number 
of eggs placed is instinctively proportionate to 
the space suitable for oviposition, to the size of 
the fully grown galls, and to the food-supplies 
available for their nutrition. Dryophanta scutellaris 
will only place from one to six eggs on a leaf which 
Neuroterus lenticularis would probably prick a 
hundred times.” 

“Whatever form the gall takes, the poten- 
tialities of the tissue-growth exhibited by it must 
be present at the spot pricked by the fly.” 

“The potentialities of growth being present, they 
are called into activity by the larva, a result advan- 
Fic. 667.—Cynips quercus- tageous to the larva and sometimes described as 

saltatrix, the gall - fly see aes 

which produces the disinterested and self-sacrificing on the part of the 

jumping galls. (Much plant. We have just seen that, so far as the larva 

enlarged.) E = 

is concerned, the peculiar structures of the gall 

owe their origin to their success in feeding and defending it; and, so far as 
the plant is concerned, these structures have been evolved in consequence 
of their value in enabling the plant to repair injuries in general, and the 
injuries inflicted by larve in particular. If John Doe raises a cane to strike 
Richard Roe, and Richard throws up his arms intuitively to parry the stroke, 
the action does not indicate a prophetic arrangement of molecules to frustrate 
John in particular, but an inherited action of defence. The first act of an 
injured plant is to throw out a blastem, and only those larva survive to hand 
down their art which emerge from an egg so cunningly placed as to excite the 
growth of a nutritive blastem. It is not always possible to keep the besiegers 
from using the waters of the moat, although there is no disinterested thought 
of the besiegers’ wants when the ditches are planned. So in the war-game 
that goes on between insect and plant, natural selection directs the moves 
of both players, but there is nothing generous or altruistic on either side.” 

The exact character of the plant’s abnormal growth has been recently 
studied by several investigators. Cook, an American student, concludes 
from his studies that in the formation of all leaf-galls (except the Cecidomyid 
or dipterous midge-galls) the normal cell-structure of the leaf is first modi- 
fied by the formation of a large number of small, compact, irregular-shaped 
cells. The mesophyll is subject to the greatest modification and many small 
fibro-vascular bundles form in this modified mesophyll. Both Adler and 
Sockeu consider that after the first stages of formation the gall becomes an 
independent organism growing upon the host-plant. Cook believes this 
to be true of the Cynipid galls. A surprising conclusion arrived at by Cook 


Wasps, Bees, and Ants 475 


is that the morphological character of the gall depends upon the genus of 
the insect producing it rather than upon the plant on which it is produced; 
ie., galls produced by insects of a particular genus show great similarity of 
structure even though on plants widely separated; while galls on a particular 
genus of plants and produced by insects of different genera show great differ- 
ences. The formation of the gall is probably an effort on the part of the 
plant to protect itself from an injury which is not sufficient to cause death. 

An additional interesting feature in the economy of Cynipid life is the 
presence in the galls of other insects besides the gall-makers. These others 
are on two footings, that is, some are guests or commensals, and some are 
true parasites, either on the gall-makers or on the guests! Curiously, among 
both guests and parasites are members of the same family, Cynipide, to 
which the makers and rightful owners of the galls belong. Others of the 
parasites may belong to the various well-known parasitic hymenopterous 
families, as the Ichneumonide, Chalcidide, Braconide, etc., while others 
of the commensals may belong to entirely distinct orders, as the Coleoptera, 
Lepidoptera, etc. Kieffer (a famous French student of galls and gall-flies) 
gives the following amazingly large list of commensals and parasites bred 
from a common root-gall on oak, Biorhiza pallida: Commensals, the larvee 
of five species of moths, of one fly, of one beetle, of one Neuropteron, and of 
two Cynipids; parasites, a total of 41 species, bred mostly from the: 
various commensals. 

The guest gall-flies, called inquilines, are often surprisingly similar to: 
the species which actually produces the gall. A similar likeness between 
host and guest exists in the case of the bumblebee (Bombus) and its guest 
Psithyrus (closely related to Bombus). It may be that the guest species is a 
degenerate loafing scion of the working stock. 

The group of gall-flies and their allies is looked on as a superfamily, the 
Cynipoide, in the latest authoritative classification (Ashmead) of the Hymen- 
optera, and divided into subfamilies, the Cynipide including the gall-makers, 
and the much smaller family, Figitide, including the parasitic species. Only 
about a score of parasitic Cynipoids are yet known in this country, while 
over 200 gall-making species and inquilines, or guest species, are known. 

To collect gall-flies the galls should be gathered especially in the 
autumn, for with the end of the growing season the larve are mostly full- 
grown and ready to pupate. They should be separated according to kind,. 
those of each kind being put into small closed bags of fine-meshed bobinet 
or tarlatan. In these the various gall-flies, inquilines, commensals of other 
orders, and the parasites will issue, and may be thus identified with their 
proper gall. 

In the account of the Cynipide reference has been made to the division 
into gall-making species and parasitic species, the latter constituting but 


476 Saw-flies, Gall-flies, Ichneumons, 


a small part of the whole family. The parasitic habit, only slightly indulged 
in among the Cynipide, is, however, the prevailing one of a majority of Hy- 
menopterous insects. Although we commonly think of bees, ants, and wasps 
as the typical Hymenoptera and as constituting the bulk of the order, it is a 
fact that in point of numbers they are far outclassed by the parasitic forms 
whose life is, like that of the social Hymenoptera, also highly specialized, 


Fic. 668.—Caterpillar of a moth killed by Hymenopterous parasites, the adult parasites 
having issued from the many small circular holes in the body-wall. (After Jordan 
and Kellogg; twice natural size.) 


but along a radically different line. In a half-dozen families, including the 
largest in all the order, nearly every species is a parasite and a parasite of 
other insects. Indeed the chief agents in keeping the great insect host so 
checked that plants and other animals have some food and room on the 
earth are insects themselves. With all the artificial remedies man has 
devised and now uses against the attacks of insect pests, the all-important, 
constantly effective check on these pests is their parasitization by the host 
of species of the Hymenopterous families of Chalcidide, Braconide, Proc- 
totrypide, Ichneumonide, etc. 

These parasitic Hymenoptera are only rarely collected by amateurs, 


Fic. 669.—Larva of a sphinx-moth with cocoons of a parasitic ichneumon-fly. 
(Natural size.) 


although caterpillar-breeders always get acquainted with some of them, to 
their dismay and disgust. But even if collected, the unsettled state of their 


Wasps, Bees, and Ants 477 


classification, together with their (mostly) small size and the slight and 
hardly recognizable differences on which their scientific distinction rests, 
would make their systematic study nearly impossible for the amateur. On 
the other hand the interesting character and the biologic and economic 
importance of their habits of life make it desirable to know as much as may 
be about their life-history. I shall, therefore, give the little space which our 
book can afford to these insects almost exclusively to a consideration of the 
ecologic aspects of their study. 


Fic. 670.—Hairy caterpillar killed by parasitic ichneumon-flies which have left the 
body through small holes in the skin. (Natural size.) 

The superfamilies and families meant to be included among the insects 
referred to when the general term “parasitic Hymenoptera” is used are 
(using Ashmead’s classification) the 
superfamily Proctotrypoidea, a great 
group of mostly minute species, many 
of which pass all their immature life 
within the eggs of other insects; the 
superfamily Chalcidoidea, an even 
larger group, also of small species, 
but with a few forms which are gall- 
makers and not parasites; and the 
superfamily Ichneumonoidea, including 
the larger parasitic Hymenoptera. 
Each of these superfamilies includes a 
number of families, and the three 
together comprise an enormous host 
of mostly little-known insect species. 
At the present time much diversity 
exists in the arrangement of the various 
parasitic families in entomological F!: 671-—Caterpillar killed by Hymen- 

opterous parasites which have issued 
manuals. In the older books the para- from the cocoons attached to the skin 
sitic habit has been looked to as in- of the caterpillar; upper figure one of 
edatrs . Sues lationshi the adult parasites. (After Jordan and 
dicating an affinity of relationship Kellogg; caterpillar and cocoons natu- 
among them all; in more recent books ‘al size; adult parasite much enlarged.) 


and papers is adopted an arrangement 
proposed by Ashmead which indicates a nearer relationship on the part of 


478 Saw-flies, Gall-flies, Ichneumons, 


the Proctotrypoidea to the digger-wasps (Sphecoidea) and to the gall-flies 
(Cynipoidea) than to the other parasitic groups (Chalcidoidea and Ichneu- 
monoidea). This latter arrangement is based on structural unlikeness among 
the parasitic groups to which Ashmead gives much classificatory importance. 
Parasitism is a condition widely spread in the animal kingdom, parasitic 
species being found in most of the invertebrate phyla. The importance of 
these parasites in causing disease and death and their peculiar biological 
interest have led to much special study of them and of the particular phe- 
nomena Of parasitic life. Parasites may be external or internal as they cling 
to the outer surface of their host or burrow within the body; permanent or 
temporary as they live their whole life or only part of it in or on the host; 
but in almost all cases except in those of our parasitic Hymenoptera the 
parasite shows a more or less marked degeneration or simplification by 
loss of parts of its body structure. Lice and fleas are the degenerate wing- 
less descendants of winged ancestors; the intestinal worms are for the most 
part without sense-organs; the tumor-like Sacculina, parasite of crabs, has 
a body made up of feeding and reproductive organs and little else. But 
the parasitic hymenoptera show little or nothing of this insidious degenera- 
tion due to the adoption of a parasitic life. The reasons for this, however, 
are fairly obvious when the life-history and life-conditions of these insects 
are inspected. 
The general course of the life and the character of the various stages of 
a parasitic hymenopteron are as follows: the winged, free-flying female (the 
males are winged and free-flying also) 
searches, often widely, for its special 
host species in that stage, egg or larval, 
on or in which its eggs are to be laid. 
This host may be always an individ- 
ual of a particular species or may be 
one of any of several usually allied 
species. The hosts represent most 
of the larger insect orders, although 
caterpillars of moths and butterflies 
Fic. 672.—A common parasite, Merisus furnish the great majority of hosts 
destructor, female, of the Hessian fly. (After for the parasitic Hymenoptera. On 
Lugger; natural size indicated by line.) - 
the surface of the body, or, more 
rarely, inserted beneath the skin, the parasite deposits one or several eggs. 
The footless, maggot-like larvae soon hatch, and if not already inside the 
host’s body very soon burrow into it. Here they lie, feeding on its body, 
tissues, growing and developing until ready to pupate. They may now 
eat their way out of the enfeebled and probably dying host to pupate in little 
silken cocoons or fluffy silken masses on or off its body-surface, or may pupate 


“<i 


Wasps, Bees, and Ants 479 


within the body. In the latter case the issuing winged adults have to bite 
their way out. The host usually dies before its time for pupation has arrived, 
but in some species it succeeds in pupating beforehand. The parasitic 
Hymenopterous larve, while degenerate in the same way as the footless, 


Fic. 673. : Fic. 674. 


Fic. 673.—A chalcid fly, Pteroptrix flavimedia. (After Howard; much enlarged.) 
Fic. 674.—A chalcid parasite, Aspidiotiphagus citrinus, of one of the scale-insects of 
the orange. (After Howard; much enlarged.) 


eyeless, antennaless maggots of house-flies, are not more so. Their parasitic 
habit has led to no such extraordinary structural specialization through 
degenerative loss or reduction of parts as is the usual condition in other 
parasites. 

While Lepidopterous larve undoubtedly furnish the majority of hosts 
for the parasitic Hymenoptera, they are by no means the only ones. The 
eggs and pupe of Lepidoptera as well as the larve, Diptera, Coleoptera, 
Hymenoptera in both egg and larval stages, some Hemiptera, especially 


Fic. 675.—Labeo longitarsis, a parasite which lives in a sac in the abdomen of a Fulgorid, 
Liburnia lentulenta. (After Swazey; five times natural size.) 


scale-insects (Coccide) and plant-lice (Aphidide), the eggs of locusts and 
other Orthoptera, and some Neuroptera in egg and larval stage, may be 
infested; in fact the kinds of insects which may serve as hosts for the para- 
sitic Hymenoptera strongly outnumber the kinds that do not. 

While as a general rule each parasite confines its attacks to a single host- 
species, there are numerous exceptions; and on the other hand the host 
itself may be attacked by more than one parasitic species; most of our familiar 
Lepidoptera are parasitized by several different parasitic Hymenoptera. 


480 Saw-tlies, Gall-flies, Ichneumons, 


For example, the American tent-caterpillar has been found by Fiske (New 
Hampshire) to be attacked by twelve species. 

With regard to the number of parasitic individuals that may live at the 
expense of a single host individual no generalization can be made; the 


Fic. 676.—Hymenopterous parasites of a social-wasp. Fig. 1, nest of Vespa sp., portion 
of two envelopes cut away (two-thirds natural size); fig. 5, an adult parasite, 
Sphecophagus (?) predator, female; fig. 6, male of same species; fig. 10, Melittobia 
sp., female. (After Zabriskie; natural size indicated by lines.) 


number varies, Howard says, from 1 to 3000. From a single caterpillar 
of the cabbage-moth, Plusia brassica, 2500 individuals of the parasite Copi- 
dosoma truncatellum have been bred. From large hosts are often bred 
large numbers of parasites, but with some parasitic species only one or a few 
eggs are ever laid on a single host, whether it be large or small. Small hosts 
cannot, of course, provide food for many parasites and hence the number in 


Wasps, Bees, and Ants 481 
their case is always limited. Still, from a single scale-insect hardly more 
than 4 inch long a dozen and more tiny parasites have been bred. 

A question of interest is that regarding how many individuals of a single 
host-species may, in a given locality, be parasitized. For the effectiveness 
of any parasite in keeping an injurious 
insect pest in check depends, of course, 
on its relative prevalence. ‘Touching 
this may be quoted Fiske’s estimate 
that less than 20 per cent of the Ameri- 
can tent-caterpillars, which are at- 
tacked by a total of twelve species 
of parasites, are destroyed annually 
in the vicinity of Durham, N. H. 
On the other hand I have found 
a constant parasitization of about 
two-thirds of all the pupating indi- 
viduals of the California oak-worm 
moth (Phryganidia californica) in 


years of its abundance in the vicin- 
ity of Stanford University, and this 
by the single ichneumon-fly, Pimpla 
behrendsii. 

The success of any form of para- 
sitism in any one locality in a given 


Fic. 677.—Larve of certain curious hymen- 
opterous parasites; at left, Platygaster 
instricator; at right, P. herricki, which 
live in the alimentary canal of Cecidio- 
myid flies. amt, antenne; /b, labrum; 
md, mandible; Ji, labium; /, /, 1,, legs; kr, 
clawed processes; /, lobe-like processes; 
hf, posterior processes. (After Kulagin; 
much enlarged.) 


season brings up also the interesting matter of host and parasite “cycles.” 
It is obvious that in the face of a scarcity of host individuals the dependent 
parasitic species are bound to find difficulty in 
maintaining themselves; and conversely, that 
with the increase of the host in numbers “ good 
hunting” arrives for the parasites. But the 
good times bring hard ones in their train, 
for when hosts are abundant the parasites 
increase so rapidly in numbers (having usually 
several generations to the host’s one) as soon 
to overcome and sometimes almost extinguish 
in any given locality the host-species, which 
of course, means starvation for the parasite 
and a new lease of life for the host. Thus are 
brought about succeeding “cycles”? of host 
and parasite abundance intimately associated with each other. In the case 
of the California oak-worm moth already referred to, a serious pest (when 
abundant) of the beautiful live and white oaks of California, the cycles are 


Fic. 678.—Pimpla sp., an ichneu- 
mon-fly. (Twice natural size.) 


482 Saw-flies, Gall-flies, Ichneumons, 


well marked, and we have come to rely on the effectiveness of the parasite spe- 
cies, Pimpla behrendsii, in overtaking by rapidly succeeding generations the 
increasing hosts of the pest, and in checking it before the actual realization 
of what is not infrequently threatened, the killing of all the live-oaks in 
certain regions of the state. 

An interesting phenomenon in the biology of these parasites is that of 
hyperparasitism. It frequently happens that the parasites of a given host 
are themselves parasitized by other (usually smaller) parasitic Hymenoptera, 
while even these secondary parasites are not infrequently parasitized in 
their turn by still other species. Indeed some 
cases are known in which the tertiary parasites 
are infested by a fourth or quaternary species. 
An excellent example of hyperparasitism is re- 
vealed by Fiske’s careful study, already referred 
to, of the hymenopterous parasites of the Ameri- 
can tent-caterpillar. Twelve species of parasitic 
hymenoptera infest these caterpillars; of these 
twelve, six are themselves attacked by parasites 
(secondary), of which as many as six species may 
attack a single species of the primary parasites. 


Fic. 679.—Ophion purga- 
tum, an ichneumon-para- 
site of army-worms. (After Among these secondary parasites are not only 


Eger, nae species distinct from the primary parasites, but 


some of the primaries parasitize each other as well as the caterpillars. Of 
the secondary parasites, four species are in turn parasitized by other (ter- 
tiary) parasites, of which three species have been noted, one occurring also 
as a secondary parasite; and finally, one of these tertiary parasites is 
infested by another of the tertiary group, which in this instance becomes 
a quaternary parasite. Thus the old rhyme of 


“Great fleas have little fleas 
Upon their backs to bite ’em, 
And little fleas have lesser fleas, 
And so ad infinitum,” 


is often realized in the biology of the parasitic hymenoptera. 

Most interesting questions are suggested when we consider the unusual 
life-conditions that may, and often do, obtain in parasitism. Lying immersed 
in the blood-lymph of the body-cavity of the host, how does the parasitic 
larva breathe, excrete, moult, etc.? The process of feeding consists prob- 
ably for the most part simply in the taking up of the food from the host’s 
blood, in many cases probably as much through the skin, by osmosis, as through 
the mouth itself. With some species, however, there seems to be a definite 


Wasps, Bees, and Ants 483 


attack on certain of the solid tissues, as muscles, fat-body, etc. Such attacks 
necessarily avoid the vital organs or the host would be killed long before 
the parasitic larva is ready to pupate. With regard to the breathing it has 
been variously suggested that the larva applies itself to air-tubes (trachea) 
in the host-body in such a way as to effect an exchange of gases; that it needs 
no more oxygen than it obtains in the body fluid of the host; that its rela- 
tion to the host is analogous to that of foetus to mother among viviparous 
animals. Seurat’s observations seem to indicate (for certain species at 
least) that solid food as well as blood-lymph is taken in; that respiration 
is effected through the skin by osmosis, that excretion from the intestine 
does not occur until after the pupal cocoon is formed, and that moulting 
actually occurs. 

The host of species and the difficulties attending their determination, 
even (for amateurs) as regards their family classification, let alone their 
generic and specific identification, have led me to avoid any reference to the 
systematic study of these parasites. Certain particular species, especially 
among the larger forms, are of course more or less re- 
cognizable and familiar to observers. Among the larger 
species, most of which belong to the superfamily 
Ichneumonoidea, those of the genera Pimpla (Fig. 678) 
and Ophion (Fig. 679) are especially familiar. P. con- 
quisitor (Fig. 680) is the commonest parasite of the tent- 
caterpillars (Clisiocampa), is also the chief one of the de- 
structive cotton-worm, A/etia argillacea, of the south and 
has been bred from half a dozen other species of moths. 
It lays its eggs not on the larve of the tent-caterpillar 
moth, but on the pup (and perhaps on the cater- Fic. 680. — Pimpla 

5 Foe ue : os conquisitor, laying 
pillars after spinning and just before pupating) inside ege in. cocoon of 
the silken cocoon (Fig. 680). P. inquisitor,a common _ Americantent-cater- 
parasite-of the tussock-caterpillars, is an ichneumon- oo (After 

: ‘= rahe 2 : iske; about natural 
fly whose life-history is given in much detail by Howard size.) 
in the Insect Book. The Ophions are light brown or 
golden in color, with abdomen much compressed laterally. A common 
species parasitizes the giant larva of the polyphemus moth; but huge as 
this caterpillar is, only one egg is laid on it by the Ophion. 

The wonderful Thalessa, with its flexible ovipositor six inches long, with 
which it drills a hole deep into a tree-trunk until it reaches a tunnel of the 
wood-boring larva of Tremex, has already been referred to (see p. 467). 
Comstock describes Thalessa as follows: “Its body is 24 inches long and it 
measures nearly ro inches from tip of antenna to tip of the ovipositor. 
When a female finds a tree infested by the Tremex she selects a place which 
she judges is opposite a Tremex-burrow, and, elevating her long ovipositor 


484 Saw-tlies, Gall-flies, Ichneumons, 


in a loop over her back, with its tip on the bark of the tree, she makes a der- 
rick out of her body, and proceeds with great skill and precision to drill a 
hole into the tree. When the Tremex-burrow is reached she deposits an 
egg in it. The larva that hatches from 
this egg creeps along this burrow until 
it reaches its victim, and then fastens itself 
to the horntail larva, which it destroys 
. by sucking its blood. The larva of Tha- 
* lessa when full-grown changes to a pupa 
within the burrow of its host, and the 
adult gnaws a hole out through the bark 
if it does not find a hole already made by 
the Tremex. Sometimes the adult Tha- 
lessa, like the adult Tremex, gets her 
ovipositor wedged in the wood so tightly 


Fic. 681. Fic. 682. 


Fic. 681.—Thalessa sp., ichneumon-parasite of the pigeon-tremex. (After Jordan and 
Kellogg; natural size.) 

Fic. 682.—Thalessa lunator drilling a hole in a tree-trunk, in order to deposit its egg in 
burrow of the pigeon-tremex. (After Comstock; natural size.) 


that it holds her a prisoner until she dies.” 

Another curious large parasitic Hymenopteron is Pelecinus polyturator 
(Figs. 683 and 684), the single American representative of the family Pele- 
cinide, of whose habits little is known, but which has attracted much atten- 
tion because of the strange discrepancy in size between male and female. 
The abdomen of the female is slender and 14 inches or more in length, while 


Wasps, Bees, and Ants 485 


that of the male is not more than } inch. The males, only about 4 inch 
long, are much more rarely seen than the females. 

Among the smaller parasitic Hymenoptera, 
the Chalcidids, Braconids, and Proctotrypids, but 
few complete life-histories are known. Many 
of the Proctotrypids, an enormous family in 
number of species, live, all but the winged adult 
stage of their life, in the eggs of other insects, 


Fic. 683. Fic. 684. 
F1G. 683.—Pelecinus polyturator, female. (Natural size.) t 
Fic. 684.—Pelecinus polyturator, male. (After Packard; three and one-half times 
natural size. 
a half-dozen individuals perhaps in a single egg; needless to say they are 
arnong our smallest insects. Some are wingless, some show a marvelous hyper- 


SS - Zr. 
A 


Fic. 685.—Meteorus hyphantrie, parasite of the green-fruit worms, Xylina sp. 
(After Slingerland; much enlarged.) 


metamorphosis in their life-history, and all present extremely interesting prob- 
lems to biological students. Howard gives in his Insect Book an account 
of the life-history, as worked out by Schwarz, of a chalcis-fly, Euplectrus 


486 Saw-flies, Gall-flies, Ichneumons, 


comstockii, which infests various caterpillars. Its larvae are external para- 
sites clinging to the skin of the caterpillar. The chalcis-flies may usually be 
recognized by the characteristic branched single vein of the fore wings (Fig. 
673). 

The economic importance of the hymenopterous parasites is obvious; 
from the point of view of the economic entomologist there are no other 


Fic. 686.—Larva of Xylina lacticinerea, green-fruit worm, killed by the parasitic grub 
of Mesochorus agilis, which has spun its cocoon beneath the caterpillar, fastening 
the latter to the leaf. (After Slingerland; natural size.) 


insects outside of the pests of such interest as these natural pest-fighters. 
Attempts have been made to make allies of them in man’s warfare against 
injurious insects by artificially disseminating them, even to the extent of 

colonizing by importation from foreign 


countries various new species in partic- 
ularly pest-ridden localities. In Cali- 
fornia a constant and aggressive war has 
to be maintained by the fruit-grower 
against many insect pests, and particu- 
larly against the scale-insects. In this 
warfare a number of attempts have been 
made to introduce from other continents 


parasitic enemies of the scales. Unques- 
87.—A caterpillar of NXylina 
lacticinerea, green-fruit worm, from Z i 
which the parasitic larva of Meteorus Some of these importations, although as 
hyphantrie has just emerged and yet no other such signal overcoming of an 
is spinning its cocoon. (After Slin- ° 
gerland; natural size.) 


tionably considerable success has attended 


insect pest by the use of these Hessians 
has occurred as attended the importation 
from Australia, several years ago, of the predaceous ladybird-beetle (Vedalia), 
enemy of the once dreaded fluted scale (see p. 189 for account of this). 
Any discussion of the parasitic families of Hymenoptera would be incom- 


7 


Wasps, Bees, and Ants 487 


plete if there were omitted all reference to certain species of Chalcidoidea 
which are exceptions to the general condition of parasitism obtaining in the 
group. A number—very small in proportion to the total number of species 
in the superfamily—of chalcidid species feed upon plants, producing small 
galls on the plants attacked. The wheat-joint worm, 
Isosoma hordei, whose larve live in small swellings 
—produced by their presence—in the stems of wheat 
and other grains, is a familiar example of these phy- 
tophagous Chalcidids. The most interesting species 
of this kind, however, is the “‘caprifying” fig-wasp, 
Blastophaga grossorum. ‘There are several species 
of chalcidid fig-insects, but the species mentioned is 
the particular one on which depends the develop- 
ment of the Smyrna fig—by far the best of the Fic. 688.—The fig-insect, 
food-figs. The male Blastophagas (Fig. 688) are Blostophaga grossorum, 
: 5 male. (After Howard; 

grotesque, wingless, nearly eyeless creatures which much enlarged.) 

never leave the fig in which they are bred, but the fe- 
males (Fig. 689) are winged and fly freely about among the trees. A fig is a 
hollow, thick, and fleshy-walled receptacle in which are situated, thickly 
crowded over the inner surface, the minute flowers. The only entrance into 
the receptacle (or fig) is a tiny opening at the blunt free end of the young 
fig, and even this orifice is closely guarded by scales that nearly close it. 
The eggs are laid by the females at the base 
of the little flowers in certain figs. The 
hatching larve produce little galls in which 
they lie, feeding and developing. They 
pupate within the galls, and the wingless 
males when they issue do not leave the 
interior of the fig, but crawl about over the 
galls, puncturing those in which females 
lie, and thrusting the tip of the abdomen 
A through the puncture and fertilizing the 
Fic. 689.—The fig-insect, Blastophaga females, The fertilized winged female 
grossorum, female. (After Howard; 

much enlarged.) gnaws out of the galls, and leaves the 
fig through the small opening at the 
blunt free end. She flies among the trees seeking young figs, into which 
she crawls, and where she lays her eggs at the bases of as many flowers as 
possible. But it is only the wild, inedible, or “‘caprifigs” that serve her 
purpose. The flowers of the cultivated Smyrna seem to offer no suitable 
egelaying ground and in them no eggs are laid. But as the female 
walks anxiously about inside the fig, seeking for a suitable place, she dusts 
all the female flowers with pollen brought on her body from the male flowers 


488 Saw-flies, Gall-flies, Ichneumons, 


of the caprifig from which she came, and thus fertilizes them. This process 
is called caprification.* Without it no Smyrna fig has its flowers fertilized 
and its seeds ‘‘set.” It is the development of the seeds with the accom- 
panying swelling of the fleshy receptacle and the storing of sugar in it that 
makes the Smyrna fig so pleasant to the palate. The trees may grow large 
and bear quantities of fruit, but if the figs (really the fig-flowers) are not 


MN 


(iz 
ZS 


fe, 


Fic. 690.—Figs on a branch; the two lower ones are mammz, winter figs, from which 
Blastophaga are about to issue; the others are profichi, spring figs, ready to receive the 
Blastophaga. (After Howard; natural size.) 


caprified, the size. sweetness, and nutty flavor of the perfect fruit are lacking. 
To insure caprification, branches laden with caprifigs containing Blastopha- 
gas just about to issue are suspended artificially among the branches of the 


* For an account of the important réle played by insects in the fertilization of flowers 
see Chapter XVI. 


Wasps, Bees, and Ants 489 


Smyrna fig. Of course the female Blastophaga entering a Smyrna fig and 
dying there leaves no progeny, for she lays no eggs. It is therefore necessary 
to maintain a plantation of caprifigs in or near the Smyrna orchard. These 
bear three crops or generations of figs: one, the ‘‘profichi,”’ ripening in the 


Fic. 691.—Figs showing effect of non-caprification and of caprification. a, outside 
appearance of non-caprified fig; 6, outside of caprified fig; c, interior of caprified 
fig; d, interior of non-caprified fig. (After Howard; natural size.) 


spring; another, the “‘mammoni,” ripening in the late summer; and the third, 
or ‘“mammz”’ generation, which hangs on the trees through the winter. By 
means of these successive generations of caprifigs a series of three genera- 
tions (or sometimes four) of Blastophaga appear each year. 

In this country California fruit-growers have long grown figs, but they 
were of a quality very inferior to the well-known Smyrna, whose home is in 
Asia Minor. But the persistent efforts of an orchard-owner of the San Joa- 
quin Valley, Mr. George Roeding, with the assistance of expert entomolo- 
gists of the United States Division of Entomology, have resulted, after numer- 
ous unsuccessful trials extending over ten years, in establishing by direct 
importation from Algeria the Blastophaga in California, and the pro- 
duction of figs of the same quality as that of the Asiatic fruit. From capri- 
fig-trees (grown from cuttings originally imported from Smyrna) scattered 
through a sixty-acre orchard of Smyrna fig-trees (also obtained from imported 
cuttings and which Mr. Roeding maintained for fourteen years without any 
financial return) figs containing Blastophagas ready to issue are taken off, 
strung on short rafha strings, and hung on the branches of the Smyrna fig- 
trees when the Smyrna fruit is ready for fertilization. In 1900 the first crop 
of California Smyrna figs was obtained—sixty tons, all from this orchard— 
and it is now practically certain that the colonization of the tiny chalcidid fly, 
Blastophaga yrossorum, in California has added another important fruit 
to the list of horticultural products of that State. 


490 Saw-flies, Gall-flies, Ichneumons, 


WASPS. 


We have now to take up the more familiar groups of wasps, bees, and 
ants, in all of which the females (and the sterile workers in those species in 
which such kind or caste of individuals exists) have a sting. The sting 
(see description of that of the honey-bee on p. 460) is really the same struc- 
ture as the slender, pointed, often long ovipositor of the parasitic Hymen- 
optera; but whereas in the saw-flies, horntails, and true Parasita this instru- 
ment is used for piercing or drilling a hole and placing the egg in it or on 
the body of the host—the egg passing along the whole length of the ovipositor 
and issuing from its tip—in the so-called aculeate Hymenoptera, that is, the 
stingers, the egg issues from the body at the base of the instrument which is 
itself used as a weapon of offence and defence. In most of the ants of our 
country the sting is rudimentary and functionless, but traces of it and its 
poison can be found. 

The Hymenopterous insects referred to by the generic term wasps are 
many and various, and their multiplicity and variety have led to the formula- 
tion of many contradictory schemes of classification for them. That adopted 
by Comstock in his Manual groups them in two superfamilies: one, the Sphe- 
cina, or digger-wasps, including fourteen families; the other, the Vespina, or 
so-called true wasps, including but three. The Vespina include the social 
forms, as the yellow-jackets and the hornets, composing the family Vespide, 
one family of solitary parasitic wasps, the Masaridz, and one other family of 
solitary mason, carpenter. leaf-cutting, mining, and digging wasps, the 
Eumenide. The Sphecina include wasps all solitary (not social), but some 
of them parasitic, some inquiline, some earth-diggers, and some carpenters 
and wood miners. The structural character separating these two super- 
families is the longitudinal folding or plaiting of the wings in the Vespina, 
a condition not present in the Sphecina. Some systematists refuse to recog- 
nize so many distinct families while others would perhaps subdivide them 
into a still larger number. The latest classification, that of Ashmead, recog- 
nizes two superfamilies, the Sphecoidea, or insect-catching wasps, including 
twelve families whose species are all solitary, none parasitic, and all diggers 
or miners, and the Vespoidea, including sixteen families of social, parasitic, 
guest, and mason wasps, together with a few diggers. The structural char- 
acter separating these two great groups of wasps is the extension of the pro- 
notum back to the tegule or shoulder-tippets (or the absence of the latter) in 
the Vespoidea, and the failure of the pronotum to extend back as far as the 
tegule in the Sphecoidea. All the bees agree with the Sphecoidea in this 
character, so that Ashmead thinks the Sphecoidea more nearly related to 
the Apoidea or bees than the Vespoidea are, despite the fact that all the 


Wasps, Bees, and Ants 491 


wasps that live a communal life, like that of the bumble- and honey-bees, 
belong to the Vespoidea. The Sphecoidea may be distinguished from the 
bees by their slender undilated tarsi, as contrasted with the swollen, pollen- 
carrying tarsi of the bees. 

The eggs of wasps are usually deposited in a nest (burrow in soil, tunnel 
in wood, receptacle built of clay, cells made of wasp-paper, etc.) in which 
food, consisting of killed or paralyzed insects, is stored for the use of the 
larva. or to which, after the larva’s 
birth, insect food is brought by the 
mother or by sterile workers. The 
parasitic wasps deposit their eggs on 
the paralyzed body of some insect, 
while the guest wasps lay their eggs 
in the nests of other wasps or bees, 
where the hatching larva can feed on 
the food stored up by the host for its 
own young. The larve are white, 
footless, soft-bodied grubs, which lie 
in their cells feeding on the food stored Fic. 692.—Nest-burrow of Oxybelus 
up or brought them and pupating in eed sere (After Peckham; one- 

5 i alf natural size.) 
the same cell. The adults on issuing 
from the pupal cuticle gnaw their way out of the cell by means of their 
strong jaws. With the social wasps all the eggs are laid by a queen or 
fertile female in each community; with the solitary ones each female lays 
eggs. 

The general external structural characters of wasps are familiar: the 
elongate but compact and trim body with usually smooth, shining surface, 
variously colored and patterned, steely blue, jet black, yellow, and rusty 
reddish being the commoner colors and the pattern usually consisting of 
narrow or broad transverse bands or rings. All have four clear membra- 
nous wings (excepting the female Mutillide), and all the females and 
workers have strong stings. The mouth-parts consist of strong toothed 
jaws, of jaw-like maxille and lobed under lip, the last two usually closely 
joined by membranes and specially fitted for lapping up sweetish liquids 
or soft viscous or solid substances. The killing or paralyzing of the prey 
(food for the young) is accomplished by the sting, while the digging and 
mining and the transporting of materials for the nest are done by the strong 
mandibles. The antennz are rather long and slender, the compound eyes 
large and many-faceted. 

The digger-wasps differ from the social kinds, such as the yellow-jackets 
and hornets, by not living together in communities, composed of a queen, 
males, and sterile workers, but by living solitarily. There are no sterile 


492 Saw-flies, Gall-flies, Ichneumons, 


worker digger-wasps, but each female makes a separate nest and provisions 
it by her own labor. The stored food consists of paralyzed or, more rarely, 
killed insects or spiders. ‘‘The nests may be of mud, and attached, for 
shelter, under leaves, rocks, or eaves of buildings, or may be burrows hol- 
lowed out in the ground, in trees, or in the stems of plants. The adult wasp 
lives upon fruit or nectar, but the young grub or larva must have animal 
food, and here the parent wasp shows a rigid conservatism, each species 
providing the sort of food that has been approved by its family for genera- 
tions, one taking flies, another bugs, and another beetles, caterpillars, grass- 
hoppers, crickets, locusts, spiders, cockroaches, aphids, or other creatures, 
as the case may be. 

“The solitary wasps mate shortly after leaving the nest, in the spring 
or summer. The males are irresponsible creatures, aiding little, if at all, 


Fic. 693.—A solitary wasp, Sphex occitanica, dragging a large wingless locustid 
(Ephippiger) to nest. (After Fabre; natural size.) 


in the care of the family. When the egg-laying time arrives the female 
secures her prey, which she either kills or paralyzes, places it in the nest, 
lays the egg upon it, and then, in most cases, closes the hole, and takes no 
further interest in it, going on to make new nests from day to day. In some 
genera the female maintains a longer connection with her offspring, not 
bringing all the provisions at once, but returning to feed the larva as it grows, 
and only leaving the nest permanently when the grub has spun its cocoon 
and becomes a pupa. 

““The egg develops in from one to three days into a footless maggot-like 
creature, which feeds upon the store provided for it, increasing rapidly in 
size, and entering the pupal stage in from three days to two weeks. In the 
cocoon it passes through its final metamorphosis, emerging as a perfect 
insect perhaps in two or three weeks, or, in many cases, after the winter 
months have passed and summer has come again. Probably no solitary 


Wasps, Bees, and Ants 493 


wasp lives through the winter, those that come out in the spring or summer 
perishing in the autumn.” 

The nest-making habits of any solitary wasp, when carefully observed, 
will prove to be of absorbing interest. On the broad salt marshes of the 


Fic. 694.—Nesting-grounds of the solitary wasp, Ammophila sp., in the salt marshes 
of San Francisco Bay. 


western shore of San Francisco Bay near Stanford University I have often 
watched an interesting species of wasp at work. This is one of the genus 
Ammophila, the thread-waisted sand-diggers. The marshes are nearly 
covered with a dense growth of a low fleshy-leaved plant, the samphire or 
pickle-weed (Salicornia), but here and there are small, perfectly bare, level, 
sandy places, which shine white and sparkling in the sun because of a thin 
incrustation of salt. In September these bare places are taken possession 


Fic. 695.—Ammophila putting inchworm into nest-burrow. (From life; natural size.) 


of by many female Ammophilas, which make short vertical nest-burrows all 
over the ground. An Ammophila having chosen a site for its nest bites 
out a small circular piece of the salty crust, and with its strong jaws digs out 
bit by bit a little well. Each pellet dug out is carried away by the wasp, 
flying a foot or two from the mouth of the tunnel, and dropped. To emerge 


494 Saw-flies, Gall-flies, Ichneumons, 


from the hole the wasp always backs upward out of it and while digging 
keeps up a low humming sound. After the tunnel is dug about three inches 
deep she covers up the mouth with a bit of salt crust or little pebbles, and 
flies away. Some minutes later she comes back carrying a limp inchworm 
about an inch long, which she drags down into the nest. Away she goes 
again and soon returns with another inchworm; repeating the process until 
from five to ten caterpillars have been stored in the tunnel. All these are 
alive, but each has been stung in one of its nerve-centers (ganglia) so that 
it is paralyzed. Finally, down she goes and lays a single egg, attaching 


Fic. 696. 


Fic. 696.—Nest-burrow of Ammophila, with food for the young; paralyzed inchworms 
in bottom and burrow nearly filled. (Natural size.) 

Fic. 697 —Ammophila bringing covering bit of salt incrustation to put over the stored 
and filled nest-burrow. (From life; natural size.) 


it to one of the paralyzed caterpillars. She then fills the tunnel with pellets 
of earth, carefully chewing up the larger pieces so as to make a close, well- 
packed filling. Lastly, she carefully smooths off the surface and puts a 
small flat piece of salt crust on top, so that the site of the tunnel shall be as 
nearly indistinguishable as possible. 

Ammophilas are common all over the country, and the nest-building 
of various species has been watched by other observers. The use by an 
individual Ammophila of a small pebble, held in the jaws, as a tool to pound 
down and smooth off the earth has been twice recorded, once in Wisconsin 
and once in Kansas. These are perhaps our only records of the use of a 
tool by an insect. 

The habits of the Ammophila described above are typical of the interest- 
ing life-history which, varying indeed in many details, is common to nearly all 
of the solitary wasps, whether belonging to the Sphecoidea or Vespoidea. 


Wasps, Bees, and Ants 495 


Exceptions are those species which live as guests of other wasps, or as para- 
sites on other insects. 

The habit common to almost all of the solitary wasps of so stinging the 
prey, caterpillars, spiders, beetles, flies, bugs, or whatever other insects 
are used to provision the nests, as not to kill but only to paralyze it, is perhaps 
the most amazing part of all the interesting behavior of all these wasps. 
The advantage is obvious: killed, the prey would quickly decompose, and 
the hatching carnivorous wasp larva would have only a mass of, to it, inedible, 
decaying flesh instead of the fresh live animal substance it demands. But 
if stored unhurt, the prey would, if a cricket or spider or similarly active 
animal, quickly escape from the burrow, or if a caterpillar or weak bug, at 
least succeed, albeit unwittingly, in crushing the tender wasp egg by wrig- 
gling about in the underground prison-cell. More than that, unhurt, some 
insects could not live without food the many days that are necessary for 
the development of the wasp larva, especially in the face of the frantic and 
exhausting efforts they would be impelled to in their attempts to escape. 
But paralyzed, there is no exertion, metabolism is slight, and life without 
food is capable of being prolonged many days. The paralysis is due to 
the stinging by the wasp of one or more of the ganglia (nerve-centers) 


Fic. 698.—Cerceris tuberculata, dragging weevil (C/eonus sp.) to nest. 
(After Fabre; natural size.) 


of the ventral nerve-cord. With a wasp species (Sphex flavipennis) observed 
by Fabre,* which provisions its nest with crickets, each cricket was stung 


* Fabre, J. H., Insect Life, rgor. 


496 Saw-tlies, Gall-fies, Ichneumons, 


three times, once in’ each thoracic ganglion which resulted in immediate 
complete paralysis. Cerceris tuberculata hunts weevils (Cleonus) (Fig. 698) 
and stings them exactly in the large central ganglion formed by the fusion 
of the three thoracic ganglia, paralyzing them immediately. Insects thus 
paralyzed will keep alive, flexible, and fresh, but immovable, as Fabre has 
observed, for six weeks, a much longer time than is necessary for the develop- 
ment of any of the wasp larve. The amazing expertness and accuracy 
displayed in plunging the sting into exactly those spots where injury will 
give rise to exactly that physiological phenomenon in the prey that will make 
it available for the special conditions attending the wasp larva’s sustenance— 
this adroitness and this seeming knowledge of the structure and the 
physiology of the prey have led some entomologists to credit the solitary 
wasp with anthropomorphic qualities that are quite unwarranted. The 
whole behavior is probably explicable as a complex and advantageous reflex 
or instinct, developed by selection. 

Similarly the whole course of the nest-building and provisioning is an 
elaborate performance wholly for the sake of the young which the mother 
will likely never see; and these young in turn will if females do the same thing, 
perfectly and in essentially if not exactly the same manner without ever 
previously seeing such remarkable processes performed. All these com- 
plex and altruistic habits have naturally led to much speculation concern- 
ing their origin and their relation to psychical conditions. Whether a con- 
sciousness of what is being done and an intelligence is brought to bear upon 
its doing; whether we may attribute to the wasp a psychical state, with its 
attributes of cognizance, reason, and emotion—these are questions which 
are debated warmly. The consensus of opinion, however, is distinctly 
adverse to the reading into the behavior of Ammophila or any of its allies 
anthropormorphic attributes of reason, consciousness, and emotion. 

The fixity and inevitableness which is, despite the slight variations of 
practice noted by the Peckhams,* pre-eminently characteristic of the behavior 
of the wasps, and the fact that each female is ab ovo adequate to carry through 
the complex train of actions without teaching, experience, or opportunity 
for imitation, practically prove all this seeming marvel of reasoned care for 
the future young to be an inherited instinct incapable of essential modification 
except by the slow process of selection through successive generations. 

Nevertheless, as Sharp well says, the great variety in the habits of the 
species, the extreme industry, skill, and self-denial they display in carrying 
out their voluntary labors, render the solitary wasps one of the most instruc- 
tive groups of the animal kingdom “The individuals of one generation 


* Peckham, Geo. W: and Eliz G., On the Instincts and Habits of the Solitary Wasps, 
Bull. 2, Wis. Geol. and Nat. Hist. Survey, 1898. 


Wasps, Bees, and Ants 497 


only in rare cases see even the commencement of the life of the next; the 
progeny for the benefit of which they labor with unsurpassable skill and 
industry being unknown to them. Were such a solicitude displayed by 
ourselves we should connect it with a high sense of duty, and poets and 
moralists would vie in its laudation. But having dubbed ourselves the 
higher animals, we ascribe the eagerness of the solitary wasp to an impulse 
or instinct, and we exterminate their numerous species from the face of the 
earth for ever, without even seeking to make a prior acquaintance with them. 
Meanwhile our economists and moralists devote their volumes to admira- 
tion of the progress of the civilization that effects this destruction and toler- 
ates this negligence.” 

Sharp divides the solitary wasps, according to their habits, roughly into 
four groups: (1) those that form no special receptacles (nests) for their young, 
but are either of parasitic or subparasitic habits or take advantage of the 
abodes of other insects, holes, etc.; (2) constructors of cells of clay formed 
into pottery by the saliva of the insect, 
and by drying; (3) excavators of burrows 
in the ground; (4) makers of tunnels in 
wood or stems of plants. Several species 
make use of both of the last two methods. 

Some of the parasitic wasps dig into 
the ground until they find some underground 
insect, usually a larva, for example a beetle- 
grub, which they sting (paralyze) and on 
which they then deposit an egg. There 
is no attempt to make a nest or to remove 
the prey from its position as found. The 
hatching wasp larva feeds on the grub but 
in such a way as not to kill it before its 
own development is complete. A common 
parasitic wasp of this habit is 77phiainornata, 
2 inch long, shining black, which paralyzes 
white grubs, the larve of June-beetles. Fic. 699.—A cow-killer, or wingless 
Other allied species, some yellow and black — P'°P: Spherophthalma similima, 

emale. (After Lugger; natural 
and much larger, prey on other larve of size indicated by line.) 
Scarabeid beetles From the nests of other 
wasps, and of both solitary and communal bees, have been bred several 
kinds of solitary wasps which live either parasitically or as guests (inqui- 


lines) in these nests. If guests, their larvae feed on the stored food of the 
host; if parasites, they feed on the actual larval or adult bodies of their 
hosts themselves. Interesting wasps living habitually in nests of other 
wasps or bees are the Mutillide, popularly known as velvet-ants, cow- 


498 Saw-flies, Gall-flies, Ichneumons, 


ants, or cow-killers. The females (Figs. 699 and 700) are wingless and 
rather like ants in appearance, although readily distinguishable from them 
by their covering of white, red, black, or golden hair and of course by the 
absence of the scale-like expansion of the basal abdominal segments char- 
acteristic of the true ants. The males are winged and much less frequently 
collected or seen. It is believed that all Mutillids 
live as guests or parasites in the nests of other wasps 
or bees. They are strong stingers and swift runners. 
Nearly two hundred species have been found in the 
United States, the center of abundance being in the 
southwest. They are common in California. Sphe- 
rophthalma californica (Pl. XII, Fig. 1) is $ inch long, 
with brick-red hair, black on bases of abdomen and 
: thorax; S. pacifica is similarly colored but much 
BiG. (1001S Pherae ore inch long; S. aureola, 4 inch long, has 
ma pacifica. (One and ger, 83 ’ 8) 
one-half times natural head, most of thorax, and posterior half of abdomen 
Se) with yellow hair, elsewhere black. 

The brilliant metallic-green little bee-like cuckoo-flies (Chrysididz) 
are not unfamiliar to collectors, and belong, because of their habits, in the 
group of parasitic wasps. ‘‘Although these insects are handsome,” says 
Comstock, ‘‘they have very ugly morals, resembling those of the bird whose 
name has been applied to them. A cuckoo-fly seeks until it finds one of 
the digger-wasps, or a solitary true wasp or a solitary bee, building a nest, 
and when the owner of the nest is off collecting provisions steals in and lays 
its egg, which the unconscious owner walls in with her own egg. Some- 
times the cuckoo-fly larva eats the rightful occupant of the nest, and some- 
times starves it by eating up the food provided for it. The bees and wasps 
know this foe very well, and tender it so warm a reception that the brilliant- 
coated little rascal has reason enough to double itself up so that the righteous 
sting of its assailant can find no hole in its armor. There is one instance on 
record where an outraged wasp, unable to sting one of the cuckoo-flies to 
death, gnawed off her wings and pitched her out on the ground. But the 
undaunted invader waited until the wasp departed for provisions, and then 
crawled up the post and laid her egg in the nest before she died.” 

Of mason- or potter-wasps, that is, solitary wasps that make a nest of 
clay or mud worked up with saliva, there are numerous species belonging 
to several different families. The daintiest mud-nests are the little vases 
of Eumenes (Fig. 7or), which are said to have served as models for early 
Indian pottery. Eumenes is a neat little black-and-yellow wasp with the 
abdomen shaped like an old-fashioned tear-drop earring. It belongs to the 
family Eumenidz, which is the only family of solitary wasps (besides the 
rarely seen parasitic Masaride) which fold their front wings longitudinally 


| Wasps, Bees, and Ants 499 


as the social wasps (yellow-jackets and hornets) do. In this family are 
found diggers, and miners in the earth, carpenters making their nests in 
twigs or boards, as well as masons or clay-handlers. The species of the 
genus Odynerus are numerous; in appearance they resemble the yellow- 
jackets, but are smaller and more slender. They are given to taking advan- 
tage of any deserted nest of another wasp, or of some already existing hole 
or tunnel, to save themselves the trouble of mining or moulding a nest of their 
own. Riley found an Odynerus cell in the tunnel through a spool, and Ash- 
mead found one in the keyhole of a door-lock. The familiar, long, thread- 


Fic. 7o1. Fic. 702. 


Fic. 701.—A vase mud-nest of Eumenes sp. (Natural size.) 
Fic. 702.—Nest of a mud-dauber wasp. (Natural size.) 


waisted, nervous, black-and-yellow or steel-blue mud-daubers that build 
several tubular cells an inch or more long side by side of mud, plastered to 
the under side of a porch roof, on ceilings, under eaves, or under flat stones, 
belong to the genus Pelopceus (Pl. XII, Fig. 15) of the large family Sphe- 
cide. These cells are provisioned with paralyzed or dead spiders. Another 
smaller kind of mud-dauber is Agenius, a genus of the Pompilidiw. The 
tiny mud-cells of these wasps, built in crevices or on stones, are also pro- 
visioned with little spiders, often with their legs torn off. Originally the 
mud-daubers built their nests in hollow trees or under overhanging rocks, as 
they do yet sometimes; but they mostly nowadays take advantage of the safe 
and convenient places man arranges for them. 

Of Sharp’s fourth group, the true diggers or miners in the ground, I 
have already described a typical species in the Ammophila of the San Fran- 
cisco Bay salt marshes. There are many species of this genus, and they 
are found all over the country. The great golden digger, Sphex ichneu- 


500 Saw-flies, Gall-flies, Ichneumons, 


monea (Pl. XII, Fig. 14), a brilliant and powerful Sphecid, is a common 
and widely distributed species, which makes a burrow from 4 to 8 inches 
deep, provisioning it with green grasshoppers. The Peckhams have described 
in detail in their fascinating book, ‘‘The Solitary Wasps,” the life and habits 
of two species of Astata, wasps 
of the family Larride, which 
make nests with funnel-like open- 
ings (Fig. 703) in sandy soil and 
provision them with bugs (He- 
miptera), most of which are 
killed, not paralyzed. The Bem- 
becide, distinguished by the pro- 
jecting, even beak-like upper lip, 
are all diggers, and include our 
largest  solitary-wasp species. 
Bembex spinole (Pl. XII, Fig. 


Fic. 703.—Nest-burrow of Astata wunicolor. H ente 
(After Peckham; natural size.) 8), u large black and _ bluish 


Ve, el =a ; 
ge wl ME oly > — => i: 


WI) 


i 


white banded form, shows an in- 
teresting variation from the usual digger-wasp habits of feeding the young. 
Throughout their entire larval life (two weeks) the female catches flies and 
brings them to the covered nest, having to dig away each time the loose soil 


Fic. 704.—Tarantula-killer, Pepsis formosa. (Natural size.) 


and to scrape it in again as she leaves the nest. One of the giant solitary 
wasps of our country is the powerful cicada-killer, Sphecius speciosus, 1} 
inches long, rusty black with yellow-banded abdomen. The wasp, attracted 


Wasps, Bees, and Ants gol 


to its prey by its shrill singing, pounces upon a cicada, paralyzes it by a swift 
stab, and then laboriously flies with or drags the heavy body to the burrow. 
This burrow may be a foot or even more in depth, usually consisting of a 
nearly vertical tunnel for 6 inches, with a sharply diverging nearly horizontal 
part as long as or longer than the entrance one. Sometimes instead of a single 
terminal cell there are several lateral cells, in each of which one or two cica- 
das are stored. Another familiar group of diggers are the spider-wasps, 
Pompilide, mostly black or steely-blue with bluish or light-bronzy wings 
(Pl. XII, Fig. 13). This is a large family including a few guest-wasps 
(Ceropales) and a few mud-daubers or mason-wasps (Agenia), as well as 
true diggers, but all of the members of the family which make their own 
nests provision them with spiders. The giant tarantula-killer, Pepsts for- 
mosua (Fig. 704), largest of all our wasps, belongs to this family. It'is common 
in California and the southwest, where its sensational combats with the great 
hairy tarantulas (Mygale) are often seen. It does not always come off vic- 
tor in these fights, or at least conquers the tarantula only at the expense 
of its own life. After one such long and fierce battle I found both fighters 
hors du combat, the tarantula paralyzed by the wasp’s sting, but the wasp 
dying from the poisonous wounds made by the great fangs of the spider. 
It is a matter of much speculation how the digger-wasps find their nests 
again after carefully covering them and going off to search for caterpillars, 
spiders, bugs, or whatever are to be stored up for the larve. The Peck- 
hams have made many interesting observations touching the problem, trac- 
ing carefully the movements (Figs. 705 and 706) and behavior of individuals 


@) 


ee 
y) 


Fic. 705. Fic. 706. 
Fic. 705.—Locality study of Cerceris deserta. (After Peckham.) 
Fic. 706.—Locality study of Cerceris deserta, (After Peckham.) 


after finishing a burrow and making ready to provision it. From these 
observations they conclude “‘that wasps are guided in their movements by 
their memory of localities. They go from place to place quite readily because 


502 Saw-flies, Gall-flies, Ichneumons, 


they are familiar with the details of the landscape in the district they inhabit. 
Fair eyesight and a moderately good memory on their part are all that need 
be assumed in this simple explanation of the problem.” 

In the last of Sharp’s divisions, on the basis of habit, are those solitary 
wasps that make nest-tunnels in wood or the stems of plants. In the pith 
of various kinds of cane-bearing plants, as brambles, blackberries, etc., 
may often be found the tunnels (Fig. 707), provisioned with plant-lice or 
other small homopterous bugs, of various small 
wasps of the families Mimesidz and Pemphredo- 
nide. The Mimesids have a petioled abdomen 
and look like little Sphecids; the Pemphredonids 
are shining black. The family Crabronide, a 
rather large group of solitary wasps distinguished 
by having only one closed submarginal cell in 
the fore wings, includes many wood-borers. Very 
common in sumac-branches, according to Com- 
stock, are the nests of slender yellow-banded Tri- 
poxylon frigidum; the cells are separated by mud 
partitions. The Peckhams found two slender- 
waisted, black species of Tripoxylon common near 
Milwaukee, namely, T. albopilosum, } inch long, 
with tufts of snowy-white hairs on the fore legs, 
and T. rubrocinctum, a little smaller and with a red 
band about the body. Although these wasps are 
normally wood-borers, they will use convenient 
cavities in any material; rubrocinctum was found 
using crevices in the mortar of a brick house, 
and the straw of a stack where thousands of 
the cut ends of the straws offered attractive 
clean nesting-holes; albopiloswm was found nest- 
Fic. 707.—Nest-tunnels of ing in holes made by beetles in posts and trees, 

two carpenter-wasps. A, but never in straws; a third common species, 
Monobia quadridens (Eume- , , 5 
nide); B, Stigmus fraternes bidentatum, seemed to nest only in burrows tun- 
(Pemphredonide). (After peled by itself in the stems of plants. Another 
Comstock; natural size.) 5 z 
carpenter-wasp, common in the eastern states, 
is the large Eumenid species, Monobia quadridens, which drills a tunnel in solid 
wood, dividing it into cells by transverse partitions (Fig. 707, A). The species 
of the genus Crabro make their nests especially in the canes of blackberry- 
and raspberry-bushes. The Peckhams found that Crabro stirpicola did 
much of its work at night, something not observed in the case of any other 
solitary wasp. This species provisioned its cells with various species of 


flies. 


Wasps, Bees, and Ants 503 


The social wasps all belong to the single family Vespide, which includes 
but three genera of American wasps, of which one is limited to the Pacific 
coast. These three genera may be distinguished by the following characters: 


Social wasps with abdomen broad and truncate at base (next to thorax) .. VESPA. 


Social wasps with abdomen spindle-shaped, tapering at both ends....... POLISTES. 
Social wasps with abdomen pedunculate, i.e., basal segment elongated to form a stem 
or peduncle; occurring only on Pacific coast...........-.-++++-+- POLYBIA. 


All these wasps fold the wings longitudinally when at rest, and in all 
there exist three castes or kinds of individuals in each species, namely, males, 
females, and sterile workers. Like the worker bees, worker wasps are 
winged, not wingless, as the worker ants are. 

The ‘‘social’’ habit, as distinguished from the “solitary” habit charac- 
teristic of all the wasps we have so far studied, consists of the founding and 
maintenance of communities by the living together in a single group through 
the spring, summer, and autumn of all the offspring, males, females, and 
workers, of a single fertilized female, the queen. This community is thus 
a single family, often indeed very large, which busies itself about the 
care of a family nest. The nest may be underground or suspended from 
the branch of a tree, placed under the eaves of a building or otherwise 
supported above ground. It is built of paper made by moistening bits 
of old wood with saliva and chewing them into pulp, and consists of one or 
more horizontally placed tiers or combs of cells, exposed or enclosed by 
paper envelopes, in which a single entrance and exit opening is left. 

The castes or kinds of individuals are not so distinctly recognizable by 
structural differences as with the social bees and the ants, but the sexual 
forms, males and females, are always obviously larger than the workers 
(Fig. 709). The special functions of the different castes are (1) the mating 
with the females by the males; (2) the building of the queen-nest (the minia- 
ture early spring nest, see next paragraph), the gathering of food for the 
first, early spring generation, and the laying of eggs for all the broods by 
the females; (3) the bringing of food, and the enlarging and building and 
care of the nest and of the young by the workers. 

It has already been mentioned that a community holds together through 
part of the year only. The life-history of a community is in general outline 
as follows: In the early spring fertilized females (queens) which have hiber- 
nated (as adults) in sheltered places, as crevices in stone walls, under logs, 
stones, etc., come out from their winter hiding-places and each makes a small 
nest (of the kind characteristic of its species, see later) containing a few 
brood-cells. In each cell an egg is laid, and food, consisting of insects, killed 
and somewhat masticated, is hunted for and brought to the larve throughout 
their brief life by the queen. The larve soon pupate in the cells and in a 


Fic. 708.—Nest of Vespa crabro, found in hollow oak-tree on Long Island. (After 
Beutenmuller. Natural size, 2 feet long by 7 inches wide.) 


504 


Saw-flies, Gall-flies, Ichneumons, etc. 505 


few days issue as winged wasps. They are exclusively workers. These 


Fic. 709.—Vespa sp. a, worker; 6, female or queen. (After Jordan and Kellogg; 


natural size.) 


workers now enlarge the nest, adding more brood-cells in which the 


queen deposits eggs. The bringing of 
food and care of the young now devolve 
on the workers. The new or second 
brood is also composed of workers only, 
and these immediately reinforce the first 
brood in the work of enlarging the nest 
and building new  brood-cells. Thus 


through the summer several broods of Fic. 710.—Two workers of the yel- 


workers are reared, until in the late sum- ow-jacket, Vespa sp. 


(From life; 
natural size.) 


mer or early fall a brood containing males 


Fic. 711.—Communal nest of 
the yellow-jacket, Vespa sp. 
(Much reduced.) 


and females as well as workers appears. The 
community is now at its maximum both as re- 
gards population and size of nest. In the species 
(Vespa sp.) which make the great ball-like aerial 
nests the community may grow to number 
several thousand individuals. The males and 
females mate (presumably with members of 
other communities), but no more eggs are laid, 
and with the gradual coming on of winter the 
males and workers and many of the females die. 
There persist only as survivors of each com- 
munity a few fertilized females; these crawl 
into safe places to pass the winter. Any 
social wasp found in winter-time is thus, almost 
certainly, a queen. Those of the queens which 
come safely through the long winter found 
the communities which live through the follow- 
ing season. 


The social wasps of the genus Vespa, the familiar yellow-jackets and 


506 Saw-flies, Gall-flies, Ichneumons, 


hornets, are the ones which build the large subspherical nests familiar to 
all outdoor observers and related to much boyish adventure. Inside the 
great globe are several horizontal combs of brood-cells in tiers, all enclosed 
by several layers of wasp-paper (Figs. 711 and 712). The large bald-faced 
hornet, V. maculata, is the best-known builder of the globe nests. The smaller 


Fic. 712.—Nest of yellow-jacket, Vespa sp., cut open to show combs within. 
(About one-third natural size.) 


yellow-jackets, V. germanica (Pl. XII, Fig. 9) and V. cuneata, build in 
hollows in stumps or stone fences or underground. Such protected or under- 
ground nests are not as thoroughly and thickly enveloped in paper as are 
the exposed arboreal globe nests. The miniature queen-nests (Fig. 713) 
of the Vespa, with the single little brood-comb inside, may often be found 
by careful searching in spring. 

The long-bodied blackish social wasps of the genus Polistes (Pl. XII, 
Fig. 2; also Fig. 714) build single exposed horizontal combs out of wasp-paper 
(chewed wood) which are attached to the under side of porch roofs, eaves, 
ceilings of outbuildings, etc., by a short central stem. The little comb 
made by the queen may contain but half a dozen cells, but after the workers 
hatch many other cells are added around the margin. But the nest and 
community never compare in size and numbers with the large commu- 
nities of Vespa. The hibernating queens of Polistes often seek hiding- 


Wasps, Bees, and Ants 507 


places in our houses. Wasps of this genus are not infrequently parasitized 
by the remarkable Stylopid beetles (Fig. 403) Xenos, of which an account is 
given on p. 295. 


Fic. 713.—Queen-nest of yellow-jacket, Vespa sp.; specimen at right in normal con- 
dition; at left cut open to show brood-cells. (Natural size.) 

Only one species of Polybia occurs in the United States, and that one, 
P. flavitarsis (Pl. XII, Fig. 12), is found only on the Pacific coast. It is 
common in California. It is readily distinguishable from the other social 
wasps by its slender pedunculate basal abdominal segment and the small 
button-like shape of the rest of the abdomen. It builds a single-comb, 
unenveloped nest, like that of Polistes, but not reaching the diameter of 
the broad disk-like Polistes comb. 

It has been mentioned that the social wasps feed their young (larvae) 
chewed insects. Differing from most of the solitary wasps, the social kinds 
do not store up food for the young, but collect and bring it constantly through 
the life of the larvae, a period of from eight to fifteen days. This food con- 
sists of the partially masticated remains of various insects pursued and killed 
by the queen or workers. The queen brings food only for the larve of the 
first small spring brood. 

The adult wasps are more catholic as regards the palate; they feed on 
insects or decomposing animal substances—fish especially attract them— 
and on exposed sweet substances, as sirups, preserved fruits, etc. 

The paper-making and nest-building are industries whose details can 
only be touched on in our limited space. The paper is not only made of 


508 Saw-flies, Gall-flies, Ichneumons, 


chewed-up bits of weathered wood gathered from old fences or outbuildings; 
“round the swampy edges of ponds or in wet ditches wasps may be seen 
gathering tough herbaceous filaments which they felt up into a texture 
stronger and better able to resist the wind and rain than a paper made of 


Fic. 714.—Polistes sp. a, nest; b, young larva; 


c, older larva; d, pupa; e, adult. 


and one-half times natural size except nest, 


which is much reduced.) 


wood scrapings.” The moulding 
of the pulp at the nest has been 
observed carefully by Ormerod 
in the case of two English spe- 
cies of Vespa “It appeared,” 
says Ormerod, ‘“‘that when a 
wasp came home laden with 
building materials she did not 
immediately apply these, but flew 
into the nest for about half a 
minute, for what purpose I could 
not ascertain. Then emerging 
she promptly set to work. 
Mounted astride on the edge of 
one of the covering sheets, she 
pressed her pellet firmly down 
with her fore legs till it adhered 
to the edge, and, walking back- 
wards, continued this same pro- 
cess of pressing and kneading till 
the pellet was used up, and her 


track was marked by a short dark cord lying along the thin edge to which she 
had fastened it. Then she ran forwards, and, as she returned again back- 


Fic. 715.—The single-comb nest of a hornet, Polistes sp. (One-half natural size.) 


wards over the same ground, she drew the cord through her mandibles, 
repeating this process two or three times till it was flattened out into a little 


Wasps, Bees, and Ants 509 


strip or ribbon of paper, which only needed drying to be undistinguishable 
from the rest of the sheet to which it had been attached. And then she gravely 
retired into the nest again. 

“By this means of marking different wasps it was evident that each wasp 
had not a place of her own to work at, but that all worked anywhere and 
anyhow. And this whether they were engaged in adding to the structure 
or in removing what had been built previously. So, a wasp which had been 
collecting white fibers joined her quota to what had been built by a wasp 
who had gathered materials of a darker color, giving a variegated appearance 
to the work. Further, it seemed clear that only the young wasps built. 
probably because they only had the power of secreting mucus in sufficient 
quantity for working up the dry fibers into a pulp. This was inferred from 
the generally larger size, and the smooth ends of the wings, of the wasps 
which were examined while thus engaged. Wasps grow smaller as they 
grow older, and the ends of their wings get tattered with advancing days. 


“By the conjoint labors of all these busy workers, here a little and there 
a little, the nest grows. The work of one week may have to be removed 
the next week, to make way for modern improvements and for the require- 
ments of the growing city; and, as we have seen, it has nearly all to be done 
twice over. But wasps work very hard, and the nest grows visibly day by 
day. The little egg-shell in which it began is lost in the changes which the 
top of the nest undergoes. The slight strap from which it hung is now quite 
inadequate to sustain the daily increasing weight, and new points of attach- 
ment are sought to projecting roots, or stones, or branches. Sometimes 
a branch runs all through a nest, materially adding to the difficulty of its 
capture. Or, failing these, the original point of support is strengthened 
by layer upon layer of paper, rubbed smooth, and thickly coated with wasp- 
gum, to preserve so vital a point from all accidents of wind and weather. 
The regular arrangement of the upper part of the nest is much disturbed 
in the course of these events, and the top of one nest comes to look very like 
the top of another. But at the bottom, at the growing part of the nest, the 
different architectural instincts of the several species are displayed quite 
to the last. The number of layers of paper employed to form the nest-cover 
varies with the species, with the season, and with the circumstances under 
which the nest has been built. Sometimes the case is so thin that the comb 
shows an edge through the wal!, while sometimes it is composed of as many 
as a dozen layers. But. however the thickness of the walls may vary, as a 
rule so invariable as to have been adopted as a means of classification, the 
combs of the nests of the Vespe have no connection with the outer case, 
except at the top of the nest. The comb and the case are mutually inde- 
pendent and separate from each other. 


510 Saw-flies, Gall-flies, Ichneumons, 


“The combs, unlike those of the honey-bee, are laid horizontally, stage 
below stage, each hanging from the one immediately above it, without any 
reference to the rest of the series. The two or three uppermost stages of 
comb, into which the first rudimentary cells have been expanded, are, in 
course of time, worked into the case of the nest at their edges. And the 
cells are cut down to allow room for the wasps to camp on the upper surface 
of the comb beneath. Wasps do not stand cold and wet, so a shelter is 
here provided for them, where they may be kept dry and warm, without 
interfering with the comfort and safety of the larve in the lower stages. Inci- 
dentally another advantage is gained by this arrangement. For the fabric 
of the nest is thus materially strengthened, by substituting, at this vital point, 
a hard, dry, light flooring for the loose, damp comb, which is almost ready 
to fall to pieces by its own weight. 

“When a new stage is to be constructed, the wasps begin by raising the 
walls of two or three adjoining cells in the center of the lowest comb. From 
these diverging roots a round cord is drawn out, as it were, on the end of 
which little cells are made, just as on the end of the footstalk from which 
the nest originally sprung. As each cell takes shape an egg is deposited in it, 
so as to lose no time; and while its walls are gradually rising the comb is 
gradually spreading, by concentric rings of cells. The mother wasp follows 
close on the traces of the worker, and the circles of larvae of the same age 
show the system on which the comb has been made. As the comb spreads, 
new stays are let down to support the weight increasing with the width. 
Meanwhile the expansion of the case keeps exact pace with the lateral growth 
of the comb; the old case is nibbled away within, and new paper is laid 
on outside, so as to make room all around the edge. And before each stage 
has attained its full dimensions, another has been commenced below it, 
just in the same manner.” 


BEES. 


In popular repute there are just two kinds of bees, honey-bees and bumble- 
bees. Actually there is a host of kinds, many of them small and hardly 
noticeable, and perhaps even when seen mistaken for other insects. Still, 
all the bees have such a ‘‘bee-y”” manner and general appearance that such 
mistakes can only be made by the most casual of observers. There are indeed 
a few slender-bodied small bees that suggest wasp more than bee perhaps 
in general seeming; and there are not a few kinds of flies (Diptera), espe- 
cially the flower-flies (Syrphidz), bee-flies (Bombyliide), and certain robber- 
flies (Asilidee) that resemble bees quite sufficiently to be often mistaken for 
them. Careful inspection will quickly reveal the deception, by showing 
the presence of but a single pair of wings on dll these bee-mimicking flies. 


Wasps, Bees, and Ants yi 


While bumblebees and honey-bees are the everywhere common, con- 
spicuous, and familiar representatives of the great superfamily of bees, the 
Apoidea, they include but a fraction of the nearly one thousand different 
kinds of bees so far recorded as occurring in this country. Indeed, all of 
our social honey-bees, although variously called German, Italian, Carniolans, 
etc., belong to a single species, and that not a native but an imported one. 
Of the bumblebees a few more than fifty native species are known. Besides 
the hive-bee and the bumblebee, then, there are nearly a thousand other bees 
in the American fauna to be taken into account. As among the wasps, 
there are parasitic, guest, solitary, and social kinds of bees; and as among 
the solitary wasps there are diggers, miners, carpenters, and masons, so 
also there are miner-, carpenter-, and mason-bees. There are bees which 
lay their eggs in the nests of other bees, so that their young feed on the stored 
food of the hosts; there are bees which make nest-burrows in the ground, 
others that tunnel in stems of plants and wood, others that mould clay cells, 
others that cut leaves and line their nest bored into the pith of canes, others 
that live in communities underground which break up each year, and finally, 
most conspicuous among them all, there is the familiar species that lives in 
great persistent communities in hives and hollow trees. 

All these thousand bee kinds can be conveniently and naturally primarily 
grouped into two divisions, the short-tongued bees (Fig. 716) (those with 
a short, broad, flattened, spoon-like tongue) 
and the long-tongued bees (Fig. 717) (those with 
a slender, elongate, subcylindrical flexible tongue). 
In the older books these groups were called fami- 
lies, namely the Andrenide (short-tongued bees) 
and the Apide (long-tongued bees), but modern 
systematists, while still recognizing the con- 
venience of this primary grouping, classify bees 
into a dozen families or more. For the purposes 
of this book, however, we shall recognize a group- 
ing on structural characters into simply two main 
divisions, short-tongued and long-tongued, and 
another grouping, on a basis of habit and of Fic. 716.—Mouth-parts of a 
psychologic development, into three general groups, ie i oo B ae 
namely, solitary bees, gregarious bees, and com- broad, flap -like tongue 
munal bees: (glossa of labium). (After 

. P Sharp; much enlarged.) 

The structural characters in which all bees 
agree among themselves and differ from the other Hymenoptera are the pos- 
session of branched or feathery hairs on the head and thorax and of swollen 
or expanded and flattened tarsal segments: the pronotum does not extend 
back to the tegule of the wings as is the case with the Sphecoid wasps, 


512 Saw-flies, Gall-flies, Ichneumons, 


but not with the Vespoid wasps, including the social kinds. The mouth 
in all bees is provided with a well-developed pair of strong mandibles, 
either sharp and toothed for digging in the ground or tunneling in wood, 
or smooth and spoon-like for moulding wax. The 
food of both adults and larva is always flower- 
nectar (made into honey) and pollen (for the very 
young larve a predigested food, bee-jelly, is 
regurgitated by the nurse workers) and never in- 
sects, paralyzed, killed, or chewed, as with the 
wasps. The bee mouth is therefore fitted for the 
lapping or sucking up of nectar, as well as for 
scraping off and crushing pollen. The maxille 
and labium are more or less intimately joined 
by membranes and chitinous bars and are capable 
of much yariety of movement in the way of fold- 
ing, retraction, and extension. The antenne are 
elbowed and their terminal, smooth, cylindrical 
segments are provided with numerous sense-pits 
and papilla, special organs of olfactory and tactile 
perception. The compound eyes are large and 
sight is undoubtedly better than in most insects. 
There are only male and female individuals in 
the solitary species, both winged, and the females 
Fic. 717.—Mouth-parts of provided with a sting; in the social species 
a long-tongued bee, An- (bumble- and honey-bees) there are in addition 
thophora pilipes. Note maitre i 
greatly extended tongue Worker individuals (females of arrested sexual 
(glossa of labium). (After development but with special structural develop- 
Sharp; much enlarged.) Jyent) which are also winged and furnished with 
a sting. The eggs are laid in cells in the ground, in plant-stems, in logs 
or posts, or made of wax (hive-bee) or hollowed out of a food-mass of 
pollen (bumblebees), and the hatching larve find stored up for them a suf- 
ficient food-supply for their Jarval life, or they are brought food constantly 
during this life. These larva are footless, white, soft-bodied grubs, which 
pupate in their cells. The issuing imagines gnaw their way out of the 
cells. 

Of the short-tongued bees all are solitary or gregarious; of the long- 
tongued most are solitary, but a few, the bumble- and the honey-bee, live in 
communities. I shall give an account of a few of the more interesting or 
more familiar kinds of bees, illustrating the various typical habits of nest- 
building as well as the gradually progressive tendency toward that speciali- 
zation of life, communism, exemplified in its extreme condition by the hive- 
bee. 


Wasps, Bees, and Ants Face) 


The hairy, medium-sized mining-bees of the short-tongued genus Col- 
letes dig short vertical burrows in the ground which they line internally with 
a sort of slime that dries to a substance like gold-beater’s skin; they partition 
the burrow into six to ten cells in each of which is deposited an egg, together 
with a store of food, pollen, and honey mixed. Colletes has the under-lip 
bilobed like that of wasps and is evidently one of the lowest of the bees. 
Prosopis is a short-tongued genus of nearly hairless, 
small, coal-black bees which tunnel into the stems of 
brambles and other plants, or dig burrows in the 
ground, or make cells in crevices in walls; the cells are 
always lined with a silken membrane, and the stored 
food is more liquid than usual with bees. 

The dainty little blue or green carpenter-bees of the 
long-tongued genus Ceratina are common and wide- 
spread; their nests are tunnels in twigs and canes of 
sumac, brambles, and other plants (Fig. 718). Com- 
stock writes of the nest-building of the species, C. du pla, 
as follows: ‘She always selects a twig with a soft pith 
which she excavates with her mandibles, and so makes a 
long tunnel. Then she gathers pollen and puts it in 
the bottom of the nest, lays an egg on it, and then 
makes a partition out of pith chips, which serves as a 
roof to this cell and a floor to the one above it. This 
process she repeats until the tunnel is nearly full, then 
she rests in the space above the last cell, and waits for 
her children to grow up. The lower one hatches first; 
and, after it has attained its growth, it tears down the 
partition above it, and then waits patiently for the one 
above to do the same. Finally, after the last one in the 
top cell has matured, the mother leads forth her full- 
fledged family in a flight into the sunshine. This is Fic. 718.—Nest-tun- 
the only case known to the writer where a solitary nel of _ carpenter. 

: ee. (Natural size.) 
bee watches her nest till her young mature. After 
the last of the brood has emerged from its cell, the substance of which the 
partitions were made, and which has been forced to the bottom of the nest 
by the young bees when making their escape, is cleaned out by the family, 
the old bee and the young ones all working together. Then the nest is used 
again by one of the bees. We have collected hundreds of these nests, and, 
by opening different nests at different seasons have gained an idea of what 
goes on in a single nest. There are two broods each year. The mature 
bees of the fall brood winter in the nests.” 

Other familiar carpenter-bees are the great black Xylocopas (Pl. XII, 


514 Saw-flies, Gall-Hies, Ichneumons, 


Fig. 7). They are as large as bumblebees and with their heavy thick 
body and black color look much like them; they have 
the body more flattened and less hairy, however, and the 
hind legs of the females are never provided with a 
“corbiculum,’”’ or pollen-basket (a concave smooth 
place bounded on each side by a row of long stiff curv- 
ing hairs), but are covered by a stiff brush of short 
hairs. These giant bee-carpenters tunnel into solid 
wood for a foot or more, dividing the burrow into a 
series of cells by partitions made of small chips stuck 
together. They are common all over the country, 
‘choosing in civilized regions fence-posts and boards.” 
Certain very large species make their nests in the 
great fallen sugar-pines and yellow pines of the Sier- 
ran forests and are among the most characteristic in- 
sects of the giant-tree forests. a 
The long-tongued family Megachilide includes a | 
Tis. ro Soest ot number of common and interesting bees, most familiar, 
leaf-cutter bee, Me- perhaps, being the mason-bees (Osmia), the potter-bees 
gachile anthracina, (Anth dium), and the leaf-cutters (Megachile). The 
(After Sharp; some- 3 s 
what enlarged.) Osmias are metallic, black, blue, or green, and make 
their nests of clay and sand, moulded into cells, and 
built in already existing cavities in stone walls, old posts, tree-trunks, etc., 
or in tunnels bored by the bee in plant-stems and twigs. The various 
species of Anthidium are black and rufous, or rufous 
and yellow, with the abdomen always banded or spotted 
with yellow, white or rufous. The females normally 
construct globular cells rather like the earthen vases 
of Eumenes (Fig. 7or), but made of the resinous exuda- 
tions of pine-trees and other plants, or dig burrows in 
the soil which they line with down stripped from 
pudescent or woolly-leafed plants. Both Osmia and 
Anthidium sometimes make their nests in deserted 
snail-shells! The leaf-cutting bees (Figs 719 and 720) 
are usually carpenters as well as tailors; that is, they first 
bore a tunnel in some plant-stem or in wood, and then Fs. 720.—Single cell 
: é : : in nest of leaf-cut- 
cut out pieces of green leaves with which they line the ter bee, Megachile 
tunnel and partition in such a way as to form a series ones eins 
of thimble-shaped cells each partially filled with a paste onlageay a 
of pollen and nectar on which an egg is deposited. The 
pieces of leaf are fastened together with a gummy secretion from the mouth 
of the bee. Comstock has found leaf-cutter nests in a “crack between 


Wasps, Bees, and Ants 5G 


shingles on a roof, beneath stones lying on the ground, and in Florida in the 
tubular leaves of a pitcher-plant.”’ 

Other common genera of solitary long-tongued bees are Anthophora 
(Pl. XII, Fig. 11), the species of which are hairy and robust-bodied, looking 
indeed much like small bumblebees, Melissodes and Synhalonia with very 
long antenne, rather like honey-bees in general appearance, and others 
of the great family Anthophoride. All these bees agree in general habits 
with those already described, but every species presents an opportunity for 
interesting and valuable work by amateurs and nature-lovers in observing 
precisely its nest-building habits and life-history. No more attractive 
opportunity for outdoor observers offers than that of the field study of the 
solitary bees. 

As mentioned at the beginning of the discussion of the solitary bees, some 
species are parasitic or, more properly named, guest or inquiline in habit. 
That is, the females of these species, instead of building a nest-burrow of 
their own and storing it with food, lay their eggs in the nest-burrows of other 
bees, so that the larve on hatching will be able to feed on the supplies stored 
up by the host-bee. This habit is not confined to a few species, but is com- 
mon to a surprisingly large number of solitary bees. Two entire families, 
including a hundred species of North American bees, are exclusively composed 
of parasitic bees (in addition a third parasitic family, an offshoot of the 
bumblebees. is mentioned in connection with the account, later, of the social 
bees). These two families are the cuckoo-bees, Nomadide, mostly bright- 
colored species, metallic blue or green with the abdomen spotted or banded 
with yellow or white, and the Stelide, differing structurally from the cuckoo- 
bees by having only two, instead of three, submarginal cells in the wings. 
Ashmead believes that the Nomadide are descended from the Anthophoride, 
and the Stelide from the Megachilide, the parasitic habit having arisen 
independently in the two groups. Howard mentions the interesting fact 
that the cuckoo-bees seem not only to be tolerated by their hosts, but that 
in some cases it has been observed that enough food is stored by the host- 
bee to enable the larvee of both host and guest to complete their development 
side by side and to issue simultaneously as adult bees. It may indeed be 
found, as has been discovered in numerous other cases of commensal life, 
that the cuckoo-bee gives, in some way, aid to the host, so that the living 
together is mutually advantageous. 

With the wasps there are no transition stages, among living forms, between 
a strictly solitary life, where each female makes her own independent nest- 
burrow, lays an egg in it and stores it with food, or brings food to the larva 
through its life, and the social or communal life exhibited by the yellow- 
jackets and hornets, where many females (of arrested sexual development, 
although not always to such a degree as to be actually incapable of producing 


516 Saw-flies, Gall-flies, Ichneumons, 


fertile eggs) called workers combine to build a common nest and numerous 
brood-cells, in which eggs are deposited by a single queen female, the mother 
of the whole community. With this division of labor has come to exist a 
certain differentiation of structure, manifest in a difference in size and in some 
anatomical details between the working females and the egg-laying female. 
But with the bees certain interesting gradations in domestic economy 
or insectean. sociology exist which throw some light on the possible line 
of progression or specialization from strictly solitary to strictly communal 
life. Numerous technically “solitary” bees show a marked gregariousness, 
a fondness, as it were, for the company and society of other individuals of 
their kind. This is chiefly manifested in the building of many nest-burrows 
close together, forming a sort of village or colony of homes, each home belong- 
ing to a single female, built by her, provisioned by her, and the young issuing 
from it her own offspring, but all these homes belonging to individuals of 
one species of gregarious or social inclination. Near Stanford University, 


Fic. 721.—Diagrams of nest-burrows of short-tongued mining-bees. B, nest of Andrena; 
A, compound nest of Halictus. 

in a roadside cutting exposing a clayey bank, lived a few years ago a great 

colony of the large mining-bee Anthophora stanfordiana, the vertical, open- 

mouth nest-burrows set about as closely as they could be without breaking 

into each other. This bee does not store up food in the nest, but brings it 

to the larva, the burrow not being closed. The whole colony covered but a 


Wasps, Bees, and Ants ag 


few square yards of the many yards of exposed surface. The nest-tunnels 
were capped by curious little chimneys, mostly curving so as to present the 
opening not directly upward, exposed to rain, but to one side or almost down- 
ward, thus preventing the flooding of the open burrows by water. Similar 
villages or colonies are made by the little short-tongued mining-bees of the 
genus Andrena. Comstock has noted Andrena villages covering only one 
square rod of ground that included several thousand nests, and he received 
from a correspondent ‘‘a description of a collection of nests of this kind 
which was fifteen feet in diameter, and in the destruction of which about 
2coo bees were killed—a terrible slaughter of innocent creatures.” 

A step farther in this social tendency is exhibited by the smallest of all 
our mining-bees, the tiny little short-tongued bees of the genus Halictus, 
the various species measuring from 1, to 5 of an inch in length. While each 
female forms her own nest-cells, lays eggs in them, and provisions them, she 
is one of a number of females that work together to build a common vertical 
tunnel with single external opening, along the sides of which the various 
cells are arranged. In this way one entrance and one corridor, built and 
used by several individuals in common, serve to give access to several dis- 
tinct homes, i.e., nest-cells. These groups of homes with common corridors 
and openings are placed thickly together in populous sand-bank colonies. 
Thus, as Comstock aptly puts it, ‘‘while Andrena builds villages composed 
of individual houses, Halictus makes cities composed of apartment-houses.” 

The next stage exhibited among present-day bees in this progressive 
specializing of the gregarious tendency is the condition under which the 
bumblebee lives. This is a long leap from the apartment-house life of Halic- 
tus, and does not explain how the differentiation into castes, i.e., the estab- 
lishment of the worker (rudimentary female) caste, composed in some 
cases of two distinct sizes, worker majors and worker minors, has come 
about. If we could but know the intermediate sociologic stages which were 
exhibited by bees now extinct (or, if living, not yet discovered), but that cer- 
tainly existed not very long ago (as geologic time-reckoning goes), the mar- 
velous division of labor, differentiation of structure, and commensal inter- 
dependence of individuals displayed by the honey-bees would be divested 
of much of its mystery. 

The bumblebees possess a domestic economy wholly like that of 
the social wasps (yellow-jackets and hornets). In each species there are 
three kinds of individuals, males, fertile females, and workers (infertile 
females) which are sometimes of two constant sizes, called worker majors 
and worker minors. The workers are all distinctly smaller than the fertile 
females and usually differ somewhat in marking (Fig. 723). The only indi- 
viduals to over-winter are fertilized females, queens, which hibernate as 
queen wasps do in sheltered places, as crevices in stone walls, holes in the 


518 Saw-flies, Gall-flies, [chneumons, 


ground, in hollow trees or under leaves, etc. When spring comes, each 
queen finds some deserted mouse’s hole, mole’s burrow, or other cavity in 
the ground, or digs one herself; she then gathers some pollen and honey 
which she brings to the hole, making there a_ball- 
like mixed pasty mass of it. On this lump of food 
she deposits a few eggs, from half a dozen to a 
score, and then, while waiting for their hatching, brings 
more food and deposits more eggs. The hatching 
larve feed on the pollen and honey paste, sepa- 
rating and eating out one or more considerable 
cavities in it. When full-grown each spins a silken 
cocoon within which it pupates. The issuing bees 
are all workers. They enlarge the nest-burrow, 
if necessary bring more food, the queen lays more 
eggs, and so for several broods. The larve ready 
to pupate are enclosed in waxen cells, sometimes 
several in a single cell, by the workers (except in the 
first brood, when there are no workers to make 
the cells). A full-sized bumblebee’s nest may be as 
large as one’s head, composed of a cluster of large 
Fic. 722.—Bumblebee at itregular waxen cells, mostly containing brood (larve 
clover-blossom. (From or pup), but some containing pollen and a few 
life; natural size.) ; 2 

honey. All may be enclosed in a loose covering of 

hay or bits of stems and roots, the whole lying at the bottom of a deep 
or shallow tunnel. There are usually two or more openings to the nest. 
In the late summer and fall males and females are reared, issue from the 
nest and mate. With the oncoming 
of cold weather the males and 


workers gradually die, leaving a few 
fertilized young queens to live 
through the winter. These are the 
founders of next year’s communities. 

All the bumblebees belong to 
the genus Bombus (family Bombidz), 
long-tongued bees with two apical 
spurs on the hind tibize and with a 


single submarginal cell in the front 


Grr BAe eee ; Fic. 723.—Worker (A) and queen (B) 
wings. Their big velvety black-and- bumblebees, Bombus sp. (After Jordan 
yellow bodies and their deep-toned and Kellogg; natural size.) 


buzz are the more familiar characters 
which distinguish them. Over fifty species of bumblebees occur in this 
country; they differ in size and in the arrangement and relative amounts 


Wasps, Bees, and Ants 519 


of the black and yellow markings (Pl. XII, Figs. 5 andro). A common eastern 
species is B. ferviotus (the “ boiling bumblebee” is good!), which has the body 
of the workers almost all yellow above, only a narrow median band across 
the thorax and the tip of the abdomen being black; B. ajfinis has (workers) 
the base of the abdomen, its posterior half, and a median band across the 
thorax black, the rest yellow; B. 
terricola has the anterior half of the 


thorax, a band across the posterior ED 
third of the abdomen, and another =f 


one on the next to the last segment 
yellow, the rest black; B. calijor- 
nicus, the most abundant species in 
California, has the anterior half of 
thorax and a single narrow band 
near tip of abdomen yellow; B. 
edwardsii, another species common 
on the Pacific coast, has a median 
band across the thorax and a broad 
anterior one across the abdomen and 
the very tip of the abdomen black, 
the rest yellow. 

The strange case of the guest 
bumblebee, species of the genus 
Psithyrus (Pl. XII, Fig. 4), is almost 
sure to come to the attention of any 
observer of bumblebee-nests. In all 
general characters and total seeming 
truly bumblebee-like, found always 
in and about bumblebee-nests, these 
insidious guests, cleverly living at the Frc. 724.—Nest of bumblebee, Bombus sp., 
bountiful table of their host, present | Showing opening at surface of ground and 

‘ : - : brood-cells in cavity underneath. (Adapted 
to us aninteresting problem touching from McCook.) 
their deceptively Bombus-like make- 
up. Are they really bumblebees, that is, bees directly descended from 
bumblebee stock, which have become degenerate and adopted a parasitic 
life, or are they bees of another stock, which, for the sake of successfully 
deceiving the bumblebees and thus gaining access to their nests, have 
gradually acquired (through long selection) the bumblebee dress and gen- 
eral appearance? The former supposition is the more probable. They 
are like bumblebees in so many structural details unnecessary for such 
deception that they must be looked on as a degenerate offshoot from the 
Bombide. Having given up the gathering and carrying of pollen, their tarsi 


ti Ma i hit | i 


520 Saw-flies, Gall-flies, Ichneumons, 


are no longer provided with a pollen-basket' (concave smooth surface 
bounded by lines of long stiff incurving hairs) and by the absence of 
this arrangement they may always be distinguished from the true bumble- 
bees. There is no working caste, infertile female workers, with these 
Psithyride, each species being represented by males and females only. 

At the head of this line of specialization among the bees, that is, the 
development of the communistic tendency, stand the two genera of honey- 
bees, Melipona and Apis. The numerous species of Melipona are restricted 


Fic. 725.—Comb of the tiny East Indian honey-bee, A pis florea, 
(After Benton; one-third natural size.) 


to tropical regions; some are very small, the so-called “‘mosquito-bees,”’ and 
in all the sting is blunted and apparently never used as a weapon. The life- 
history of no one of the species has been fully made out, and there is some 
doubt as to whether each community—some of the nests are known to include 
an enormous number of individuals—has but a single queen—that is, single 
egg-laying female—or not. “Of the other genus, Apis, there are but few 
species, the best known being the common hive-bee, A. mellifica, which 
extends naturally over all the northern half of the Old World and from there 
has been introduced into nearly all the countries of the globe. In its long 
domestication several varieties or races have been created by artificial selec- 
tion, the more familiar ones being the German or black race, the Italian 
or amber race, and the Carniolan or striped race. 


Wasps, Bees, and Ants G21 


A community of the hive-bee, which may live, of course, not in a hive at 
all, but in a hollow tree, as undoubtedly was the habit of the species in wild 
state (the ‘“‘bee-trees” of America, however, are inhabited by bee colonies 
which have swarmed away from domesticated ones and are only wild by 
virtue of escaping from the slave-yards of their human 
masters), consists normally of about 10,000 (winter) to 
50,000 (summer) individuals, of which one is a fertile fe- 
male, the queen; a few score to several hundred are 


Fic. 726. Fic. 727. 


Fic. 726.—The honey-bee, A pis mellifica. A, queen; B, drone; C, worker. (Natural 
size.) 

Fic. 727.—Hind leg of worker honey-bee, A pis mellifica, showing pollen-basket. (Much 
enlarged.) 


males, the drones; and the rest are infertile females, the workers. These 
three kinds of individuals are readily distinguishable by structural charac- 


Fic. 728.—Ovaries of queen (A) and worker (B) honey-bee, Apis mellifica. et, egg- 
tubes; sp, spermatheca; pg, poison-gland; ps, poison-sac. (After Leuckart; much 
enlarged.) 

ters. The queen (Fig. 726) has a slender abdomen one-half longer than that 

of a worker, she has no wax-plates on the under side of the abdominal seg- 


522 Saw-flies, Gall-flies, Ichneumons, 


ments, and no transverse series of comb-like hairs, the planta (Fig. 734), on 
the under side of the broad first tarsal segment of the hind feet, and no pollen- 
basket (Fig. 727) on the outer surface of the hind tibia. The drones, males, 
(Fig. 726), have a heavy broad body excessively hairy on the thorax, and 
lack pollen-basket, planta, wax-plates, and other special structures of the 
workers. The workers are smaller than queen or drones, and possess cer- 
tain special structures or body modifications to enable them to perform cer- 
tain special functions connected with their performance of the various indus- 
tries characteristic of the species. These special structures will be described 
in some detail later when the various special industries are particularly con- 
sidered. In internal organization the workers differ from the queen in 
having the ovaries rudimentary (Fig. 728), so that only in exceptional cases 
can a worker produce fertile eggs. 

In functions the three castes differ as they do in the social wasps and 
the bumblebees, only more constantly; that is, the queen lays the eggs, never, 
as with Bombus and the Vespids, doing any food-gathering or nest-building; 


Fic. 729.—Honey-bees gathering pollen and nectar. (From life.) 


the males act simply as consorts for the queen, which means that only one 
of every thousand, perhaps, performs any necessary function at all in the 
communal economy; the workers build brood- and food-cells, gather, pre- 
pare, and store food, feed and otherwise care for the young, repair, clean, 
ventilate, and warm the hive, guard the entrance and repel invaders, feed 
the queen, control the production of new queens, and distribute the species, 
founding new communities, by swarming. 

The life-history of a community is as follows: A “swarm” (how and 
when a swarm is formed will be explained later), consisting of a queen (fertile 
female) and a number of workers (from two to twenty thousand or more), 


Wasps, Bees, and Ants 2g 


issues from a community nest (hive, hollow tree, or elsewhere) and finds, 
through the efforts of a few of the workers, a place for a new nest (in another 
sheltered hollow place, usually, through the intervention of the bee-keeper, 
another hive). Taking possession of this new nesting-place, the workers 
immediately begin to secrete wax (method described later) and to build 
“comb,” i.e., double-tiered layers of waxen cells, usually as ‘‘curtains” 
or plates hanging down from the ceiling of the nest (the bee-keepers supply 
artificially made “foundations” or beginnings of these curtains in vertical 
frames set parallel and lengthwise of the hive, so that the combs will be 
built symmetrically and conveniently for the bee-keeper’s handling). In 
many of these cells the queen, which has received the fertilizing sperm-cells 


Fic. 730.—Brood-cells from honey-bee comb showing different stages in the metamor- 
phosis of the honey-bee; worker brood at top and three queen-cells below; begin- 
ning at right end of upper row of cells and going to left, note egg, young larva, old 
larva, pupa, and adult ready to issue; of the large curving queen-cells, two are cut 
open to show larva within. (After Benton; natural size.) 


from a male during a mating flight high in the air, lays fertilized eggs, one 
at the very bottom of each cell. In other cells, pollen and honey brought 
by workers (the honey brought as flower-nectar and made from this, as 
explained later) are stored for food. In three days the eggs hatch, the tiny 
larve being footless, white, soft-bodied, helpless grubs. They are fed at 
first exclusively with ‘‘bee-jelly,” a highly nutritious, predigested substance 
elaborated in the bodies of the nurse workers and regurgitated by them 
into the mouths of the larve. After a couple of days of feeding with this 
substance, the larve are fed, in addition to bee-jelly, pollen and honey taken 
by the nurses frorn the cells stored with these food-substances. After three 
days of this mixed feeding, the larve having grown so as to fill half or two- 
thirds of the cell, lying curled in it (Fig. 730), a small mass of mixed pollen 


524 Saw-tlies, Gall-fies, Ichneumons, 


and honey is put into each cell, which is then capped, i.e., sealed over with 
a thin layer of wax. The larva feeds itself for a day or so longer on the 
“bee-bread”’ and then pupates in the cell. The quiescent non-feeding 
pupal stage lasts for thirteen days, when the fully developed bee issues from 
the thin pupal cuticle, gnaws away the wax cap and emerges from the cell. 
For from ten days to two weeks the bee does not leave the hive; it busies 
itself with indoor work, particularly nurse work, the feeding and care of 
the young. Then it takes its place with the fully competent bees, makes 
foraging expeditions or undertakes capably any other of the varied indus- 
tries of the worker caste. 

_ After numerous workers have been added to the community, egg-laying 
by the queen going on constantly day after day, so that the young come to 
maturity, not in broods, but consecutively, day after day, certain hexagonal 
cells of plainly larger diameter are made by the comb-building workers, and 
in these the queen lays unfertilized eggs. This extraordinary capacity for 
producing either fertilized or unfertilized eggs, as demanded, depends upon 
the queen’s control of the male fertilizing cells held in the spermatheca. 
This reservoir of fertilizing cells can be kept open as eggs pass down the ovi- 
duct and by it on their way out of the body, thus allowing the sdermatozoids 
to swim out, penetrate (through the micropyle in the egg-envelopes) and 
fertilize the eggs, or it may be kept closed, preventing the issuance of the 
spermatozoids and, consequently, fertilization. From the unfertilized eggs 
laid in the larger cells hatch larvee which are fed and cared for in the same 
way as the worker larve, but which require six days for full growth, the 
pupal stage lasting fifteen days. When finally the fully developed bees 
issue from these cells it will be found that all are males (drones). This 
parthenogenetic production of drones, discovered about 1840 by Dzierzon, 
and long accepted as proved, was recently questioned by Dickel and one 
or two other naturalists and was therefore reinvestigated by Petrunkewitsch 
and others, with the result of confirming, on new evidence and by new 
methods of investigation, the declarations of the discoverer of the fact. 

If, now, our community has increased so largely in numbers that its 
quarters begin to be insufficient for further expansion, certain excited groups 
of workers will be seen tearing down certain cells and replacing them by a new 
giant cell which is usually built up around one of the fertilized eggs laid in a 
small hexagonal cell. The egg hatches before the cell is finished, and the 
larva lies in the large open cavity of the growing cell, on which numerous 
nurses are in constant attendance. Often several of these unusual giant 
cells may be built at one time. The larva which hatches from the fertilized 
egg in one of these cells is fed the nutritious bee-jelly through all of its life, 
little or no pollen or honey being given it. When the larva is five days 
old a quantity of the milky semi-fluid jelly is put into the cell, which is then 


Wasps, Bees, and Ants 525 


capped, the opening being at the bottom of the hanging, nut-shaped cell, 
and in only seven days more the fully developed bee issues. This bee is a 
queen. Very rarely a worker and not a queen issues from a queen-cell. 
That is, a larva hatching from a fertilized egg laid by the queen in a small 
hexagonal cell, if fed bee-jelly for two or three days and then pollen and honey, 
will develop into a worker; that larva from the same egg, if fed bee-jelly 
all its life, and reared in a large roomy cell, will develop into a queen. The 
difference between a queen honey-bee and a worker honey-bee, both struc- 
tural and physiological, are, as already pointed out, conspicuous. The 
influence of a varying food-supply is something mysteriously potent, and 
this case of the queen bee gives great comfort to those biologists who believe 
that the external or extrinsic factors surrounding an animal during develop- 
ment have much influence in determining its outcome. 

As there is by immemorial honey-bee tradition but one queen in a com- 
munity at one time, when new queens issue from the great cells something 
has to happen. This may be one of three things: either the old and 
new queens battle to death, and it is believed that in such battles only does 
a queen bee ever use her sting, or the workers interfere and kill either the 
old or new queen by “balling” her (gathering in a tight suffocating mass 
about her), or either old (usually old) or new queen leaves the hive with a 
swarm, and a new community is founded. If several new queens are to 
issue, the workers usually, by thickening from the outside the walls of one 
or more of the cells, compel the issuing to be successive and not simultaneous. 
This results in a series of royal battles, or a series of swarmings, or a com- 
bination of the two. A queen ready to issue from a cell makes a curious 
piping audible some yards from the hive, which is answered by a louder 
piping, a trumpeting, from the old queen. At these times there is great 
excitement in the hive, as indeed there is during all of the queen-raising 
season. 

The swarming out, it is apparent, does not break up the old community; 
in fact only accident, or the successful attacks of such insidious enemies 
as the bee-moth, and various contagious diseases, break up the parent 
colony. In this respect is to be noted an important difference between 
the other social bees and wasps with their communities annually destroyed 
and refounded, and the honey-bee with its persistent one. Of course workers 
die and so do drones and queens. The tireless workers which hatch and 
labor in the spring and summer months rarely live more than six or eight 
weeks, while the workers born in the late autumn and remaining quietly 
in the shelter of the hive through the winter live for several months. Queens 
live, usually, if ne accident befalls, two or three years; an age of four or 
five years is occasionally attained. Most of the drones in each community 
either die naturally before winter comes or are killed by the workers. Feeble 


526 Saw-flies, Gall-flies, Ichneumons, 


workers and larve and pupe are also sometimes killed just before winter, 
if the food-stores which are to carry the community through the long flower- 
less season are for any reason not likely to prove sufficient for so large a num- 
ber of individuals. In all these matters, that is, the making of queens and 
when, the swarming out and when, and the reduction of the community to 
safe winter numbers, the decision is made by the workers and not the queen. 
The queen is no ruler; she is the mother, or, better, simply the egg-layer 
for the whole community. 

The drones, we have seen, have one particular function to perform in 
the community life, the queen another single particular function; but the 
workers have numerous varied performances to achieve if the community 
shall live successfully. It might be expected, from analogous conditions 
elsewhere existing in animal life, that with the division of labor in the honey- 
bee economy there should be a corresponding differentiation of structure 
or polymorphism inside the species. This polymorphism or existence of 
structurally different kinds of individuals occurs in bees only to the extent 
already pointed out; there are three kinds of individuals: the queens, with 
a special function, the drones, with a single special function, and the workers, 
each capable of performing, and, for the time of the performance, doing it 
exclusively, any of the varied industries necessary to the community life. 
All worker honey-bees are alike, each possessing all the special structural 
specializations, as pollen-basket, wax-plates, wax-shears, trowel-like jaws, 
etc., which have been developed for the special performance of particular 
industries. In some other communal insects a differentiation or polymor- 
phism among the workers exists; many ant species have two or even three 
kinds of workers, the termites have soldiers as well as workers, etc. I pur- 
pose now to describe briefly each of the principal special industries achieved 
by the workers, at the same time describing the structural specialization 
connected with each of these industries. 

The wax produced by the workers is a secretion which issues as a liquid, 
soon hardening, from pairs of thin five-sided plates, one pair on the ventral 
surface of each of the last four abdominal segments (Fig. 731). It is secreted 
by modified cells of the skin lying under the chitinized cuticle of the plates, 
and oozes out through fine pores in the plates. To produce it certain work- 
ers eat a large amount of honey, then massing together form a curtain or 
festoon hanging down from the ceiling of the hive or frame, and increase 
the temperature of their bodies by some strong internal exertion; after the 
lapse of several hours, sometimes indeed two or three days, fine, thin, glisten- 
ing, nearly transparent scales of wax appear on the ‘‘wax-plates.” These 
wax-scales continue to increase in area and soon project beyond the margin 
of the segment, when they either fall off or are plucked off by other workers 
or by the wax-producing worker itself. They are then taken in the mouth, 


Wasps, Bees, and Ants | S277, 


sometimes chewed and mixed with some saliva, and carried to the seat of 
the comb-building operation. Here the wax is pressed against the frame roof 
(or artificial foundation) and by means of the trowel-like mandibles moulded 
into the familiar hexagonal cells; each comb being composed of a double 


Fic. 731. 


Fic. 731.—Ventral aspect of abdomen of worker honey-bee, showing wax-plates. (Three 
times natural size.) 

Fic. 732.—Wax-plate from ventral aspect of abdomen of honey-bee. (Much enlarged.) 

layer of these cells, a common partition serving as base or bottom of each 

tier. Although most bee books speak rather glibly of the comb-building 

operations, it is still undetermined whether the wax-producers leave the cur- 

tain and carry their own wax to the new comb and help mould it, or whether 


Fic. 733-—Honey-bees building comb. (After Benton.) 


the scales are taken away by other (building) workers, or whether they are 
nipped off with the wax-shears (Fig. 734) of the hind legs, and if so, whether 
by the wax-maker or a helper or builder, or whether they fall off to the bot- 


528 Saw-flies, Gall-flies, Ichneumons, 


tom of the hive and are there gathered up by helpers or builders, or whether 
all or most of these various performances occur—which from my own obser- 
vations and those of my students seems true. In building cells for storing 
honey, new wax is almost exclusively used; for brood-cells old wax and 
wax mixed with pollen may be used. Any comb or 
part of a comb not needed is torn down and the wax 
used to build other comb- or cap-cells. 

The seeking and collection of pollen and honey 
is not undertaken by a bee until from ten to fifteen 
days after its emergence from the pupal cuticle, these 
first days being spent in the hive at nurse or other 
indoor work. Then short orienting flights begin to 
be made, and soon the long-distance flights (a mile 
or more sometimes), which are often necessary for 
successful foraging, are undertaken. The pollen is 
taken up or brushed off from the ripe anthers of the 
flowers with the mouth-parts, fore legs, or ventral 
body-wall, the pollen-grains being readily entangled 
in the numerous branching hairs, and then, by 
clever manipulation of the fore, middle, and hind 
legs aided by special pollen-brushes (planta) (Fig. 
734) on the inner side of the front tarsal segments of 
the hind feet, transferred to and packed into the 
pollen-baskets (Fig. 734), one in the outer face of 
Fic. 734.—First tarsal each hind tibia. A forager loaded with pollen re- 

segment of hind legs, j zi 

front and back view, turns to the hive, and, seeking an empty cell near 
of honey-bee. 1, the brood-cells, stands over and with his hind legs 
drone; 2, worker; and ais A 

3, queen. a, distal tip Partly in it and thrusts off the two masses, with the 
of tibia; 6, first tarsal aid of the middle legs (the spurs of the middle tibie 
seme being apparently often used as pries). This pollen 
segment. (After is tamped down in the cell by inside workers and 
Tee much en- receives no further manipulation. 

The ‘‘honey”’ which is collected by the foragers 
is not yet bee-honey, but is nectar of flowers, too watery and too likely not 
to “keep” to be stored in the cells without further treatment. It is sucked 
and lapped up by the complicated elongate flexible mouth-proboscis, swal- 
lowed into the fore stomach or honey-sac (Fig. 735), and carried in this to 
the hive Bees have been seen to exude drops of water on their return 
flight when honey-laden, and it is possible that it comes from the nectar in the 
honey-stomach. At any rate, some ten or twelve per cent. of the water con- 
tent of the nectar has to be evaporated before this nectar becomes honey. 
When the foraging worker with honey-sac full returns to the hive it 


Wasps, Bees, and Ants 529 


regurgitates its nectar either into the mouth of another bee or into a clean (new 
wax) cell, usually near the margin of the comb. At the bottom of the honey- 
sac is the so-called stomach-mouth, a little pea-like protuberance with two 
cross-slits, making four lips. These lips can be opened or closed voluntarily ; 
if the bee drinking nectar wishes to bring it back to the hive to store it, she 
keeps them closed, thus making a sac of the honey- 
stomach, open only through the mouth; whenever she 
wishes to feed herself she opens them, thus allowing 
the honey or pollen to pass on into the true or digest- 
ing stomach. This arrangement also permits of the 
regurgitation of the bee-jelly or bee-milk (fed the 
larvae by the nurse workers), which is believed to be 
prepared in the true stomach, pressed past the lips 
forward into the honey-stomach and on through the 
cesophagus into the mouth. 

When the nectar is put into the honey-cells it has 
still to have much water evaporated from it. To 
accomplish this an effective system of ventilation | 
(see p. 530) is now set up in the hive, so that air- Fic. 735.— Alimentary 
currents pass constantly over the open nectar-con- ne sricaae on 
taining cells; moreover, by the very vigor of this honey-sac lying di- 
activity on the part of the bees the temperature of — Tectly behind (e) 

5 Sele A aye cesophagus. (Much 
their bodies is raised; by radiation of heat from the enlarged.) 
bodies the temperature in the hive is sensibly in- 
creased, and the currents of warm air soon carry off the excess water. To 
make the honey “‘keep,’’ that is, to make it antiseptic, formic acid is added 
to it, probably from glands in the head whose secretions distinctly show its 
presence. It is just possible that the formic acid is supplied by the poison- 
sacs, the poison introduced by the bee’s sting being largely composed of 
formic acid. But it is much more probable that at the time of the regurgi- 
tation of the nectar from the honey-stomach through the mouth the formic- 
acid secretions from the head-glands are mixed with it. 

Nectar for honey-making is obtained by bees from a great many different 
plants, but that from some makes honey better, to our taste, than that from 
others. Among the most important producers of the best honey in the east and 
north are white clover, basswood, buckwheat, and the fruit-trees and small 
fruits; in the middle states are the tulip-tree, sorrel-tree, sweet clover, and 
alfalfa; in the south are the mangrove, cabbage- and saw-palmettos, and 
sorrel-tree; while in the west are alfalfa and white sage. The best and 
most of the California honey is from the wild white sage. 

Besides pollen and nectar, two other substances are collected and brought 
to the hive by the foraging workers. At some seasons of the year when 


530 Saw-flies, Gall-flies, Ichneumons, 


many larva are being reared, and the supply of water derived by con- 
densation of the moisture in the warm hive atmosphere as this air strikes 
the cooler hive-walls is insufficient, the workers drink up dew from leaves, 
or water from puddles, which they hold in the honey-sac and bring to the 
hive, regurgitating it into the thirsty larval mouths. For the filling in of 
crevices, the stopping up of holes, the fastening together of loose parts, etc., 
the bees use a substance called propolis, which is simply the resinous exuda- 
tions of various plants. This propolis is collected and packed into the pol- 
len-baskets as pollen is and brought in by the foragers. Some of my bees, 
needing propolis, discovered a house just in course of painting, and made 
a gallant though hopeless struggle to bring in all the fresh paint as fast as 
it was put on by the painters! This house must have seemed a remarkable 
sort of propolis-producing plant! Propolis is not packed in cells, but is 
used as soon as brought in, the trowel-mandibles being the instruments used 
in putting and moulding it in the needed place. 

Of the indoors work there is much besides those industries already referred 
to, namely, wax-making, comb-building, honey-making, crevice-chinking. 
Because the queen and nurses (bees less than two weeks old) do not leave 
the hive their excreta are voided within doors; there are also bits of old, dirty 
wax, occasional dead bees, and various other waste substances constantly 
accumulating in the hive. Or, rather, this detritus would accumulate if 
the workers were not always keenly careful to carry out all such stuff; the 
hive is constantly being cleaned, and is on any day in the week a model of 
good housekeeping. 

Besides keeping the hive clean the workers must keep it ventilated, that 
is, clean of atmosphere as well as clean of floor and wall. This is done by 
setting up air-currents through the hive which carry out constantly the viti- 
ated air and thus compel fresh air to enter. Always near the exit and scat- 
tered through the hive, especially along its floor, may be seen bees standing 
with head down and body diagonally up and wings steadily vibrating with 
great rapidity. These are the ventilating agents, and they have an exhaust- 
ing and tedious work. 

About the entrance may be also always seen bees which seem neither to be 
leaving the hive nor entering it, but which move about constantly and meet and 
touch antenne with all incomers. These are the warders of the gate. There 
are never wanting enemies of the industrious, well-stocked honey-bee com- 
munity, whose entrance into the hive must be vigorously guarded against. 
Yellow-jackets hover tentatively around the opening; they are arrant rob- 
bers and are ready to take any chance to get at the full honey-cells. But 
more dangerous because of the habit of attacking en masse are honey-bees 
of other hives. Not infrequently a desperate foray by hundreds of other 
bees will be made into a hive, especially a weak one, and a pitched battle 


Wasps, Bees, and Ants sew 


will occur in and about the entrance and inside the hive itself, resulting in 
the death of hundreds, even thousands, of bees. More insidious and even 
more dangerous are the stealthy invasions of a small dusty-winged moth, 
the bee-moth (Galleria mellonella), which, slipping in at night unobserved, 
lays its eggs in cracks; the larva which hatch from the eggs feed on the 
wax of the combs, and as they spin a silken net over them wherever they go, 
the presence of many such works great injury both in the actual destruction 
of comb and in the felting and cobwebbing of the interior of the hive with 
the tough silken netting. Other still more insidious enemies there are, as 
the minute bee-lice (Braula), which attach themselves to the bees and suck 
out their body-juices, and the invisible bacterial germs of foul-brood and 
other characteristic bee diseases. But all these are beyond the sensitiveness 
of the guards to recognize, and for the successful fighting of them the aid 
of the bee-keeper is necessary. 

The feeding and care of the young bees, the larvae, have already been 
partly described in the account of the life-history of the different kinds of 


Fic. 736.—An ordinary beehive made into an observation-hive by inserting glass panes 
in sides and putting a glass sheet under the wooden cover. (Drawn from hive in 
the author’s laboratory.) 


individuals in the community and cannot be further referred to in this brief 
history of the honey-bees’ domestic economy. Of course only the more con- 
spicuous features in this economy have been described at all; a host of inter- 
esting details cannot even be mentioned. But enough has been said, surely, 
to indicate the fascinating field for observation afforded by a honey-bee com- 
munity. If such a community be kept in an observation-hive and this hive 


532 Saw-Hies, Gall-flies, Ichneumons, 


be placed conveniently near the house, or, better, inside one’s room, it will 
prove a never-failing source of interest and pleasure. 

Perhaps it had better be explained how an observation-hive can be kept 
in one’s room without interfering with coincident human occupancy. The 
observation-hive, in the first place, may be, as shown in Fig. 736, simply an 
ordinary outdoors hive into each side of which a large pane of glass has 
been let, with swinging outer wooden doors, one on each side, which, when 
shut, keep the hive in normal darkness, but opened, allow “‘observing”’ to 
go on. In addition to the side glasses a loose sheet of glass is inserted just 
under the ordinary ‘“‘honey-board” or removable top of the hive. Or the 
observation-hive may be, as shown in Fig. 737, a special, narrow, two-frame 


Fe 


yyy 


a 


Fic. 737.—An observation-hive holding only two frames, with the two sides wholly of 
glass, so that any single bee can be continuously watched. (Drawn from hive in 
author’s laboratory.) 


hive, with both sides wholly composed of glass held in the narrow wooden 
frame which forms the ends and the top and bottom of the hive. A black 
cloth jacket should be kept on the hive when “ observing” is not going on. 
In such a hive, which will obviously hold but a small community (one of 
not over 10,000 individuals) any single bee can be kept continuously under 


Wasps, Bees, and Ants 1548) 


observation, as there are no side-by-side frames between which it can crawl 
and thus be hidden from view. To keep either of such hives in the house it 
is only necessary to substitute for a pane of glass in a window a thin wooden 
pane in whichis cut a narrow horizontal opening, the size of the regular hive- 
opening (if the latter is too broad it can be closed for a few inches at each 
end). Ora narrow board strip of the full width of the window can be inserted 
so that the lower sash of the window, when closed, will rest on this strip. 
In the strip cut a narrow opening of the width or less of the hive-opening. 
Set the observation-hive on a table or shelf against the window so that the 
hive-opening corresponds with that in the window-pane or window-strip. 
Or, better, place it six or seven inches from the window and connect hive and 
window-opening by a shallow broad tunnel of wooden bottom and sides but 
glass top. Over the glass top of this tunnel lay a sheet of black cardboard, 
which will keep the tunnel dark normally, but which can be simply lifted 
off whenever it is desired to see what is going on at the entrance. Here can 
be seen the departure of the foragers and their arrival with pollen, propolis, 
or honey, the alertness of the guards, the repelling of robbers and enemies, 
the killing of drones, the ventilating, etc., etc. Through the glass sides of 
the hive itself can be seen all the varied indoors businesses in their very under- 
taking; the life-history of each kind of individual can be followed in detail; 
the wax-making and comb-building, the storing of the food-cells, the feeding 
of the young by the nurses, the excitements, the joys, and the discourage- 
ments, the whole course of life in this microcosm. 

The natural questions of the thoughtful observers of honey-bee life touch- 
ing the probable origin and causal factors of this elaborate train of behavior 
will be found, not answered, to be sure, but discussed, at the end of this chap- 
ter. For before undertaking any consideration of the much-discussed prob- 
lem of reflexes, instincts, and intelligence in the communal-living insects, 
we should examine the life and ways of the ants, the most specialized of all 
the social animals. 


ANTS. 


Unlike the wasps and bees, the two other great groups of Hymenoptera 
that contain communal-living species, the ants (superfamily Formicina) 
include no solitary species at all, every one of the twenty-five hundred or 
more known ant species living in communities. The development or evolu- 
tion of social life in persistent communities is accomplished for the whole 
group; no connecting or gradatory forms living in annually destroyed com- 
munities (like those of the bumblebees and social wasps) or in simple colonies 
of gregarious individuals (like Halictus and other mining-bees) exist to con- 
nect the ants with the solitary or independent life common to the great 


534 Saw-flies, Gall-flies, Ichneumons, 


majority of insects.* And the division of labor, establishment of castes or 
kinds of individuals, and marked differentiation of structure are developed 
to the extreme among the ants. The variety of habits and the special adap- 
tations to different conditions are also represented in their widest range and 
most complex stage of development among the ants. Obviously the ants 
are at the head, the extreme forefront of this kind of specialization in insect 
life. 

No insects are more familiar. They live in all lands and regions; they 
exist in enormous numbers; they are not driven away by the changes in 
primitive nature imposed-by man’s occupancy of the soil; they mine and 
tunnel his fields and invade his dwellings. And many things which man 
attempts they do more successfully than he does, and may be his teachers! 

But few other insects can be mistaken for ants even by the most super- 
ficial observer; the wingless Mutillid wasps, so-called velvet ants, are rather 
like them in general appearance, and the smaller termites, or white ants, 
bear just a slight superficial resemblance to true ants, especially in the case 
of the sexual individuals with their long narrow wings. But ants may be 
at once definitely distinguished from all other insects by the readily made 
out structural character of the basal segments or peduncle of the abdomen. 
One or two of these segments are expanded dorsally to form a little scale 
or flat button-like knot—a characteristic exhibited by no other insects. For 
the rest, ants show a body structure like that, in general, of the wasps and 
bees: compact and well-distinguished thorax and abdomen; wings (present 
only in males and fertile females, and in them easily removable) with a few 
sparsely branching veins and few cells; the mouth furnished with strong 
biting-jaws, which in most species can be used without the opening or even 
the moving of the other mouth-parts (maxilla and lips); antenna slender, 
cylindrical, and sharply elbowed at the end of the rather long basal segment; 
legs long and strong and fitted for running, and the body-wall firm and 
smooth. Many ants have a stridulating (sound-making) organ situated 
on the articulating surface of one of the peduncular abdominal segments, 
which are always extremely mobile. Ants show few special structures of 
the kind so characteristic of the honey-bee; that is, modifications of the 
body to suit the various particular industries undertaken by the insect. They 
seem to use the strong mandibles as universal tools to dig and tunnel, to 
obtain food, carry it and manipulate it, to fight, to carry tenderly their eggs 
and young from place to place, to cut leaves, husk seeds. and what not else. 
While some ants have the sting well developed and capable of inflicting a 
wound even more painful than that of a honey-bee, in most of our species 


* Wheeler’s recent studies of the Ponerine ants of Texas, referred to later in this 
chapter, seem to show that this long-believed generalization must be modified: the com- 
munities of some of these ants seem to be annual growths. 


Wasps, Bees, and Ants 535 


the sting is rudimentary, short and blunted, and no longer a weapon. The 
mandibles are relied on by the stingless ants as means of defence and offence. 
An ant species always includes at least three kinds of individuals, as a 
social wasp or bee species does, and may include several more (Fig. 738). 
There are always winged males, 
which die soon after their issu- 
ance from the nest to take part 
in the mating-flight swarm, and 
winged females, or queens, which 
pull off their wings immediately 
after this flight. Thus winged 
ants are to be seen only at cer- 
tain seasons of the year, the 
fertile females when found in 
the nest being almost always in Fyc. 738.—A California black ant, species un- 
wingless condition. In addition determined, showing winged forms and wing- 
= eee less worker. (After Jordan and Kellogg; 
to the winged individuals there twice natural size.) 
are wingless workers which are 
infertile females, i.e., with rudimentary egg-glands and lacking also the 
spermatheca. These workers in many species, probably most, are of two 
sizes, worker minors and worker majors; the two are not wholly distinct, 


Fic. 739. Fic. 740. 


Fic. 739.—Soldier (a) and worker (c) of Pheidole lamia; 6, head of soldier in profile. 
(After Wheeler; much enlarged.) 

Fic. 740.—Male (a) and ergatoid female (b) of Tomognathus sublevis. (After Wheeler; 
much enlarged.) 


however, as intermediate sizes are occasionally to be noted. In addition 
there may exist workers with extra-large heads and jaws which are known 
as soldiers (Fig. 739), but also between these and ordinary workers interme- 


536 Saw-tlies, Gall-flies, Ichneumons, 


diate stages are sometimes seen. Finally there may exist ergatoid (worker- 
like) wingless but fertile females and males. Wheeler finds among the ants 
of the family Poneride, which includes the most generalized or simplest 
of the ant kinds, that the ‘‘queen and worker differ but little in size and 
structure; ergatoid females or forms intermediate between the queens and 
workers are of normal and comparatively frequent occurrence in some _ species; 
the habits of the queen and workers are very similar; the female is not an 
individual on whom special attention is bestowed by the workers, and the 


Fic. 741.—The little black ant, Monomorium minutum. a, female; b, female with wings; 
¢, male; d, workers; e, pupa; /, larva; g, egg of worker. (After Marlatt; natural 
size indicated by line.) 

workers show no tendency to differentiate into major and minor castes.” 

This investigator has also noted at the other extreme a dimorphism of the 

queens (winged females) in Lasius latipes, a member of the specialized family 

Camponotide, and in two genera, Leptogenys and Tomagnathus, the absence 

of any winged female, the queens having become degenerate to the extent of 

losing their wings. Hand in hand with this differentiation into castes and 
the accompanying differences in structure goes, of course, a division of labor 
or specialization of function, as will soon be pointed out. 

We have no such detailed and complete knowledge of the community 
life of ants as we have of the social wasps and bees; in particular we are 


Wasps, Bees, and Ants 537 


lacking in knowledge concerning the exact mode or modes of the estab- 
lishment and beginning life of new colonies. Whether after the mating 
flight a fertilized queen unaccompanied by workers can found a new com- 
munity, or whether such fertilized queens are found after they come to 
the ground and remove their wings and are taken charge of by a group 
of workers which then take the queen into an already existing community 
or with her establish a new one; or whether, as seems probable, most of 
these modes of procedure are repre- 
sented in the life-history of various differ- 
ent ant species—all these questions are 
by no means well answered on a basis 
of careful observation and experimenta- 
tion. Most of the observations which 
have been made on the founding of new 
communities seem to show that a fertil- 
ized queen begins alone the establish- 
ment of a new community by building a Fic. 742.—Soldier and worker of Phei- 
little nest, laying a few eggs, caring for ras Nuon 1a ice? WWkss SS AS: 
the hatching larve herself, and thus 

raising by her unaided exertions a small brood of neuter workers which 
are always normally undersized, probably from insufficient nourishment. 
This mode of community founding is just like that obtaining among 
the social wasps and the bumblebees. Leidy and Comstock have ob- 
served such a mode of founding new colonies by the common carpenter- 
ant of the East, Camponotus pennsylvanicus, and in Europe Myrmica 
ruginodis, Camponotus ligniperdus, and Lasius alienus have been noted 
to follow the same procedure. An interesting fact in these cases is that 
the food given the larve by the queen is supplied from her own body, 
by regurgitation through the mouth, no food whatever being brought into 
the nest from the time that the queen first begins to lay eggs until this first 
brood is matured. Wheeler, whose admirable recent studies of American 
ants have revealed many important and intensely interesting facts in the 
life of our American ant communities, finds among the Ponerine species, 
undoubtedly in most respects the least specialized of the ants, that the colonies, 
all of which are small, “appear to be annual growths, formed by swarming 
as in the bees, and not by single fertilized female ants unaccompanied by 
workers.” 

The workers of the first brood begin immediately to take on themselves 
the work of the little community, the queen from now on having only to pro- 
duce eggs. First of all comes the enlarging of the nest. Ants’ nests, com- 
prising a sum of irregular chambers and galleries, are mostly built under- 
ground, although some have a considerable part above the normal ground 


538 Saw-flies, Gall-Hies, Ichneumons, 


surface, built up as a mound or hillside, of more or less symmetry and greater 
or less size. This part above ground may be composed chiefly or wholly 
of soil brought up from below surface, or may be partly or wholly made 
up of bits of wood, grass and weed stems, chaff or pine-needles. The 
nest may be made under a stone or log, or be placed in a wholly exposed 
place. Most ants keep their nests fairly near the surface, but a few are 
deeply subterranean miners. Still other species tunnel out their corridors 
and rooms in wood—an old log or stump, dry branches, or what not—while 
yet others live in the stems of plants, in old plant-galls, in hollow thorns and 
spines; finally, a few make nests of delicate paper or tie leaves together with 
silken threads. Very wonderful are some of the interrelations between 
certain plants and certain ant species in tropic regions, whereby the plant 
seems to have developed suitable cavities for the accommodation of the 
ants, whose presence is in turn advantageous to the plant by the protection 
it affords against the ravages of certain leaf-eating insects which are repelled, 
or rather attacked as prey, by the ants. In many cases two ant species will 
live together in a compound or mixed nest, the relation between the two 
species being (a) simply that of two close neighbors, friendly or unfriendly; 
(b) that of two species having their nests with ‘“‘inosculating galleries” and 
their “households strangely intermingled but not actually blended”; (c) 
that of one species, usually with workers of minute size, which lives in or 
near the nests of other species and preys on the larvae or pupz or surrepti- 
tiously consumes certain substances in the nests of their hosts—some different 
larger species—that is, the relation of thief and householder; (d) that of two 
species living in one nest but with independent households, one of these 
species living as a guest or inquiline at the expense of the food-stores of the 
other, but consorting freely with their hosts and living with them on terms 
of mutual toleration or even friendship; and (e) that of slave-maker and 
slave, a relation not at all rare and readily observed all over our country. In 
addition certain other as yet little studied cases of the living together of dis- 
tinct ant species occur which, when understood, may reveal yet other sym- 
biotic relations. 

Inside the nest the eggs are laid by the queen or queens in large numbers, 
not in separate cells as with the wasps and bees, but in little piles heaped 
together in various rooms and sometimes moved about by the workers. 
The hatching larvee, tiny, white, footless, helpless, soft-bodied grubs, are 
fed by the workers either a predigested food regurgitated from the mouth, 
or chewed fresh insects, caught and killed by the workers, or dry seeds or 
other vegetable matter brought into the hive and stored in the ‘“‘granary’’ 
rooms. A single species of ant may use all these different kinds of food, 
but for the most part the ants belonging to one species habitually do not. 
The primitive food consists of seeds and cut-up insects. The importance 


Wasps, Bees, and Ants 539 


of knowing the exact facts with regard to this matter will be appreciated 
when the reader comes to the later discussion of the probable origin of the 
various castes in the communal insect species. The adult ants feed on a 
variety of substances, both animal and vegetable, almost all, however, having 
a special taste for sweetish liquids, such as the secreted honey-dew of plant- 
lice, scale-insects, certain small beetles and others, and the sugary sap of cer- 
tain trees. The males and fertile females are fed by the workers. 

Besides feeding the larvae, the nurses have to see that the young enjoy 
suitable temperature and humidity of the atmosphere; this is accomplished 
by moving the larve or pup from room to room, farther below the sur- 
face, up nearer the surface, or even out into the warm sunshine above 
ground. The carrying about of ants’ “eggs,” which are not eggs but 
usually the cocooned pup, by the workers, is a familiar sight around any 
ant-nest, particularly a disturbed one. The various special industries under- 
taken by ants, as the attendance on and care of honey-dew-secreting plant- 
lice, the fungus-growing in their nests, the harvesting (but not planting!) 
of food-seeds, the waging of wars for pillage or slave-making, the long migra- 
tions, etc., etc., all more or less familiar through much true and some inaccu- 
rate popular writing, will be referred to in what detail our space permits in 
the later descriptions of the life of certain interesting species of American 
ants. 

In any community there may live at one time several (two to thirty) 
queens with wings removed. In small colonies there is, however, usually 
but one. As already mentioned, winged ants are to be seen only at certain 
times in the year. When a brood of sexual individuals (males and females) 
is matured in the community, these winged forms issue on a sudden impulse 
(comparable in a way with the outwinging ecstasy of bees at swarming- 
time) from all the openings of the nest and take wing. The air may be 
swarming with them, flights from neighboring nests intermingling and joining. 
This is the mating flight, and after it is over and those ants which have 
escaped the bird attacks and other dangers attending this bold essay into the 
outer world alight or fall exhausted to the ground, the males soon die, while 
the females pull the wings from the body and get under cover. In the com- 
munal nest, therefore, winged ants are rarely found. The life of the workers 
of most ant species is conspicuously longer than that of other social insect 
workers: they live for from one to three or four or even five years. Lub- 
bock has kept workers until six years old, and queens until seven. The 
males all die young, but both other kinds of individuals are exceptionally 
long-lived for insects. 

About two hundred species of North American ants constituting the 
superfamily Formicina or Formicoidea are comprised in three principal 
families. Some authors recognize five or six families, but it is doubtful if 


I ee 


540 Saw-flies, Gall-flies, Ichneumons, 


such a division of the group can be fairly made. These three families can 
be distinguished by the following key: 


Basal peduncle of the abdomen composed of a single segment (the first) (Fig. 743). 
Abdomen not constricted between the second and third segments (Fig. 743, 1). 
CAMPONOTID. 

Abdomen constricted between the second and third segments (Fig. 743, 2) . PONERIDE. 
Basal peduncle of the abdomen composed of two segments (Fig. 743, 3). . MyRMICID&. 


Of these families that of the Poneride is the smallest in number of species, 
and includes the least specialized (as regards sharply marked division of 
labor, differentiation into castes, and complexity of 
tre ? id # the communal life) of all the ants. In the following 
ae i brief accounts of a few of the better known American 
ants the family relationship of each of the species 
referred to is indicated. 
Of the Poneride only about 25 species are so far 
2 VAR known in this country; all are stingers, although 
not very strong ones, and but a few species are at 
all common. Little was known of their habits 
3 LPT and life-history before the recent studies of Profes- 
sor Wheeler on three species occurring in Texas, 
Fic. 743—Diagrams of namely, Odontomachus hematodes, Pachycondyla 
lateral aspect of abdo- frarpax, and Leptogenys elongata. The nests, made 
en Ct eee ee under stones or logs, are primitive structures, com- 
ants: 1, Camponotide; posed of a few simple and irregular burrows or gal- 
a Ngee leries, some of which run along the surface of the 
abdominal segment; c, soil immediately beneath the stone or log, while 
eer care do, Others extend obliquely or vertically downwards 
inal segment. for from 8 to to inches. There are no widened 
chambers. The nests of L. elongata comprise ten 
to fifty individuals, those of P. harpax fifteen to one hundred, and those of 
O. hematodes one hundred to two hundred. Ergatoid (worker-like) females, 
no larger than and almost exactly like the true workers, existed in all the 
nests; the workers of none of the species fed each other or the males and 
females, and the larvee were fed simply by giving them pieces of freshly killed 
insects, which they chewed and devoured by means of their unusually well- 
developed mandibles. This method of larval feeding is more primitive 
(demands less care and manipulation on the part of the workers) than in 
the case of any other ants,—indeed of any other social insects, for even the 
wasps, which also feed their young pieces of insects, masticate these insect 
morsels thoroughly before turning them over to the tender larve. The 
feeding of the Ponerine larve is also very irregular and capricious both as 


Wasps, Bees, and Ants 541 


to quantity and time. If the regulation by the workers of the kind and 
quantity of food given the larva is the cause or one of several influencing 
factors in determining the caste or kind of individual into which the larva 
shall develop, as is believed by most 
students of social insects, then the 
unmanipulated food of the Ponerine 
larve and the inequality of its con- 
trol as to quantity and time of feed- 
ing may explain how it is that the 
caste distinctions are so much less 
marked in this primitive ant family 
than in the Myrmicide and Campo- 
notide, where, as we shall see, the 
character and amount of the food 
given the larve is carefully controlled 
by the workers. 

The family Myrmicide includes a 
large number of our most interesting 
ants; almost all are stingers, and all are readily distinguished from members 
of either of the other families by having the basal two abdominal segments 
knot-like, and forming the peduncle. Some of the Myrmicids are well 
known because of their abundance, wide distribution, and troublesome ten- 
dency to invade our houses, like the common little red ant, Monomorium 
pharaonis, while others are familiar through the accounts which have been 
written by various authors of their specialized 
habits. Among the latter are the harvesting or 
agricultural ants (Pogonomyrmex), a single species: 
of which, the large harvester of Texas, P. barbatus 
var. molijaciens, has had a_three-hundred-page 
book devoted to it, and the fierce marauding ants 
of the genera Eciton and Atta best known through 
certain famous tropic kinds, but represented in this 
country by several thoroughly interesting and char- 
Fic. 745.—An agricultural- acteristic species. 

ant worker, Pogonomyr- Nine species of harvesters (Pogonomyrmex) (Fig. 
mex imberbicolus. (After , , c 
Wheeler; much enlarged.) 745) occur in this country (in the southern, south- 
western, and Pacific coast states) all (except one 
small retiring species) as far as known forming small or large communities 
in nests partly underground and partly heaped up in conspicuous mounds 
(Figs. 746 and 747) in open, sunny, and usually grassy places. They live 
specially abundantly in the great western plains and indeed in nearly desert 
regions. Into the nest they bring great stores of seeds and grains, gathered 


Fic. 744.—A Ponerine ant, Leptogenys 
elongata, (After Wheeler; enlarged.) 


542 Saw-flies, Gall-flies, Ichneumons, 


from the neighboring grasses, and their well-marked runways make dis- 
tinct paths through the dense grass surrounding the nest. Immediately 


Ce 


Me he 4 VE: ZL / 


Fic. 746.—Mound-nest of the western i ee eae ant, Pogonomyrmex occidentalis. 
(After photograph by G. A. Dean, Wallace, Kans.) 


around the nest this grass is cleanly cut away. The widespread popular 
belief that these ants plant or sow (with purpose or intention) the seeds of a 


Ly 


ee 
y Wi) 
i) ZY 
WES er” 


| ig | 
\\ | | ' 
Fic. 747.—Vertical section of mound-nest of the western agricultural ant, Pogonomyrmex 


occidentalis; this nest about 5 feet deep by 6 feet in diameter. (After photograph 
by G. A. Dean, Wallace, Kans.) 


favorite grass, Aristida, is shown by Wheeler to be untrue; what does often 
happen is that the carrying out of the chaff and sometimes sprouted seeds 


Wasps, Bees, and Ants 543 


(unfit for food) from the nest, and dropping them at the edge of the cleared 
circle, results in a kind of unintentional planting of grain and grass, and as 
Aristida seeds make up an exceptionally large part of the food-stores, a 
majority of the plants in the ring about the nest may often be Aristida. A 
common Californian agricultural ant, P. subdentatus, found abundantly by 
Professor Heath at Monterey, is a splendid fighter as well as provident grain- 
storer, its stings being declared 
by Heath to be more painful than 
those of the honey-bee. 

Eciton, the driver-ant, a genus 
long famous for the marauding 
and pillaging habits of certain 
Brazilian species — in _ these 
marches the great procession is 
said to be marshaled by big- 
headed officers and led by scouts! 
—is represented in the south- 
western part of our country by a 
few species, E. cecum, E. schmitti, 
E. opacithere, and others. 
These show in their life the char- 
acteristic habit of indulging in 
maurauding expeditions to the 
nests of other ants for the pur- 
pose of seizing and carrying off 
the larve and pupe, which are 
used for food by the Ecitons. 
Not all the booty is devoured yy. 748.—Shed-nest of Cremastogaster lineolata, 
at once; some of it may be stored 18 inches long by 12 inches in circumference, 
in the Eciton nest (which is taken several feet from the ground in a bur- 


s row in Hyde County, North Carolina; this ant 
usually but a temporary habita- usually nests under sticks and logs. (After 


tion) and gradually used through Atkinson.) 

several days after the expedition. 

The Ecitons are restless ants, and have a great predilection for moving about 
on long marches or migrations. On these marches they carry with them stored 
booty, which may consist of the dead bodies of various small insects, as well 
as the living larve and pupe of pillaged ant communities. The nests of 
Eciton are entirely subterranean, and are usually simply a cavity, partly 
natural, partly dug out by the ants under some sheltering stone or other 
object lying in the ground. The males and females differ remarkably from 
the workers and from each other in appearance, so much so indeed that the 
few sexual Eciton forms that have already been discovered have mostly been 


544 Saw-flies, Gall-flies, Ichneumons, 


first described as members of new genera. A flourishing Eciton colony 
may comprise several thousand individuals. 

Interesting and common Myrmicids are the little Cremastogasters, of 
which one of the most abundant Eastern species is C. lineolata, the shed- 
builder ant. It is a small black and yellowish-brown species, the workers 
measuring from } to 4%, inch in length, which usually lives in nests in 
decaying logs or stumps or in the ground under stones. But sometimes it 
builds a nest out of chewed wood, like a large rough gall attached to some 
bush above ground. Atkinson describes such a nest (Fig. 748) 18 inches long 
and 12 inches in circumference which contained adults, larve, and pupe. 
In addition to these nest-sheds, small temporary sheds are sometimes built 
at some distance from the nest ‘‘over the herds of Aphids, or scale-insects, 
from which they obtain honey-dew.” 

Another interesting and abundant Myrmicid is the minute yellow “thief- 
ant,”’ Solenopsis molesta. Although it sometimes lives in independent nests, 
more often by far it is to be found living in association with some larger ant 
species—it consorts with many different hosts—feeding almost exclusively 
on the live larvee and pupz of the host. The thief-ant is so small and obscurely 
colored that it seems to live in the nest of its host practically unperceived. 
The Solenopsis nest may be found by the side of the host-nest, around it, 
or partly in it, the tiny Solenopsis galleries ramifying through the nest-mass 
of the host, and often opening boldly into these larger galleries. Through 
their narrower passages, too narrow to be traversed by the hosts, the tiny 
thief-ants thread their way through the other nest in their burglarious excur- 
sions. 

As an example of Myrmicids which live in compound or mixed nests the 
species Myrmica brevinodes, a common red-brown ant that lives under stones 
in the East, and the smaller Leptothorax emersoni may be referred to. 
The interesting symbiotic life of these ants has been studied and carefully 
described by Wheeler (American Naturalist, June, 1901). The little Lep- 
tothorax ants live in the Myrmica nests, building one or more chambers with 
entrances from the Myrmica galleries, so narrow that the larger Myrmicas 
cannot get through them. When needing food the Leptothorax workers 
come into the Myrmica galleries and chambers and, climbing on to the backs 
of the Myrmica workers, proceed to lick the face and the back of the head 
of each host. A Myrmica thus treated ‘‘paused,” says Wheeler, “as 
if spellbound by this shampooing and occasionally folded its antenne as if in 
sensuous enjoyment. The Leptothorax, after licking the Myrmica’s pate, 
moved its head around to the side and began to lick the cheeks, mandibles, 
and labium of the Myrmica. Such ardent osculation was not bestowed in 
vain, for a minute drop of liquid—evidently some of the recently imbibed 
sugar-water—appeared on the Myrmica’s lower lip and was promptly lapped 


Wasps, Bees, and Ants 545 


up by the Leptothorax. The latter then dismounted, ran to another Myrmica, 
climbed onto its back, and repeated the very same performance. Again it 
took toll and passed on to still another Myrmica. On looking about in 
the nest I observed that nearly all the Leptothorax workers were similarly 
employed.’’ Wheeler believes that the Leptothorax get food only in this 
way; they feed their queen and larve by regurgitation. The Myrmicas 
seem not to resent at all the presence of the Leptothorax guests, and indeed 
may derive some benefit from the constant 
cleansing licking of their bodies by the sham- 
pooers. But the Leptothorax workers are careful 
to keep their queen and young in a separate cham- 
ber, not accessible to their hosts. This is prob- 
ably the part of wisdom, as the thoughtless 
habit of eating any conveniently accessible pupe 
of another species is wide-spread among ants. 

The third family, Camponotide, a large one, 
includes a majority of the familiar ants of 
eastern North America. The large black car- 
penter-ant, Camponotus pennsylvanicus (Fig. 
749), which builds extensive nests in logs, 
stumps, building timbers, and even living trees; 
the large black-and-red mound-builder, For- 
mica exsectoides, whose ant-hills are from five to 
ten feet in diameter; and Lasius brunneus, the 
little brown ant ‘‘whose nests abound along the 
borders of roads, in pastures, and in meadows,” 
are all familiar Camponotid species. The last- — |qiltl pwAll (| 
named one is known in the middle states as the ee NS 
corn-louse ant because of its interesting associa- Fic. 749.—Galleries and cham- 
; : é bers in wood of the Eastern 
tion with the wide-spread corn-root louse, Aphis large black carpenter-ant, 
maidi-radicis. In the Mississippi valley this ee tat 
aphid deposits in autumn its eggs in the ground 
in corn-fields, often in the galleries of the little brown ant. The following 
spring, before the corn is planted, these eggs hatch. Now the little brown 
ant is especially fond of the honey-dew secreted by the corn-root lice. So when 
the latter hatch in the spring, before there are corn-roots for them to feed 
on, the ants with great solicitude carefully place them on the roots of cer- 
tain kinds of knotweed (Setaria and Polygonum) which grow in the field, 
and there protect them until the corn germinates. They are then removed 
to the roots of the corn. ; 

A curious Camponotid is the honey-ant, Myrmecocystus melliger, found 
in the southwestern semi-arid states. McCook studied these ants in the 


546 ~ Saw-flies, Gall-flies, Ichneumons, 


Garden of the Gods near Colorado Springs, where he found hundreds of the 
low-mounded nests in the gravelly soil. The name honey-ant is derived 
from the curious structural modification and habits of certain workers, where- 
by these become simply the containers of stored honey, which fills out the 


Note honey-bearers 


1 size.) 


(Twice natura! 


with swollen abdomen in the largest chamber. 


Fic, 750.—Underground nest of the California honey-ant, Prenolepis im paris. 


abdomen to the size and shape of a currant or small grape. These honey- 
bearers hang by their feet from the ceiling of small dome-shaped chambers 
in the nest; their yellow bodies stretch along the ceiling, but the rotund 
abdomens hang down as almost perfect globules of transparent tissue through 


Wasps, Bees, and Ants 547 


which the amber honey shines. The honey is obtained by the workers 
from fresh (growing) Cynipid galls on oak-trees, which exude a sweetish 
sticky liquid which is brought in by the foraging workers and fed to the 
sedentary honey-holders by regurgitation. It is held in the crop of the 
honey-bearer, the distention of which produces the great dilation of the 
abdomen. The stored honey is fed on demand to the other workers by 
regurgitation; a large drop of honey issues from the mouth of the honey- 
bearer, resting on the palpi and lips, and is eagerly lapped up by the feeding 
individuals, two or three often feeding together. A somewhat similar honey- 
ant, Prenolepis imparis (Fig. 750), is common in California. 

The most interesting, however, of the familiar American ants are the 
“‘slave-makers” and their “slaves.” Three species of slave-makers occur 
in North America, of which two belong to the family under present discussion. 
These are Formica sanguinea, represented by five subspecies, and Polyergus 
rufescens, the shining slave-maker, represented by two subspecies. The 
third slave-making species, Tomognathus americanus, is a rare Myrmicid. 
The slaves of F’. sanguinea are other smaller species of the same genus, espe- 
cially F. subsericea, F. nitidiventris, and F. subenescens, while the slaves of 
Polyergus are the same species of Formica and the additional one, particu- 
larly common as a slave form, F. schaufusst. Communities of the slave- 
making species are occasionally found in which there are no slaves; when 
slaves are present they may be few or many; usually they are more numerous, 
proportionally, the smaller the numbers of the slave-makers in any com- 
munity. The slaves are captured by the attack, by a body of slave-making 
workers, on a slave-ant community and of the pillage of the attacked nest of 
larve and pup; some of these may be eaten, but others are brought back 
unharmed to the slave-makers’ nest. Here more yet may be eaten, but most 
are cared for and soon hatch to become the slaves of their captors. Never 
are adults enslaved; they are killed or driven off during the attack. The 
slaves undertake unhesitatingly all the varied work of bringing in food, nest- 
building, and caring for the young in the community. Indeed in some cases 
the slave-makers come to be very dependent on the slaves, which ought really 
then to be called auxiliaries or helpers, for the slave-maker workers also 
assist in all the community undertakings, while the ‘‘slaves” often seem 
to dominate, or at least to be quite as important as, their would-be rulers in 
the determination of the course of events in the compound community. So 
far does this dependence go in the case of certain foreign ants that the origi- 
nally dominant species loses its workers, and is thus absolutely dependent 
on the auxiliary species for the maintenance of the community. In the 
general division of labor in the compound community the fighting is always 
done, at any rate chiefly, by the slave-makers. McCook has described in 
some detail the community life of the shining slave-maker, Polyergus lucidus, 


548 Saw-flies, Gall-flies, Ichneumons, 


and its auxiliary, Formica schaufussi (Proc. Phil. Acad. Sci., 1880, p. 376 
et seq.). 

The observation and study of ants’ ways must be partly done in the 
field, but, thanks to the obliging manner in which most species will readily 
live in artificial nests prepared for them indoors, much intensely interesting 
work in the study of ants can be done on one’s own reading-table. Several 
types of artificial formicaries (ants’ nests) have been devised, one by Lub- 
bock, another by Forel, another by Janet, another by White, etc., any one 
of which seems to give good results. Professor Comstock gives the follow- 
ing directions for making a Lubbock nest: “The principal materials needed 
for the construction of a nest of this kind are two panes of window-glass ten 
inches square, a sheet of tin 11 inches square, and a piece of plank 1} inches 
thick, 20 inches long, and at least 16 inches wide. 

“To make the nest, proceed as follows: Cut a triangular piece about 
1 inch long on its two short sides from one corner of one of the panes of glass. 
From the sheet of tin make a tray $ of an inch in depth. This tray will be 
a little wider than the panes of glass and will contain them easily. On the 
upper side of the plank a short distance from the edge cut a deep furrow. 
This plank is to form the base of the nest, and the furrow is to serve as a 
moat, which is to be kept filled with water in order to prevent the escape 
of the ants. It is necessary to paint the base with several coats of paint to 
protect it from water and thus prevent its warping. 

“To prepare the nest for use, place the tin tray on the base, put in the 
tray the square pane of glass, lay on the edges of the glass four strips of wood 
about 4 inch wide and a little thicker than the height of the ants which are 
to be kept in the nest, cover the glass with a layer of fine earth of the same 
thickness as the strips of wood, place upon this layer of earth and the strips 
of wood the pane of glass from which one corner has been cut, and cover the 
whole with a cover of the same size and shape as the upper pane of glass. 
In the nest figured the cover is made of blackened tin, and one-half of it is 
covered by a board. This gives a variation in temperature in different parts 
of the nest when it stands in the sunlight. 

“The ants when established in the nest are to mine in the earth between 
the two plates of glass. The removal of one corner from the upper pane 
provides an opening to the nest. The thickness of the strips of wood between 
the edges of the two panes of glass determines the depth of the layer of earth 
in which the ants live. This should not be much thicker than the ants are 
high; for, if it is, the ants will be able to conceal themselves so that they can- 
not be observed. 

“The nest being prepared, the next step is to transfer a colony of ants to it. 
The things needed with which to do this are a two-quart glass fruit-can, or 
some similar vessel that can be closed tightly, a clean vial, and a garden 


Wasps, Bees, and Ants 549 


trowel. With these in hand find a small colony of ants, such as are com- 
mon under stones in most parts of the country. Collect as many of the ants 
and of the eggs, larva, and pupz as possible, and put them in a fruit-can, 
together with the dirt that is scooped up in collecting them with the trowel. 
Search carefully for the queen; sometimes she is found immediately beneath 
the stone covering the nest, but often it is necessary to dig a considerable 
distance in order to find her. She can be recognized by her large size. If 
the queen is not found, empty the contents of the can back into the nest, 
and take up another colony; without a queen the experiment will be a failure. 
Wh_n the queen is found place her in the vial so that she shall not be injured 
while bing carried to the schoolroom. 

“Having obtained a queen and a large part of her family, old and young, 
return to the schoolroom and empty the contents of the fruit-can onto the 
board covering the upper pane of glass, and place the queen there with her 
family. If much dirt and rubbish has been collected with the ants, remove 
some of it so that not more than half a pint of it remains. When this is 
done leave the ants undisturbed for a day or two. Of course the moat should 
be filled with water so that they cannot escape. 

“Usually within twenty-four hours the ants will find the opening leading 
into the space between the two panes of glass and will make a mine into 
the layer or earth which is there, and will remove their queen and young to 
this place. This process can be hastened by gradually removing the dirt 
placed on the cover of the nest with the ants. 

‘After the ants have made a nest between the panes of glass they can 
be observed when desired by merely lifting the board forming the cover of 
the nest. 

“With proper care a colony can be kept in a nest of this kind as long 
as the queen lives, which may be several years. The food for the ants can 
be placed on the base of the nest anywhere within the moat, and may con- 
sist of sugar, minute bits of meat, fruits, etc. With a little care the kinds 
of food preferred by the colony can be easily determined. The pupz of 
ants, which can be collected from nests in the field during the summer months, 
will be greedily devoured. The soil in the nest should be kept from becom- 
ing too dry by putting a little water into one side cf the tin tray from time 
to time.” 

White prefers for a formicarium an inverted bell-glass (Fig. 751) mounted 
on a wooden block which is set like an island in a shallow pan of water. 
“Enough of the contents of a nest should be removed and transferred to 
the bell-glass to occupy about half of its available space. A cover either of 
baize or brown paper should be placed over the sides of the glass so as to 
conceal the contained earth and to allow the light to filter only through the 
surface, so that the ants may be thus induced to work against the transparent 


550 Saw-flies, Gall-flies, Ichneumons, 


sides of the formicarium. The darkness occasioned by the screen leads 
them to believe that they are working underground, at certain distances 
from the surface, and thus induces them to construct many tiers of chambers 
and connecting corridors within the range of practical observation. This 


iL : 


Fic. 751.—A convenient bell-jar formicary. The dish in which the bell-jar stands is sur- 
rounded by water held in the large zinc pan. 


we may judge to our satisfaction when, after a few days, the screen is with- 
drawn for a short season, and the marvels of the constructive instinct of the 
little people revealed to our wondering gaze.” 

Janet, a distinguished French student of ant life, uses a block of porous 
earthenware in which several little chambers or hollows have been made, 


| Ollofle 


Fic 752.—Plan of a Janet nest. 0, opening covered by opaque cover, c; we, wet chamber. 
(After Janet.) 


connecting with each other by little surface grooves, the whole covered with 
a glass plate, and over that an opaque cover (Fig. 753). Into a cavity at 


one end of the block he puts water which soaks some distance along the 
length of the block, thus rendering some chambers humid, while others at 


Wasps, Bees, and Ants isin 


the far end are dry. He gives the ants no soil, forcing them to use the already 
made chambers. This formicarium reveals, therefore, none of the secrets 
of nest-building, but it does reveal admirably a host of those interesting pro- 
cesses connected part cularly with the life-history of the individuals of the 
colony. Miss Fielde uses still another kind of nest, also like Janet’s with 


ZZ iw 
SS Do ee a em ae 


—_ eS | 


AERC ERE 


Fic. 753.—A Janet nest in vertical section. w.c., wet chamber; 1, 2, 3, brood-chambers; 
0., circular openings for brood-chambers made in ¢., a transparent cover; 0.c., glass 
cover in three removable pieces; d.p., opaque cover; 6.p., base plate. (After Janet.) 


fixed chambers, but made wholly of glass, the requisite moisture being fur- 
nished by a bit of sponge kept soaked with water and placed in one of the 
communicating chambers. Fig. 754 with its caption explains the make-up 
of a Fielde nest. 

In the study of the life of ants by means of such formicaries as have just 
been described, as well as through observations in the field, the student, 
amateur or professional, should keep in mind certain particular desiderata 
in formicology. It is highly de- 
sirable to determine for as many 
species as possible the exact 
method of founding a new colony: 
isolate a queen in a small artifi- 
cial formicary, well provided - oom V Sa 
with food, and see if she can and 
will begin one; isolate a small 
group of workers with some eggs 
or young larve, but without a 
queen, and see if they can and do 
produce a queen and establish Fyg, 754.—Plan of the Fielde ant-nest, to 
themselves as a permanent com- inches by 6 inches. a, entrance and exit to 
munity. The characteristic habits pains SoS cap ed Se Aa a 
of feeding the young should be 
determined for various species; the presence of or possibility of producing 
ergatoid (wingless, worker-like) fertile females and males in the case of vari- 
Ous species should be noted; and special attention should be given in all 
observations to determining in how far the behavior in general, and single pro- 
cesses in particular, can be explained as machine-like reflexes of unintelligent 


| 
Miles 
m. 


\ 
: 
a 


bre Saw-tlies, Gall-flies, Ichneumons, 


organisms, or make necessary the assumption that ants have a choice-making 
and generally adaptive and teachable intelligence. Can ants dislocate in 
time their reactions to stimuli? Are ants conscious? 

Curious interrelations of ants with some other animals have already 
been referred to, as their care of plant-lice 
(Aphidide) from which they obtain the much- 
liked honey-dew, and their association with various 
species of their own general kind in the rela- 
tions of slave-maker and slave, host and parasite, 
or host and guest. But still another kind of inti- 
mate association with other animal species is com- 
mon in ant-life, namely, that of the occurrence in 
their nests of many different species of other in- 
sects (as well as certain mites, spiders, and myri- 
apods) which force their presence on their ant 
hosts by cleverness or deception, or are tolerated 
Fic. 755.—Ecitoxenia brevi- or even encouraged by the hosts. A few of these 

fe s; a rove-beetle (Staphy- arthropods which inhabit ants’ nests are true para- 

inide), which lives inthe , 3 

nests of the robber-ant, Sites or predaceous enemies, such as have to be 
Eciton schmittii, in Texas. endured by almost all other insect kinds, but the 
Note absence of wings and ae 5 
curiously modified shape. large majority of these so-called myrmecophiles do 
(After Brues; natural little or no injury to their ant hosts, while a few 
length one-eighth inch.) even return in some degree the advantages which 
they receive by the association. These advantages are (a) ready-made 
subterranean cavities and lodging-places, defended against most enemies by 
the fierce and capable owners 
of the nest; (b) a pleasant 
and favorable temperature 
maintained despite the frigid 
ity of the outer atmosphere; 
(c) stores of vegetable food, 
as seeds, etc., garnered by 
the ants, and supplies of ani- Fic. 756. Fic. 757. 
mal food, as bits of freshly Fic. 756. — Termitogaster texana, a rove-beetle 
killed insects, etc., collected by  (Staphylinide), which lives in the nests of the 
the hosts, as well as the larve termite, Eutermes cinereus, in Texas. (After 


5 Brues; natural length 14 mm.) E 
and pupe, and even the dead fyg. 757.—/Enigmatis blattoides, a Phorid fly, which 


bodies of the ants themselves; _ lives in the nests of the ant, Formica fusca, in 
Denmark. (After Meinert; thirteen times natural 
size.) 


(d) the sweetish liquid food 
readily regurgitated by most 
ant workers in response to certain stimuli, and normally used for feeding 
the queens, males, and occasionally other workers; and finally (e) means 


Wasps, Bees, and Ants 553 


of safe transportation due to the migrating habits of many of their host 
species. 

The myrmecophilous (ant’s-nest-inhabiting) insects are limited to no 
single order. Of the total of 1177 insect species recorded by Wasmann 
in 1900 as living for part or all of their life in ants’ nests, 993 are beetles, of 


Fic. 758.—Ant-guests; at left, Psyllomyia testacea, female; next at right, Ecztomyia 
wheeleri, female; at extreme right, male of last-named species. These two insects 
are species of flies of the family Phoride, the females of which have become 
extremely degenerate because of their myrmecophilous life. (After Wheeler; 
much enlarged.) 


which the families Staphylinide (rove-beetles), Pselaphide, Pausside, Clavi- 
geride, Histeride, Silphide, Thorictide, Lathridictide, and Scydmenide 
make up all but roo species, these latter representing 22 
other families; 76 are Hemiptera, of which 15 are plant- 
lice and scale-insects; 39 are Hymenoptera, of which 22 
are other ant species; 26 are Lepidopterous larve, 20 
are Thysanura, 18 Diptera, 7 Orthoptera, 1 a Pseudo- 
Neuropteron, 34 are mites, 26 are spiders, and g are 
isopod crustaceans. While most of these only derive 
advantage from this commensalism with ants, some, and 
notably the small Paussid, Clavigerid, Pselaphid, and 
other beetles, live truly symbiotically with their hosts, 
—being of immediate reciprocal benefit to them. 
These little beetles, many of which show most amazing 
modifications of body structure (Figs. 755, 756) (such 
modifications, usually degenerative, are displayed also. by a Me ree Hers 
numerous other ant guests, particularly Phorid flies (Figs. to the larva of the 
757> 758), in adaptation to this extraordinary life, ant  Pachycondyla 
; “4 z : . : harpax. (After 
secrete a sweet substance which is greedily eaten by Wheeler; much en- 
the ants. The hosts in return care for, clean, and feed __larged.) 
by regurgitation the curious little beetles. 
The “wonderful” and “marvelous” character of the behavior of the 


554 Saw-flies, Gall-flies, Ichneumons, 


ants, bees, and wasps has long been a subject of popular interest and an 
object of much scientific observation and experimentation more or less 
rigorously conducted. Speculation, both popular and scientific, concerning 
the causal factors concerned has run a wide gamut, from the declaration 
of Bethe that ants are simply complex machines responding mechanically, 
with fixed strictly reflex reactions, to physico-chemical stimuli, to the anthro- 
pomorphic comparisons of the natural-history popularizer, who reads into 
the behavior of the ‘wonderful little ant people” human emotions, human 
reason, intelligent discrimination, and volitional action. 

A difficulty met with at the very beginning of any discussion of the be- 
havior of social insects is the lack of precise definitions of three presumably 
classificatory terms distinguishing, on a basis of cause, three kinds of behavior 
or action, viz., reflexes, instincts, and intelligence. Another more funda- 
mental difficulty in the actual study and interpretation of animal behavior 
is the absolute lack in ourselves of any criterion or means of interpretation 
of action other than our experience of our own sensation and psychology. 
Nevertheless the matter can be, and is now being, undertaken in a rational 
and unbiased spirit, and is attaining important positive results based on 
observation and experiment conducted with rigorously scientific method 
and expressed with scientific caution. Although little more than an ap- 
preciable beginning has been made in this work, we can already dis- 
tinguish some of the springs or factors, both intrinsic and extrinsic, which 
determine the actions of these insects, and we can define scientifically some 
of the limitations as well as some of the possibilities of their purposeful 
behavior. 

Between the cleanly mechanical or reflex theory of Bethe, Uexkull, and 
others, and the reflexes plus instincts and animal-memory theory of Was- 
mann, Loeb, and Wheeler, or between this and the instincts plus intelligence 
theory of Lubbock and Forel, there is no sharp line, although between Bethe 
and Forel there is a wide gulf. What modern investigation has clearly and 
positively done is to cut away the anthropomorphism of the careless popu- 
larizer, and to compel a strong leaning toward a belief in the efficiency of 
reflex and instinct to explain most if not all of ant behavior. What would 
not have been heard with any patience at all a few years ago, that is, a purely 
mechanical, i.e., reflexive reaction to physico-chemical stimuli, explanation 
of many of the ‘‘wonderful’’ actions of ants, as their perception of paths, 
their recognition of nest-mates, and swift attack on strangers, their refrain 
from attack on other species living in symbiotic relations with them, etc., etc., 
is now heard with careful attention. Couple with this purely reflexive theory 
the theory of inherited specialized instincts developed by natural selection 
from widely diffused generalized instincts and most of us are inclined to 


| 


Wasps, Bees, and Ants 555 


find in the combination the springs of most if not all ant behavior; and what 
will explain the complex activities of ants will certainly explain those of all 
the other so-called “intelligent insects,’ namely, bees and wasps, both soli- 
tary and social. 

A final problem in the life of the social insects is that touching the origin 
and establishment of the various castes or kinds of individuals inside the 
single species. The presence of two, often widely differing kinds of indi- 
viduals, namely, male and female, is so familiar as to lose, for some of us, 
part of its significance and importance. But why the young produced by 
the union of male and female can differ so widely as they may, that is, to the 
extent of the difference between male and female, seems to us explicable by 
the fact that just such two differing parent individuals take part in the pro- 
duction of the new individuals, and by the fact that such a phenomenon 
is the usual and ordinary one of heredity. (However little we may under- 
stand the natural phenomenon or jaw of heredity just as little do we under- 
stand gravitation, which we habitually are content to assign as an ultimate 
cause for certain effects). But with the social insects we have always one, 
and often more than one, still different individual among the offspring, and 
one which takes no part whatever in the (embryonic) production of new 
individuals; it can hand on nothing to the offspring by heredity. The ques- 
tion is, then, how are two kinds of individuals (male and female) able to 
produce not only their own kinds, but a third kind which has no part in pro- 
ducing or fertilizing the egg-cell from which it develops? 

And on the heels of this question comes a second. How is it that if the 
present-day forms and kinds of animals are due to the results of the com- 
bined influences of variation, natural selection, and heredity—that is, that 
the inevitably appearing slight congenital differences as they are of advantage 
or disadvantage in the life of the animal are preserved or destroyed in the 
species by natural selection—how, it may be asked, have the characters of 
the worker castes been thus determined by selection, for in this case the 
modified individuals have no part in the transmission of their characteristics 
by heredity ? 

The first question is answered as far as it at present can be in terms not 
wholly agnostic, by the statement that it is probably true among ants, as 
has been shown actually to be true with certain other social insects, namely, 
the termites (p. rrr) and the honey-bee (p. 525), that the difference between 
queen (fertile female) and worker (infertile female) is brought about during 
postembryonal development by differences regulated by the nurses in the 
quality and quantity of food supplied the developing individuals. Sharp 
says: “There is a considerable body of evidence suggesting that the quality 
or quantity of the food or both combined are important factors in the treat- 


556 Saw-flies, Gall-flies, Ichneumons, 


ment by which the differences are produced. The fact that the social insects 
in which the phenomena of caste or polymorphism occur, though belonging 
to very diverse groups, all feed their young, is of itself very suggestive. When 
we add to this the fact that in ants, where the phenomena of polymorphism 
reach their highest complexity, the food is elaborated in their own organs 
by the feeders that administer it, it appears probable that the means of pro- 
ducing the diversity may be found herein.” 

The answer to the second query—a query anticipated by the keen-minded 
Darwin as voicing an apparently insuperable objection to the selection 
theory—as made in the Origin of Species at the end of the chapter on Instinct 
has, by the investigation of modern students of ants, only been strengthened. 
This answer made by Darwin, and repeated with new supporting observa- 
tions and ingenious arguments by the present-day Neo-Darwinians, is briefly: 
that the differences between the queens and the various worker castes are 
quantitative rather than qualitative, that gradatory conditions exist between 
the extreme points of the various lines of structural and physiological speciali- 
zation, individuals being found in almost every ant species, so far carefully 
studied, standing as connecting links between queen and highly specialized 
infertile worker (or soldier); that there has been a gradual achievement 
of this differentiation of structure through the advantage to the species of 
the slight congenital tendencies toward sterility on the part of some of the 
young, and by consequence their special devotion to the nest industries, leav- 
ing the fertile individuals freer for reproductive activity; that the evolution 
has been one of communities rather than of individuals; that those fertile 
males and females have persisted which have shown a tendency to produce 
some sterile individuals among their progeny which, living in consociation 
with the fertile individuals of the brood, were of special advantage to the 
community more and more as they possessed such variations of structure 
as would fit some for general work and others for the special defence of the 
colony; and, finally, that such advantages to the community have been 
quite sufficient as handles for the action of natural selection, with the final 
result as seen to-day in developing ant species in which there is a fairly sharp 
division between fertile and sterile forms, and between two or three different 
castes of the sterile individuals. Those species are the modern ones whose 
fertile females produce several well-modified kinds of individuals. Darwin 
and the Neo-Darwinians of to-day not only find in this answer an adequate 
explanation of the development of the modern highly specialized ant com- 
munity by the action of natural selection, but find the existence of such com- 
munities a convincing fact telling against the belief of Lamarckians and 
Neo-Lamarckians in evolution by the accumulation of inherited structural 
and physiological characters acquired in the lifetime of individuals. As 


Wasps, Bees, and Ants 557 


Darwin says: “‘The case (of ant communities with worker castes) also is 
very interesting, as it proves that with animals, as with plants, any amount 
of modification may be effected by the accumulation of numerous, slight, 
spontaneous variations, which are in any way profitable, without exercise 
or habit having been brought into play. For peculiar habits, confined 
to the workers of sterile females, however long they might be followed, could 
not possibly affect the males and fertile females, which alone leave descend- 
ants. I am surprised that no one has hitherto advanced this demonstrative 
case of neuter insects against the well-known doctrine of inherited habit as 
advanced by Lamarck.” 

It will be noted that the answer to the first question as to how the marked 
differences between the fertile and the sterile forms of ants in any nest are 
brought about during individual development, and the answer of Darwin 
to the second question as to how these differences have been brought about 
in the species itself, are not thoroughly in harmony. Darwin’s answer 
would at first glance seem to assume differences in the eggs laid by a single 
queen capable of determining the difference in the individuals developed 
from these eggs; so that no special treatment (feeding) of an individual 
would be necessary to produce the ultimate differences in the matured indi- 
viduals. But the congenital differences may be potential and not definitive; 
the feeding treatment, namely, the addition of certain extrinsic or envizon- 
mental factors, might be necessary to discover or make actual the latent or 
potential differences congenitally resident in the eggs. 

Still a third question arises in connection with the specialized conditions 
obtaining in modern ant communities. It is this: How have the compound 
and mixed communities, in which two ant species live in some kind or degree 
of symbiosis, arisen? How has it come about that two species of ants which 
normally are deadly enemies ready to do battle with each other at any meet- 
ing—a condition which seems to be curiously general throughout the group 
of ants, not only different species being always ready to attack one another, 
but members of different communities of the same species showing a deadly 
animosity for each other—how is it that these two species have come to 
live peaceably together in a mixed community ? 

In the first place in some of the cases the animosity still exists; the “thief” 
ants which live in other ants’ nests escape with their lives only because of 
their minute size and obscure coloring, their careful avoidance of detection, 
and the care with which they keep the galleries of their own part of the nest 
too small for the entrance of the hosts; they appear to manage this double 
household arrangement by vigilance, cleverness, and deceit. Cases of true 
symbiosis with mutual benefit are readily explicable by the selection theory. 
Their beginning is a little hard to understand, but an association with recip- 


558 Saw-tlies, Gall-flies, Ichneumons, 


rocal advantages, once begun, could readily be developed into such a curi- 
ous condition as that, for example, of Myrmica and Leptothorax described 
on p. 544. The beginning of such an association requires the assumption, 
of course, that the apparent general rule of mutual animosity existing among 
ants shall have its natural exceptions; that their instincts are not wholly 
immutable or all embracing. To take a particular case, Wheeler has admi- 
rably shown the remarkable differences of instinct exhibited by the species 
of the single genus Leptothorax. While systematists agree that this large 
and widely distributed genus is unusually homogeneous, Wheeler shows 
that m habits its species are singularly diverse: ‘‘Many of the forms have 
no tendency to consort with ants of other species, but differ considerably 
in the stations which they inhabit. Some prefer to live under stones, others 
in moss, others under bark or in dead wood, and still others, like one of the 
Texan species, in cynipid galls, or, like our New England L. longispinosus 
Rog., in the worm-eaten hickory-nuts among the dead leaves under the 
trees. Many species, however, have a pronounced penchant for entering 
into more or less intimate symbiotic relations with other Formicidae, as shown 
in the following conspectus: 

“tr. The European L. muscorum often lives in plesiobiosis [double nest] 
with Formica rufa. 

“9. A similar tendency is undoubtedly exhibited by our American L. cana- 
densis Provancher, which I have had occasion to observe since the second 
part of this paper was written.’ [Here Wheeler describes in detail the 
symbiosis of L. canadensis and Cremastogaster lineolata, the common shed- 
builder ant of the north and east.] 

“3. L. pergandei lives, probably as a guest, in the nests of Monomorium 
minutum, var. minimum. 

““4. The single colony of the Mexican L. petiolatus which I hive seen 
was living in parabiosis [interlacing nest] with species of Cryptocerus and 
Cremastogaster. 

“5. L. tuberum, var. unifasciatus, lives with the European Formicoxenus 
ravouxt, the relations between the species being, perhaps, the same as those 
which obtain between Formica ruja and Formicoxenus nitidulus. 

“6, L. muscorum, L. acervorum, and L. tuberum live as slaves or auxili- 
aries with the European Tomognathus sublevis. 

“7, L. curvispinosus probably performs the same role in the nests of 
T. Americanus. 

“8. L. tuberum has been found associated with Strongylognathus testa- 
ceus. Here, too, the Leptothorax probably acts as the slave of the dulotic 
species. 

“9, L. emersoni lives with Myrmica brevinodis as described [on p. 544].” 


4 


Wasps, Bees, and Ants 559 


It is evident, therefore, says Wheeler, that the ants of this genus 
have originally possessed certain traits which made it specially easy for 
them to enter into symbiotic relations with other species of ants. Some 
of these fundamental or original traits may still be recognized in the genus, 
to wit: 

“ry. The genus has a very wide geographical distribution, a prerequisite 
to the establishment of such numerous and varied relations with other ants. 

“9. The species are all of small size. This must undoubtedly facilitate 
their association with other ants. 

‘©3. The colonies consist of a relatively small number of individuals. 
This, too, must greatly facilitate life as guests or parasites in the nests of 
other ants. 

“4. Most of the species are rather timid, or at any rate not belligerent. 
They are, therefore, of a more adaptable temperament than many other 
ants even of the same size (e.g., Tetramorium cespitum). Forel has 
shown that L. tubero-ajfinis will rear pupe of L. mylanderi and even of 
Tetramorium cespitum and live on good terms with the imagines when they 
hatch. 

‘“‘<. There is no very sharp differentiation in habits between the queens 
and workers of Leptothorax. This, too, should facilitate symbiosis. The 
queens, as I have shown in the case of L. emerson, may retain the excavating 
instinct and the instincts which relate to the care of the larve. 

“6. The similarity in instinct between the queens and workers of Lepto- 
thorax finds its physical expression in the frequent occurrence of interme- 
diate or ergatogynous forms. So-called microgynic individuals, or winged 
queens no larger than the workers, have been frequently observed by Forel 
and Wasmann in L. acervorum. Those observed by the latter author also 
showed color transitions between the normal queens and workers.” 

Finally, Wheeler points out that this heterogeneity of habit and these 
existing gradatory steps between strictly non-working fertile queen and 
strictly non-fertile working-worker, are evidence for the selection theory as 
explaining the division of labor and differentiation of structure in the special- 
ized ant communities. ‘‘Viewed as a whole, these different symbiotic rela- 
tions cannot be said to bear the ear-marks of internal developmental causes 
operating in a perfectly determinate manner. Indeed, appearances are 
quite otherwise and seem rather to point to indeterminate variations which 
have been and are still in process of being seized on a fixed by natural selec- 
tion. It must also be admitted that the same appearance is presented by 
the whole complex of conditions in compound and mixed nests, but the 
demonstration is more cogent when it can be shown that we have relations 
as different as those of dominant species (L. emersonz) and slaves (L. acer- 


560 Saw-flies, Gall-flies, Ichneumons, 


vorum) not only in the same genus but among closely allied forms. This 
jact also suggests that the instincts of the same species may be so generalized 
as to enable it to junction like man, either as a slave or master, according to 
the circumstances.” 

And this leads us to consider briefly that extremest form of consociation 
between two ant species, namely, the so-called dulosis, the living together of 
slave-makers and slaves. To put summarily the result of various careful 
studies of dulotic communities made by both European and American 
observers, it may be said that this condition has grown out of the general 
instinct that most ants show, to obtain when and where possible the larve 
and pupe of other ant species for food. From a raid on a neighboring com- 
munity and the immediate devouring of as many larve and pupz as possible 
to a similar attack and feast plus the bringing home of a supply of this choice 
food to be stored for eating through the next few days is a natural, and as 
exemplified by numerous observed cases, an actual s‘ep. Then if the booty 
be large in amount, it is inevitable that some of the pupz shall transform 
in the new nest. Now, are these newly issued workers to be at once 
attacked and eaten? This depends on whether the proper stimulus is 
present or not. As practically certainly determined by numerous observa- 
tions and experiments the stimulus for attack and war among ants (as 
well as bees) is odor; recognition of nest mate and perception of intruder 
or foreigner depends probably solely on the sense of smell, and the 
stimulation of this sense has come during the evolution of the instincts 
of ants to be a stimulus to direct reflexive action; the odor of the home 
community determines friendly behavior, the odor of any other community 
gives direct rise to attack. Now, this odor has several component ele- 
ments; one, for example, inherited (by the inheritance of a characteristic 
metabolism) from the queen, so that descendants of a common mother, or 
of sister-mothers (common grand-maternal inheritance), have an odor with 
something in common; another element and a strong one is, however, the 
nest odor compounded of all the individual odors in a community and gradu- 
ally taken on by each hatching young. If the young be removed from one 
community and be hatched in another they seem to take on the odor 
of the second community. And so the living booty brought back by the 
raiders, issuing in the new nest, becomes endowed with the odor of the new 
community and is unmolested. But the instinct of the hatched workers 
is to work; and so work they do. If their work is of advantage to the raider 
community, natural selection will do the rest. In the beginning there 
were no slave-makers; raiders there were which raided other nests, not for 
slaves, but for food. But bringing home extra supplies of this food, which 
hatched and lived and worked in the new nest, evolution from food to slaves 
and from raiders to slave-holders has naturally taken place. Now such 


Wasps, Bees, and Ants 561 


an extreme in this specialization has been reached as shown by Polyergus 
which is abjectly dependent on its slaves. It is no longer capable of digging, 
is unable to take enough food, unaided by its slaves, to keep it from starva- 
tion in a nest stored to repletion, nor can it care forits own young. Speciali- 
zation is leading Polyergus to its end! 


CHAPTER XVI 


INSECTS AND FLOWERS 


HE nectar of flowers is a favorite food with many insects; 
all the moths and butterflies, all the bees and many kinds 
of flies are nectar-drinkers. Flower-pollen, too, is food 
for other hosts of insects, as well as for many of those 
which take nectar. The hundreds of bee kinds are the 
most familiar and conspicuous of the pollen-eaters, but 

many littie beetles and some other obscure small insects feed largely on 
the rich pollen-grains. But the flowers do not provide nectar and pollen to 
these hosts of insect guests without demanding and receiving a payment 
which fully requites their apparent hospitality. And several particular 
things about this payment are of especial interest to us: these are, first, 
the unusual character of the payment received; second, the great value of 
it to the plants; and finally, the strange shifts and devices which the plants 
exhibit for making the payment certain. 

In the course of this book, so far chiefly devoted to a systematic con- 
sideration of various kinds of insects and their habits, several interesting 
ecological relations between plants and insects have been referred to. That 
plants furnish the nesting-grounds, or ‘‘homes,” of many insects has been 
shown: the wood-borers pass their long, immature life concealed and pro- 
tected in burrows in the bark or wood of trees and bushes; the delicate little 
leaf-mining caterpillars wind their devious tunnels safely in the soft tissues 
of even the thinnest of leaves; while in more specialized manner the extraor- 
dinary galls developed on the oaks and roses and other plants serve as safe 
houses for the soft-bodied Cynipid larve enclosed by them. The making 
of homes like these often, indeed usually, serves the double purpose of both 
housing and feeding the insect; as it gnaws or bites out its protecting bur- 
row in stem or leaf it is getting the very food it most prefers; as the plant 
swiftly builds up about the gall-making larva masses of succulent tender 
tissue, it is supplying in unstinted quantity the very food (plant-sap) which 
the larva has to have or starve. 

But the food relation may and mostly does exist between plant and insect 


without combination with the nest or home relation. To the countless hosts 
562 


——E—— 


Insects and Flowers 563 


of plant-feeding insects, the leaf-eating beetles and locusts and caterpillars, 
the sap-sucking bugs and plant-lice, the plant furnishes food alone; and 
in furnishing it, under a rough compulsion, is nearly always the loser, even, 
often enough, to death. The special relation between insects and plants 
to which this chapter is devoted is also a kind of food relation, but with the 
unusual character of being one in 
which the plant is not at all a loser DUTT RT PS, = 
but a gainer, and in as great measure = 

as the insect itself. Only plants with } G/N 
flowers and mostly only those with 
bright-colored, odorous, and _nectar- 
secreting flowers, have any part in 
this relation, which is, as the reader 
has already recognized, that interest- 
ing phenomenon, the cross-pollination 
of flowers by their insect visitors. 
As this interrelation of flowers and 
insects is one of very large importance 
in the life of many insect kinds, pro- 
found modifications of their structure 
and habits depending on it, and as 
popular knowledge of the subject is 
likely to be extremely general in its 
scope, I have thought it advisable to 
present a brief special account of this 
phenomenon. 

The agency of insects in effecting 
the cross-pollination of flowers has 
long been recognized. Credit is given to 
Sprengel for first publishing accounts 
of the interesting modifications of 
flowers due to their interrelation with 
insects, and for discovering that the 
insects were instrumental in pollinating 
the flowers. (Das entdeckte Geheim- 
niss der Natur im Bau und in der Fig!) 760\-2Snandeacon betog visited by 
Befruchtung der Blumen, von Chris- honey-bees. (From nature.) 
tian Konrad Sprengel, Berlin, 1793). 

But that this pollination by insects was (nearly) exclusively cross-pollination 
he did not apparently fully understand, or at least he did not fully under- 
stand the significance of cross-pollination. It was reserved for Darwin 
(On the Fertilization of Orchids by Insects, London, 1862), on a basis not 


564 Insects and Flowers 


merely of his acquaintance with the observations of Sprengel, Waechter, 
Delpino, Hooker, and others, but of characteristically keen and careful 
investigations of his own (particularly on orchids) to reveal the wide diffu- 
sion and great specialization of this interrelation, and to explain the causal 
factors in determining the marvelous phenomena attending its development. 
These causal factors are (1) the real advantage to the plant species of cross- 
fertilization, and (2) the action of natural selection in modifying both flowers 
and insects for the sake, or by reason of, this advantage. 

Fertilization among plants is like fertilization among animals; a germ- 
(sperm-) cell from one individual (male or hermaphrodite) fuses with a germ- 
(egg-) cell from another (female or hermaphrodite) individual or from the 
same (hermaphrodite) individual. The sperm-cells are contained in pollen 
produced in the anthers of stamens; the egg-cells lie in the ovaries at the 


Fic. 761.—Diagram of section of pistil and ovary of a flower, showing the descent of 
the pollen-tube and its entrance into the ovule. .g., pollen-grain; .t., pollen- 
tube; e.s., embryo-sac; e.c., egg-cell; s.2., sperm-nucleus. Left-hand figure (1) 
shows the pollen-tube grown down around and up into the ovary with the sperm- 
nucleus just entering the ovule; right-hand figure (2) shows the fusion of the 
sperm-nucleus and egg-nucleus. (After Stevens.) 


base of the pistils, these pistils having an exposed pollen-catching surface 
(stigma) at their free tip. Before actual fertilization can occur pollination 
must take place; pollination being the bringing and applying of ripe pollen- 
grains to the ripe surface of the stigma. How fertilization then takes place 
is succinctly explained by Fig. 761 and its caption, which is copied from 
Stevens (Introduction to Botany, Boston, 1902). 

Cross-pollination is simply the bringing of pollen from one plant indi- 
vidual to the stigmas of another individual of the same species.  Self-pol- 


Insects and Flowers 565 


lination is the getting of pollen from the stamens of one flower onto the 
stigma of the same flower. The advantage of cross-pollination, as first experi- 
mentally proved by Darwin, and since then confirmed by other experimenters 
and, without scientific intention but none the less effectively, by hosts of 
economic plant-breeders (horticulturists, florists, etc.), lies in the fact that 
the seeds produced when the ovules of one plant are fertilized by the sperm- 
celis (in the pollen) of another develop plant individuals of markedly stronger 
growth (shown in size of plant and its fruits, in number of seeds, etc.) than 
seeds produced by the fertilization of ovules by sperm-cells of the same plant. 
To effect this advantageous cross-pollination two lines of specialization or 
modification of floral structures have arisen (presumably through the action 
of natural selection): (1) modifications such as to attract insects and insure 
cross-pollination as the result of their visits (and to much less extent to attract 
other anima!s, particularly humming-birds), and (2) modifications tending 
to prevent self-pollination. Coupled with both these general lines of modi- 
fication are others to effect certain auxiliary or accessory conditions the 
necessity for which grows out of the larger needs; such are, for example, 
modifications to prevent the stealing of nectar and pollen by other animals 
(insects particularly) than those on which cross-pollination specially depends, 
and to make possible self-pollination in cases where cross-pollination, 
although probable, may for some accidental or other rare cause not take 
place. Coincidently, and reciprocally with the development of modifications 
of the flower structures, has occurred the specialization of certain structures 
and habits among those insects which are the cross-pollinating agents. 
These modifications occur chiefly in the structure of the mouth-parts and 
legs of bees, wasps, flies, and a few other insects and in their food and 
flight habits, and the care of their young. The reciprocal modifications 
of flowers and insects have gone so far in some cases that certain species of 
plants and certain species of insects cannot now live except by virtue of 
their inter-relation. Many flowers are not fertile when pollinated by their 
own pollen, and yet have no other possible means of getting pollen from 
other plants except that of insect visits. 

The principal means which have been developed to avoid self-fertiliza- 
tion are the following: (a) the having each flower unisexual instead of bi- 
sexual, that is, producing either pollen (staminate) or ovules (pistillate) but 
not both; these unisexual flowers may occur on the same plant individual 
(moncecious) or on separate individuals (dicecious); (b) the having both 
pistils and stamens on each flower, but with the anthers and the stigma not 
maturing coincidently (dichogamous), either the anthers breaking open 
and discharging the pollen before the stigmas are ready to receive it (pro- 
terandrous) or the stigmas maturing before the pollen ripens and is dis- 
charged (proterogynous); (¢c) the having the stamens and pistils (in the 


566 Insects and Flowers 


same flower) different in length so that the pollen would be unlikely to fall 
on the stigmas, or (d) the having the stamens and pistils so situate with 
regard to each other that it is difficult or very unusual for the pollen to reach 
a stigma. All these devices are familiar to every student of botany, and 
to gardeners, florists, and flower-lovers generally, and examples of them all 
can readily be found among our common garden and field plants. Any 
simple manual of botany will put one in the way of hunting them out for 
one’s self. 

To recur now to the first of the two principal lines of specialization 
referred to as those which have arisen in connection with the advantage 
of cross-pollination, namely, the modification of the floral structures, we 
shall find these modifications to consist of (a) the secretion of nectar to 
attract the insects, (0) the development of odor, color, pattern, and shape 
to guide them to the flower and when there to the nectar and pollen in such 
a way as to insure their brushing against both, or either, pollen and stigma, 
(c) the modification of shape so as to prevent the stealing of nectar and 
pollen by non-helpful insects, and (d) the blossoming at those times in 
the year (seasonal flowering) when the particularly helpful insects are most 
numerous, and the opening of the flowers at such times, in daylight, twilight, 
or at night, as specifically accords with the food-seeking flights of these 
insects. The manifold variety of these modifications will be indicated and 
illustrated by accounts of a few specific cases exemplifying certain more 
or less distinct kinds of modification and reciprocal relation with insects, 
but a few general statements may first be made. 

The pollen collected for food by the bees and a few other insects is, of 
course, a normal product of the flower, and it is only necessary that there 
be enough of it to supply the insects and yet suffice for the plant’s own uses, 
ie., in fertilization. As the oldest, the most primitive, means developed 
among plants to effect cross-pollination, a means still used by all the conifers, 
the grasses, and many other plants mostly characterized by the total absence 
of colored floral envelopes (petals and sepals), is the production of vast quan- 
tities of light, non-adherent, pollen grains to be distributed by the wind, 
the more specialized entomophilous flowers (those depending on insects 
to carry their pollen) probably started with enough and more of pollen to 
supply their own needs as well as the demands of their visitors. 

The nectar, however, is a special product, developed in direct connection 
with the insect pollinating specialization. It is a “‘more or less watery solu- 
tion of sugar and of certain salts and aromatic substances secreted by a 
special tissue known as the nectary and expelled at the surface through the 
epidermis by breaking down of the tissues, or through a special opening 
of the nature of a stoma. The nectar either remains clinging to the surface 
of the nectary or it gathers in large drops and falls into a nectar receptacle 


Insects and Flowers 567 


provided for it, as in the case of violets, where horn-like outgrowths from 
the two lower stamens secrete the nectar and pour it into a cup formed by 
the base of the lower petal. 

“The nectaries may occur on any part of the flower, but they are most 
frequently found at the bases of the stamens, petals, and ovaries, and rarely 
on the calyx. In the plum and peach they form a thick inner lining of 
the cup-shaped receptacle. In nasturtiums the nectar is secreted in a long 
spur from the calyx. 

“‘Some flowers of simple construction expose their nectar freely to all 
sorts of insects, but others conceal it in various ways so that it is accessible 
only to insects of certain kinds. A frequent device is to have some parts 
of the corolla close over the way to the nectar so that small insects which 
would not assist in cross-pollination are excluded, and only those which 
are strong enough to push aside the barrier or have proboscides of proper 
construction to thrust past it can obtain the nectar and accomplish the trans- 
ference of the pollen.” 

With nectar and pollen ready for the insect the plant has yet to advertise 
its sweets, and for that brilliant colors and attractive odors are relied on. 
An attractive odor for insects is not always pleasing to us: certain Aracee, 
some Trilliums, and others have a carrion-like odor, combined with ‘dull 
colors often marked with livid blotches or veins like dead animal bodies, and 
these flowers attract flesh-flies and carrion-beetles which are the pollinating 
agents.” It appears from various experiments that odor is the chief factor 
in attracting insects from a considerable distance, and that with the nearer 
approach of the insect color becomes an important guide. Despite the 
poor sight (formation of incomplete images, and this possible only within 
certain limited focal distances) of insects they appear to distinguish colors 
at distances where the forms of objects must be very indistinct to them. 
Once attracted to the flower by odor or color, or by both, the pattern and 
fine color streaks and spots play their part in guiding them to the nectaries. 
(See discussion on p. 580 of the sight and color recognition of insects.) The 
shape of the flower now has also its influence; this it is which compels the 
visitor, in order to get at the nectar, to ea against the pollen, or the stigma, 
or both as the case demands, and thus to render fairly its payment for the 
special food provided. The particular shape and make-up, too, often have 
reference to the necessity of keeping away illegitimate visitors, who would 
drain the secreted stores without recompense. Small creeping insects, as 
ants (very fond of nectar), thrips, and others may be shut out of the nectaries 
by fine, stiff little hairs densely set in the throat of the flower-cup, like those 
on the stamens of spiderwort or at the bases of the stamens of Cobwa scan- 
dens, or may be denied access even to the flower itself by sticky giandular 
hairs on the stem and leaves. I once counted nearly a hundred dead or 


568 Insects and Flowers 


hopelessly entangled small insects on the tall sticky stem of a single Salpo- 
glossus plant. But sometimes the burglars are successful. Needham, in a 
careful study of the insect visitors on the blue flag (ris versicolor) near Lake 
Forest, Ill., found a dozen or more successful pollen and nectar thieves 
among them, while several other would-be thieves were deceived by the 
curious markings of the flower as to the proper entrance and so failed to 


Fic. 762.—Blue flag, Jris sp., being robbed of nectar by skipper-butterfly; at left diagram 
showing position of butterfly’s proboscis (represented by the arrow) with reference 
to openings of the nectaries. (After Needham; natural size.) 


make entry and get to the stores. The most persistent nectar thieves were 
several species of Pamphilas (skipper-butterflies) which stood outside the 
flower and inserted the proboscis obliquely between the sepal and the base 
of the style, plying and thrusting with it until one of the two holes leading 
to the nectary is found (Fig. 762). The actual pollinating visitors were 
chiefly small Andrenid bees. 

It will also be well to note, before taking up the special examples to be 
described, the general character of the modifications which have arisen 
among the regular visitors whose advantage in the way of getting food sup- 
plies of nectar and pollen has been sufficient to impose, on some of them 
at least, very considerable adaptive structural changes. The great majority 
of nectar-drinking insects are bees, moths, and butterflies and two-winged 
flies (of these especially the Syrphide). The pollen collectors are mostly 


Insects and Flowers 569 


bees, who use pollen not only directly themselves, but carry it in quantities 
to their nests as food for their young, and in the case of honey-bees for the 
other workers busy indoors. To show the affinities and the number of 
species of the insect visitors to entomophilous flowers I have compiled the 
following figures from Robertson’s records of his observations on flowers 
in the neighborhood of Carlinville, Ill. In twenty-six observing days 275 
insect species visited the flowers of Pastinaca sativa, of which 1 was a Neurop- 
teron, 6 were Hemiptera, 9 were moths and butterflies, 14 were beetles, 72 
were Diptera, and the rest Hymenoptera, of which 21 were bees, 39 saw- 
flies and parasitica, and the remainder wasps, solitary and social. Of 115 
species visiting the milkweed Asclepias verticillata, 52 were Hymenoptera, 
42 Diptera, 16 Lepidoptera, and 3 Coleoptera; of 52 species visiting Rham- 
nus lanceolata, 23 were various solitary bees; of 87 species found at the 
flowers of the willow Salix cordata in seven days, 43 were Hymenoptera, 39 
Diptera, 4 Coleoptera, and 1 Hemipteron; 112 species of insects visited Ceano- 
thus americanus in five days; 79 species visited sweet-clover in two days; 
71 species visited the little spring beauty, Claytonia Virginica, in twenty-six 
days, while 18 species visited the yellow violet in seven days. The hive- 
bee and the bumblebees are the pre-eminent cross-pollinating insect agents, 
some flowers, as clover for example, having its pollen distributed by bumble- 
bees alone (although Robertson found 13 different species of butterflies rob- 
bing nectar from red clover). The willow Salix humilis, watched for eleven 
days, had its staminate flowers wholly monopolized by honey-bees, although 
5i kinds of nectar-feeding insects visited its pistillate flowers. Of the 488 
species of American entomophilous flowers which have been studied by 
Robertson I find by going through his records that the honey-bee visits nearly 
all, while bumblebees are recorded from a large number. 

The adaptations for pollen-gathering are mostly limited to bees and 
consist of (a) the development of hairs, simple and branched or feathery, 
specially situated to brush up and hold the pollen grains as the bee clambers 
over the stamens, and (5) in the honey-bees and bumblebees the develop- 
ment of the well-known pollen-basket, or corbiculum (see description and 
figure on p. 528). The adaptations for nectar-drinking consist in the elon- 
gation and tube-forming modification of the mouth-parts of bees, flies, and 
moths and butterflies. While in the less specialized bees the mouth-parts 
are short, with the labium in the condition of a short broad flap-like lip 
(Fig. 716), in the specialized nectar-drinkers, as the bumbles, the hive-bee, 
and the other so-called long-tongued forms, the maxilla and labium are 
long and slender and the various parts can be so held together as to form a 
very effective lapping and sucking proboscis (Fig. 717). Similar conditions 
exist among the two-winged flies (Diptera); the proboscis of a flower-fly 
(Syrphid) or bee-fly (Bombiliid), for example, is a long, slender, sucking beak 


570 Insects and Flowers 


very different from the broad-ended labellum of a house-fly, But it is in 
the Lepidoptera that this specialization of the mouth structure in connection 
with the nectar-feeding habit reaches its widest application and the extreme 
of its specialization. Almost no other food than nectar is taken by the whole 
great host of moths and butterflies (Lepidoptera), and throughout the order 
the mouth-parts are greatly modified, so as to form a perfect flexible, often 
very long, slender sucking proboscis (Fig. 510). (Some moths and butter- 
flies, however, take no food at all in the imago (winged) stage and these 
mostly have only rudimentary mouth-parts.) This proboscis is composed 
of the two greatly elongated maxille with their grooved inner faces so opposed 
and locked together as to form a closed perfect tube open at its two ends, the 
tip of the proboscis and its base, the mouth (see p. 361). By means of an ex- 
pansion of the pharynx, to whose upper wall muscles running to the dorsal 
wall of the head are attached, an effective pumping arrangement is obtained, so 
that when the proboscis is thrust down a flower-cup into the nectary a stream 
of nectar may be drawn up into the throat. The proboscis of some moths 
is very long so as to enable them to drink from the deepest tubular corollas; 
for example that in our larger sphinx-moths, like the common tomato-worm 
moth (five-spotted sphinx), is 6 inches long (Fig. 509); in Brazil there lives a 
sphinx-moth, Macroxilia cluentius, with proboscis 8 inches long. An orchid 
grows in Madagascar with nectary 12 inches long, with almost an inch of 
nectar in the bottom, but the sphinx-moth, which almost certainly exists, 
with a proboscis long enough to reach this sweet store has not yet been found. 

The following few examples, showing varying degrees of specialization, 
illustrate specifically many of the already generally described adaptations 
due to the reciprocal relation between flowers and insects. 

The simpler entomophilous flowers, such as those of the apple, cherry, wild 
rose, ranunculus, etc., brightly colored and fragrant, are mostly wide open and 
accessible to a large variety of insect visitors. They are all abundant pollen 
providers and some secrete nectar which is easily got at. But to get either 
nectar or pollen the insects have to scramble over and among the many 
crowded stamens of the center, dusting themselves well during the process 
with pollen, which is carried on to the next flower visited and there probably 
rubbed off on to the stigma. In such simple forms the stigma of the first 
flower visited is likely to be fertilized with its own pollen by the scrambling 
visitors, if both anthers and stigma are coincidently mature (which in many 
of these flowers is not the case). But even then if the stigma is also pollinated 
by foreign pollen grains, it seems to be more strongly affected by them than 
by its own pollen. Experiments have demonstrated the superior potency 
of the foreign pollen in actually effecting fertilization. 

Open flowers of more specialization in general botanical relations, 
although of little more as concerns the particular one under discussion, are 


Insects and Flowers 571 


the Umbellifere and the numerous Compositz. In the umbels and flower- 
heads, often rather inconspicuous but nearly always well provided with 
nectar, the sweet drink is easily got at even by short-tongued insects, so 
that some of the species have a surprising host of visitors. For example, 
Robertson found 275 different insect species visiting Pastinaca sativa (an 
umbellifer with exposed nectar) in the neighborhood of Carlinville, Ill., 
238 visiting Cicuta maculata, and 191 visiting Sium cicutefolium; observing 
some of the composites, more specialized, Robertson noted 146 insect species 
at goldenrod (Solidago canadensis) in eleven days during August, September, 
and October, and too at Aster paniculatus in four days in October. 

Of course not all the insect visitors to a flower are cross-pollinating agents; 
some are deliberate thieves, some may or may not help in cross-pollination, 
and some are reliable, although, of course, unwitting, pollinators. As an 
interesting test of the proportion of actual pollinators to the whole number 
of insect visitors may be taken Robertson’s observations on the milkweed 
(Asclepias) and its visitors (see account of the conditions in Asclepias on 
p- 573). Of 115 insect species which visited flowers of Asclepias verticillata 
(Carlinville, Ill.) in fifteen days, representatives of 58 of these actually got 
pollinia (pollen-masses) attached to themselves; while of 80 species visit- 
ing A. incarnata in twenty-four days, 63 carried off pollinia. I do not know 
of any other records which show the proportion of actual pollination to 
total number of visitors, but it is highly desirable that such observations 
be made for other flowers. Asclepias obviously offers a particularly favor- 
able opportunity for such tests (on account of the conspicuousness of the 
pollinia), but an ingenious observer will be able to study the matter success- 
fully with other plants. 

With the flowers of tubular corolla the pollinating insects are of course 
neither so many nor do they represent such varied insect groups. The 
long-tongued bees and flies can get nectar from a flower-cup not too deep, 
but in the deeper cups the moths and butterflies are the only insects which 
- can reach the nectar. The common jimson-weed, Datura stramonium, is, as 
Stevens says, an excellent illustration of this. ‘‘The corolla is about five centi- 
meters long, and the cavity of the tube is nearly closed at about the middle 
of its length by the insertion of the filaments there. When the flower opens 
in the evening it emits a strong musky odor, and a large drop of nectar is 
already present in the bottom of the tube; so that large sphinx-moths, leav- 
ing the places of seclusion occupied by them during the day, are attracted 
by the strong odor and white color of the flowers. 

“Flying swiftly from flower to flower, the moth thrusts its long proboscis 
to the bottom of the tube and secures the nectar; and while it is tarrying 
briefly at each flower, keeping itself poised by the swift vibration of its wings, 
it is pretty certain to touch with its proboscis both anthers and stigmas, 


572 Insects and Flowers 


which stand close together at about the same height near the mouth of the 
corolla. Both cross- and self-pollination might be brought about in this 
way, but, as Darwin has shown, the foreign pollen would probably possess 


Fic. 763.—Hawk-moth posed before a jimson-weed, Datura stramonium. (After 
Stevens; one-half natural size.) 
the greater potency, and cross-fertilization would be apt to result. Fig. 763 
is a photograph of a sphinx moth and Datura-flower, posed to show the rela- 
tive lengths of the moth’s proboscis and the corolla tube.” 

Another kind of specialization in flower structure which tends to pre- 
serve the nectar for certain spe- 
cific insect visitors is well illus- 
trated by the salvias, the snap- 
dragon, and other similarly 
irregularly tubular flowers (La- 
biate, Leguminose, Scrophu- 
lariacee, etc.). Probably all 
such flowers are pollinated by 
insects (a few species by hum- 
ming-birds). The irregularity 
in corolla is accompanied by a 
specific disposition of the stamens 
and pistil, so that the insect 
Fic. 764.—Salvia-flower. A, showing position yjsitors are compelled to visit 

of pistil and stamens; B, anthers of stamens 5 ‘ 

in normal position; C, anthers of stamens the nectary In one particular 
tipped down; D, bee entering flower; E, flower, manner, a manner devised to 
a condition. (After Lubbock; natural insure their touching, or being 

touched by, the anthers or stigma 
or both. In the snapdragon (Fig. 760) the opening of the flower-cup is 
normally closed, but when a bee alights on the broad keel or platform (com- 
posed of two petals grown together) its weight so depresses this platform as 
to open the way into the flower-cup, which closes at once when the bee goes 
in and drinks the nectar. Scrambling and twisting about in the narrow 
chamber it thus thoroughly dusts itself with pollen, or thoroughly dusts the 


Insects and Flowers 573 


stigma with pollen acquired from a previous visit to another flower. 
Miscellaneous small insects alighting on the keel are not heavy enough 
to depress it, and thus are prevented from entering and stealing the nectar. 
In the salvias (sages) the corolla is similarly tubular below and_ two- 
lipped above, the lower lip serving as an alighting-platform for the 
insect visitors (usually bees), while the arched upper lip covers and pro- 
tects the stamens and pistil. In Salvia officinalis (Fig. 764) the stamens 
do not come immediately into contact with the bee as it enters, but they have 
to be moved in a particular manner, which is accomplished as follows: “Two 
of the stamens are minute and rudimentary. In the other pair the two 
anther-cells, instead of being, as usual, close together, are separated by a long 
connective. Moreover, the lower anther-cells contain very little pollen; 
sometimes, indeed, none at all. This portion of the stamen, as shown in 
Fig. 764, hangs down and partially stops up the mouth of the corolla-tube. 
When, however, a bee thrusts its head into the tube in search of the honey, 
this part of the stamen is pushed into the arch, the connectives of the two 
large stamens revolve on their axis, and consequently the fertile anther-cells 
are brought down onto the back of the bee.’ 

In the scarlet sage (Salvia sp.) cross-pollination is accomplished by 
humming-birds, which, hovering in front of the narrow mouth of the 
flower-cup, thrust deeply into it their long bills in the search for small insects 
which may have entered for nectar. Other flowers regularly visited and 
cross-pollinated by humming-birds are the scarlet currant, various painted 
cups (Castilleias), the scarlet mimulus, the wild columbine, the trumpet-creeper, 
the spotted touch-me-not, the cardinal-flowers, cannas, and fuchsias. Red 
seems to be the attractive color for humming-birds. As the only humming- 
bird species east of the Rocky Mountains is the ruby-throat (Trochilus ruber), 
this one species is to be credited with being the chief pollinating agent of a 
considerable number of flowers; in California and the southwest there are 
several species to do the work. 

Another marked and easily seen variant in this specialization of flowers 
to insure cross-pollination by insects is that shown by the milkweeds of the 
genus Asclepias. Stevens has described this so well (Introduction to Botany, 
p- 191 et seq.) that I simply quote here most of his account. ‘ Asclepias- 
cornuti, common everywhere in this country, is perhaps the best species for 
demonstrating this [peculiar specialization of the milkweeds]. As shown in 
Fig. 765, the sepals and petals are reflexed; the stamens are joined throughout 
their length, and are united to a thick and flat structure at their apices, 
known as the stigmatic disk, which is also united with the top of the two 
pistils. The pistils are entirely enclosed by the stamens and the stigmatic disk. 
Five spreading, hollow receptacles for the nectar grow out and upward from 
the bases of the stamens. 


574 Insects and Flowers 


“Each pollen-sac contains a compact mass of pollen-grains which never 
become separated from one another, and so constitute what is termed a 
pollintum. The two contiguous pollinia of adja- 
cent anthers are united by horny rods which con- 
verge upward and join with a horny dark body 
known as the corpusculum, which is hollow and 
has a slit along its outer face. This slit is rel- 
atively broad at the bottom, and tapers toward 
the top, thus forming a clip in which the feet of 
the insects get caught. Between each pair of 
anthers there is a deep recess closed by two vertical 
lips which stand wider open at the bottom than 
at the top, and the recess also narrows at the top. 
The opening between the lips at the top stands 
exactly beneath the slit in the corpusculum. 

“The surface of the flower is slippery, so that 
eee a when a bee, for instance, visits it, a good foothold 
legs still fastinastigmatic is not obtained until the bee slips its foot into the 
Senay Canes omens recess between the anthers, termed the stigmatic 
natural size.) * chamber. Having obtained a foothold, the bee 
thrusts its sucking-apparatus into the hollow nectar- 
receptacle and obtains the nectar which has invited it to the flower. When the ¥ 
bee, however, seeks to go to another flower, its foot slips upward and becomes 
caught in the slit in the corpusculum. A struggle 
now ensues which usually results in the bee pull- 
ing the two pollen-masses, united to the corpus- 
culum, through the narrow slits at the tops of the 
pollen-sacs; and thus laden, it seeks another flower, 
and there slips its foot, together with the pollen- 
masses, into the stigmatic chamber. 

“Now when the bee attempts to leave the flower, 
the pollen-masses become tightly wedged at the 
narrow apex of the chamber, and a hard pull is re- 
quired to break them loose from the foot. Finally, 
as the foot is being drawn from the stigmatic 
chamber it catches into the corpusculum directly Fic. 766.—Cabbage-butter- i 
above and pulls out a second pair of pollen- fly caught by legs in 
masses. Thus the bee goes from flower to flower corpuscula of two Ascle- 

; : pias-flowers. (After 
and from plant to plant, repeatedly pulling pollen- Stevens; natural size.) 
masses from their sacs and depositing them in 
the stigmatic chamber. Fig. 765 is from a photograph of a honey-bee 
gathering nectar from Asclepias-flowers. One of the hind legs is still 


Insects and Flowers 575 


held in the stigmatic chamber of the flower, which the bee has just 
deserted.” 

Hive-bees, although common visitors to Asclepias, are really hardly 
strong enough to insure pulling loose from the flowers, and many of them, 
besides numerous flies and small butterflies, get caught and die on the flower- 
heads. Robertson has noted nine species of insects thus killed by A. cor- 
nuti. Bumblebees and large wasps and large butterflies are the most cer- 
tain milkweed pollinators. 

Still another markedly different kind of specialization to effect cross- 
pollination by insects is that shown by many Araceze and Aristolochiacez. 
The flower (Fig. 767) in these plants consists of a long tubular perianth 
(spathe) with a constriction near the base, the 
narrow opening into the cavity below being 
nearly closed by stiff downward-pointing hairs, 
so as to make a sort of floral eel-trap. It really 
is an insect-trap: small flies crawl down the 
long tube and through the narrow opening in 
search of nectar; but when ready to return find 
themselves imprisoned by the downward-point- 
ing hairs. After a while the stigmas which 
mature before the anthers and have likely 
been pollinated (with pollen brought from 
other flowers) by the entering insects, wither, 
a drop of nectar is secreted for the benefit of 
the captured insects, and the anthers mature, 
exposing their ripe pollen-grains. The hairs 
in the throat of the flower gradually shrivel up Fic. 767.—Flower of Aristolo- 

> : chia clematitis in longitudinal 
and release the insects, which are now well — ccction: A, Ieeltors Gaadllione 
showered with pollen falling on them from the __ tion by little fly; B, after fer- 
anthers above. Visiting another Arum-flower, ae eve me ae 
they hardly fail to rub off some of this pollen wb, without bristly hairs. 
on the mature stigmas. Sometimes more than (After H. Miller.) 
a hundred small flies will be found imprisoned in a single Arum. 

Classic examples of apparently the wildest vagaries in flower structure 
are those presented by the orchids. But Darwin’s fine work revealed the 
method in all this floral madness. Orchids are pollinated almost exclu- 
sively by insects, and the extravagant shapes and color-patterns are all means 
for accomplishing cross-pollination. Any one interested at all in the inter- 
relation between flowers and insects should read Darwin’s account of the 
orchids and their insect visitors, in his book ‘“‘On the Fertilization of Orchids 
by Insects.” As this book is generally accessible, I will here only call atten- 
tion to one new and peculiar feature generally characteristic of the speciali- 


576 Insects and Flowers 


zation in orchids, namely, the development of sensitive parts in the flower, 
so that with a proper stimulus certain purposeful motions or movements 
are performed by certain of the floral parts. Most of the orchids offer their 
pollen in masses, pollinia, which adhere to the insect and are carried around 
by it during its visits to other flowers. The stalks of these pollinia bend 
(by contracting) after they are attached to the insect so as to bring the pollen- 
masses into the most effective position for insuring contact with the stigmatic 
surfaces of the flowers visited. In the remarkable orchid Catasetum, a 
certain part of the flower is endowed with such sensitiveness and is nor- 
mally restrained in such a tense position that when it is touched by an insect 
(or any foreign body) it springs in such a way as to throw the pollinia at 
and against the intruder. Darwin once irritated one of these flowers in 
the presence of Lubbock, who was amazed to see the pollinium thrown 
“nearly three feet, when it struck and adhered to the pane of a window.” 

Some other flowers, not orchids, also possess sensitive parts; familiar 
examples are various species of Berberis, whose stamens ‘‘when touched 
near the base, as happens when a bee is probing for honey, will spring vio- 
lently inward, shaking off the pollen and scattering it upon the insect visit- 
ors.” Kalmia presents a somewhat similar case ‘‘where the stamens are 
bent over into little pockets, from which they spring out when touched, 
throwing the pollen to some distance.” 

In the examples thus far chosen the flower has been the more conspicu- 
ous beneficiary in the partnership, and has shown the chief adaptations. 
The advantage to the insect visitor is almost exclusively a food advantage, and 
its adaptation has been usually simply one of the structure of its mouth-parts. 
But there is known at least one case in which the insect pollinator does much 
more for itself by its flower visits than find food for immediate use, and in 
which an amazing adaptation of habit has arisen on its part. On the other 
hand the plants concerned depend solely on the one insect kind for pollination. 
This is the famous case of the cross-pollination of Yuccas by the small moths 
of the genus Pronuba. There are several species of Yuccas (Spanish bayo- 
nets) in this country, and several Pronubas, but a brief account (taken largely 
from Stevens’s Introduction to Botany) of the relations between the com- 
mon Yucca grown in gardens (Y. jilamentosa) and the moth species, Pronuba 
yuccasella, will be typical of the interrelations of all. 

The Yucca has a lily-like flower composed of three sepals and three 
petals, all creamy white, six stamens with fleshy outward-curving filaments 
surrounded by small anthers, and a pistil extending much above the tops 
of the stamens with three carpels imperfectly united at the top, and thus 
leaving a tube entirely open at the apex. ‘‘The inner surface of this tube 
is stigmatic. This stigmatic tube does not open directly into the cavities 
of the ovary, but sends off three very narrow branches, each of which com- 


Insects and Flowers 577 


municates with the cavity of a carpel. Accordingly, when pollen is once 
deposited on the inner surface of the main stigmatic tube, the pollen-tubes 
find easy access to the ovules in each of the three carpels. The pollen is 
sticky and hangs together in masses, so that it is not adapted to being carried 
by the wind, and it is apparently impossible for it to get to the stigmatic 
tube without some outside agent. 

‘A small amount of nectar is secreted, but it is excreted at the very base 
of the pistil, so that insects seeking it would be far removed from the stigmas. 
Indeed, the low position of the nectar would seem rather to lead insects away 
from the stigmas. The flowers are borne in compound racemes high aloft 
on a strong woody shaft, and, because of their rather strong odor when new 
buds are opening in the evening and their white color, they are quite cer- 
tain to make their presence known to insects flying in the twilight. 

“Tf we take these facts as our clew and attentively watch these flowers 
about eight o’clock in the evening, the method of cross-pollination will be 
made clear. A white moth, known as the 
Pronuba-moth, is seen to mount a stamen, 
scrape together the sticky pollen, and 
pack it against the under side of its head 
by means of a spinous structure known 
as the maxillary tentacle, which seems 
to have been specially developed for this 
purpose, for in other moths it is a mere 
vestige. In gathering the pollen it hooks 
its tongue over the end of the stamen, 
evidently to secure a better hold. Having 
become well loaded with pollen, as shown 
in the photomicrograph of the moth’s 
head, it descends the stamen and flies  Fyc. 768—Pronuba-moth depositing 
to another flower. There it places itself eggs in ovary of Yucca. (After 
on the pistil between two of the stamens Stevens; nabiral size.) 

(see Fig. 768) and thrusts a slender ovipositor through the wall of the ovary 
and into the cavity occupied by the ovules. 

“Having deposited an egg, it ascends the pistil, and by means of the 
maxillary tentacles and tongue, which at other times are coiled around the 
load of pollen, it rubs pollen down the inner surface of the stigmatic tube. 
Fig. 769 isa[drawing made from a] flashlight photograph of a moth performing 
this act. The moth then descends the pistil, and standing between another 
pair of stamens it deposits another egg within the ovary; then it ascends 
the pistil and rubs pollen on the stigmatic surface as before. This process is 
repeated untilit may be that each of the six lines of ovules is provided with an 
egg, and the process of pollination has been as many times accomplished. 


578 Insects and Flowers 


“The full meaning of this wonderful series of operations will not be 
understood until subsequent developments have been followed. Since the 
process of pollination has been so thoroughly done, most of the numerous 
ovules become fertilized and the seeds 
begin their development. In the mean time 
the moth eggs hatch into larva, which find 
their food in the developing seeds. But the 
seeds are so numerous that the larva reach 
their growth, gnaw a hole in the seed-pod 
and escape, while many uninjured seeds 
still remain in the pod. ‘The larva spins 
a thread by which it descends to the 
ground, and, burrowing beneath the sur- 
face, it passes the winter in its pupal 
state, emerging as a fully developed moth 
at the time of the flowering of the Yucca 
the following summer. 

“Tt appears that the mature moth takes 
Fic. 769.—Pronuba-moth rubbing no food, unless it secures some of the 

pollen down the stigmatic tube of % : > 
Yucca. (After flashlight photo- nectar of the Yucca blossoms in which it 
graph by Stevens; natural size.) —_ js wont to pass the day, with its head close 
to the bottom of the flower where the nectar 
is excreted. It does not eat the pollen which it gathers, and it seems certain 
that it is prompted to place the pollen in the stigmatic tube after each act 
of oviposition solely by the instinct to provide for its young; for it is readily 
understood that if the ovules are not fertilized the seeds would not develop 
and the larvee would be without food. 

“The Yucca flower, instead of having elaborate devices to secure cross- 
pollination, simply prohibits self-pollination by its tubular stigmas and its 
relatively short and reflexed stamens; and then, the sticky pollen and 
an abundance of ovules being provided, the performance of pollination 
is intrusted to the wise instinct of the Pronuba-moth; and not pollina- 
tion simply, but cross-pollination, for it has been noticed that it is the habit 
of the moth after securing the pollen to fly to another flower before it begins 
to lay its eggs.” (This extraordinary interrelation between Yucca and — 
Pronuba was discovered and carefully studied by C. V. Riley in 1872, and 
his intensely interesting detailed accounts of his observations are to be found 
in Vol. 3 Trans. St. Louis Acad. Sci., his 5th and 6th reports as state ento- 
mologist of Missouri, and in the 3d Ann. Rept. of the Missouri Botanical 
Garden). 

The above various and interesting examples of the interrelations between 
flowers and insects are not exceptional cases; indeed this state of affairs 


Insects and Flowers 579 


with its accompanying mutual adaptation is the rule throughout the families 
of flowering plants, the Spermatophyta. The absence of it is the exception; 
cross-pollination is far more abundant than self-pollination. And the 
devices by which it is brought about are in their details almost as many 
and as various as are the different shapes and color-patterns of flowers. 
The student who may be interested to learn what flowers have been studied 
to discover the kinds of insect visitors and the character of the modifications 
that have arisen for the sake of cross-pollination should refer to the many 
papers (published in the Botanical Gazette, Trans. St. Louis Acad. Sci., 
and elsewhere) of Robertson, who between 1886 and 1895 studied 488 species 
of American insect-pollinated flowers; to Lubbock’s ‘British Wild Flowers 
in Relation to Insects,” in which similar studies on English flowers are 
recorded; to H. Miiller’s ‘‘Fertilization of Flowers,’ a bulky volume of 
observations on European insect-pollinated flowers together with much more 
general discussion, and a detailed consideration of the structure of the 
most important insect pollinators; to the same author’s ‘‘Alpenblumen,”’ 
an account of the relation between insects and the flowers of the Alps; and 
to Darwin’s book, already mentioned, on the fertilization of orchids by insects. 

It is plain that this fact of the adaptation of flower structure and pat- 
tern for the sake of cross-pollination by insects explains a great deal of the 
manifold variety of form and color-marking which exists among flowers. 
The adaptation of the flower to its insect visitors goes even farther: to a cer- 
tain extent the flowering season of many plants is determined by the time 
of the appearance in winged stage of its more important insect visitors. 
Robertson sums up his interesting observations concerning this fact (based 
on the study of nearly 500 plant species and their insect visitors) as follows: 
“We have reviewed the principal groups of insect-pollinated plants and 
have noted a correspondence more or less well marked between their bloom- 
ing seasons and the seasons of the insects upon which they depend.” But 
it is only fair to presume that the insects, at least those which get a large 
amount of food from the flowers, may have become adapted as to their flight- 
time in some degree to the blossom-time of their host-flower. That this is 
true of the bees, which get practically all of their food (pollen and nectar), 
both for themselves and for their young, from flowers, seems certain. 

But the easy and sweeping way in which this theory has been made to 
explain the immense variety and often intricate condition of floral struc- 
ture and pattern has, naturally and wisely, led to a more rigid scrutiny 
of its all-sufficiency for the explanation of floral variety. It is apparent of 
course that flowers in their fundamental structural character are controlled 
largely by heredity, and this heredity is largely an expression of phylogeny, 
that is, ancestral history. Flowers of close natural relationship are bound 
to be more alike than those widely separated genealogically. But beyond 


580 Insects and Flowers 


this there really seems to be no other explanation of flower shape and appear- 
ance having the same validity as that of adaptation to insect visitors. 

The most effective criticism of this explanation is one against its effective- 
ness in explaining color, and particularly color-pattern. It is based on the 
general consensus of belief among zoologists and entomologists concerning 
the poorness of insect vision. The general character of this vision, with an 
account of the eye structure, is explained on pp. 30-33 of this book. The 
fixed short focal distance, the incompleteness and lack of detail incident to a 
mosaic image, and the lack of accommodation (only partly provided for by 
the shifting of the peripheral pigment) to varying light intensity, which are 
admitted conditions of insect vision, make it seem difficult to account for the 
intricacy in pattern common to many flowers on a basis of adaptation to 
animal visitors of such poor seeing capacity as insects. 

Experimental evidence touching this criticism is singularly meager when 
one considers the importance of the subject. If insects can accurately dis- 
tinguish colors, and at some distance, and can perceive fine and intricate 
details of color-pattern at very short distance, then the explanation of floral 
structure and pattern or adaptation to insect visitors has solid foundation 
for even the amazingly large and varied results which it attempts to explain; 
if not, it is hard to understand how the explanation is valid (at least in any 
such all-sufficient degree as commonly held), despite its logical character 
(in the light of our knowledge of the nearly limitless capacity for modifica- 
tion of natural selection) and the abundant confirmatory evidence. 

Most of the experimental evidence so far offered is that included in Dar- 
win’s account (‘‘ On the Fertilization of Flowers by Insects”’); in Lubbock’s 
account of his experiments on honey-bees, familiar because of its presentation 
in his readable book, “ Ants, Bees, and Wasps’’; and in Plateau’s account 
of his more recent but less familiarly known experiments with various insects, 
including bees. Both Lubbock and Plateau are investigators ingenious 
in device, keen in deduction, and of unquestioned scientific honesty. Yet 
their conclusions are in direct contradiction. Lubbock believes that bees 
recognize colors at a considerable distance, that they “prefer one color to 
another, and that blue is distinctly their favorite.’ Plateau finds that neither 
the form nor the brilliant colors of flowers seem to have any important attrac- 
tive réle, ‘“‘as insects visit flowers whose colors and forms are masked by 
green leaves, as well as continue to visit flowers which have been almost 
totally denuded of the colored parts”; that insects show no preference or 
antipathy for different colors which flowers of different varieties of the same 
or of allied species may show; that flowers concealed by foliage are readily 
discovered and visited; that insects ordinarily pay no attention to flowers 
artificially made of colored paper or cloth whether these artifacts are provided 
or not with honey, while, on the contrary, flowers artificially made of living 


Insects and Flowers 581 


green leaves and provided with honey are visited (from the attraction of the 
“natural vegetable odor’). From these observations Plateau concludes 
that ‘insects are guided with certainty to flowers with pollen or nectar by 
a sense other than that of vision and which can only be that of smell,’ and 
finds particular proof of this in the facts, according to his observations, (1) 
that insects tend, without hesitation, towards flowers usually neglected by 
reason of the absence or poverty of nectar, from the moment that one 
supplies these flowers with artificial nectar, represented by honey; (2) that 
insects cease their visits when one cuts out the nectary without injuring 
the colored parts, and re-begin their visits if one replaces the destroyed nec- 
tary by honey; (3) that it suffices to attract numerous insects if one puts 
honey on or in normally anemophilous flowers, simply green or brown in 
color, which are normally practically invisible and almost never visited by 
insects; and (4) that the visiting of flowers artificially made of fresh green 
leaves and containing honey demonstrates plainly the réle of the sense of 
smell. 

It must be said that, despite many just criticisms which may be made on 
the character of his experiments, Plateau has made necessary more experi- 
mentation for the relief of the general theory that floral adaptation of color 
is due to the color preferences of insect visitors. It seems to me probable 
that the truth of the matter is in a large degree expressed by the statement 
that the distant attraction is exerted by the odors of flowers working on a 
very sensitive sense of smell in insects (chemotropism, in the language of 
the modern believers in reflexes), while the intimate guiding to the particu- 
lar flower and the nectary is controlled chiefly by the color and pattern.. 

Finally we come to the question of the origin of this mutually advan- 
tageous interrelation and its many-branched course of development or 
specialization. Advantage and natural selection are looked on as the chief 
factors in this development. “‘It is extremely probable,’ says the botanist 
Campbell, “‘that all the primitive flowers were anemophilous (cross-polli- 
nated by the wind), and that from these have been derived the more special- 
ized entomophilous and ornithophilous forms. It is evidently of advantage 
to the plant to have the great waste of pollen necessitated by wind-pollina- 
tion reduced, and this is possible when insects or birds are the agents in its 
transfer. It is probable that entomophily began by the casual visits of 
insects to flowers, attracted by the pollen, which is still the principal object 
of visits by many insects, serving as an important source of food. Flowers 
which had more conspicuous stamens or perianth would stand a better chance 
of visits from insects, and from the slight variations thus started may have 
proceeded the development of the conspicuous flowers of the modern ento- 
mophilous plants.’ To attract insects not pollen-eaters the development 
of the nectar has been necessary. However sweet-smelling or beautiful, 


582 Insects and Flowers 


flowers would not be visited by insects unless they had some inducemer 
more substantial to offer. These inducements are the pollen and, to 
great majority of flower-visiting insects, the nectar. ; 

It is of distinct interest to note that no plants with colored flower-pz 
or special floral envelopes existed (in geological time) before the time of 
winged insects. The oldest fossil Angiosperms, monocotyledons as well 
as dicotyledons, are from the lower Cretaceous rock strata; in Tertiary times 
there was a great increase in the number and variety of the dicotyledons, 
and most of the present families were probably in existence in those times. — 


to the lower more generalized eee which to-day take little part in cross- 
pollination. Not until Jurassic times did the higher orders appear, the 
Hymenoptera, Lepidoptera, and Diptera, which include the great majority 
of the cross-pollinating insect agents. Thus the insects which we know to- 
day as the pollen- and nectar-feeders, hence flower-visitors, began to be abun- — 
dant coincidently with or a little in advance of the flowering plants. Recip- 
rocally helpful and mutually adapting themselves to the growing interrela- 
tion, the flies; bees, moths, and butterflies on the animal side and the — 
dicotyledonous plants with varied flower-shapes, color, and pattern on the 
vegetable side have developed so successfully that in present times both 
flower-visiting insects and insect-attracting flowers have come to be the | 
most specialized and notable members of each of their respective groups of — 
organisms. 


CHAPTER. XVII 
COLOR AND PATTERN AND THEIR USES 


CONSPICUOUS characteristic of the insect 
body is its color-pattern. The painted butter- 
flies, the great moths, the burnished beetles, 
the flashing dragon-flies, the green katydids 

and brown locusts, all attract attention first 

ff i) q by the variety or intensity of their colors 
Ne my ie 7 Oh and the arrangement of these colors in simple 
el tS Ai iii or’ intricate symmetry of pattern. Even the 

Mii - D TW Wit small and, at casual glance, obscure and 

i i ) hing monochrome insects reveal on careful ex- 
ad aminat.on a large degree of color development 
and an ofttimes amazing intricacy and beauty of pattern. So uniformly 
well developed is color-pattern among insects that no thoughtful collector or 
observer of these animals escapes the self-put question, What special cause 
is it that results in such a high degree of specialization of color and its 
arrangement throughout the insect class? and if he be an observer who 
has taken seriously the teachings of Darwin and the utilitarian school of 
naturalists, his question becomes couched in the form, What is the use to 
the insects of all this color and pattern? 
For the attitude of any modern student of Nature, confronted by such 

a phenomenon, is that of the seeker for the significance of the phenomenon. 

And the key to significance in such a case is to be sought in utility. The 

usefulness of color in animate Nature as an inspirer and satisfier of our 

own esthetic needs and capacities, or of color-patterns as means whereby 

we may distinguish and recognize various sorts of animals and plants, is a 

usefulness which may be answer enough to the passing poet on the one hand, 

and the old-line Linnean systematist on the other, but is, of course, no answer 
to science. Science demands a usefulness to the color-bearing organisms 
themselves; and a usefulness large and serious enough to be the sufficient 
cause for so highly specialized and amazing a development. 

The explanations of some of the color phenomena of insects are obvious; 
some uses we recognize quickly as certain, some as probable, some as possible. 

583 


584 Color and Pattern and their Uses 


Some colors are obviously there simply because of the chemical make-up 
of parts of the insect body. That gold is yellow, cinnabar red, and certain 
copper ores green or blue are facts which lead us to no special inquiry after 
significance; at least significance based on utility. And if an insect has 
part of its body composed of or containing a substance that is by its very 
chemical and physical constitution always red or blue or green, we may 
be content with knowing it and not be too insistent in our demand to the 
insect to show cause, on a basis of utility, for being partly red or blue or 
green. And even if this red or blue be disposed with some symmetry, some 
regularity of repetition, either segmentally or bilaterally, this we may well 
attribute to the natural segmental and bilaterally symmetrical repetition of 
similar body parts. Some color and some color-pattern, then, may be 
explicable on the same basis as the color of a mineral specimen or of a tier 
of bricks. 

But no such explanation will for a moment satisfy us as to the presence 
and arrangement of colors in the wing of Kallima, the dead-leaf butterfly 
(Pl. XIII, Fig. 1), or in Phyllium, the green-leaf Phasmid (Pl. XIII, Fig. 2). 
We demand an explanation based on direct and large usefulness to the insect. 

Certain uses seem pretty apparent: the brown and blackish pigments 
in the compound eyes have the function of absorbing light-rays so that these 
rays may be prevented from passing through the walls of adjacent ommatidia, 
and thus confusing the mosaic vision; the pigment of the simple eye-flecks 
of some insect larve serves, as in the eye-spots of other simple animals, to 
absorb light at a certain spot especially sensitive and thus make possible 
a recognition of light intensity, a low grade, not of seeing, but of simple appre- 
ciation of the presence or absence of light. Some color in the skin of insects 
may serve, too, as is pretty certainly the case with many vertebrates, to 
absorb heat or prevent its radiation, or, on the other hand, to reflect it, or 
to allow it to radiate freely. In view of the cold-bloodedness of insects this 
must be a use, in this class of animals, extremely restricted and infrequent. 
But such uses as these are at best explanatory of but little of the wealth of 
color and pattern manifest in the insect class. A utility more important, 
and common to many more individuals and capable of explaining a specializa- 
tion of color and pattern much more complex, is needed as a basis for color 
significance. 

The green katydid singing in the tree-top or shubbery is readily known 
to be there by its music, but just which bit of green that we see is katydid 
and which is leaf is a matter to be decided by unusually discriminating eyes. 
The clacking locust, beating its black wings in the air, is conspicuous enough, 
but after it has alighted on the ground it is invisible, or, rather, visible but 
indistinguishable; its gray and brown mottled color-pattern is simply con- 
tinuous with that of the soil. The green larve of the Pierid butterflies 


 SOMAIAMaeTA AVITIATOAT 


-q2 smiled Pe 
; ge muillydd ss 


— — gysdoud simolilsO no vb euesiq euloigisbuseq sagoyt to svist .2 bh 
a .2usimolilas euluoetiy 


ere 


PLATE XIII. 


PROTECTIVE RESEMBLANCE. 


1. Kallima sp. 
2. Phyllium sp. 


3, 4,5. Larvae of Lycena pseudargiolus piasus Bdvl. on California buckeye, 
Esculus californicus. 


PLATE Xill 


Mary Wellman, del 


Color and Pattern and their Uses 585 


lying longitudinally along green grasses simply merge into the color scheme 
of their environment. The gray moth rests unperceived on the bark of 
the tree-trunk. Hosts of insect kinds do really thoroughly harmonize with 
the color-pattern of their usual environment, and by this correspondence 
in shade and marking are difficult to perceive for what they are. Now 
if the eyes that survey the green foliage or run over the gray bark are those 
of a preying bird, lizard, or other enemy of the insect, it is quite certain— 
our reason tells us so insistently—that this possession by the insect of color 
and pattern tending to make it indistinguishable from its immediate environ- 
ment is advantageous to it: advantageous to the degree of often saving its 
life. Now such a use of color and pattern is obviously one which can be 
wide-spread through the insect class, and may be to many species which 
lead lives exposed to the attacks of insectivorous animals of large—even 
of life and death—importance. And naturalists, most of them at least, 
believe that this kind of usefulness is real, and that it is the principal clue 
to the chief significance of color and pattern. And this not alone in the 
case of insects, but of most other animals as well. 

From this point of view, namely, that color-patterns may be of advantage 
in the struggle for existence, just as strength, swiftness, and other capacities 
and conditions are, the specialization and refinement, all the wide modifica- 
tion and variety of colors and patterns, are explicable by the hypothesis of 
their gradual development in time through the natural selection of naturally 
occurring advantageous variations. On this basis, such special instances 
of resemblance to particular parts of the environment, as that shown by 
Kallima in its likeness to a dead leaf, and Diapheromera in its simulation 
of a dry, leafless twig, are simply the logical extremes of such a line of speciali- 
zation. 

But the nature observer may be inclined to ask how such brilliant and 
bizarre color-patterns as those of the swallowtail-butterflies and the tiger- 
banded caterpillars of Anosia can be included in any category of “protective 
resemblance”’ patterns. They are not so included, but are explained inge- 
niously by an added hypothesis called that of ‘‘warning colors,” while for 
the striking similarities of pattern often noted between two unrelated con- 
spicuously colored species still another clever hypothesis is proposed. In 
these cases it is not concealment that the color-pattern effects, but indeed 
just the opposite. Since the pioneer studies of Bates and Wallace and Belt, 
naturalists have been observing and experimenting and pondering these 
exposing as well as these concealing conditions of color and pattern, and 
they have proposed several theories or hypotheses explanatory of the various 
conditions. These hypotheses are plausible; but they are much more than 
that; they are each more or less well backed up by observation and experi- 
ment, and some of them have gained a large acceptance among naturalists. 


586 Color and Pattern and their Uses 


Both the reasoning and the observed facts on which these hypotheses rest 
are based on the usefulness of the colors and patterns to the animals in their 
relation to the outside world. And the influence of advantage and natural 
selection is given the chief credit for determining the present-day conditions 
of these colors and patterns. 

Before, however, we take up these hypotheses, defining them and looking 
over some of the evidence adduced for their support, as well as some of the 
criticism leveled at them, we may advisedly look to the actual physical causa- 
tion of color in insects. Whatever the use or significance of color, our 
understanding of this use must be based on a knowledge of the method or 
modes of the actual production of color. 

Color in organisms is produced as color in inorganic Nature is. Certain 
substances have the capacity of selective absorption of light-rays so that 
when white light falls on them, certain colors (light-waves of certain length) 
are absorbed, while certain others (light-waves of certain other lengths) are 
reflected. An object is red because the substance of which it is (superficially) 
composed reflects the red rays and absorbs the others. Certain other objects 
or substances may produce color (be colored) because of their physical rather 
than their chemical constitution: their surfaces may be so composed of 
superposed lamelle, or so striated or scaled, that the various component 
rays of white light are reflected, refracted, and diffracted in such varying 
manner (at different angles and from different depths) that complex inter- 
ference effects are produced, resulting in the practical extinguishing of cer- 
tain colors (waves of certain length), or the reflection of some at angles so 
as not to fall on the eye of the observer, and so on. Such colors will change 
with changes in the angle of observation, and are the so-called metallic or 
iridescent colors. These two categories of color have been aptly called 
chemical and physical: chemical color depending on the chemical make-up 
of the body, physical on its structural or physical make-up. As a matter 
of fact we shall find that most insect colors are due to a combination of these 
two kinds. 

Substances that produce color by virtue of their capacity to absorb certain 
colors and reflect only one or more others we may call, in our discussion of 
color production, pigments, and pigmental may be used as practically synony- 
mous with chemical in referring to colors thus produced, while structural 
may be sometimes used as synonymous with physical in referring to colors 
dependent on superficial structural character of the insect body. For colors 
produced by the co-operation of both pigment and structure, combination 
or chemico-physical may be used as a defining name. In a recent valuable 
paper by Tower * the history of and authority for the adoption of these 
various names is given. 

* Tower, W. L. Colors and Color-patterns of Coleoptera. Decennial Pubs. of 
Univ. of Chicago, 1903, vol. X, pp. 33-70. 


Color and Pattern and their Uses 587 


Tower finds, on the basis of his own researches and those of various other 
investigators of insect colors, that among insects the chemical colors are 
yellow, orange, red, buff, brown, black, and rarely green-blue and black; 
physical colors are the pearly colors, almost all whites, and rarely violet- 
greens, reds, and some metallic and iridescent colors; while chemico-physical 
colors are violet, greens, reds, and iridescent and almost all metallic colors. 
Tower believes it probable that but few really pure physical colors will be 
found in insects, by far the larger part of those now classed as such falling 
into the category of the chemico-physical. Tower finds white to be the 
only purely physical color occurring among the Coleoptera (the insect group 
whose colors he has specially studied). 

With regard to the situation of the pigments on which chemical and, 
partly, physico-chem cal colors depend, these colors may be divided into 
cuticular and hypodermal (first defined by Hagen) and subhypodermal 
(defined by Tower). The cuticular colors are produced by coloring sub- 
stances situated in the chitinized cuticle that overlies the whole insect body; 
they are permanent colors, not fading after death, and are insoluble, without 
actual dissolution of the cuticle, in water, acids, alkalies, ether, or essential 
oils; they are browns, blackish, drab, some yellows, and possibly some reds. 
The hypodermal colors are produced by pigments lying in the hypoderm 
(cellular layer of the skin, just underneath the cuticle) and are of two sub- 
categories, viz., first some yellows and green which are due to xyanthophyll 
and chlorophyll taken from plant-food, and which are not permanent, 
fading after death and on exposure, and soluble in the usual organic 
solvents; and second, certain permanent colors, reds and chrome yellows, 
due to definite pigment granules imbedded in the cytoplasm of the hypo- 
dermal cells. The subhypodermal colors, found practically only in larve, 
are due to various substances, as derived plant pigments and others, 
in the hemolymph (blood) which show through the skin (hypoderm and 
cuticle). 

The structural or physical colors, and the combination or physico-chemical 
colors, to which two classes belong all white and all metallic, pearly and 
iridescent colors, including most blues, greens, violet, and golden, depend 
for their production on a superficial or surface structural condition of the 
insect body or part consisting either of the superposition of one or more 
thin transparent or translucent lamellae over a darker layer, or the fine 
roughening of the surface by means of stria, pits, or minute hair-like processes. 
Tower has offered a graphic classification of these colors (together with the 
one already explained of chemical colors) in the table which follows. The 
classification is sufficiently explained in the table to make unnecessary any 
further discussion of the various kinds of structures involved in color pro- 
duction among insects. 


588 Color and Pattern and their Uses 


TABLE OF INSECT COLORS. 
By W. L. Tower. 


Permanent. Insoluble in water, 
Black Located alcohol, ether, oils, weak acids, 
Cuticular } Dark brown in or alkalies 
colors Brown primary | Soluble in strong concentrated 
Straw yellows J cuticula mineral acids with dissolution of 
the cuticula 
Chrome na 
yellows Located in g rice: ne il eee 
Red hypodermal | £ ne ss 5) De: Ss) elke he ? 
T) Vermilion cells as 3 Bere eet e)e NE isles 
© | Soluble in ether or other 
Scarlet granules a, 
BING 3 fatty solvents 
Chemical : 
colors eee Not permanent. 
colors 
Tbeatedin Fade at death or 
on exposure 
Green or between Derived Soluble in water, al- 
243 Yellow the hypo- é 
=e pigments cohol, etc, 
White dermal Aremichloronavll 
cells parities 
anthophyll de- 
xy P. 
rivatives largely 
: Located in Not permanent. Fade 

Sub- Green the body- Denved at death or on ex- 
hypodermal 4 Yellow cavity in aenente posure 
colors White hemolymph Eee Soluble in usual or- 

or fat-body ganic solvents 

Reflection | White Caused by air included within scales, etc. The most 
colors common, and perhaps the only true physical, color 

Caused by combining white and 
some metallic refraction color, 
Physical | Refraction | Metallic Opalescent usually with pigment present. 
colors colors colors colors Frequently caused by thin irregu- 
lar lamelle over pigment, giving 

effect of Newton’s rings 

Diffraction {Iridescent } 
eSlas 1 colors j See next class 
Reflection Colored surfaces Bee Caused by a polished lamellar 
pigmental + with polished ap- Vellows surface over layer of pig- 
colors (a) | pearance Reds | ment, 

Refracti Almost all E . A 
siepieial ae ‘lic Cee Pe refractive lamella overlying a 
colors (b) | colors Byeiot pen 

Chemico- ; f 
Ena Pee (ae er Cause—surface structures, pits, ridges on refrac- 
Sere PIS s a ipcescen tive lamella overlying a layer of pigment 
colors (c) colors ying y pigm 
Various iridescent metallic and Berpre Mae 
Combination opalescent metallic colors; cte,, doptera and almost ex- 
calor in which colors of groups a, b, ] ee ie 4 jedetie 
and c combine to produce color bpbrebbet dma 
eirente sects or areas bearing 
scales 


Color and Pattern and their Uses 589 


That our discussion of insect colors may be made more explicit we may, 
with the foregoing account of the causes and kinds of colors in mind, 
endeavor to see just how the color-pattern of a certain single group of insects 
is produced. This group is that of the moths and butterflies, in which 
color and pattern obviously reach a maximum of development and special- 
ization. 

If the wing of a moth or butterfly be rubbed gently between finger and 
thumb, a spot on the wing will soon lose its color and become transparent, 
while on finger and thumb will be found a fine sparkling powder, the “flour” 
of the miller-moth, the jewel-dust of the butterfly. This dust, rubbed on 
a glass slide and examined under the microscope, will be seen to be com- 


Fic. 770.—Single scale from moths and butterflies. @, from Tolype velleda; b, from Cast- 
nia sp.; c, from Micropteryx aruncella. (Greatly magnified.) 


posed of symmetrical tiny scales, each composed of a flattened blade and 
short stem or pedicel (Fig. 770). A considerable variety of shape will be 
noticeable among these scales, and if scales are rubbed from other moths 
and butterflies, many new shapes will be found. But through all this diver- 
sity of appearance, a fundamental plan of make-up 
may be recognized in each of these minute structures. 
Most commonly the scales are more or less ovate in 
outline with the little stem projecting from the narrower 
end. The broader end has its margin entire or with 
dentations of varying depth and number. These den- 
tations may be so deep that the scale looks like a 
several-fingered little hand. In size the scales vary 
from .o7 mm. (4, inch) to .8 mm. (4 inch) if we Fic. 771.—Scale of 
exclude the long hair-like forms common near the base soi caseu en es 
of each wing, and also the slender elongate ones mary and secondary 
which project from the wing-margins. In width the a 
scales vary from hair-like to a breadth of .4 mm. (¢y inch). ° j 

Some scales are as broad as long, or even broader than long. Running 
longitudinally from base to outer margin are many fine little subparallel 


590 Color and Pattern and their Uses 


lines or stria. These strie vary in distance apart, on different scales, from 
.0007 mm., as in the scales of the great blue Morpho butterflies, to .co4 mm., 
as in the sulphur-yellow butterfly, Catopsila eubule. 
The scales cover (in all but the few ‘‘clear-winged” moths) the wings 
; on both upper and lower sides, 
being insecurely attached to the 
wing membrane by having their 
short pedicels inserted in little 
pockets or cups on the wing sur- 
face. They show an interesting 
and varying manner of arrangement. 
This arrangement varies from an 
extremely uniform one in the but- 
terflies and higher moths to one 
of much less regularity of disposi- 
tion in the lower moths. On the 
wings of a butterfly the scales are 
inserted with their pedicels directed 
toward the base of the wing in 


Fic. 772—A_small, partly denuded part of : 
the wing of a butterfly, Lycena sp., showing subparallel rows running trans- 


the scales and pits in a wing membrane, versely across the wing, i-e., from 
into which the tiny stems of the scales are = = ws Gael 
inserted. (Photomicrograph by George O. 28tenor to posterior margin, 

Mitchell; greatly magnified.) the scales in each row are at 


approximately equal distances apart. Their distance is less than the width 


of each scale, so that adjoining scales 
overlap laterally and thus make each row 
to be composed of two tiers of scales, an 
upper and an under one: the insertion- 
cups of one tier are very slightly but per- 
ceptibly advanced beyond those of the 
other tier. The scales of the upper tler 
alternate with those of the lower tier, and 
each upper scale overlaps laterally two 
under ones. But in addition to this 
lateral overlapping, the distance between 
the rows of insertion-cups is les than 
the length of the scales, sw that there 


Fic. vie denuded wing of a 
z= - buttertiy, Gragée sp.. to show rows 
overlapping of the tip of the of insertion-pits onupperand lower 
be sides, with three scales in position. 
(Greatly magnified.) 


iS aL 
scales of one row over the bases of the 
scales in the next row in front. By this 
ng there is formed a complete shingled covering of scales 


over each surface (upper and under) of each wing. 


double overlapr 


Color and Pattern and their Uses sgl 


This close placing and overlapping, and the small size of the scales, 
bring it about that the number of scales on a single wing is truly prodigious. 


Fic. 774.—Diagram to show shingled arrangement of scales over surface of butterfly’s 
wing; the short black bars indicate scales in cross-section; the broad central bar, 
the wing in cross-section. 


In Morpho sp., for example, the distance apart of the lines of insertion-pits 
on a bit of the upper wing surface taken from the middle of the fore wing 
is .151 mm.; the distance apart of the pits in a line is .o43 mm. (on the 
under surface the pits are .o5 mm. apart); so that in a space 25 mm. by 
25 mm. (1 square inch circa) there would be 165 lines of scales with 600 scales 
in each line, or 99,000 scales to each square inch of wing-surface. As the 
upper and under surfaces of the fore and hind wings combined equal about 
15 square inches, the total number of scales on the wings of Morpho may 
be roughly approximated at 1,500,000. 

The pedicels of the scales are of slightly varying shapes and of different 
lengths, corresponding with the pockets into which they fit. Those which 
enter insertion-cups which are expanded at the base, or at some point between 
the base and the mouth, present at the tip or be- 
tween the tip and the point of merging into the 
blade of the scale, respectively, a slight expan- 
sion, so that they are pretty firmly held in the cup 
by a sort of ball-and-socket attachment. The 
scales are held in position by the elasticity of 
the cups which closely clasp the pedicels. After 
death of the moth or butterfly this elasticity is 
largely lost, by desiccation of the wing mem- ee pre one ue 
brane, and the pedicels are more easily brushed Morpho sp. (Greatly mag- 
from the wing than when the insect is alive. mcuy) 

Now to pay attention to the actual structure or make-up of individual 
scales. When studied carefully under the microscope singly and in cross- 
sections of the wing the scales are seen to be tiny flattened sacs, composed 
of two membrances, enclosing sometimes only air, sometimes ‘pigment 
granules attached to the inner face of one of the membranes, and some- 
times (as observed in cabinet specimens) the dry remains of wha: may have 
been during life an internal pulp. The striae are confined to the outer mem- 
brane (that farthest from the wing-membrane) and are probably folds in 
this outer membrane. These strie are plainly elevated above the inter- 


592 Color and Pattern and their Uses 


strial space. All scales, excepting some androconia (scent-scales on male 
butterflies) (Fig. 777), possess these longitudinal stria, which traverse the scale 
from base to outer margin and are very sharp, and sepa- 
rated from one another by equal distances. The strize 
sometimes curve in at the lower angles of the blade, con- 
verging toward the origin of the pedicel; in other cases 
they fade out at these angles. In scales of Anosia 
plexippus from 33 to 46 strie, averaging .co2 mm. apart, 
are present on each scale. There would thus be 12,500 
of these striae to the inch. On transparent scales from 
Morpho sp. the striae were .oo15 mm. to .oo2 mm. apart; 
on opaque (pigment-bearing) scales from the same spec- 
Fic. 776—Scale imen the strie were from .0007 to .ooo72 mm. apart, 

of Lycomorpha or at the rate of about 35,000 to the inch. 

conten Tee If we examine a long series of scales brushed off from 

ing cross-stne. 

(Greatly mag- different parts of a wing of moth or butterfly, we can 

nibed:) always note a series of gradating forms running from slender 
hair-like form to typical short, broad, flat scale. The significance of this, 
when we come to inquire about the origin Wp 
of scales, is plain. Scales are unusual struc- W/Z 
tures among insects: besides the moths and 
butterflies, only a few beetles, the mosquitoes, 
the fish-moths, and a few other scattering insects 
have them. But all insects have hairs. Hairs 
are structures common throughout the class. 
And it is certain that scales are derived or de- 
veloped from hairs. They are a specialized, a 
highly modified sort of hair. On the lower, the 4 
more generalized moths, the hair-like scales are 
the more abundant. The wings show a thick 
intermixing of loose, fluffy hair-scales or scale- 
hairs with more typical scales irregularly ar- 
ranged. In the higher Lepidoptera, the spe- 
cialized sort of hairs, namely the scales, com- 
pose almost exclusively the wing-covering, and 
these scales are arranged in the specialized _,, ... 


. sae A = 777-_ Androconia from 
uniform shingling manner previously described. wings of male butterflies. a, 


But even on the wings of a butterfly all the  '°™ wing of Nymphalid 
butterfly; b, from wing of 


gradations from hair to scale can be found by  Pierid ‘butterfly; c, from 
going from base out to discal area of the wing. Wing of Lycsnid butterfly. 
= : : : pee (All greatly magnified.) 
These gradation series vary in character in dif- 

ferent families, as shown in Figs. 778, 779, 780, and 781. In some the 


Color and Pattern and their Uses 593 


hair becomes a scale by shortening and broadening, keeping its free 
tip entire; in others the hair splits distally and then each branch splits 


Fic. 778.—Scales taken from a single fore wing of Megalopyge crispata, showing grada- 
tions from true hair to specialized scale. (Greatly magnified.) 


again, and so on, while the base is continually shortening and broadening 
so that the scale form finally reached is a fingered or deeply-toothed 


Fic. 779.—Scales from a single fore wing of Gloveria arizonesis, showing gradations from 
scale-hair to specialized hair. (Greatly magnified.) 
one. But in all the series the final result is that from a long, slender, sub- 
cylindrical hair is evolved a short, broad, flattened, little scale. A study 
of the actual development of an individual scale on the forming wing of a 
butterfly during the pupal or chrysalid stage confirms the hypothesis of the 
evolution of the scales. In the growing developing wing the scales begin 
as hairs, arising by the extension of certain hypodermal cells in the wing- 


594 Color and Pattern and their Uses 


membrane which gradually change in the few or many days of pupal develop- 
ment into typical scales (Figs. 782 and 783). 


(NY 


Fic. 780.—Scales from a single fore wing of Heliconia sp., showing gradations from scale- 
hair to specialized scale. (Greatly magnified.) 


We have studied now with some care the general character of the scale- 
covering of moths and butterflies, and the actual structural make-up and 


(Greatly magnified.) 


Fic. 781.—Scales from a single hind wing of the 
goat-moth, Prionoxystus robine, showing gra- 
dations from scale-hair to specialized scale. the myriad little scales 


the origin of the indi- 
v.dual scales. And we 
learned at the very begin- 
ning of our study that 
it is the scale - covering 
which is the producer or 
carrier of all the brilliant 
and varied color and 
pattern which character- 
ize the moths and butter- 
flies. When we rub off 


the wings themselves are 


found to be colorless, transparent. We have now to note how it is that 
the scales, the color-carrying organs, actually produce the colors. 


The scales in their fully 
developed dry condition are 
ch‘efly cuticular in structure, 
but they may contain pig- 
ment granules and various 
substances left by the hypo- 
dermal cell-layer in drying. 
The colors of the scales are 
to be classified then as both 
cuticular and hypodermal in 
character, and both chemical 
and physical in origin. For 
the most part they are strictly 
combination colors due to 


i 


TREN ect 


Fic. 782.—Diagrammatic figures showing the devel- 
opment of the scales on a wing of Euvanessa anti- 
opa; at left, cross-section of bit of pupal wing show- 
ing the two wing-membranes and intervening space 
or wing-cavity; at right, cross-section of a single 
wing-membrane in older pupal wing, s.c., scale- 
cells; iyp., hypodermal cells; /, leucocytes; s, devel- 
oping scales. (After Mayer; greatly magnified.) 


Color and Pattern and their Uses 595 


chemical (pigmenta’) substances within the scale and to the structural 
character of the scale-walls. The pigment granules within the scales are 
brown, yellowish, or reddish, and as they mostly transmit the same colors as 
they reflect, the colors of strongly pigmented scales are the same by trans- 
mitted light (light shining through them) as by reflected light. But with 


Fic. 783.—Diagrammatic figures showing late stages in development of scales of the 
wing of Anosia plexippus; figure at right showing older stage than figure at left. s, 
scale; sc, scale-cell; /, leucocyte. (After Mayer; greatly magnified.) 


the physical colors this is not the case. Scales which produce brilliant 
blues and other colors are often empty, and these when viewed by trans- 
mitted light are nearly colorless. Or they may contain pigment and then 
when viewed by transmitted light show a dull brownish or yellowish color 
entirely different from the metallic iridescence which they show by reflected 
light. 

The physical color effects produced by scales are due to their (a) lamina- 
tion and (0) striation. Each scale is composed of a pair of thin subtrans- 
parent laminz (lamella), the thin dry sides of the flattened sac, and when 
arranged in the shingling sheath over the wing-membrane, overlapping 
each other at sides and ends, they produce a layer of superposed thin trans- 
parent lamella which is exactly the structural condition necessary to the 
production of varied refraction (interference) effects of color. This scale 
layer produces color by virtue of its structure just as a piece of laminated 
mica or bit of old weathered glass or film of soap-bubble produces color 
(Newton’s rings). In addition the stria-bearing outer surface of each scale 
is essentially the same as a ruled surface or grating, producing color by 
diffraction and interference just as do the well-known Rowland’s and Ruther- 
ford’s gratings, familiar to students in physical laboratories. In the finest 
of these artificially striated gratings the lines are about .ooo6 mm. apart: 
in butterfly scales the stria are from .oo2 to .coo7 mm. apart. 


596 Color and Pattern and their Uses 


The blacks, browns, yellows, and dull reds of butterflies and moths, 
then, are produced chiefly by pigment; while all the brilliant metallic colors, 
the iridescent blues and greens, and hosts of allied shades, are due to the 
structural or physical make-up of the scale-covering. The patterns, varied 
and intricate, with lines and spots and bars, sharply deliminated or softly 
merging into the ground color or into one another, depend on the fact that 
the color-units, the scales, are so small that by the juxtaposition of scales 
containing different pigments, or varying slightly in structure, different 
colors may be produced abruptly or gradually, depending upon the degree of 
differences in pigment and structure of adjacent scales. By the extremely 
regular arrangement, in the higher moths and butterflies, of the short, rigid, 
little scales, definite lines and sharp limits to spots and bars are possible. 
In the lower, fluffy moths where the scales are hair-like and irregularly ar- 
ranged such sharp delimitations of pattern parts are not possible. Thus 
the specialization of the scales, both as to structure and arrangement, in 
the brilliantly colored and complexly patterned day-flying Lepidoptera is 
seen to be exactly connected with the specialization of color and pattern. 

The studies that have so far been made upon the character and origin 
of types of pattern have brought some aspect of orderliness into what seems 
at first glance a chaos of complexity, but our knowledge of this matter is 
yet too little organized to make it available in such a brief general account 
of insect color and pattern as this one necessarily is. In the actual develop- 


Fic. 784.—Diagrammatic series showing development of color-pattern in pupal wings 
of the monarch butterfly, Anosia plexippus. (After Mayer; one-half natural size.) 


ment or course of appearance of the color-pattern in the wings of any individual 
moth or butterfly certain conditions regularly obtain, as shown by Van Bem- 
meln, Urech, Haase, Mayer, and others. Mayer’s account and figures of 
the development of color in the fore wings of the monarch butterfly, Anosia 
plexippus, show a typical case. The pupal stage of Anosia lasts from one 
to two weeks. ‘“‘For the first few days,”’ says Mayer, ‘‘the wings are perfectly 
transparent, but about five days before the butterfly issues they become pure 
white. An examination of the scales at this period shows that they are 


Color and Pattern and their Uses 597 


completely formed and merely lack pigment. In about forty-eight hours 
after this (see Fig. 784, a) the ground-color of the wings changes to a dirty 
yellow. It is interesting to note that the white spots which adorn the mature 
wings remain pure white. Fig. 784, 8, illustrates the next stage, where the 
black has begun to appear in the region beyond the cell. The nervures 


Fic. 785.—Diagrammatic series showing development of color-pattern in pupal wings 
of the promethea moth, Callosamia promethea; female wings in vertical series at left, 
male at right. (After Mayer; one-half natural size.) 


themselves, however, remain white. Fig. 784, c, shows a still later condition, 
where the dirty yellow ground-color has deepened into rufous, and the black 
has deepened and increased in area and has also begun to appear along the 
edges of the nervures. In Fig. 784, d, the black has finally suffused the 
nervures, the base of the wing and the submedian nervure being the only 


598 Color and Pattern and their Uses 


parts that still remain dull yellow. It is apparent that in Anosia plexippus, 
as in Callosamia promethea, the central areas of the wings are the first to 
exhibit the mature colors, and that the nervures and costal edges of the 
wings are the last to be suffused.’’ 

The development of the wing-patterns in the male and the female of the 
promethea moth, as worked out by Mayer, is shown by Fig. 78s. 

Other butterflies and moths which have been thus followed through 
the pupal life show a similar possession of color-appearance. ‘Tower has 
similarly followed the color-development in certain beetles. Tower’s figures 
illustrating the development in the large blackish-brown Prionid beetle, 


Fic. 786.—Diagrammatic series showing development of color-pattern in pup and young 
adults of the giant wood-boring beetle, Orthosoma brunnea. The first three figures in 
the upper line, counting from the left, are pupz of successive ages, the rest of the 
figures adults of successive ages. (After Tower; natural size.) 


Orthosoma brunnea, are shown in Fig. 786. Tower finds that in all the 
insects so far studied the chemical colors of the body follow the general course 
illustrated by Orthosoma. The color begins to form on the head and anterior 


parts first and gradually spreads posteriorly. 


Color and Pattern and their Uses 599 


Now that we have got in some degree acquainted with the ways in which 
colors are actually produced among insects, we may come back to the ques- 
tion asked in the first paragraph of this chapter, namely, ‘‘What is the use 
to the insect of all this variety of color and pattern?”’ We may attempt now 
to get some clue to the significance of the color phenomenon. So wide-spread 
and well developed are color and pattern among insects that the presump- 
tion is strong that the utility of color-pattern is large. 

The only hypothesis that gives to colors and markings a value in the life 
of insects at all comparable with the degree of specialization reached by 
these colors and markings and by the special structures developed to make 
them possible, is that already referred to as the theory of protective and 
aggressive resemblances, of warning and directive patterns, and of mimicry. 
These various uses of color-patterns are all concerned with the relation of 
the insect to its environment; they are means of protecting the insect from 
its enemies or of enabling it to capture its prey. They are uses obviously con- 
cerned with the ‘‘struggle for existence’; they are ‘‘shifts for a living.” 
For the sake of clearness in the discussion of these various uses—a discussion 
which must by the limitations of space be most unsatisfactorily condensed— 
the uses will be rather arbitrarily classified into several categories which in 
Nature are not as sharply distinguished as the paragraph treatment of them 
might suggest. 

General protective resemblance.—The general harmonizing in color and 
pattern w th the color scheme of the usual environment is a condition which 
every field student of insects recognizes as widely existing. The difficulty 
of distinguishing a resting moth from the bark on which it is resting, a green 
caterpillar or leaf-hopper or meadow grasshopper from the leaf to which it 
clings, a roadside locust or bug from the soil on which it alights, is a diffi- 
culty which has to be reckoned with by every collector. Now while there 
are few human collectors of insects, there are hosts of bird and toad and lizard 
insect-hunters, to say nothing of the many kinds of predaceous insects them- 
selves who use their own cousins for chief food. So that where this diffi- 
culty of distinguishing the resting insect from its environment is sufficient 
to postpone success on the part of the insect-hunting bird or lizard, the life 
of the protectively-colored insect is obviously saved, for the time, by its dress. 
This is a utility of color and pattern than which there can be, from the insect 
point of view, nothing higher. 

Variable protective resemblance.—While with most insects all the indi- 
vidua!s of one species show a similar color and pattern, it is noticeable that 
with a few species there is a marked variability or difference in color and 
sometimes in markings. Locusts of various species of the genus Trimero- 
tropis show a variability in color of indiv-duals rang’ng through gray, brown, 
reddish, plumbeous, and bluish, and such accompanying variab lity in mark- 


600 Color and Pattern and their Uses 


ing as to result in producing much variety of appearance in a single 
series of collected individuals. I have noted in collecting these locusts in 
Colorado and California that this variability of coloration is directly associ- 
ated with the color-differences in the soil of the localities in which these locusts 
live; the reddish individuals are taken from spots where the soil is reddish, 
the grayish where it is sand-colored, and the plumbeous and bluish from soil 
formed by decomposing bluish rock. 

On the campus of Stanford University there is a little pond whose shores 
are covered in some places with bits of bluish rock, in other places with bits 
of reddish rock, and in still others with sand. The toad-bug, Galgulus ocula- 
tus, lives abundantly on the banks of this little lake. Specimens collected 
from the blue rocks are bluish in ground-color, those from the red rocks 
are reddish, and those from the sand are sand-colored. But the colors 
of these insects are fixed; they cannot, like the chameleon and certain other 
lizards, or like numerous small fishes and some tree-frogs, change color, 
quickly or slowly, with changes in position, that is, movements from green 
to brown or to other colored environment. Variable protective resemblance 
in insects is, as far as known, a variability directly induced, to be sure, by 
varying environment, but all acquired during the development of the in- 
dividual insects, and fixed by the time they reach the adult stage. 

The well-known exper'ments of Tr men, Miiller, and Poulton with the 
pupating larve of swallow-ta‘led butterflies, Papilio sp., and Poulton on 
other butterflies with naked chrysalids, show that the chrysalids of numerous 
butterfly kinds take on the color, or a shade approaching it, of the substance 
surrounding the pupating larve, and show also that the result is due to a 
stimulus of the skin by the enclosing color, and not to a stimulus received 
through the eyes, and carried to the skin by the nerves. Larve just ready 
to pupate were enclosed in boxes lined with paper of different colors; the 
chrysalids when formed were found to be colored to harmonize with that 
particular color of paper by which they were surrounded while pupating. As 
these chrysalids in Nature hang exposed on bark and in other unsheltered 
places, without protecting cocoon or cover of any kind, the actual protective 
value of this harmonious coloration is obvious. 

The larve (caterpillars) of various moths, particularly Geometrid and 
Sphingid species, often appear in two color types, one brown and the other 
green. Poulton has shown by experiment and observation with some of 
these species that those larva reared among green leaves and twigs and 
branches become brown. This variable protective resemblance, like that 
of Trimerotropis, Galgulus, and the Papilio chrysalids, also is fixed after 
being once acquired. 

An interesting example of color harmony wh'ch may be class fied under 
the head of variable protective resemblance that has come under my obser- 


Color and Pattern and their Uses 601 


vation while writing this chapter is the case of the larvae of Lycena sp., 
abundant on the flower-heads of the just-blossoming (May) California 
buckeye, 4 sculus calijornicus. The buds of the buckeye are green, or green 


Fic. 787.—The dead-leaf butterfly, Kallima sp., a remarkable case of special protective 
resemblance. (Natural size.) 


and rose, or even all rose externally. The quiet slug-like Lycenid larve 
lie longitudinally along the buds and their short stems, and are either green 


602 Color and Pattern and their Uses 


with faint rosy tinge, especially along the dorsi-meson, or are distinctly 
rosy all over, depending strictly upon the color-tone of the particular inflo- 
rescence serving as habitat for the larva (Pl. XIII, Figs. 3, 4, and 5). The 
correspondence in shade of color is stnxingly exact: the utter invisibility, 
or rather indistinguishability, of the larve is something that needs to be 
experienced as my artist, my students, and I have experienced it in the last 
few weeks, to be fairly realized. We have watched the larve through their 
whole life, and all the time the safe position along the bud and the immobility 
are maintained. 

Special protective resemblance.—The figures of Kallima (Pl. XIII, Fig. 1, 
also text Fig. 787) and of Phyllium (Pl. XIII, Fig. 2, also text Fig. 788), 
referred to in an early paragraph in this chapter, illustrate extreme and 
often-referred-to examples of a protective 
resemblance which may be called “special” 
in that the insect’s appearance simulates in 
more or less nearly exact way some par- 
ticular part of the habitual environment, this 
being, in the case of Kallima, a dead leaf, 
in the case of Phyllium a green leaf. The 
details of this simulation are extreme: in 
Kallima the projections or tails of the hind 
wings represent the leaf-stem, the long cen- 
tral midrib of the leaf is represented by a 
brown line continuously across both wings, 
the lateral leaf-veins corresponding on one 
side to the actual course of the wing-veins, 
but on the other being represented by brown 
lines running at right angles, nearly, to the 
wing-veins; in Phyllium the flattened and 

; expanded head, thorax, legs, and abdomen 

pidbaoee: on Fic incectis baokt with the broad green wing-covers, leaf-veined 

green with scattered yellowish and spotted with yellow like a _ fungus- 

sare a dra foarte attacked or insect-punctured leaf compose a 

make the insect almost indistin- false picture of great effectiveness. Are 

guishable when at rest among not these details of deceit almost past 
green leaves. 

belief ? 

The slender grass-green larve of many moths and butterflies are much 
like green grass-leaves; their slimness and, if Weismann’s interpretation 
be accepted, the few longitudinal whitish lines which serve as air-lines 
to divide the body into two or three (apparent) grass-blades, are special 
characters of importance. The inch-worms or larvae of Geometrid moths 
are familiar examples of special protective resemblance. Abundant as 


Color and Pattern and their Uses 603 


these larve are, they are only occasionally seen, and then usually when “loop- 
ing” along on the ground or sidewalk. When in their habitual haunts in 
trees and bushes, the slightest disturbance, as the approach of bird or lizard 
or human observer, causes them to “go stiff,’ holding the body (Fig. 789) 


Fic. 789. Fic. 790. 


Fic. 789.—An inch-worm, larva of geometrid moth, in protective position. (After Jor- 
dan and Kellogg; natural size.) : 
Fic. 790.—The walking-stick, or twig-insect, Diapheromera femorata. (Slightly enlarged.) 


rigidly out from the branch or stem to which they cling by the posterior 
two pairs of prop-legs, and looking so like a short twig, or broken one, that 
they are only rarely recognized for what they really are. The skin is brown or 


604 Color and Pattern and their Uses 


green (variable resemblance, depending on their nurture) and roughened 
and tubercled like a bud-scarred bit of twig. The absence of the middle 
prop-legs prevents the harm to this illusion that would come from their pres- 
ence. An interesting point in this simulation—and one which is commoner 
in such cases than has been generally referred to—is the combining of a 
habit or kind of behavior with the structural and color modification to make 
the illusion successful. 

Another familiar and extreme case of special protective resemblance is 
that of the walking-stick, or twig-insect, Diapheromera jemorata (Fig. 790), 
a Phasmid wide-spread over the whole of our country. The absence of 
wings, the extreme elongation and slenderness of body and legs, and the 
dichromatic condition, individuals being either green or brown, all com- 
bine to make this insect a masterpiece of deceit. The moths of the genus 
Cymatophora and their larve also mostly harmonize excellently with the 
gray bark on which they rest; the moths adding to their general simulation 
the curious habit of resting often with folded wings at an angle of 45° with 
the tree-trunk, head downwards, with the curiously blunt and uneven wing- 
tips projecting, so as to imitate with great fidelity a short broken-off branch 
or chip of bark. Numerous other moths and caterpillars resemble bark 
and habitually rest on it. The Catocalas, Schizura, and others are ex- 
amples familiar to the moth-collector. + 

Any field student of insects by paying attention to the matter of special 
protective resemblance can soon make up a formidable list of examples. 
Some of these may appeal more to him than to persons seeing his speci- 
mens in the collecting-boxes, and some indeed will probably be questionable 
to other naturalists. But nevertheless no collector or field student but has 
noted many examples of this clever artifice of Nature to protect her 
children. 

Warning colors.—Ii the field student may be relied on to note and record 
a long list of insects colored and marked so as to harmonize well with their 
general environment or with some specific part of it, he may also be relied 
on to bring in a list of opposites: a record of bizarre and conspicuous forms, 
colored with brilliant blues and greens and streaked and spotted in a man- 
ner utterly at variance and in contrast with the foliage or soil or bark or 
whatever is the usual environment of the insect. The great red-brown mon- 
arch butterfly and its black-striped green and yellowish larva, the tiger- 
banded swallowtails, the black and yellow wasps and bees, the ladybird- 
beetles with their sharply contrasting colors, the brilliant green blister-beetles, 
the striped and spotted Chrysomelids—in all these and many others there 
can be no talk of protective resemblance: if only such a paradoxical theory 
as protective conspicuousness could be established, then these colors and 
markings might well be explained by it. 


Color and Pattern and their Uses 605 


Exactly such an explanation of brilliant color and contrasting markings 
is afforded by the theory of warning colors. It has been conclusively shown, 
by observation and experiment, by several naturalists,* that many insects 
are distasteful to birds, lizards, and other predaceous enemies of the insect 
class. 

The blood-lymph or some specially secreted body fluid of these insects 
contains an acrid or ill-tasting substance so that birds will not, if they can 
recognize the kind of insect, make any attempt to catch or eat them. This 
letting alone is undoubtedly the result of previously made trials, that is, has 
been learned. Now it would obviously be of advantage to those species of 
insects that are ill-tasting if their coloring and pattern were so distinctive 
and conspicuous as to make them readily learned by birds, and once learned 


Fic. 791.—Larva of the monarch butterfly, Anosia plexippus, conspicuously marked with 
black and whitish yellow rings, and distasteful to birds. (Natural size.) 


easily seen. A distasteful caterpillar needs to advertise its unpalatability so 
effectively that the swooping bird will recognize it before making that single 
sharp cutting stroke or peck that would be about as fatal to a caterpillar 
as being wholly eaten. Hence the need and the utility of warning colors. 
And indeed the distasteful insects as far as recognized are mostly of con- 
spicuous color and pattern. 

Such warning colors are presumably possessed not only by unpalatable 
insects, but also by many that have certain special means of defence. The 
wasps and bees, provided with stings, dangerous to most of their enemies, 
are almost all conspicuously marked with yellow and black. Many bugs, 
well defended by sharp beaks, possess conspicuous color-patterns. 

Terrifying appearances.—Certain other insects which are without special 
means of defence and are not at all formidable or dangerous are yet so marked 
or shaped and so behave as to present a curiously threatening or tertifying 
appearance. The large green caterpillars of the sphinx-moths have a cyrious 
rearing-up habit which seems to simulate threatened attack (Fig. 792). 
They have, too, a great pointed spine or horn on the back of the posterior 


* A most interesting recent account of a long series of such observations and experi- 
ments is presented in “‘The Bionomics of South African Insects,’’ by G. K. Marshall 
and E. B. Poulton, Trans. Ent. Soc. Lond., 1902. This paper contains the records of 
five years of careful study in the field of the phenomena relating to the theories of warning 
colors and mimicry. 


606 Color and Pattern and their Uses 


tip of the body which has a most formidable appearance, but is, as a matter 
of fact, not at all a weapon of defence, being quite harmless. Numerous 
stingless insects when disturbed wave about the hind part of the body or 
curl it over or under much as stinging insects do, and seem to be threatening 
to sting. The striking eye-spots of many insects are believed by some 
entomologists to be of the nature of terrifying markings. Marshall tried 
feeding baboons a full-grown larva (about 7 in. long) of the sphinx-moth, 


Fic. 792.—Larva of the pen-marked sphinx-moth, Sphinx chersis, showing threatening 
attitude. (After Comstock.) 


Cherocampa osiris. The larva has large strongly colored eye-spots and 
is ‘remarkably snake-like, the general coloring somewhat recalling that 
of the common puff-adder, Bitis arietans. The female baboon ran forward 
expecting a titbit, but when she saw what I had brought she flicked it out 
of my hand on to the ground, at the same time jumping back suspiciously; 
she then approached it very cautiously, and after peering carefully at it from 
the distance of about a foot she withdrew in alarm, being clearly much 
impressed by the large blue eye-like markings. The male baboon, which 
has a much more nervous temperament, had meanwhile remained at a 
distance surveying the proceedings, so I picked up a caterpillar and brought 


i 
i 
f 


Color and Pattern and their Uees 607 


it towards them, but they would not let me approach, and kept running 
away round and round their pole, so I threw the insect at them. Their 
fright was ludicrous to see; with loud cries they jumped aside and clambered 
up the pole as fast as they could go, into their box, where they sat peering 
over the edge watching the uncanny object below.”’ (Marshall.) Marshall 
also writes concerning the eye-like markings on the wings of the mantis, 
Pseudocreobotra wahlbergi: ‘“‘They are, I think, almost certainly of a terrify- 
ing character. When the insect is irritated the wings are raised over its 
back in such a manner that the tegmina stand side by side, and the markings 


Fic. 793.—Larva of the puss-moth, Cerura sp.; upper figure showing larva in normal 
attitude; lower figure showing larva when disturbed. (After Poulton; enlarged.) 
(See description of this larva on p. 394.) 


on them then present a very striking resemblance to the great yellow eyes 
of a bird of prey or some feline animal, which might well deter an insec- 
tivorous enemy. It is noticeable that the insect is always careful to keep 
the wings directed towards the point of attack, and this is often done without 
altering the position of the body.” 

Directive coloration.—Still another use is believed by some entomologists 
to be afforded by such markings as ocelli and other specially conspicuous 
spots and flecks on the wings of butterflies and moths, and by such apparently 
useless parts as the ‘‘tails” of the hind wings of the swallowtail and Lycenid 
butterflies, and others. Marshall busied himself for a long time with collect- 
ing butterflies which had evidently been snapped at by birds (in some cases 
he observed the actual attack) and suffered the loss of a part of a wing. 
Examining these specimens when brought together, Poulton and Marshall 


608 Color and Pattern and their Uses 


noted that the ‘‘great majority [of these injuries to the wings] are inflicted 
at the anal angle and adjacent hind margin of the hind wing, a considerable 
number at or near the apical angle of the fore wing, and comparatively few 
between the points.’ In this fact, coupled with the fact that the apical 
and hind angles of the fore and hind wings respectively are precisely those 
regions of the wings most usually specially marked and prolonged as angular 
processes or tails, Poulton sees a special significance in the patterns of these 
wing-parts: he thinks they are ‘directive marks which tend to divert the 
attention of an enemy from more vital parts.’ It is obvious that a butterfly 
can very well afford to lose the tip or tail of a wing if that loss will save losing 
a head or abdomen. Poulton sees a “‘remarkable resemblance of the marks 
and structures at the anal angle of the hind wing, under side, in many 
Lycenide to a head with antennz and eyes,’ and recalls that this has been 
independently noticed by many other observers. ‘‘The movements of the 
hind wings by which the ‘tails,’ the apparent antennz, are made continually 
to pass and repass each other add very greatly to this resemblance.” 

Mimicry.—Of all the theories accounting for the utility of color and 
pattern, that of mimicry demands at first thought the largest degree of credulity. 
As a matter of fact, however, the observation and evidence on which it rests 
are as convincing as are those for almost any of the offered explanations 
of the usefulness of color-pattern. Although the word mimicry could often 
have been used aptly in the account of special protective resemblance, it 
has been reserved for use in connection with a specific kind of imitation, 
namely, the imitation by an otherwise defenceless insect, one without poison, 
beak, or sting, and without acrid and distasteful body fluids, of some other 
specially defended or inedible kind, so that the mimicker is mistaken for 
the mimicked form and, like this defended or distasteful form, relieved from 
attack. Many cases of this mimicry may be noted by any field student of 
entomology. 

Buzzing about flowers are to be found various kinds of bees, and also 
various other kinds of insects, thoroughly bee-like in appearance, but in 
reality not bees nor, like them, defended by stings. These bee-mimickers 
are mostly flies of various families (Syrphide, Asilide, Bombyliide), and 
their resemblance to bees is sufficient to and does constantly deceive collectors. 
We presume, then, that it equally deceives birds and other insect enemies. 
Wasps, too, are mimicked by other insects; the wasp-like flies, Conopide, 
and some of the clear-winged moths, Sesiide (Fig. 794), are extremely wasp- 
like in general seeming. 

The distasteful monarch butterfly, Anosia plexippus, wide-spread and 
abundant—a “successful” butterfly, whose success undoubtedly largely 
depends on its inedibility in both larval and imaginal stage—is mimicked 
with extraordinary fidelity of detail by the viceroy, Basilarchia archippus 


Color and Pattern and their Uses 609 


(Plate XI, Figs. 1, 4, also text Fig. 795). The Basilarchias, constituting a 
genus of numerous species, are with but two or three exceptions not at all 
of the color or pattern of Anosia, but in the case of the particular species 
archippus not only the red-brown ground-color but the fine pattern details 
in black and whitish copy faithfully the details in Anosia; only in the addi- 


Fic. 794.—Various moths and wasps, the moths having the appearance of wasps, prob- 
ably through mimicry, and protected by being mistaken for the stinging insects. 
(Photograph by author; natural size.) 


tion of a thin blackish line across the discal area of the hind wings does 
archippus show any noticeable difference. Viceroy is believed not to be dis- 
tasteful to birds, but its close mimicry of the distasteful monarch undoubt- 
edly leads to its being constantly mistaken for it by the birds and thus left 
unmolested. 

The subject of mimicry has not been studied largely among the insects 
of our country, but in the tropics and subtropics numerous striking examples 
of mimetic forms have been noted and written about. The members of 
two large families of butterflies, the Danaide and Heliconide, are distasteful 
to birds, and are mimicked by many species of other butterfly families, espe- 
cially the Pieride, and by the swallowtails, Papilionide. Many plates 
illustrating such cases have been published by Poulton and Marshall, Haase, 


610 Color and Pattern and their Uses 


Weismann, and others. Shelford,* in an extended account of mimicry as 
exemplified among the insects of Borneo, refers to and illustrates many striking 
examples among the beetles, the Hemiptera, Diptera, Orthoptera, Neurop- 
tera, and moths: distasteful Lycid beetles are closely mimicked by other 
beetles, by Hemiptera, and by moths; distasteful ladybird-beetles are mim- 
icked by Hemiptera, Orthoptera, and by other beetles; stinging Hymen- 


Fic. 795.—The monarch butterfly, Anosia plexippus (above), distasteful to birds, and 
the viceroy, Basilarchia archippus (below), which mimics it. 


optera are mimicked by stingless Hymenoptera, by beetles, flies, bugs, and 
moths. Poulton and Marshall, in their account of mimicry among South 
African insects, publish many colored plates revealing most striking resem- 
blances between insects, well defended by inedibility or defensive weapons, 
and their mimickers. 

Our space unfortunately prevents any specific consideration of these 
various interesting cases. 

The special conditions under which mimicry exists have been studied and 
are of extreme interest. It is obvious that the inedible or defended mimicked 
form must be more abundant than the mimicker, so that the experi- 
menting young bird or lizard may have several chances to one of getting an 

* Shelford, R. Observations on some Mimetic Insects and Spiders from Borneo 


and Singapore, Proc. Zool. Soc. Lond., 1902, pp. 230 et seq. 


Color and Pattern and their Uses 611 


ill taste or a sting when he attacks an insect of certain type or pattern. This 
requirement of relative abundance of mimicker and mimicked seems actu- 
ally met, as proved by observation. In some cases only females of a species 
indulge in mimicry, the males being unmodified. This is explained on the 
ground of the particular necessity for protection of the egg-laden, heavy- 
flying, and long-lived and hence more exposed females, as compared with 
the lighter, swifter, shorter-lived males. 

It has been found that individuals of a single species may mimic several 
different species of defended insects, this polymorphism of pattern existing 
in different localities, or indeed in a single one. Marshall believes that the 
seasonal polychromatism of certain butterfly species is associated with the 
mimicry of certain defended butterflies of different species, these different 
species appearing at different times of the year. 

Criticisms and general consideration of the foregoing hypotheses of 
color use.—It is needless to say that such hypotheses and theories of the 
utility of color and pattern have been subjected to much criticism, both 
adverse and favorable. The necessity for limiting results within the working 
range of efficient causes has been the soundest basis, to my mind, for the 
adverse criticism of the theories of special protective resemblance, warning 
colors,and mimicry. Until recently most of the observations on which the 
theories are based have been simply observations proving the existence of 
remarkable similarities in appearance or equally striking contrasts and 
bizarrerie. The usefulness of these similarities and contrasts had been 
deduced logically, but not proved experimentally nor by direct observation. 
In recent years, however, a much sounder basis for these theories has been 
laid by experimental work. There is now on record a large amount of strong 
evidence for the validity of the hypothesis of mimicry. Certainly no other 
hypothesis of equal validity with those of protective resemblance and mimi- 
cry has been proposed to explain the numerous striking cases of similarity 
and the significant conditions of life accompanying the existence of ‘these 
cases, which have been recorded as the result of much laborious and indefati- 
gable study by certain naturalists. 

Plateau and Wheeler have tasted so-called inedible or distasteful insects 
and found nothing particularly disagreeable about them. But as Poulton 
suggests, the question is not as to the palate of Plateau and Wheeler nor of 
any men: it concerns the tastes of birds, lizards, etc. Better evidence is 
that afforded by actual observation of feeding birds and lizards; of experi- 
mental offering under natural conditions of alleged distasteful insects to 
their natural enemies. Marshall’s observations and experiments on the 
point are suggestive and undoubtedly reliable. Much more work of the 
same kind is needed. 

The efficient cause for bringing color and pattern up to such a high 


612 Color and Pattern and their Uses 


degree of specialization has been assumed, by nearly all upholders of the 
use hypotheses, to be natural selection. This agent can account for pur- 
posefulness, which is obviously an inherent part of all the hypotheses. And 
no other suggested agent can. Weismann makes, indeed, of this fact, by 
inverting the problem, one of his most effective arguments for the potency 
and Allmacht of natural selection. He declares that the existence of 
special protective resemblance, warning colors, and mimicry proves the 
reality of selection. But it must be asked, while admitting the cogency of 
much of the argument for natural selection as the efficient cause of high 
specialization of color and pattern as we have seen it actually to exist, how 
such a condition as that shown by the mimicking viceroy butterfly has come 
to be gradually developed, gradual development being confessedly selection’s 


Fic. 796.—The owl-butterfly, Caligo sp., under side. (Two-thirds natural size; photo- 
graph by the author.) 


only mode of working. Could the viceroy have had any protection for itself, 
any advantage at all, until it actually so nearly resembled the inedible mon- 
arch as to be mistaken for it? No slight tinge of brown on the black and 
white wings (typical color scheme of the genus), no slight change of mark- 
ing would be of any service in making the viceroy a mimic of the monarch. 
The whole leap from typical Basilarchia to (apparently) typical Anosia had 
to be made practically at once. On the other hand is it necessary for Kallima, 


Color and Pattern and their Uses 613 


the simulator of dead leaves, to go so far as it has in its modification? Such 
minute points of detail are there as will never be noted by bird or lizard. 
The simple necessity is the effect of a dead leaf; that is all. Kallima 
certainly does that and more. Kallima goes too far, and proves too much. 
And there are other cases like it. Natural selection alone could never carry 
the simulation past the point of full advantage. 

But whatever other factors or agents have played a part in bringing 
about this specialization of color and pattern, exemplified by insects showing 
protective resemblances, warning colors, terrifying manners, and mimicry, 
natural selection has undoubtedly been the chief factor, and the basis of 


Fic. 797.—The death’s-head sphinx-moth. (Photograph by the author.) 


utility the chief foundation, for the development of the specialized condi- 
tions. 

If any readers of this brief discussion of color and its uses among the 
insects care to refer to more detailed accounts of the general subject of color 
and pattern, or to parts of it, they will find the following books and papers 
useful: Poulton’s ‘‘The Colour of Animals’’; Beddard’s ‘‘ Animal Coloration”’; 
Newbigin’s ‘‘Color in Nature”; Wallace’s “‘ Darwinism,” Chaps. VIII, IX, 
and X; papers by Mayer on ‘‘The Development of the Wing-scales and their 
Pigment in Butterflies and Moths” (Bull. Mus. Comp. Zool., Vol. XXIX, 
No. 5, 1896), on “‘The Color and Color-patterns of Moths and Butterflies ” 
(Bull. Mus. Comp. Zool., Vol. XXX, No. 4, 1897), and on “‘ Effects of Natural 
Selection and Race-tendency upon the Color-patterns of Lepidoptera” (Bull. 


614 Color and Pattern and their Uses 


“Color and Color-patterns of Coleoptera” (Decenn. Pubs. Univ. of Chi 
Vol. X, 1903); a paper by Kellogg on ‘The Taxonomic Value of the Sca 
of the Lepidoptera” (Kansas Univ. Quar., Vol. III, No. 1, 1894); the pap 
by Poulton and Marshall referred to on page 605, and that by Shelford 
referred to on page 610. : 


CHAPTER, XVII 
INSECTS AND DISEASE 


HROUGHOUT this book reference is constantly 
made to the injuries done by insects to our 
forest-trees, flowers, fruits, vegetables, and 
grains. The millions of dollars lost annually 
because of the sap-sucking of the San José 
scale, the grape-phylloxera, the chinch-bug, 
and the Hessian fly, and the biting and chewing 
of beetles and caterpillars, grubs and borers, 

are a sort of direct tax paid by farmers and 

fruit-growers for the privilege of farming and growing fruit. If this tax 
were levied by government and collected by agents with two feet instead 
of being levied by Nature and collected by six-footed agents, what a swift 
revolt there would be! But we have, most of us, a curious inertia that leads 
us to suffer with some protesting complaint but little protesting action the 

“ways of Providence,’ even when we fairly well recognize that Providence 

is chiefly ourselves. 

When we reflect on the four hundred millions of dollars a year lost to 
our pockets by insect ravages we may incline to believe that the only kind 
of insect study which should claim our attention is the study of how to rid 
our lands of these pests. We may be excused for affirming of bugs, as was 
said of Indians by some epigrammatist, that the only good ones are the 
dead ones. When, however, we learn, as we are learning in these present 
days, that insects are not simply serious enemies of our crops and purses, 
but are truly dangerous to our very health and life, we must become still 
more extravagant in our condemnatory expressions concerning them. 

We have long looked on mosquitoes, house-flies, and fleas as annoyances 
and even torments, but that each of these pests actually acts as an inter- 
mediate host for, and is an active disseminator of, one or more wide-spread 
and fatal diseases is knowledge that has been got only recently. Mosquitoes 
help to propagate, and are, almost certainly, the exclusive disseminating agents 
615 


616 Insects and Disease 


of malaria, yellow fever, and the various forms of filariasis; house-flies aid 
in spreading typhoid fever and other diseases; fleas are agents in distribut- 
ing the germs of bubonic plague. Other insects are known to spread other 
diseases. Howard says: ‘‘While in malaria and typhoid we have two 
principal diseases common to the United States which may be conveyed 
by insects, the agency of these little creatures in the transfer of the disease-germs 
is by no means confined to human beings. In Egypt and in the Fiji Islands 
there is a destructive eye-disease of human beings the germs of which are 
carried by the common house-fly. In our southern states an_eye-disease 
known as pinkeye is carried by certain very minute flies of the genus Hip- 
pelates. The so-called Texas fever of cattle is unquestionably transferred 
by the common cattle-tick, and this was the earliest of the clearly demonstrated 
cases of the transfer of disease by insects. In Africa a similar ‘disease of 
cattle is transferred by the bite of the famous biting fly known as the tsetse- 
fly. The germs of the disease of cattle known as anthrax are carried by 
gadflies, or horse-flies, and when these flies subsequently bite human beings 
malignant pustules may result. And other discoveries of this nature are 
constantly being made. Even the common bedbug is strongly suspected 
in this connection.” 

These statements are not guesses; they are proved facts of science. It 
will be some time before these facts and their significance receive their full 
recognition in medical practice; the knowledge of medicine is always in 
advance of its practical recognition. But modern medical practice is much 
swifter to incorporate the new facts of biology than was the practice of even 
a decade or two ago, and in such lines of work as army and other govern- 
mental service the new methods of preventive medicine are quickly adopted. 
Already there are organized movements all over the world to make use of 
the new knowledge concerning the relation of insects to human disease. 
As I write these pages comes the report of the work of Major Ronald Ross, 
cne of the discoverers of the malaria-disseminating capacity of the mosquito 
and one of the leaders in the anti-mosquito crusade, in nearly stamping out 
malaria in the long notorious pest-hole of Ismailia. Malarial cases have been 
reduced there from 300,000 cases annually to 300, by effective war on mos- 
quitoes. Dr. Cruz reports that Rio Janeiro has abolished its old-fashioned 
quarantine regulations, and vessels with yellow fever on board will hereafter 
simply be disinfected and supervised. In October, 1903, Cruz directed the 
operations of twelve hundred men specially employed in destroying the 
larve of the mosquito in their breeding-places in and around the city, and as 
a result only nine cases of yellow fever developed in the midsummer months 
of January and February (1904), as against 275 cases in the same months 
in 1903. In the period from 1850 to 1896, 51,600 deaths occurred in Rio 
Janeiro from this disease, and at times as many as 2000 patients have been 


Insects and Disease 617 


cared for in the isolation hospital, which is now closed. The benefits of the 
war waged on the mosquito at Rio Janeiro have been as great as those obtained 
at Havana, where the vigorous work of the American authorities during our 
occupation of the islands practically stamped out yellow fever in a city long 
notorious the world over as a plague-center. 

Mosquitoes and malaria.—First of these known cases of the dissemina- 
tion of human disease by insects to be worked out in detail was the relation 
of mosquitoes to the breeding and distribution of the causative germs of 
malaria. Malarial fevers occur the world over and have long been associated 
in the popular mind with low wet localities or with localities near marsh 
or swamp. Mosquitoes live in great abundance precisely in such regions, 
but for a long time no association between mosquitoes and malaria was 
even suspected. Miasma, the effluvia from low wet ground, was held to be 
the causative, or at least carrying, agent of malaria. It was not until 1880, 
when Laveran discovered and described the actual parasitic sporozoon 
(minute one-celled amoeba-like animal) of malaria, that the actual cause of the 
disease was recognized. 

Malaria as we know it in the United States is a wide-spread and serious 
disease, but not commonly a fatal one. But in India five million deaths 
occurred in a single year, 1897, from malarial fever. Giles declares that the 
malarial parasite is responsible for by far the greatest proportion of all sick- 
ness and death in the tropics. ‘Cholera and plague,’ he says, “are the 
insignificant enemies that perhaps kill a few thousands a year—in an impres- 
sive way, it is true; but the quiet insidious malaria sweeps off its millions.” 
The serious state of affairs in India, as well as on the Gold Coast of Africa, 
on the Roman Campagna, and in other notoriously malaria-stricken regions, 
finally led to careful scientific study of the life-history of the malaria-pro- 
ducing sporozoon by well-trained English and Italian physicians and natu- 
ralists, with the result that we now know in definite and accurate detail the 
whole marvelous story of the interrelations of the malarial parasite, the 
mosquito, and the human host. 

Lankester was the first to find an amoeba-like parasite living in the blood 
of animals, Drepanidium ranarum of frog’s blood, but since his discovery 
numerous other similar protozoon blood-parasites, collectively called Hama- 
tozoa, have been found in reptiles, birds, bats, cattle, and monkeys. The 
hematozoon infesting cattle discovered by Theobald Smith, an American 
investigator, produces the disease known as Texas fever, and is spread from 
animal to animal by ticks. The particular blood-parasites, called Hama- 
moebze, which produce malarial fevers, are not restricted to man alone, but 
infest birds, bats, and monkeys as well. 

In 1885 Golgi discovered that the malaria-producing Hamameebe of the 
human body exist in three varieties, each apparently responsible for one 


618 Insects and Disease 


of the three well-known types of malarial fever, namely, quartan, tertian, 
and remittent. And soon after 1885, Golgi and other investigators, Italian, 
English, and American (Celli, Grassi, Mannaberg, Bignami, Danielewsky, 
Carter, Osler, Labbé, Koch, Manson, Councilman, Thayer, MacCallum, 
and others), succeeded in working out in minute detail the behavior, develop- 
ment, and pathological effects, direct and indirect, of the parasites in the 
human blood. From these researches I may summarize the life of the malaria- 
producing Hamameebe in the human body as follows: The youngest para- 
sites, or amcebulz, are found living within the red blood-corpuscles; here 
they grow at the expense of the corpuscle substance. They increase rapidly 
in size, while the blood-corpuscle begins to degenerate. From the break- 
ing down of the hemoglobin of the corpuscle, due to the metabolism of the 


Fic. 798.—Diagrammatic figure of stages in the development of the malaria-producing 
Hemameeba (Plasmodium) in a red blood-corpuscle of the human body. 


parasite, granules of a blackish pigment are formed; this is the melanin 
long known as a regular diagnostic characteristic of malaria. After a few 
days, from one to several depending on the variety of the Hamameeba, the 
amoebule reach maturity. They begin now to sporulate; that is, the nucleus 
and cytoplasm divide into many small parts, each nuclear part having aggre- 
gated about it part of the cytoplasm. The walls of the blood-corpuscle then 
break, and these many Hamamceba spores are released into the blood-plasma. 
Each of these spores soon attaches itself to a fresh blood-corpuscle, pene- 
trates it, and begins a new life-cycle. It is obvious that such a parasitic life 


Insects and Disease 619 


in the blood-corpuscles, using up their substance and breaking them down, 
must work much harm to the human body. This harm is exactly that which 
we recognize as the result of malaria. The fever and other ills that are a 
part of malaria are the direct and indirect pathological effects of the growth 
and metabolism and multiplication of the Hamamoebe in our blood. From 
a single infection the sporulation or escape of the myriads of spores from the 
breaking-down corpuscles into the blood-plasma takes place practically simul- 
taneously and makes the beginning of the malarial spasm. This kind of 
multiplication of the Hamameebe, by sporulation, is termed asexual; there 
is no participation of individuals of two kinds, or sexes, in the reproduction. 
It is a sort of multiplication common to a great many minute, simple animals 
and plants, but it does not seem in any of these to be the only mode of mul- 
tiplication. Scores, even hundreds, of successive generations may be pro- 
duced asexually, but finally there occurs another kind of reproduction, which 
has for its essential characteristic the meeting and fusing of the nuclei or 
parts of them, and sometimes the body protoplasm or parts of it, of two 
individuals of the species. In all but the very simplest organisms these two 
conjugating individuals differ somewhat in size, shape, and manner of behavior. 
Scientists began to ask when and how and where conjugation occurred in 
the Hemamoebz of malaria; their questioning was made more insistent by 
the discovery that some of the amcebulz in the blood-corpuscles did not sporu- 
late, but continued to circulate in the blood without any particular function 
at all. More than that, it was noted that whenever they were withdrawn 
from the circulation, as when a drop of blood was taken out of the skin with 
a pipette for examination under the microscope, these traveling amcoebule 
would swell up and liberate themselves from their enclosing corpuscle, and 
that some of them would emit a number of long motile filaments; these fila- 
ments could be seen lashing about strongly, and often succeeded in breaking 
away from the parent cell, and darting away among the corpuscles. This 
phenomenon can always be observed in the blood drawn from a malarial 
patient, in from ten to fifteen minutes after its withdrawal from the circula- 
tion. What is the meaning of it? A further insistent question came up at 
this time. And that is, If the Hamamoebe are the actual and sole cause of 
malaria, how do they get from man to man? How is the malaria dissem- 
inated ? 

The explanation of the significance of the phenomenon of the formation 
of the motile filaments from amcebule in blood withdrawn from circulation, 
and the answer to the question as to the mode of transmissibility of malaria, 
are closely connected, and were reached chiefly through the brilliant work 
of Manson and Ross, two English investigators of tropical diseases. Espe- 
cially interesting is the work of Ross in establishing the actual fact of the carry- 
ing by the mosquito of the Hamamcebe from man to man. The following 


620 Insects and Disease 


long quotation from Ross, taken from a lecture delivered by him on March 2, 
1900, before the Royal Institution of Great Britain, gives a detailed account 
of this work, answers both the questions asked above, and at the same time 
serves to reveal a typical instance of the faith and persistence of the men 
to whom we owe scientific progress. 

“Tt was reserved for Manson,” says Ross, ‘‘to detect the ultimate (though 
not the immediate) functions of these bodies [the motile filaments]. He 
asked why the escape of the motile filaments occurs only after the blood 
is abstracted from the host (a fact agreed upon by many observers). From 
his study of these filaments, of their form and their characteristic movements, 
he rejected the Italian view that they are regressive forms; he was convinced 
that they are living elements. Hence he felt that the fact of their appearance 
only after abstraction from the blood (about fifteen minutes afterwards) 
must have some definite purpose in the life-scheme of the parasites. What 
is that purpose? It is evident that these parasites, like all others, must pass 
from host to host; all known parasites are capable of not only entering the 
host, but, either in themselves or their progeny, of leaving him. Manson 
himself had already pushed such methods of inductive reasoning to a bril- 
liantly successful issue in discovering by their means the development of 
Filaria nocturna in the gnat. He now applied the same methods to the 
study of the parasites of malaria. Why should the motile filaments appear 
only after abstraction of the blood? There could be only one explanation. 
The phenomenon, though it is usually observed in a preparation for the 
microscope, is really meant to occur within the stomach-cavity of some suctorial 
insect, and constitutes the first step in the life-history of the parasite outside 
the vertebrate host. 

“Tt is perhaps impossible for any one, except one who has spent years in 
revolving the subject, to understand the full value and force of this remarkable 
induction. To my mind the reasoning is complete and exigent. It was 
from the first impossible to consider the subject in the light which Manson 
placed it without feeling convinced that the parasite requires a suctorial 
insect for its further development. And subsequent events have proved 
Manson to have been right. 

“The most evident reasoning—the connection between malarial fever 
and low-lying water-logged areas in warm countries—suggested at once 
that the suctorial insect must be the gnat (called mosquito in the tropics); 
and this view was fortified by numerous analogies which must occur at once 
to any one who considers the subject at all, and which it is not necessary to 
discuss in this place. 

“Needless to say, since Manson’s theory was proved to be the right 
one it has been shown to be not entirely original. Nuttall, in his admirable 
history of the mosquito theory, demonstrates its antiquity. Eleven years 


Insects and Disease 621 


before Manson wrote, King had already accumulated much evidence, based 
on epidemiological data, in favor of the theory. A year later (1884), Laveran 
himself briefly enunciated the same views, on the analogy with Filaria noc- 
turna. Koch and, later, Bignami and Mendini were also advocates of 
the theory—partly on epidemiological grounds and partly because of a possible 
analogy with the protozoal parasites of Texas cattle-fever which Smith and 
Kilborne had shown to be carried by a ¢ick. Hence many observers had 
independently arrived at the same theory by different routes. .. . 

“To leave these interesting theories and to return to actual observations— 
I should begin by remarking that Manson thought the motile filaments to 
be of the nature of zoospores—that is, motile spores which escape from the 
gametocytes in the stomach-cavity of the gnat, and then occupy and infest 
the tissues of the insect. In this he was proved, two years later, to have 
been wrong. The motile filaments are not spores, but microgametes—that 
is, bodies of the nature of spermatozoa. I have said that some of the amcebulz 
in the blood-corpuscles of the host become sporocytes, which produce asexual 
spores (nomospores); while other amoebule become gametocytes, which 
have no function within the vertebrate host. As soon, however, as these . 
gametocytes are ingested by a suctorial insect they commence their proper 
functions. As their name indicates, they are sexual cells—male and female. 
About fifteen minutes after ingestion (in some species) the male gametocytes 
emit a variable number of microgametes—the motile filaments—which 
presently escape and wander in search of the female gametocytes. These 
contain a single macrogamete, or ovum, which is now fertilized by one of the 
microgametes, and becomes a zygote. We owe this beautiful discovery 
to the direct observation of MacCallum (1897), confirmed by Koch and 
Marchoux, and indirectly by Bignami. . . . Directly MacCallum’s discovery 
was announced Manson saw the important bearing of it on the mosquito. 
Admitting that the motile filaments themselves do not infect the gnat, he 
at once observed that it was probably the function of the zygote to do so— 
and this time he was perfectly right. 

“T must now turn to my own researches. Dr. Manson told me of his 
theory at the end of 1894, and I then undertook to investigate the subject 
as far as possible. I began work in Secunderabad, India, in April, 1895; 
and should take the present opportunity for acknowledging the continu- 
ous assistance and advice which I received from Dr. Manson and from 
Dr. Laveran, and later from the Government of India. Even with the aid of 
the induction the task so lightly commenced was, as a matter of fact, one 
of so arduous a nature that we must attribute its accomplishment largely 
to good fortune. The method adopted—the only method which could be 
adopted—was to feed gnats of various species on persons whose blood con- 
tained the gametocytes, and then to examine the insects carefully for the 


622 Insects and Disease 


parasites which by hypothesis the gametocytes were expected to develop 
into. This required not only familiarity with the histology of gnats, but a 
laborious search for a minute organism throughout the whole tissues of each 
individual insect examined—a work of at least two or three hours for each 
gnat. But the actual labor involved was the smallest part of the difficulty. 
Both the form and appearance of the object which I was in search of, and 
the species of the gnat in which I might expect to find it, were absolutely 
unknown quantities. We could make no attempt to predict the appearance 
which the parasite would assume in the gnat; while owing to the general 
distribution of malarial fever in India, the species of insect concerned in the 
propagation of the disease could scarcely be determined by a comparison 
of the prevalence of different kinds of gnat at different spots with the preva- 
lence of fever at those spots. In short, I was forced to rely simply on the 
careful examinations of hundreds of gnats, first of one species and then of 
another, all fed on patients suffering from malarial fever—in the hope of 
one day finding the clue I was in search of. Needless to say, nothing but 
the most convincing theory, such as Manson’s theory was, would have sup- 
ported or justified so difficult an enterprise. 

“As a matter of fact, for nearly two and a half years my researches were 
almost entirely negative. I could not obtain the correct scientific names of 
the various species of gnats employed by me in these researches, and con- 
sequently used names of my own. Gnats of the genus Culex (which abound 
almost everywhere in India) I called ‘gray’ and ‘brindled’ mosquitoes; 
and it was these insects which I studied during the period referred to. At 
last, the particular nugatory results which had been obtained with gnats 
of this genus determined me to try other methods. I went to a very mala- 
rious locality, called the Sigur Ghat, near Ootacamund, and examined the 
mosquitoes there in the hope of finding within them parasites like those of 
malaria in man. The results were practically worthless (except that I 
observed a new kind of mosquito with spotted wings); and I saw that I 
must return to the exact methods laid down by Manson. The experiments 
with the two commonest kinds of Culex were once more repeated—only to 
prove once more negative. The insects, fed mostly on cases containing 
the crescentic gametocytes of Ha@momenas precox, were examined cell by 
cell—not even their excrement being neglected. Although they were known 
to have swallowed Hemameebide, no living parasites like these could be 
detected in their tissues—the ingested Heemamoebide had in fact perished in 
the stomach-cavity of the insects. I began to ask whether after all there 
was not some flaw in Manson’s induction; but no—TI still felt his conclusion 
to be an inevitable one. And it was at this moment that good fortune gave 
me what I was in search of. . 

“In a collecting-bottle full of larve brought in by a native from unknown 


Insects and Disease 623 


source I found a number of newly hatched mosquitoes like those first observed 
by me in Sigur Ghat—namely, mosquitoes with spotted wings and boat-shaped 
eggs. Eight of these were fed on a patient whose blood contained crescentic 
gametocytes. Unfortunately I dissected six of them either prematurely or 
otherwise unsatisfactorily. The seventh was examined, on August 20, cell 
by cell; the tissues of the stomach (which was now empty owing to the meal 
of malarial blood taken by the insect four days previously being digested) 
were reserved to the last. On turning to this organ I was struck by observ- 
ing, scattered on its outer surface, certain oval or round cells of about two 
or three times the diameter of a red blood-corpuscle—cells which I had never 
before seen in any of the hundreds of mosquitoes examined by me. My 
surprise was complete when I next detected within each of these cells a few 
granules of the characteristic coal-black melanin of malarial fever—a substance 
quite unlike anything usually found in mosquitoes. Next day the last of the 
remaining spotted-winged mosquitoes was dissected. It contained precisely 
similar cells, each of which possessed the same melanin; only the cells in 
the second mosquito were somewhat larger than those in the first. 

“These fortunate observations practically solve the malarial problem. 
As a matter of fact, the cells were the zygotes oj the parasite of remittent fever 
growing in the tissues of the gnat; and the gnat with spotted wings and boat- 
shaped eggs in which I had found them belonged (as I subsequently ascer- 
tained) to the genus Anopheles. Of course it was impossible absolutely 
to prove at the time, on the strength of these two observations alone, that the 
cells found by me in the gnats were indeed derived from Hemamcebide 
sucked up by the insects in the blood of the patients on whom they had 
been fed—this proof was obtained by subsequent investigations of mine; 
but, guided by the presence of the typical and almost unique melanin in the 
cells, and by numerous other circumstances, I myself had no doubt of the 
fact. The clue was obtained; it was necessary only to follow it up—an 
easy matter... . 

‘“‘Farly in 1898, mainly through the influence of Dr. Manson, Sir H. W. 
Bliss, and the United Planters’ Association of Southern India, I was placed by 
the Government of India on special duty in Calcutta to continue my inves- 
tigations. Unable to work with human malaria—chiefly on account of the 
plague-scare in Calcutta—I turned my attention to the Hemameebide of 
birds. Birds have at least two species of Hemameebide. I subjected a 
number of birds containing one or the other of these parasites to the bites 
of various species of mosquitoes. The result was a repetition of that pre- 
viously obtained with the human parasites. Pigmented cells precisely simi- 
lar to those seen in the Anopheles were found to appear in gnats of the species 
called Culex fatigans Wiedemann, when these had been fed on sparrows and 
larks containing Hemameba relicta. On the other hand, these cells were 


624 Insects and Disease 


never found in insects of the same species when fed on healthy birds or on 
birds containing the other parasite, called Haemameba danilewskii. 

“Tt will be evident that this fact was the crucial test both as regards the 
parastic nature of these cells and as regards their development from the 
hemocytozoa of the birds; and it was not accepted by me without very close 
and laborious experiment. The actual results obtained were as follows: 

“ Out of 245 Culex fatigans fed on birds containing H. relicta 178, or 72 
per cent., contained ‘pigmented cells.’ But, out of 41 Culex fatigans 
fed on a man containing crescentic gametocytes, 5 on a man containing imma- 
ture tertian parasites, 154 on birds containing H. danilewskii, 25 on healthy 
sparrows, and 24 on birds with immature H. relicta—or a total of 249 insects, 
all carefully examined—not one contained a single ‘pigmented cell.’ 

“Another experiment was as follows: Three sparrows, one containing 
no parasites, another containing a moderate number of H. relicta, and the 
third containing numerous /. relicta, were placed in separate cages within 
three separate mosquito-curtains. A number of Culex jatigans, all bred 
simultaneously from larve in the same breeding-bottle, were now liberated 
on the same evening partly within the first mosquito-netting, partly within 
the second, and partly within the third. Next morning many of these gnats 
were found to have fed themselves on the birds during the night. Ten of 
each lot of gnats were dissected after a few days, with the following result: 

“The ten gnats fed on the healthy sparrow contained no ‘pigmented 
cells.’ The ten gnats fed on the sparrow with a moderate number of para- 
sites were found to contain altogether 202 ‘pigmented cells,’ or an average 
of 29 ineach gnat. The ten gnats fed on the sparrow with numerous parasites 
contained 1oog ‘pigmented cells,’ or an average of too cells in each gnat. 
These thirty specimens were sent to Manson in England, who made a similar 
count of the cells. 

“T may mention one more out of several experiments of the same kind. 
A stock of Culex fatigans, all bred from the larva, were fed on the same 
night partly on two sparrows containing H. relicta, and partly on a crow 
containing H. danilewskii (placed, of course, under separate mosquito- 
nettings). Out of 23 of the former lot, 22 were found to have pigmented 
cells; while out of 16 of the latter, none had them. 

“Hence no doubt remained that the ‘pigmented cells’ really constitute 
a developmental stage in the mosquito of these parasites; and this view 
was accepted both by Laveran and Manson, to whom specimens had been 
sent. In June, 1898, Manson published an illustrated paper concerning 
my researches, and showed that the pigmented cells must in fact be the 
zygotes resulting from the process of fertilization discovered by MacCallum. 

‘Tt remained to follow out the life-history of the zygotes. For this purpose 
it was immaterial whether I worked with the avian or the human parasites, 


aa, ans 
= 
SS 


aa 


Insects and Disease 625 


since these are so extremely like each other. I elected to work with the 
avian species, chiefly because the plague-scare in Bengal still rendered obser- 
vations with the human species almost impossible. By feeding Culex 
fatigans on birds with H. relicta and then examining the insects one, two, 
three or more days afterwards, it was easy to trace the gradual growth of 
the zygotes. Their development briefly is as follows: After the fertilization 
of the macrogamete has taken place in the stomach-cavity of the gnat, the 
fertilized parasite or zygote has the power of working its way through the 
mass of blood contained in the stomach, of penetrating the wall of the organ, 
and of affixing itself on, or just under, its outer coat. Here it first appears 
about thirty-six hours after the insect was fed, and is found as a ‘pigmented 
cell’—that is, a little oval body, about the size of a large red corpuscle, and 
containing the granules of melanin possessed by the parent gametocyte 
from which the macrogamete originally proceeded. In this position it shows 
no sign of movement, but begins to grow rapidly, to acquire a thickened 
capsule, and to project from the outer wall of the stomach, to which it is 
attached, into the body-cavity of the insect-host. At the end of six days, if 
the temperature of the air be sufficiently high (about 80° F.), the diameter 
of the zygote has increased to about eight times what it was at first; that is, 
to about 60 microns. If the stomach of an infected insect be extracted at 
this stage, it can be seen, by a low power of the microscope, to be studded 
with a number of attached spheres, which have something of the appear- 
ance of warts on a finger. These are the large zygotes, which have now 
reached maturity and which project prominently into the mosquito’s body- 
cavity. 

‘All this could be ascertained with facility by the method I have men- 
tioned: and it should be understood that gnats can be kept alive for weeks 
or even months by feeding them every few days on blood, or, as Bancroft 
does, on bananas. But a most important point still required study. What 
happens after the zygotes reach maturity? I found that each zygote as 
it increases in size divides into meres, each of which next becomes a blastophore 
carrying a number of blasts attached to its surface. Finally, the blastophore 
vanishes, leaving the thick capsule of the zygote packed with thousands 
of the blasts. The capsule now ruptures, and allows the blasts to escape 
into the body-fluids of the insect. 

“These blasts, when mature, are seen to be minute filamentous bodies, 
about 12-6 in length, of extreme delicacy, and somewhat spindle-shaped— 
that is, tapering at each extremity. Prof. Herdman and I have adopted 
this word ‘blast’ for these bodies after careful consideration, but others 
prefer other names. They are, of course, spores; but spores which have 
been produced by a previous sexual process, and are in fact the result of 
a kind of polembryony. Just as a fertilized ovum gives rise to blasts, 


626 Insects and Disease 


which produce the cluster of cells constituting a multicellular animal, so, 
in this case, the fertilized ovum, or zygote, gives rise to blasts, each of 
which, however, becomes a separate animal. Prof. Ray Lankester suggests 
for the blasts of the Hamameebide the simple term ‘filiform young.’ 

“At this point the investigations took a turn of extreme interest and 
importance, scarcely second even to that attached to the first study of the 
zygotes. Since the blasts are evidently the progeny of the zygotes, they 
must carry on the life-history of the parasites to a further stage. How do they 
do so? What is their function? Do they escape from the mosquito, and 
in some manner, direct or indirect, set up infection in healthy men or birds? 
Or, if not, what other purpose do they subserve? It was evident that our 
knowledge of the mode of infection in malarial fever—and perhaps even 
the prevention of the disease—depended on a reply to these questions. 

“As I have said, the zygotes become ripe and rupture about a week 
after the insect was first infected—scattering the blasts into the body-cavity 
of the host. What happens next? It was next seen that by some process, 
apparently owing to the circulation of the insect’s body-fluids (for the blasts 
themselves appear to be almost without movement), these little bodies find 
their way into every part of the mosquito—into the juices of its head, thorax, 
and even legs. Beyond this it was difficult to go. All theory—at least all 
theory which I felt I could depend upon—had been long left behind, and 
I could rely only on direct observation. Gnat after gnat was sacrificed in 
the attempt to follow these bodies. At last, while examining the head and 
thorax of one insect, I found a large gland consisting of a central duct sur- 
rounded by large grape-like cells. My astonishment was great when I 
found that many of these cells were closely packed with the blasts (which 
I may add are not in the least like any normal structures in the mosquito). 
Now I did not know at that time what this gland was. It was speedily 
found, however, to be a large racemose gland consisting of six lobes, three 
lying in each side of the insect’s neck. The ducts of the lobes finally unite 
in a common channel which runs along the under surface of the head and 
enters the middle stylet, or lancet, of the insect’s proboscis. 

“Tt was impossible to avoid the obvious conclusion. Observation after 
observation always showed that the blasts invariably collect within the cells 
of this gland. It is the salivary or poison gland of the insect, similar to the 
salivary gland found in many insects, the function of which, in the gnat, 
had already been discovered—although I was not aware of the fact. The 
function is to secrete the fluid which is injected by the insect when it punc- 
tures the skin—the fluid which causes the well-known irritation of the punc- 
ture, and which is probably meant either to prevent the contraction of the 
torn capillaries or the coagulation of the ingested blood. The position of 
the blasts in the cells of this gland could have only one interpretation— 


Insects and Disease 627 


wonderful as that interpretation is. The blast must evidently pass down 
the ducts of the salivary gland into the wound made by the proboscis of 
the insect, and thus cause infection in a fresh vertebrate host. 

“That this actually happens could, fortunately, be proved without difficulty. 
As I had now been studying the parasites of birds for some months, I possess 
a number of birds of different species, the blood of which I had examined 
from time to time (by pricking the toes with a fine needle). Some of them 
were infected, and some, of course, were not. Out of 111 wild sparrows 
examined by me in Calcutta, I had found H. relicta—the parasite which I 
had just cultivated in Culex jatigans—in 15, or 13.5 per cent. As a rule, 
non-infected birds were released; but I generally kept a few for the control 
experiments mentioned above, and the blood of these birds had consequently 
been examined on several occasions, and had always been found free from 
parasites. At the end of June I possessed five of these healthy control birds— 
four sparrows and one weaver-bird. All of them were now carefully examined 
again and found healthy. They were placed in their cages within mosquito- 
nets, and at the same time a large stock of old infected mosquitoes were 
released within the same nets. By ‘old infected mosquitoes’ I mean 
mosquitoes which had been previously repeatedly fed on infected birds, 
and many of which on dissection had been shown to have a very large number 
of blasts in their salivary glands. Next morning numbers of these infected 
gnats were found gorged with blood, proving that they had indeed bitten 
the healthy birds during the night. The operation was repeated on several 
succeeding nights, until each bird had probably been bitten by at least a 
dozen of the mosquitoes. On July 9 the blood of the birds was examined 
again. I scarcely expected any result so complete and decisive. Every 
one of the five birds was now found to contain parasites—and not merely 
to contain them, but to possess such immense numbers of them as I had 
never before seen in any bird (with H. relicta) in India. While wild sparrows 
in Calcutta seldom contain more than one parasite in every field of the micro- 
scope, those which I had just succeeded in infecting contained ten, fifteen, 
and even more in each field—a fact due probably to the infecting gnats 
having been previously fed over and over again on infected birds, a thing 
which can rarely happen in nature. 

“The experiment was repeated many times—generally on two or three 
healthy birds put together. But now I improved on the original experiment 
by also employing controls in the following manner: A stock of wild sparrows 
would be examined, and the infected birds eliminated. The remainder 
would then be kept apart, and at night would be carefully excluded from 
the bites of gnats by being placed within mosquito-nets. These constituted 
my stock of healthy birds. From time to time two or three of these would 
be separated, examined again to insure their being absolutely free from 


628 Insects and Disease 


parasites, and then subjected to the bites of ‘old infected mosquitoes,’ 
and, of course, kept apart afterwards for daily study. Thus my stock of 
healthy birds was also my stock of control birds. Until they were bitten 
by gnats, I found that they never became infected (except in a single case 
in which I think I had overlooked the parasites on the first occasion), although 
large numbers of healthy birds were kept in this manner. The results in 
the case of the sparrows which were subjected to the bite of the infected gnats 
were different, indeed. Out of 28 of these, dealt with from time to time, 
no less than 22, or 79 per cent., became infected in from five to eight days. 
And, as in the first experiment, all the infected birds finally contained very 
numerous parasites. 

“Tt was most interesting to watch the gradual development of the parasitic 
invasion in these birds; and this development presented such constant 
characters that, apart from other reasons, it was quite impossible to doubt 
that the infection was really caused by mosquitoes. The course of events 
was always as follows: The blood would remain entirely free from parasites 
for four, five, six, or even seven days. Next day one or perhaps two parasites 
would be found in a whole specimen. The following day it was invariably 
observed that the number of organisms had largely increased; and this 
increase continued until in a few days immense numbers were present—so 
that, finally, I often observed as many as seven distinct parasites contained 
within a single corpuscle! Later on many of the birds died; and their 
organs were found to be loaded with the characteristic melanin of malarial 
fever. 

“T also succeeded in infecting on a second trial one of the six sparrows 
which had escaped the first experiment; and also a crow and four weaver- 
birds; and, lastly, gave a new and more copious infection to four sparrows 
which had previously contained only a few parasites. 

“These experiments completed the original and fundamental observa- 
tions on the life-history of the Hamamcebide in mosquitoes. The parasites 
had been carried from the vertebrate host into the gnat, and had finally 
been carried back from the gnat to the vertebrate host. The theories of 
King, Laveran, Koch, and Bignami, and the great induction of Manson, 
were justified by the event: and I have given a detailed historical and critical 
account of these theories, and of my own difficulties, in the hope of bringing 
conviction to those who might perhaps otherwise think the story to be too 
wonderful for credence.” 

Since Ross’s work, a host of new observations and facts have been made 
known by various investigators. All of these studies only add to the cer- 
tainty that the malaria parasite depends absolutely upon mosquitoes for 
its full development and for its dissemination. Many of these observations 
and experiments have to do with actual tests of malaria prevention. Con- 


Insects and Disease 629 


spicuous among these tests was that of two English physicians, Sambon and 
Low, in 1900, in the ‘“‘malaria-house”’ in the Roman Campagna. This ex- 
periment is described by Howard as follows: “‘ Doctors Sambon and Low had 
constructed a comfortable little five-roomed wooden house about three hours’ 
drive from Ostia, in one of the most malarious portions of the Campagna. 
The house was tightly built and was thoroughly screened. The experi- 
menters lived in this house through the period when malaria is most prevalent. 
They took no quinine and no health precautions beyond the fact that at 
sundown each day they entered the house and remained there until day- 
light the next morning. Dr. Rees, of the London School, visited them 
and occupied the house with them for a portion of the time, and all three 
conducted laboratory work in one of the rooms, which was fully equipped 
for such a purpose, and led a busy and contented life. They visited the 
neighboring villages and investigated outbreaks of the fever in men and 
cattle. They received and entertained many visitors who were interested 
in the experiment. They turned indoors before six o’clock and then stood 
at the windows and timed the first appearance of Anopheles, which would 
come at a certain hour each evening and try to enter the screened windows 
and doors. As Dr. Rees expressed it, ‘It must have been very tantalizing 
for them to be unable to get at us.’ When the rains set in, every one said 
that that was the critical time of the experiment. The people in the sur- 
rounding country generally became feverish and ill, which meant simply 
that they were all full of malaria, and the chilling caused by the rain brought 
about an explosion of the fever. The experimenters, however, went out 
into the rain and got soaked to the skin, but their health remained perfect. 
Not the slightest trace of malaria developed in either of them; as above 
stated, the spot where the house was built was probably the most malarious 
one in the whole Campagna, and it was situated on the banks of one of the 
canals, which was literally swarming with Anopheles larvae. The prevalent 
idea that the night air of the Campagna is in itself so dangerous was included 
in the experiments, and the windows were always left open at night, so that 
if the marsh air had anything to do with malaria they would have contracted it. 

“A check experiment was carried on at the same time. Anopheles 
mosquitoes which had been fed on the blood of a sufferer from malaria in 
Rome, under the direction of the Italian authority Bastianelli, were sent 
to London early in July. A son of Dr. Patrick Manson, the famous inves- 
tigator who first proved the transfer of filariae by mosquitoes, offered himself 
as a subject for experiment, and allowed himself to be bitten by the mosquitoes. 
He had never been in a malarious country since he was a child, but in due 
time was taken with a well-marked malarial infection of the double tertian 
type, and microscopical examination showed the presence of numerous para- 
sites in his blood.” 


630 Insects and Disease 


Another test in the same year was made by Professor Grassi near Salerno. 
“The objects of this experiment were,’’ writes Howard, “‘(1) to afford 
absolute proof of the fact that malaria is transmitted exclusively by the 
bite of Anopheles mosquitoes; (2) to found, on the results of recent research, 
a code of rules to be adopted for freeing Italy from malaria in a few years. 
The experiment consisted in protecting from malaria railway employees 
and their families, living in ten cottages, at the stations of St. Nicolo, Var- 
co, and Albanella, situated along the Battipaglia-Reggio Railway. They 
numbered one hundred and four persons, including thirty-three children 
under ten years of age. Of these one hundred and four individuals, at 
least eleven, including four children, had never suffered from the disease, 
not having previously lived in a malarious district; a certain number, it 
appeared, had not suffered from it in two or three years, and all the others, 
that is to say, the large majority, had suffered from it during the last malarial 
season, some of them even in the winter. During the malarial season the 
health of the protected individuals was good, with the exception of a few 
cases of bronchitis and a case of acute gastro-enteritis. None of these cases 
was treated with quinine. The one hundred and four persons, with three 
exceptions, had remained free from malaria up to September 16th, the date 
of the report.” 

These two experiments alone would be conclusive. Since rg00, however, 
the brilliantly successful results of actual practical measures undertaken 
on a large scale in Africa under the supervision of English experts, and in 
many European and American localities by army, governmental, and munici- 
pal authorities, have settled the matter of malaria infection for all time. 
It only remains now to adopt in medical practice everywhere and in the work 
of boards of health, other municipal and country boards of supervision, the 
efficacious methods, well proved, of fighting malaria by fighting mosquitoes. 
An account of some of these methods, together with the facts of the life-history 
of mosquitoes, and information regarding the distinguishing characters 
of the malaria-bearers (Anopheles) and the non-malarial kinds (Culex and 
others), are given on pp. 305 et seq. of this book. In addition I may simply 
say, when in malarial regions avoid the bite of a mosquito as you would that 
of a rattlesnake. One can be quite as serious in its results as the other. 

Mosquitoes and yellow fever.—So much space has been given to the 
account of the relation of mosquitoes to the propagation and dissemination 
of malaria that we can do only scant justice to the mosquitoes in their rdle 
as disseminators of other diseases. 

Although yellow fever is a plague long known and one much studied, 
so that its diagnosis and its treatment are well understood and are the neces- 
sary knowledge of every physician practicing in tropical regions, and although 
we know certainly that it is the result of the growth in the body of a parasitic 


Insects and Disease 631 


organism, and that this organism is disseminated by mosquitoes, infection 
being accomplished only by the puncture of a mosquito, it is a curious fact 
that the causative germ or parasite has not yet been isolated; in other words, 
is not yet specifically known. Whether bacterium or sporozoon, whether 
inhabiting the blood solely or occurring also in other tissues, answers to 
these questions remain to be discovered. Numerous claims have been made 
by various physicians of the discovery of the parasite; the latest claim has 
been published within the last few months, but so far none of these reputed 
determinations of the yellow-fever parasite has been proved to the satisfac- 
tion of scientific men. That the yellow-fever germ, whatever it is, is how- 
ever actually carried by mosquitoes, and apparently in no other way, and that 
the dissemination of the disease thus depends upon the intervention and aid 
of mosquitoes, are facts that have been proved largely through the able and 
courageous work of American investigators. 

An early suggestion that mosquitoes might be the agents in spreading 
yellow fever came from an Havana physician, Dr. Carlos Finlay. His 
theory was based chiefly on observations of the correspondence between 
an abundance of mosquitoes and a period of increase of yellow fever. In 
1g0o an Army Yellow Fever Commission, composed of Major Walter C. Reed, 
surgeon, U. S. A., and three acting assistant surgeons was appointed by 
Surgeon-General Sternberg to investigate the disease. Two members of 
the Commission, Major Reed and Dr. Lazear, lost their lives from the attacks 
of the disease they were studying. "The Commission was soon able to report 
that yellow fever followed the bite of mosquitoes of the species Stegomyia 
jasciata, after the mosquitoes had first been allowed to suck blood from 
yellow-fever patients. Soon after it was able to report that yellow fever did 
not follow as a result of exposing non-immune subjects to contact with clothes 
or bedding or other belongings of patients actually suffering and dying from 
yellow fever. On the basis of these discoveries the Commission made certain 
crucial experiments whose outcome is convincing proof of the facts of the 
transmission of the disease by mosquitoes, and that it is transmitted in no 
other way. 

A small house was built, thoroughly screened against mosquitoes. In 
this house seven non-immune persons lived during sixty-three days; three 
of them occupied the room each night for twenty days, sleeping on sheets, 
pillow-cases, and blankets brought from beds occupied by yellow-fever patients 
in Havana, soiled by their discharges. Some of the bedding and clothing worn 
by the subjects in the yellow-fever house were purposely infected with the 
discharges of a fatal case of yellow fever. During all the sixty-three days the 
average temperature of the house was kept at 76.2° F., a considerable amount 
of humidity was maintained, and little sunlight or freely circulating air was 
admitted, all of these conditions being highly favorable for the development 


632 Insects and Disease 


of yellow fever. Not a single one of the seven inhabitants of the house was 
attacked by the disease. 

Another similar building was erected near by, well provided with doors 
and windows for thorough ventilation. It was divided into two rooms 
by a wire-screen partition extending from floor to ceiling. All articles 
admitted to the building were carefully disinfected by steam before being 
placed therein. Into the large room of this building mosquitoes which had 
been previously contaminated by biting yellow-fever patients were admitted. 
Non-immunes were placed in both rooms. In the room in which mosquitoes 
were not admitted the experimentalists remained in perfect health. In 
the other room six out of seven persons bitten by infested mosquitoes came 
down with yellow fever. In all, of persons bitten by infested mosquitoes 
that had been kept twelve days or more after biting yellow-fever patients 
before being allowed to bite them, 80 per cent. were taken with the disease. 

Other similar crucial tests were made by the Commission and have been 
made by other investigators working in other places. The conclusions are 
positive. Yellow fever is caused by a germ, as yet undetermined, which 
lives for part of its life in the blood of human beings, and is carried from 
man to man by mosquitoes, being sucked up with blood by mosquitoes which 
find access to yellow-fever patients, and transmitted to the blood of new 
subjects from the beak during puncturing. An interval of about two weeks 
after the mosquito is affected is necessary before the mosquito is capable 
of conveying the infection, which means that the yellow-fever germ is under- 
going a certain necessary part of its development in the mosquito’s body. 

As I have already mentioned (p. 308), the mosquito species Stegomyia 
jasciata, the carrier of the yellow fever in the West Indies, is the most abundant 
mosquito species in the Hawaiian Islands and also in the Samoan Islands. 
In neither of these groups of tropic islands has yellow fever yet found a 
footing, but is it not possible that with the cutting of the Panama Canal and 
the direct passage of ships from the West Indies to these islands, the whole 
passage being made within tropical regions, yellow-fever-infested mosquitoes 
will be carried alive to the Pacific islands? It is certainly a matter which 
must receive scientific attention. 

Mosquitoes and filariasis.—Filariasis is the rather generic term for a 
number of diseases, or for one disease which manifests itself in several ways, 
due to the presence in the body of the infected patient of filarize or thread- 
worms. 

These organisms are of much higher organization than the minute unicel- 
lular Hamamoebe that cause malaria; they belong to the group of round- 
worms, the Nematoda, and in fully developed condition some species of 
filaria are very long, the notorious guinea-worm, Filaria medinensis, which 
parasitizes the human body in the tropics of the Old World, attaining a 


Insects and Disease 633 


length of three feet. Other species vary from an inch to a foot in length. 
All the species of the genus Filaria are parasites of other animals living 
mostly in the stomach and intestine, sometimes in the connecting tissue and 
elsewhere in the body. One species lives in the heart of dogs, another in 
the body-cavity of the horse, donkey, and ox, still another in the eyes of 
negroes in West Africa, while Filaria bancrofti, the particular species 
which is the cause of filariasis, lives in the blood and lymphatic vessels of 
men in tropic lands of both Old and New World. The young or larval 
filaria (sometimes called F. sanguinis-hominis) live in the blood, but they 
finally lodge in the lymphatic glands and there mature. 

The most common form of filariasis is called elephantiasis. The presence 
of the parasite in the lymphatic glands and vessels leads to a subcutaneous 
hypertrophy of tissue which often results in a most frightful malformation 
of parts of the body. The legs and arms are particularly affected, and such 
a member may become of enormous size and be hideously repu!sive in appear- 
ance. A single leg may come to weigh as much as all the rest of the body. 
An arm may become a foot thick, the fingers being mere papillar-like processes 
at the end of it. In Samoa fully one-third of the natives are attacked by this 
disease, which is incurable, and, though slow in development and nearly 
painless, certainly fatal. 

Manson, to whose keen inductions much of the credit for the discovery 
of the relation between the mosquito and malaria is due, was the first to 
suggest, on a basis of some observation and special investigation, that the 
mosquito is the secondary or intermediate host of the elephantiasis-produc:ng 
filariae and that the mosquito is probably responsible for the dissemination 
of the disease. 

The subsequent researches of Manson, Bancroft, and others have proved 
that the filarie actually do live in the bodies of mosquitoes, being taken into 
the alimentary canal with the blood sucked from men affected by the disease. 
These filariz work their way through the walls of the alimentary canal and 
gather in the thoracic muscles. Here they live for some time, two or three 
weeks probably, and are then ready for their further development in the 
blood and lymph of man. Exactly how th‘s transfer is made is not definitely 
proved as yet, although much evidence has been secured to show that the 
transmission is made by the mosquito-bite. Manson suggested that the 
female mosquitoes coming to reservo.rs, ponds, or puddles of water to lay 
the’r eggs would often die there so that their bodies would fall on to the sur- 
face of the water. As they disintegrated by rapid decay, the larval filarie in 
the thoracic muscles would escape into the water, and live there until taken into 
the alimentary canal of people drinking some of the water from the reservoir 
or pond. Bancroft believes, however, that the filaria are transmitted by 
the bite or puncture of the mosquito, and has actually observed the migration 


634 Insects and Disease 


of the filarie from the thoracic muscles forward into the head and “beak”’ 
of the mosquito. He has seen a filaria larva issuing from a fine opening 
near the tip of the labium. According to Bancroft’s theory the filaria 
escapes from the beak of a puncturing mosquito into the skin of a man, 
finishes its development and growth in the skin, becomes adult, pairs and 
produces embryos which get into the lymphatic spaces or vessels, and are 
carried by the lymph into the blood. Here they circulate over the body, 
finally lodging in the lymphatic glands and causing the characteristic hyper- 
trophy of tissue. Further investigation is necessary, however, before the 
question of transmission is fully understood. That the mosquito is the 
actual disseminating agent of the disease is, however, certain. 

The species of mosquito which acts as intermediate host and distributing 
agent of the filaria in Australia is Culex fatigans, var. skusii. Anopheles 
rossii is also known to carry the filarie. In Samoa, where elephantiasis 
is more prevalent than anywhere else in the world, I have found the most 
abundant mosquito to be Stegomyia fasciata, the same species that spreads 
yellow fever. This species is also the most abundant mosquito in the Hawaiian 
Islands, and is indeed wide-spread over the tropics and subtropics of the 
whole world. If, as is probable, it is the principal carrier in Samoa of the 
filarie that cause elephantiasis, it is the most formidable single species among 
all the insect scourges of mankind. 

In this brief account of the réle played by certain insects in the propa- 
gation and dissemination of certain human diseases only a small part of the 
story, as already known, has been told. Cockroaches, bedbugs, and other 
household insects are being found to be hosts for the germs of other familiar 
diseases. A host of investigators is at work; reports of discoveries are being 
published constantly, and in a few years our knowledge of this causal rela- 
tion of insects to human disease will fill books instead of chapters. 


CHAPTER XIX 
REFLEXES, INSTINCTS, AND INTELLIGENCE 


N recent years many biologists have come to believe that most 
{ of the behavior of the simplest animals and some of the actions 
| of the higher are controlled in a much more rigidly mechan- 
ical way than has usually been admitted; that, in a word, much 
of the action, and apparent instinctive or intelligent response of animals to 
external conditions, is an immediate physico-chemical rather than an inex- 
plicable vital phenomenon; that the animal body in its relation to the external 
world is much more like a passive, senseless, although very complex, machine, 
stimulated and controlled by external factors and conditions, than like the per- 
cipient, determining, purposeful creature that our usual conception of the 
organism makes it out to be. 

Clever experimenters, as Loeb, Lucas, Radl, Bethe, Uexkull, and numer- 
ous others, believe themselves justified in explaining a host of the simpler 
actions or modes of behavior of animals on a thoroughly mechanical basis,, 
as rigorous, inevitable reactions to the influence or stimulus of light, heat, 
contact, gravity, galvanism, etc. Phototropism, stereotropism, geotropism, 
etc., are the names given to these phenomena of response by action and 
behavior to stimuli of light, contact, gravity, etc., respectively. 

Some of these biologists are ready to carry their giving up of other than 
mechanical behavior among animals to great lengths. Loeb introduces a 
paper written in 189go on instinct and will in animals as follows: 

“Tn the biological literature one still finds authors who treat the ‘instinct’ 
or the ‘will’ of animals as a circumstance which determines motions, so that 
the scientist who enters the region of animated nature encounters an entirely 
new category of causes, such as are said continually to produce before our 
eyes great effects, without it being possible for an engineer ever to make use 
of these causes in the physical world. ‘Instinct’ and ‘will’ in animals, as 
causes which determine movements, stand upon the same plane as the super- 
natural powers of the theologians, which are also said to determine motions, 
but upon which an engineer could not well rely. 


635 


636 Reflexes, Instincts, and Intelligence 


“My investigations on the heliotropism of animals led me to analyze in 
a few cases the conditions which determine the apparently accidental direc- 
tion of animal movements which, according to traditional notions, are called 
voluntary or instinctive. Wherever I have thus far investigated the cause 
of such ‘voluntary’ or ‘instinctive’ movements in animals, I have without 
exception discovered such circumstances at work as are known in inanimate 
nature as determinate movements. By the help of these causes it is possi- 
ble to control the ‘voluntary’ movements of a living animal just as securely 
and unequivocally as the engineer has been able to control the movements 
in inanimate nature. What has been taken for the effect of ‘will’ or 
‘instinct’ is in reality the effect of light, of gravity, of friction, of chemical 
forces, etc.” 

But Jennings, a very careful and tireless investigator of the behavior of 
the protozoa, closes a fascinating volume on his work with the following 
paragraph: 

“The present paper may be considered as the summing up of the general 
results of several years’ work by the author on the behavior of the lowest 
organisms. This work has s! own that in these creatures the behavior is 
not as a rule on the tropism plan—a set, forced method of reacting to each 
particular agent—but takes place in a much more flexible, less directly 
machine-like way, by the method of trial and error. This method involves 
many of the fundamental qualities which we find in the behavior of higher 
animals, yet with the simplest possible basis in ways of action; a great por- 
tion of the behavior consisting often of but one or two definite movements, 
movements that are stereotyped in their relation to the environment. This 
method leads upward, offering at every point opportunity for development, 
and showing even in the unicellular organisms what must be considered the 
beginnings of intelligence and of many other qualities found in higher animals. 
Tropic action doubtless occurs, but the main basis of behavior is in these 
organisms the method of trial and error.” 

In a rough way the responses or reactions of animals to stimuli, their 
behavior, in a word, are grouped into reflex behavior or reflexes, instinctive 
behavior or instincts, and intelligent behavior or action from reason. To 
Cistinguish sharply between reflexes and instincts on the one hand, and 
instincts and reason on the other is impossible. Reflexes may be defined 
to be local responses of congenital type (that is, not acquired by experience, 
imitation, or teaching) which usually involve, in higher animals, only a par- 
ticular organ or cefinite group of muscles, and which are initiated by more 
or less specialized external stimuli. Instincts may be defined as complex 
groups of coordinated acts which are, on their first occurrence, independent 
of experience; which tend to the well-being and preservation of the race; 
which are due to the cooperation of external and internal stimuli; which are 


ore 


Reflexes, Instincts, and Intelligence 637 


similarly performed by all the members of the same more or less restricted 
group of animals; but which are subject to variation, and to subsequent 
modification under the guidance of experience. Intelligent behavior may be 
distinguished roughly from instinctive behavior by being the outcome and 
product of experience; by involving usually the element of choice among a 
number of possible responses; by revealing a capacity to act with special. 
reference or adaptation to new circumstances, and by revealing an individ- 
uality in dealing with the complex conditions of a variable environment.. 
In reflex and instinctive behavior the animal acts like a piece of well-made 
and adequately wound clockwork; in intelligent behavior the clockwork 
seems protean; it is a plastic machine capable of swift adaptation to exter- 
nal needs. 

In the brief discussion of insect behavior constituting this chapter, I shall 
assume a general acceptance of the above definitions of and distinctions 
among reflex, instincts, and intelligence—these definitions being substan- 
tially in the words of C. L. Morgan, the thorough-going Darwinian student 
of animal behavior; and I shall consider the particular illustrations of insect 
behavior taken up in the light of the classification established by the defini- 
tions. It is needless to say that the actual character and conditions of the 
behavior in each case are the essential things to keep in mind in any analyt- 
ical discussion of the subject, and not the uncertain, if more or less conve- 
nient, attempt to classify the cases. 

From Loeb’s point of view all animal responses differ only in degree, 
not at all in kind, and are all, from simplest to most complex, rigidly me- 
chanical reactions to actual physico-chemical stimuli. From the anthropo- 
morphic naturalists’ point of view on the contrary, a mystic capacity, 
incident only to living matter, of reason and psychical functioning reveals 
itself in almost all animal behavior, and the sluggish movements of the star- 
fish toward the water or around its prey are due to appreciation and likes 
and that intelligent determination familiar as factors in human action. 
Finally, from the point of view of the churchman naturalist the distinction 
between the springs of human behavior and “animal’’ behavior is as sharp 
as the assumed distinction between the possession of soul and spiritual ex- 
istence on the part of man and the absence of these attributes in the lower 
animals. Our point of view will be, however, as stated; that fairly safe one 
between the rigid mechanicalism of the tropism believers and the mysticism 
of the believers in a divinely endowed creature of psyche as contrasted with 
a long series of unfortunate soulless brutes. 

While the interested observation and recognition of insect habits and 
behavior has long occupied naturalists and poets, the careful, thoroughly 
checked and guarded study of this behavior has been curiously wanting, 
And only in very recent years has anything like experimental investigation 


638 Reflexes, Instincts, and Intelligence 


of insect behavior been undertaken. The truth is that insects are all highly 
specialized animals, and by that fact, offer themselves as thoroughly inter- 
esting but extremely difficult subjects for the student of animal behavior. 
It seems at first sight impossible in the face of the well-developed nervous 
system and highly specialized and complex character of the behavior of 
insects to expect to analyze successfully this behavior into its separate com- 
ponent reactions with their stimuli; to recognize among insects simple rigidly 
mechanical reflexes of the nature of direct inevitable response to external 
physico-chemical stimuli as light, temperature, humidity, gravitation, con- 
tact, etc. Yet recent studies have shown that this can in certain cases be 
done. It has been done, in fact. And a few examples of this work and 
its results are given in the following paragraphs. 

Reflexes and Tropisms. The first considerable piece of careful experi- 
mental study of insect reflexes was probably that of Loeb on the heliotropism 
of caterpillars, moths, fly larvee, flies, plant-lice, and ants; the results of which 
were published in 1899. This original and able experimenter obtained 
positive results from this work and from them was led to conclude that light 
controls or causes certain movements or behavior of these insects in a very 
definite mechanical way; that it is the direction of the light rays that is the 
chief controlling factor in the influence exerted by the light on the insects, 
and finally that “the conditions which control the moyements of the animals 
toward light are identical, point for point, with those which have been shown 
to be of paramount influence in plants.’”? Therefore Loeb maintains that 
these phenomena of insect orientation and movement in the presence of light 
cannot depend upon specific characteristics of the central nervous system, 
that is, are not manifestations of intelligence or instinct (in the common 
understanding of the term), but are phenomena much more like those rigidly 
mechanical ones of iron filings in a field of magnetic force, or of sunflowers 
turning toward the sun. 

Since Loeb’s epoch-making work numerous observations and experi- 
ments have been made which have revealed other similar reflex phenomena 
among insects. These phenomena are commonly called ‘“tropisms”’ and 
include whatever movements or special behavior can be explained as the 
immediate rigorously controlled reaction in response to localized external 
physico-chemical stimuli, such as heliotropism or phototropism, reactions 
to light; geotropism, responses to gravitation; chemotropism, behavior 
dependent on the influence of chemical stimuli affecting the organs of taste, 
smell, etc.; stereotropism or thigomotropism, movement or cessation of moye- 
ment produced by the stimulus of contact with solid substance; hydrotropism, 
reactions to the stimulus of moisture or water; anemotropism, response to 
the stimulus of air-currents; thermotropism, behavior controlled by tem- 
perature, etc., etc. Thus Davenport kas ascertained the movements of 


Reflexes, Instincts, and Intelligence 6 39 


certain small simple insects (Poduride) which he found living in the sand 
beaches of Long Island to be determined as follows: 
“T, General movements. 
A. Running: oxygen, lack of (?). 
B. Springing: currents of air, or jarring of substratum. 
II. Special locomotive movements. 
1. Whirling: touch, water. 
Descent into the sand: touch, water, gravity. 
Rising from sand: water, gravity. 
Running up stones: gravity, light. 
Moving toward wind: current of air. 
. Leaping into air: gravity, currents, oxygen-need.” 

Most insect nonaS ior is likely to be due to several or many stimuli 
acting at once so that the behavior itself is the complexly formed result- 
ant of various reactions. And in most cases it is difficult or impossible 
to analyze it into its component parts. Insects are really very complexly 
organized animals and their physiology and psychology is a synthesis of 
many elements. But occasionally an insect species may be found which lends 
itself fairly readily to the analytical study, by experimental methods, of its 
behavior. Or other species may be found which reveal at one or another 
stage in their life a period when some one reaction or reflex is all-dominant 
and its relation to its special stimulus is plainly revealed. Two examples 
of the determination of tropismic behavior on the part of highly specialized 
insect species which have come under my own observation may be described. 

In the course of some experiments on the sense reactions of honey-bees, 
I have kept a small community of Italian bees in a glass-sided, narrow, high 
observation hive, so made that any particular bee, marked, which it is de- 
sired to observe constantly, cannot escape this observation. The hive con- 
tains but two frames, one above the other, and is made wholly of glass, 
except for the wooden frame. It is kept covered, except during observation 
periods, by a black cloth jacket. The bees live contentedly and normally 
in this small hive, needing only occasional feeding at times when so many 
cells are given up for brood that there are not enough left for sufficient stored 
food-supplies. One spring at the normal swarming time, while standing 
near the jacketed hive, I heard the excited hum of the beginning swarm 
and noted the first issuers rushing pellmell from the entrance. Interested 
to see the behavior of the community in the hive during such an ecstatic 
condition as that of swarming, I lifted the cloth jacket, when the excited 
mass of bees which was pushing frantically down to the small exit in the 
lower corner of the hive turned with one accord about face and rushed 
directly upward away from the opening toward and to the top of the hive. 
Here the bees jammed, struggling violently. I slipped the jacket partly on; 


ANY »p 


640 Reflexes, Instincts, and Intelligence 


the ones covered turned down; the ones below stood undecided; I dropped 
the jacket completely; the mass began issuing from the exit again; I pulled 
off the jacket, and again the whole community of excited bees flowed—that 
is the word for it, so perfectly aligned and so evenly moving were all the 
individuals of the bee current—up to the closed top of the hive. Leaving 
the jacket off permanently, I prevented the issuing of the swarm until the 
ecstasy was passed and the usual quietly busy life of the hive was resumec. 
About three hours later there was a similar performance and failure to issue 
from the quickly unjacketed hive. On the next day another attempt to 
swarm was made, and after nearly an hour of struggling and moving up 
and down, depending on my manipulation of the black jacket, most of the 
bees got out of the hive’s opening and the swarming came off on a weed 
bunch near the laboratory. That the issuance from the hive at swarming 
time Cepends upon a sudden extra-development of positive heliotropism 
seems obvious. The ecstasy comes and the bees crowd for the one spot of 
light in the normal hive, namely, the entrance opening. But when the cover- 
ing jacket is lifted and the light comes strongly in from above—my hive was 
under a skylight—they rush toward the top, that is, toward the light. Jacket 
on and light shut off from above, down they rush; jacket off and light 
stronger from above than below and they respond like iron filings in front 
of an electromagnet which has its current suddenly turned on. What pro- 
duces the sudden strong heliotropism just as the swarming ecstasy comes 
on? That is beyond my observation. 

The other example is as follows: Silkworm moths (Bombyx mori) are 
sexually mature and eager to mate immediately on issuing from the pupal 
cocoon. They take no food (their mouth-parts are atrophied), they do not 
fly, they are unresponsive to light; their whole behavior, in fact, is deter- 
mined by their response to the mating and egg-laying instincts. We have 
thus an animal of considerable complexity of organization, belonging to a 
group of organisms well advanced in the animal scale, in a most simple 
state for experimentation. 

The female moth, nearly immobile, protrudes a paired scent-organ from 
the hindmost abdominal segment, and the male, walking nervously about 
and fluttering its useless wings, soon finds the female by virtue of its chemo- 
tactic response to the emanating odor. Males find the females exclusively 
by this response. 

A male with antennz intact, but with eyes blackened, finds females im- 
mediately and with just as much precision as those with eyes unblackened. 
A male with antenne off and eyes unblackened does not find females unless 
by accident in its aimless moving about. But if a male with antenne off 
does come into contact, by chance, with a female it always (or nearly so) 
readily and immediately mates. The male is not excited before touching 


Reflexes, Instincts, and Intelligence 641 


the female, but is immediately and strongly so after coming in contact with 
her. Males with antenne on become strongly excited when a female is 
brought within several inches of them. 

The protruded scent-glands of the female are withdrawn into the body 
immediately on her being touched by a male. If the scent-glands are cut 
off and put wholly apart from the female, males are as strongly attracted to 
these isolated scent-glands as they are to unmutilated females; on the con- 
trary they are not at all attracted to the mutilated females. If the cut-out 
scent-glands are put by the side of and but a little apart from the female from 
which they are taken, the males always neglect the near-by live female and 
go directly to the scent-glands. Males attracted to the isolated scent-glands 
remain by them persistently, moving excitedly around and around them and 
over and over them with the external genitalia vainly trying to seize them. 

The behavior of males with the antenna of only one side removed is 
striking. A male with left antenna off when within three or four inches of a 
female (with protruded scent-glands) becomes strongly excited and moves 
energetically around in repeated circles to the right, or rather in a flat spiral, 
thus getting (usually) gradually nearer and nearer the female and finally 
coming into contact with her. A male with right antenna off circles or 
spirals to the left. It is a curious sight to see two males with right and left 
antenna off, respectively, circling violently about in opposite directions when 
the immobile female a few inches removed protrudes her scent-glands. 
This behavior is quite in accordance with Loeb’s explanation of the forward 
movement of bilaterally symmetrical animals. 

The results of all the experiments tried show how rigorously the male 
moths are controlled by the scent attraction (chemotropism) and how abso- 
lutely dependent mating (the one adult performance of the males) is on this 
reaction. If we can find specialized animals in a condition where response to 
all attractions and repulsions (stimuli) but one are eliminated, we may readily 
perceive the rigorous control exercised by this remaining one. Weare, unfor- 
tunately, in the general circumstances of animal life too much limited to the 
use of very simply organized animals for reaction and reflex experimenta- 
tion. This tends to make it difficult to carry over to the behavior of com- 
plexly organized animals the physico-chemical interpretation which is 
steadily gaining ground as the key to the understanding of the springs and 
character of the behavior of the simplest organisms. But where the com- 
plex stimuli and reactions that determine the behavior of complexly organized 
forms can be isolated and studied, the inevitableness of much of this 
behavior can be recognized. 

instincts. Examples and accounts of instincts are scattered all through 
this book. Complex and elaborate behavior in connection with egg-laying, 
care of young, food-getting, defense, offense, nest-making, parasitic, com- 


642 Reflexes, Instincts, and Intelligence 


mensal and communal life, and various other specialized phases of insect 
life, is described often in considerable detail. So that reference to these 
accounts may suffice in this place in lieu of repeating these descriptions or 
of adding new ones. For miscellaneous examples of insect instincts, or be- 
havior satisfying our definition of instinct, the reader may refer to the accounts 
of the egg-laying of bot-flies on p. 337, of the ham-fly on p. 348, of the bee- 
moth on p. 379, of the monarch butterfly on p. 452, of the California oak- 
moth on p. 407, of the fig Blastophaga on p. 487, of Tremex and Thalessa on 
pp. 467 and 483, of gall-flies and their guests on p. 468, of the lace-wing fly 
on p. 228, of Mantispa on p. 234, of the blister-beetles on p’ 290; accounts 
of the building of protecting larval cases or tents by caddis-flies on p. 240, 
by leaf-rollers on p. 375, by bag-worms on p. 385, and by tent-caterpillars 
on p. 415; the account on p. 230 of the ant-lion and its pit, on p. 396 of 
the “going stiff’ of the inch-worms, on p. 394 of the threatening of the 
puss-moth larva, on p. 107 of the tunnel-building of the termites, on p. 352 
of the wing-removing of Lipoptena; the accounts of mrymecophily on 
p- 552, of the elaborate economy of solitary bees and wasps on pp. 490 and 
510; and of the complex communal life of the social bees, wasps, and ants. 

With these or some of them well in mind the reader is ready to take 
part in a consideration of some of the pertinent questions and problems 
which such behavior, such long, highly coordinated series of actions, such 
complex apparently psychic manifestations, inevitably bring up to the stu- 
dent of animal life. On what sort or degree of organization of nervous 
system does this complexity and high and effective coordination of behavior 
depend? Is the behavior thoroughly adaptive? How rigid or invariable is 
the behavior; that is, is there any apparent capacity to modify the behavior 
to suit special cases or suddenly appearing new conditions? Is there any 
element of reason, any intelligent choice of action, in the behavior? Or on 
the other hand in how far can complex instincts be analyzed into simple 
rigorous tropismic or reflex actions ? 

There is space here to consider but one or two of these problems, and 
we may select those which are perhaps of most interest. Let us select the 
matter of the degree of rigorousness or invariability of behavior manifest in 
insect instinct, and the matter of the possession by insects of any degree of 
intelligence or reason; that is, the question of whether or not insect behavior 
is exclusively reflexive and instinctive or is chiefly instinctive but tempered 
by some degree of intelligence. 

This particular problem has been considered and discussed most per- 
haps in connection with the elaborate and highly specialized behavior of the 
solitary and social Hymenoptera (wasps, bees, and ants). And there are 
strong champions for both points of view. Three observers and students of 
insect life are preeminently conspicuous by virtue of their detailed and long 


Reflexes, Instincts, and Intelligence 643 


pursued studies of the habits of the solitary wasps. These observers are 
J. H. Fabre (France) and G. W. and E. G. Peckham (husband and wife, 
Wisconsin). Now while Fabre holds positively and consistently the belief 
that this behavior is exclusively instinctive, the Peckhams hold as certainly 
that it is the result of instinct tempered with and modified by reason. And 
on this side also stands C. L. Morgan, the great English student of animal 
behavior in general. 

In the first of Fabre’s nine fascinating volumes entitled “ Souvenirs 
Entomologiques,”’ there are two chapters entitled respectively the Science of 
Instinct and the Ignorance of Instinct. In one of these is pictured the mar- 
yelous precision, coordination, and certainty of the nest-making and the 
catching, paralyzing, and storing of the living food by the solitary wasp, for 
its young. As an example of this behavior, but of this behavior observed 
without any such illuminating experimental treatment as that with which 
Fabre accompanies his observations, my account of the behavior of the 
Ammophila of the Palo Alto salt marshes (see p. 493 of this book) may be 
referred to. In the second of Fabre’s chapters, the one on the “ignorance 
of instinct,’’ there is pointed out on the other hand the definite limitations of 
the wasp’s behavior. I quote from a translation of this chapter. 

“The Sphex has just shown us with what infallible, transcendent art she 
acts, guided by the unconscious inspiration of instinct: she will now show 
how poor she is in resources, how limited in intelligence, and even illogical 
in cases somewhat out of her usual line. By a strange contradiction, charac- 
teristic of the instinctive faculties, with deep science is associated ignorance 
not less deep. Nothing is impossible to instinct, however great be the 
difficulty. In constructing her hexagonal cells with their floor of three loz- 
enge-shaped pieces, the bee resolves, with absolute precision, the arduous 
problems of maximum and minimum, to solve which man would need a 
powerful mathematical mind. Hymenoptera, whose larve live on prey, 
have methods in their murderous art hardly equalled by those of man versed 
in the most delicate mysteries of anatomy and physiology. Nothing is diffi- 
cult to instinct so long as the action moves in the unchanging groove allotted 
to the animal, but, again, nothing is easy to instinct if the action deviates 
from it. ‘The very insect which amazes us and alarms us by its high intel- 
ligence, will, a moment later, astonish us by its stupidity before some fact 
extremely simple, but strange to its usual habits. The Sphex will offer an 
example. 

“Tet us follow her dragging home an ephippiger. If fortune favors us, 
we may be present at a little scene which I will describe. On entering the 
shelter under a rock where the burrow is made, the Sphex finds, perched on 
a blade of grass, a carnivorous insect which, under a most sanctimonious 
aspect, hides the morals of a cannibal. The danger threatened by this ban- 


644 Reflexes, Instincts, and Intelligence 


dit in ambush on her path must be known to the Sphex, for she leaves her 
game and runs bravely at the Mantis to administer some sharp blows and 
dislodge, or at all events, alarm and inspire it with respect. It does not 
move, but closes its deadly weapons—the two terrible saws of the arm and 
forearm. The Sphex returns to her prey, harnesses herself to the antenna, 
and passes audaciously under the blade of grass where the Mantis sits. From 
the direction of her head one can see that she is on her guard, and is holding 
the enemy motionless under her threatening eyes. Such courage is duly 
rewarded; the prey is stored without further misadventure.” 

The author introduces a digression here and then proceeds: “ We return 
to the Sphex, with whose burrow we must make acquaintance before going 
further. It is made of fine sand, or rather in the fine dust at the bottom of 
a natural shelter. Its passage is very short—an inch or two without a turn, 
leading into a single spacious oval chamber, and all is a rude, hastily made 
den, rather than a dwelling hollowed with art and leisure. I have already 
said that the captured prey, left for a brief moment or two where it was 
hunted, is the cause of the simplicity of this abode and of there being but 
one chamber or cell to each hollow. For who can say whither the chances 
of the day’s hunt may lead? The dwelling must be near the heavy prey, 
and to-day’s abode, too far off to admit of carrying the second ephippiger 
there, cannot be used to-morrow. Thus each time prey is caught there 
must be new digging out—a new burrow with its one cell, now here, now 
there. Now let us try some experiments to see how the insect behaves amid 
circumstances new to it. 

“First experiment.—A Sphex, dragging her prey, is at a few inches from 
her burrow. Without disturbing her I cut the antenne of the ephippiger, 
which we already know serve as harnesses. Having recovered from her 
astonishment at the sudden lightening of her load, the Sphex returns and 
unhesitatingly seizes the base of the antenne, the short stumps not cut off. 
Very short they are—hardly a millimetre long; no matter, they suffice for 
the Sphex, who grips what remains of her ropes and drags anew. With 
many precautions not to hurt her, I cut off the two stumps, now level with 
the skull. Finding nothing to seize at the parts familiar to her, she takes 
hold on one side of one of the long palpi of her victim, and drags it, not at 
all put out by this modification in her style of harnessing herself. I leave 
her alone. The prey is got home and placed with its head to the mouth of 
the burrow. The Sphex enters to make a short inspection of the interior 
before proceeding to store provisions. Her tactics recall those of S. flavi- 
pennis in like circumstances. I profit by this brief moment to take the aban- 
doned prey, deprive it of all its palpi, and place it a little farther off—a pace 
from the burrow. The Sphex reappears and goes straight to her game, 
which she saw from her threshold. She seeks above the head, she seeks 


— 


Reflexes, Instincts, and Intelligence 645 


below, on one side, and finds nothing to seize. A desperate attempt is made; 
opening wide her mandibles she tries to grasp the ephippiger by the head, 
but her pincers cannot surround anything so large, and slip off the round, 
polished skull. She tries several times in vain; at length, convinced of the 
futility of her efforts, she draws back, and seems to renounce further attempts. 
S.e appears discouraged—at least she smooths her wings with her hind feet, 
while with her front tarsi, first passing them through her mouth, she washes 
her eyes, a sign among Hymenoptera, as I believe, that they give a 
thing up. 

“Yet there were points by which the ephippiger might be seized and 
cragged as easily as by the antenne and palpi. There are the six feet, there 
is the ovipositor—all organs slender enough to be thoroughly grasped and 
used as traction ropes. I own that the easiest way of getting the prey into 
the storehouse is to introduce it head first by the antennae; yet, drawn by 
one foot, especially a front one, it would enter almost as easily, for the orifice 
is wide and the passage short, even if there be one. How came it then that 
the Sphex never once tried to seize one of the six tarsi or the point of the 
ovipositor, while she did make the impossible, absurd attempt to grip with 
the mandibles far too short the huge head of her prey? Perhaps the idea 
did not occur to her. Let us try to suggest it. I place under her mandi- 
bles first a foot, then the end of the abdominal sabre. She refuses obsti- 
nately to bite; my repeated solicitations come to nothing. A very odd kind 
of hunter this to be so embarrassed by her game and unable to think of 
seizing it by a foot if it cannot be taken by the horns! Perhaps my pres- 
ence and all these unusual events may have troubled her faculties; let us 
leave her to herself, with her burrow and ephippiger, and give her time to 
consider and to imagine in the calm of solitude some means of managing 
the business. I walked away and returned in a couple of hours to find the 
Sphex gone, the burrow open, and the ephippiger where I had laid it. The 
conclusion is that the Sphex tried nothing, but departed, abandoning home, 
game—everything, when to utilize them all that was needed would have been 
to take the prey by one foot. Thus this rival of Flourens, who just now 
startled us by her science when pressing the brain to induce lethargy, is 
invariably dull when the least unusual event occurs. The Sphex, which 
knows so well how to reach the thoracic ganglia of a victim with her sting, 
and those of the brain with her mandibles, and which makes such judicious 
difference between a poisoned sting that would destroy the vital influence of 
the nerves, and compression causing only momentary torpor, cannot seize 
her prey in a new way. To understand that a foot may be taken instead of 
the antenne is impossible; nothing will do but the antennz or another fila- 
ment of the head or one of the palpi. For want of these ropes her whole 
race would perish, unable to surmount this trifling difficulty. 


646 Reflexes, Instincts, and Intelligence 


“Second experiment.—The Sphex is busy closing her burrow where the 
prey is stored and the egg laid. With her fore tarsi she sweeps backward 
before her door, and launches from the entrance a spurt of dust, which 
passes beneath her, and springs up behind in a parabolic curve as continuous 
as if it were a slender stream of some liquid, so rapidly does she sweep. 
From time to time she chooses some sand grains with her mandibles, 
strengthening materials inserted singly in the dusty mass. To consolidate 
this she beats it with her head, and heaps it with her mandibles. Walled 
up by this masonry, the entrance rapidly disappears. In the midst of the 
work I intervene. Having put the Sphex aside I clear out the short gallery 
carefully with the blade of a knife, take away the materials which block it, 
and entirely restore the communication of the cell with the outer air. Then, 
without injuring the edifice, I draw the ephippiger out of the cell where it is 
lying with its head to the far end, and its ovipositor to the entrance. The 
egg is as usual on its breast, near the base of one of the hind legs—a proof 
that the Sphex had given her last touch to the burrow, and would never 
return. These dispositions made and the ephippiger placed safely in a box, 
I gave up my place to the Sphex, who had been watching while her domi- 
cile was rifled. Finding the entrance open, she entered and remained some 
moments, then came forth and took up her work where I interrupted it, 
beginning to stop the entrance conscientiously, sweeping the dust backward, 
and transporting sand grains to build them with minute care, as if doing a 
useful work. The orifice being again thoroughly blocked, she brushed her- 
self, seemed to give a glance of satisfaction at her work, and finally flew off. 

“Yet she must have known that the burrow was empty, since she had 
gone inside, and made prolonged stay, but yet after this visit to the plun- 
dered dwelling, she set to work to close it with as much care as if nothing 
had happened. Did she propose to turn it later to account, returning with 
a fresh prey, laying a new egg? In that case the burrow was closed to 
defend it from indiscreet visitors while the Sphex was away. Or it was a 
measure of prudence against other miners who might covet a ready-made 
chamber, or a wise precaution against internal wear and tear, and, in fact, 
some predatory Hymenoptera are careful when obliged to suspend work to 
defend the mouth of their burrow by closing it up temporarily. I have seen 
certain Ammophile, whose burrow is a vertical well, close the entrance with 
a little flat stone when the insect goes a-hunting, or stops mining when the 
hour to leave off work comes at sunset. But in that case the stoppage is 
slight—a mere slab set on the top of the well. It takes but a moment when 
the insect comes to displace the little flat stone, and the door is open. But 
what we have just seen the Sphex construct is a solid barrier—strong masonry, 
where layers of alternate dust and gravel occupy the whole passage. It is 
definitive, and no temporary work, as is sufficiently shown by the careful 


Reflexes, Instincts, and Intelligence 647 


way in which it is constructed. Besides, as I think I have already proved, 
it is very doubtful, considering the manner in which she acted, whether the 
Sphex would return to use the dwelling which she had prepared. A new 
ephippiger will be caught elsewhere, and elsewhere too will the storehouse 
destined for it be hollowed. As, however, these are but conclusions drawn 
by reasoning, let us consult experiment, more conclusive here than logic: I 
let nearly a week pass in order to allow the Sphex to return to the burrow so 
methodically closed, and use it if she liked for her nest-laying. Events 
answered to the logical deduction; the burrow was just as I had left it, well 
closed, but without food, egg, or larva. The demonstration was decisive; 
the Sphex had not returned. 

“Thus we see the plundered Sphex go into her house, pay a leisurely 
visit to the empty chamber, and the next moment behave as if she had not 
perceived the absence of the big prey which a little while before had encum- 
bered the cell. Did she not realize the absence of food and egg? Was she 
really so dull—she, so clear-sighted when playing the murderer—that the 
cell was empty? I dare not accuse her of such stupidity. She did perceive 
it. But why then that other piece of stupidity which made her close, and 
very conscientiously too, an empty chamber which she did not mean to 
store? It was useless—downright absurd—to do this, and yet she worked 
with as much zeal as if the future of the larva depended on it. The various 
instinctive actions of insects are then necessarily connected; since one thing 
has been done, such another must inevitably follow to complete the first, 
or prepare the way for the next, and the two acts are so necessarily linked that 
the first must cause the second, even when by some chance this last has 
become not only superfluous, but sometimes contrary to the creature’s inter- 
est. What object could there be in stopping a burrow now useless, since it 
no longer contained prey and egg, and which will remain useless, since the 
Sphex will not return to it? One can only explain this irrational proceeding 
by regarding it as the necessary consequence of preceding actions. In the 
normal state of things the Sphex hunts her prey, lays an egg, and closes the 
hole. The prey has been caught, the egg laid, and now comes the closing of 
the burrow, and the insect closes it without reflecting at all, or guessing the 
fruitlessness of her labor. 

“Third experiment.—To know all and nothing, according as the condi- 
tions are normal or otherwise, is the strange antithesis presented by the in- 
sect. Other examples drawn from the Sphegide will confirm us in this prop- 
osition. Sphex albisecta attacks middle-sized Acridians, the various species 
scattered in the neighborhood of her burrow all furnishing a tribute. From 
the abundance of these Acridide the chase is carried on near at hand. When 
the vertical well-like burrow is ready, the Sphex merely flies over the ground 
near, and espies an Acridian feeding in the sunshine. To pounce and sting 


648 Reflexes, Instincts, and Intelligence 


while it struggles is done ina moment. After some fluttering of the wings, 
which unfold like carmine or azure fans, some moving of feet up and down, 
the victim becomes motionless. Next it must be got home by the Sphex on 
foot. She performs this toilsome operation as do her kindred, dragging her 
game between her feet, and holding one of the antennz in her manaibles. 
If.a grass thicket has to be traversed, she hops and flutters from blade to 
blade, keeping firm hold of her prey. When within a few feet of her dwell- 
ing, she executes the same manceuvre as does S. occitanica, but without 
attaching the same importance to it, for sometimes she neglects it. The 
game is left on the road, and though no apparent danger threatens the dwell- 
ing, she hurries toward its mouth, and puts in her head repeatedly, or even 
partly enters, then returns to the Acridian, brings it nearer, and again leaves 
it to revisit her burrow, and so on several times, always with eager haste. 

“These repeated visits have sometimes annoying results. The victim, 
rashly abandoned on a slope, rolls to the bottom, and when the Sphex returns 
and does not find it where she left it, she must hunt for it, sometimes in vain. 
If found, there will be a difficult climb, which, however, does not prevent 
her leaving it once more on the perilous slope. The first of these repeated 
visits to her cell is easily explained. Before bringing her heavy load she is 
anxious to make sure that the entrance is clear, and that nothing will hinder 
her carrying in the prey. But what is the use of her other visits, repeated so 
speedily one after another? Are the Sphex’s ideas so unstable that she for- 
gets the one just made, and hurries back a moment later, only to forget that 
she has done so, and so on? It would indeed be a slippery memory where 
impressions vanished as soon as made. Let us leave this too obscure ques- 
tion. 

“ At length the game is brought to the edge of the well, its antennae hang- 
ing into the mouth, and there is an exact repetition of the method used by 
S. flavipennis and, though in less striking conditions, by S. occitanica. She 
enters alone, reappears at the entrance, seizes the antenne, and drags in 
the Acridian. While she was within I have pushed the prey rather farther 
off, and have always obtained precisely the same result as in the case of the 
huntress of crickets. In both Sphegide there was the same persistence in 
plunging into their burrows before dragging down their prey. We must 
recollect that S. flavipennis does not always allow herself to be duped by 
my trick or withdrawing the insect. There are elect tribes among them,— 
strong-minded families,—who after a while find out the tricks of the experi- 
menter, and know how to baffle them. But these revolutionaries capable of 
progress are the few; the rest, rigid conservatives in manner and customs, 
are the majority, the crowd. I cannot say whether the hunters of Acridide 
show more or less cunning in different districts. 

“But the most remarkable thing, and the one to which I want specially 


Reflexes, Instincts, and Intelligence 649 


to come, is this: After withdrawing the prey of S. albisecta several times 
from the mouth of the hole, and obliging her to fetch it back, I profited by 
her descent to the bottom of her den to seize and put the prey where she 
could not find it. She came up, sought about for a long time, and, when 
quite convinced that it was not to be found, went down again. A few mo- 
ments later she reappeared. Was it to return to the chase? Not the least 
in the world; she began to close the hole, and with no temporary cover, such 
as a small flat stone to mark the orifice, but with a solid mass of carefully 
collected dust and gravel swept into the passage until it was quite filled. S. 
albisecta makes only a single cell at the bottom of her well, and puts in but one 
victim. This one specimen had been caught and dragged to the edge of the 
Lole, and if it was not stored, that was my fault, not her’s. The Sphex 
worked by an inflexible rule, and according to that rule she completed the 
work by stopping up the hole even if empty. Here we have an exact repe- 
tition of the useless labor of S. occitanica, whose dwelling I rifled. 

“Fourth experiment.—It is almost impossible to be certain whether S. 
flavipennis, which makes several cells at the bottom of the same passage, 
and heaps several grasshoppers in each, commits the same irrational mis- 
takes when accidentally disturbed. A cell may be closed, although empty 
or imperfectly stored, and yet the Sphex will return to the same burrow to 
make others. Yet I have reason to believe that this Sphex is subject to the 
same aberrations as her two relations. The facts on which I base my belief 
are these: When the work is completed, there are generally four grass- 
Loppers in each cell, but it is not uncommon to find three or only two. Four 
appears to me the usual number—first, because it is the most frequent, and 
secondly, when I have brought up young larve dug up when eating their 
first grasshopper, I found that all, even those provided with only two or three, 
easily finished those offered, up to four, but after that they hardly touched 
the fifth ration. If four grasshoppers are required by the larva to develop 
fully, why is it sometimes provided with only three or even only two? Why 
this immense difference in the amount of food? It cannot be from any 
difference in the joints served up, since all are unmistakably of the same 
size, but must come from losing prey on the road. In fact, one finds at the 
foot of the slopes whose upper parts are occupied by Sphegide, grasshop- 
pers killed, and then lost down the incline, when, for some reason or other, 
the Sphex has momentarily left them. These grasshoppers become the prey 
cf ants and flies, and the Sphex who finds them takes good care not to pick 
them up, as they would take enemies into the burrow. 

“These facts seem to demonstrate that if S. flavipennis can compute 
exactly how many victims to catch, she cannot attain to counting how many 
reach their destination, as if the creature had no other guide as to number 
than an irresistible impulse leacing her to seek game a fixed number of times. 


650 Reflexes, Instincts, and Intelligence 


When this number of journeys has been made,—when the Sphex has done 
all that is possible to store the captured prey,—her work is done, and the 
cell is closed, whether completely provisioned or not. Nature has endowed 
her with only those faculties called for under ordinary circumstances by the 
interests of the larva, and these blind faculties, unmdiofied by experience, 
being sufficient for the preservation of the race, the animal cannot go farther. 

“JT end then as I began: instinct knows everything in the unchanging 
paths laid out for it; beyond them it is entirely ignorant. The sublime 
inspirations of science, the astonishing inconsistencies of stupidity, are both 
its portion, according as the creature acts under normal conditions or under 
accidental ones.” 

Now for the other side. I quote from the concluding chapter in the 
Peckhams’ book on the Solitary Wasps: 

“Our study of the activities of wasps has satisfied us that it is imprac- 
ticable to classify them in any simple way. The old notion that the acts 
of bees, wasps, and ants were all varying forms of instinct is no longer ten- 
able and must give way to a more philosophical view. It would appear to 
be quite certain that there are not only instinctive acts but acts of intelligence 
as well, and a third variety also—acts that are probably due to imitation, 
although whether much or little intelligence accompanies this imitation, is 
admittedly difficult to determine. Again, acts that are instinctive in one 
species may be intelligent in another, and we may even assert that there is 
a considerable variation in the amount of intelligence displayed by different 
individuals of the same species. We have met with such difficulty in our 
attempt to arrange the activities of wasps in different groups that we are 
forced to the conclusion that any scheme of classification is merely a con- 
venience, useful for purposes of study or generalization, but not to be taken 
for an absolutely true expression of all the facts. This kind of perplexity 
is well understood and allowed for in all morphological work, but it has 
never been fully realized in the study of habits. The explanation is not far 
to seek. The habits of but few animals have been studied in sufficient 
detail to bring out the evidence that there is as much variation on the psy- 
chological as on the morphological side.” 

In a recent account of observations made on twenty-eight species of 
solitary wasps in Texas, Carl Hartman also takes strong ground for the 
variability of instincts. He has in his own mind, as a result of his long 
series of observations, no doubt of this variability. And he notes also the 
interesting point that this “variability in mental traits and dispositions as 
reflected in the wasps’ actions seems to be proportionate to the physical 
variability. At any rate, Bembex belfregi, the species of Bembidula, and 
Microbembex monodonta, for example, are all very variable species in size 
and coloration as well as in the demeanor of different individuals.” 


Reflexes, Instincts, and Intelligence 651 


The Peckhams arrange the activities of the wasps they have studied 
into two groups, instincts and acts of intelligence, “it being understood 
that these classes pass by insensible stages into each other, and that acts 
that are purely instinctive when performed for the first time are probably 
in some degree modified by individual experience.” In the category instinct 
they place “all complex acts that are performed previous to experience and 
in a similar manner by all members of the same sex and race, leaving out 
as non-essential, at this time, the question of whether they are or are not 
accompanied by consciousness.’’ Under intelligence they place those “con- 
scious actions which are more or less modified by experience.’’ With these 
definitions in mind they group the activities of solitary wasps under the 
two heads as follows: 

“Tnstinct.—With the Pelopeus wasps we were present on several occa- 
sions when the young emerged from the pupa case and gnawed their way 
out of the mud cell. They were limp and their wings had not perfectly 
hardened, and yet when we touched them they tried to attack us, thrusting 
out the sting and moving the abdomen about in various directions. These 
movements were well directed, and, so far as we could observe, quite as 
perfect as in the adult wasp. Stinging, then, is an instinctive act. 

“The particular method of attack and capture practiced by each species 
in securing its prey is instinctive. Ammophila pricks a number of ganglia 
along the ventral face of the caterpillar; Pelopzus, we believe, stabs the 
spider in the cephalothorax, and probably the several species of Pompilus 
do the same. Astata bicolor adopts the same tactics in capturing her bugs, 
while it is said of the fly-catchers that they commonly oyercome their vic- 
tims without using the sting. It is by instinct, too, that these wasps take 
their proper food-supply, one worms, another spiders, a third flies or beetles. 
So strong and deeply seated is the preference that no fly-robber ever takes 
spiders, nor will the ravisher of the spiders change to beetles or bugs. 

“The mode of carrying their booty is a true instinct. Pompilus takes 
hold of her spider anywhere, but always drags it over the ground, walking 
backward; Oxybelus clasps her fly with the hind legs, while Bembex uses 
the second pair to hold hers tightly against the under side of her thorax, 
Each works after her own fashion and in a way that is uniform for each spe- 
cies. 

“The capturing of the victim before the hole is made, as in the case of 
P. quinquenotatus, or the reverse method pursued by Astata, Ammophila, 
Bembex, and others of preparing the nest before the food-supply is secured 
is certainly instinctive; as is also the way in which some of these wasps act 
after bringing the prey to the nest. For example S. ichneumonea places her 
grasshopper just at the entrance to the excavation and then enters to see 
that all is right before dragging it in. In experimenting with a French 


652 Reflexes, Instincts, and Intelligence 


Sphex which has the same habit, Fabre moved the creature a little way off; 
the wasp came out, brought it to the opening as before, and went within a 
second time. This was repeated again and again until the patience of the 
naturalist was exhausted, and the persistent wasp took her booty in after 
her appropriate fashion. She must place the grasshopper just so close to 
the doorway, she must then descend and examine the nest, and after that 
must come out and drag it down. Nothing less than the performance of 
these acts in a certain order satisfies her impulse. There must be no dis- 
turbance of the regular method or she refuses to proceed. Again, we see 
Oxybelus scratching open her nest while on the wing and entering at once 
with the fly held tightly in her legs. Each way is characteristic of the species 
and would be an important part of any definition of the animal based upon 
its habits. 

“The general style of the nest depends upon instinct. Trypoxylon uses 
hollow passages in trees, posts, straws, or brick walls; Diodontus ameri- 
canus, a member of the same family, always burrows in the ground, as do 
Bembex, Ammophila, and Sphex. In the case of Trypoxylon the passage 
may be ready for use or may require more or less preparation; the instinc- 
tive part is the impulse that impels the insect to use a certain kind of habi- 
tation. Any one familiar with 7. rubrocinctum would never look for their 
nests in standing stems or under stones; to use Mr. Morgan’s test, he would 
be willing to bet on the general style of the dwelling-place. All of these 
acts are similarly performed by individuals of the same sex and race, not in 
circumstantial detail but quite in the same way in a broad sense. Variation 
is always present, but the tendency to depart from a certain type is not 
excessive. In the drawing of the nest of Cerceris nigrescens the burrow is 
seen to be tortuous, this style of work being common to many species in 
the genus and very characteristic. No Sphex nor Ammophila constructs 
any such tunnel. The adherence of all the members of a species to a certain 
style of architecture is, then, due to instinct. 

“The spinning of the cocoon, in those species in which the larva is pro- 
tected in this manner, and its shape, are instinctive. We find that closely 
allied species in the same genus make very different cocoons, as is seen in 
T. rvubrocinctum and T. bidentatum. Some wasps never cover themselves 
with a cocoon, as in the Australian species Alastor eriurgus and Abispa 
splendida. It is a well-known fact that silkworms sometimes omit the spin- 
ning of a cocoon; but this does not affect the argument, since the descend- 
ants of these individuals make the characteristic covering. Such cases are 
probably due to individual variation or perhaps to atavism, this throwing 
back being not uncommon among forms that are well known. 

“Not all of the instinctive facts here enumerated are displayed by each 
species studied, although as a general proposition they are common to most 


Reflexes, Instincts, and Intelligence 653 


of them. We have doubtless overlooked some activities that should come 
under this head, as we have not made a thorough study of any sufficient 
number of species to make a final settlement of the matter. For conve- 
nience we give the eight primary instincts that we have enumerated in tabular 
form: 


INSTINCTS 
. Stinging. 
Taking a particular kind of food. 
. Method of attacking and capturing prey. 
. Method of carrying prey. 
. Preparing nest and then capturing prey, or the reverse. 
. The mode of taking prey into nest. 
. The general style or locality of nest. 
. The spinning or not spinning of a cocoon, and its specific form 
when one is made. 


Oar An WN H 


“Tntelligence.—It is obviously more difficult to distinguish actions of this 
class than of the other. One must be familiar with the normal conditions 
of the insects in question before he is able to note those slight changes in 
the environment that offer some opportunity for an adaptation of means to 
ends, or before he is competent to devise experiments which will test their 
powers in this direction. 

“We find two classes of intelligent actions among the Hymenoptera 
which are sufficiently distinct to be considered separately, although, like all! 
natural groups, they grade into each other. The first of these includes. 
those actions that are performed by large numbers in a similar fashion under 
like conditions, while in the second class each act is an individual affair, as 
where a single wasp, uninfluenced in any way by the example of those about 
it, displays unusual intelligence in grappling with the affairs of life. Exam- 
ples of the first class are found in such modifications of instinct as are shown 
by Pelopzus and other wasps in the character of their habitations. Pelopzus,,. 
instead of building in hollow trees or under shelving rocks, as was the ancient 
custom of the race, now nests in chimneys, or under the eaves of buildings. 
We have found 7. rubrocinctum taking advantage of the face of a straw 
stack that had been cut off smoothly as the cattle were fed through the 
winter. The same power of adaptation is shown by Fabre’s experiment 
with Osmia, in which he took two dozen nests in shells from a quarry, where 
the bees had been nesting for centuries, and placed them in his study along 
with some empty shells and some hollow stems. When the bees came out, 
in the spring, nearly all of them selected the stalks to build in as being better 
suited to their use than the shells. All of these changes are intelligent adap- 
tations to new modes of life, serving to keep the species in harmony with its. 


654 Reflexes, Instincts, and Intelligence 


surroundings. ‘The same thing may be seen when a number of social wasps 
work together to replace the roof of their nest when it has been torn off. 

“An instance of the second class is seen in one of our examples of Pom- 
pilus marginatus, This species, while searching for a nesting-place, leaves 
its spider lying on the ground or hides it under a lump of earth, in either of 
which positions the booty is subject to the attacks of ants; the wasp in ques- 
tion improved upon the custom of her tribe by carrying the spider up into a 
plant and hanging it there. We have now and then seen a queen of Polistes 
fusca occupy a comb of the previous year instead of building a new one for 
herself, showing a better mental equipment than her sisters who were not 
strong-minded enough to change their ways and so built new nests along- 
side of unoccupied old ones which were in good condition. In Bembex 
society it is good form to close the door on leaving home, but sometimes a 
wasp will save time by leaving the entrance open. This, however, is a 
doubtful case, as the advantage would, perhaps, be more than balanced by 
the exposure of the nest to parasites. ‘The most conspicuous example that 
we have seen of intelligence among wasps was in that individual of Ammo- 
phila that rose above her fellows by using a stone to pound down the earth 
-over her nest. 

“The general impression that remains with us as a result of our study of 
these activities is that their complexity and perfection have been greatly over- 
estimated. We have found them in all stages of development and are con- 
vinced that they have passed through many cegrees, from the simple to the 
complex, by the action of natural selection. Indeed, we find in them beau- 
tiful examples of the survival of the fittest.” 

In a short note published after the issuance of their book, the Peckhams 
describe an experiment with a Sphex whose results to their minds plainly 
show the tempering of the Sphex instinct by a certain degree of intelligence. 
Fabre once experimented on a Sphex, taking advantage of the moment that 
the wasp was out of sight below to remove her prey to a little distance with 
the result that when the wasp came up she brought her cricket to the same 
spot and left it as before, while she visited the interior of the nest. Since he 
repeated this experiment about forty times, and always with the same result, 
it seemed fair, says the Peckhams, to draw the conclusion that nothing less 
than the performance of a certain series of acts in a certain order would 
satisfy her impulse. She must place her prey just so close to the doorway; 
she must then descend and examine the nest, and after that must at once 
drag it down, any disturbance of this routine causing her to refuse to pro- 
ceed. 

“We recently found a Sphex ichnewmonea at work storing her nest,” 
continue the Peckhams, “and thought it would be interesting to pursue 
Fabre’s method and find out whether she were equally persistent in follow- 


Reflexes, Instincts, and Intelligence 655 


ing her regular routine. We allowed ker to carry in one grasshopper to 
establish her normal method of procedure, and found that, bringing it on 
the wing, she dropped it about six inches away, ran into the nest, out again, 
and over to the grasshopper, which she straddled and carried by the head 
to the entrance. She then ran down head first, turned around, came up, 
and, seizing it by the head, pulled it within. On the following day, when 
she had brought the grasshopper to the entrance of the nest, and while she 
was below, we moved it back five or six inches. When she came out she 
carried it to the same spot and went down as before. We removed it again 
with the same result, and the performance was repeated a third and a fourth 
time; but the fifth time that she found her prey where we had placed it, she 
seized it by the head and, going backward, dragged it down into the nest 
without pausing. On the next day the experiment was repeated. After 
we had moved the grasshopper away four times, she straddled it and carried 
it down into the nest, going head foremost. On the fourth and last day of 
our experiment she replaced the grasshopper at the door of the nest and ran 
inside seven times, but then seized it and dragged it, going backward into 
the nest. 

“How shall this change in a long-established custom be explained except 
by saying that her reason led her to adapt herself to circumstances? She 
was enough of a conservative to prefer the old way, but was not such a slave 
to custom as to be unable to vary it.” 

Morgan believes that a fair weighing of the evidence put forward by 
Fabre and the Peckhams leads one to conclude that “among the solitary 
wasps and mason bees the behavior, though founded on instinct, is in large 
degree modified by intelligence.” In the behavior of the Ammophilas ob- 
served by Williston in Kansas and the Peckhams in Wisconsin, which used 
a small stone to tamp down and level off the soil filling the nest hole, Mor- 
gan sees “an intelligent behavior rising to the level to which some would 
apply the term rational. For the act may be held to afford evidence of the 
perception of the relation of the means employed to an end to be attained, 
and some general conception of purpose.” 

After all, to attempt to make sharp distinctions between reflexes and 
instincts and between instincts and intelligence is bound to lead to more or 
less verbal quibbling. I believe that the distinctions will be more and more 
effaced with increasing knowledge of animal behavior on our part. And on 
the whole it seems to me quite fair to say that our present point of view, in 
the light of the increasing evidence for mechanical or physico-chemical 
explanations of insect actions, should be that of the believer in the simpler 
and less anthropomorphic explanations of behavior, i.e., the explanation of 
tropisms and reflexes, and complex and coordinated series of them, which 
may be termed instincts. 


APPENDIX 
COLLECTING AND REARING INSECTS 


Tue simpler the equipment the better for the beginning collector of 
insects. A net, collecting-bottle, box for pinning specimens, papers for 
“‘papered” ones, a few empty vials and pill-boxes, and a few vials contain- 
ing 85 per cent. alcohol—this is outfit enough for general work. For special 
visits to ponds and brooks, a water- or dredging-net, and a jar or tin pail for 
carrying home living specimens, are needed. A large-bladed jack-knife 
for digging and prying under stones, cutting into logs and stumps, and split- 
ting canes and galls is always useful. A pair of forceps, for handling sting- 
ing specimens, and very small or delicate ones, is convenient. 

The net (Fig. 799) should be of some strong non-tearing cloth netting— 
bobinet is excellent—rz2 to 14 inches in diam- 
eter at the mouth and about 24 inches deep, 
tapering to arounded bottom about 4 to 6 inches 
in diameter. The handle should be light and 
about 34 feet long. The wire ring supporting 
the net should be strong—No. 3 galvanized iron 


Fic. 799. Mc. 800. 

Fic. 799.—Collecting-net. (After Packard.) 
Fic. 800.—Insect-killing bottle; cyanide of potassium at bottom covered with plaster of 

Paris. (After Jenkins and Kellogg.) 
wire is good—and firmly fixed in the handle. For a water-net the meshes 
should be coarse and the handle, wire, and netting all extra strong. 

The killing-bottle (Fig. 800) is prepared by putting a few small lumps 
(about a teaspoonful) of cyanide of potassium into the bottom of a wide- 

656 


Collecting and Rearing Insects 657 


mouthed bottle from three to six inches high (a quinine or quassia bottle is 
good) and covering this with wet plaster of Paris. When the plaster sets 
it will hold the cyanide in place, and allow the fumes given off by its gradual 
volatilization to fill the bottle. Or the cyanide may be covered with damp 
sawdust over which is placed a cardboard disk cut so as to fit tightly into 
the bottle. The advantage of the sawdust covering instead of plaster of 
Paris is that it allows one to clean out the bottle after the cyanide is used 
up and to recharge it. The plaster of Paris is broken out of a used-up bott!e 
only with difficulty. The disadvantage of the sawdust and cardboard cover 
is that it is likely to be loosened if the bottle is jarred often. Insects dropped 
into a cyanide bottle will be killed in from two to six or seven minutes. Keep 
a little tissue-paper in the bottle to soak up moisture and to prevent the 
specimens from rubbing. Also keep the bottle well corked. Label it 
‘poison,’ and do not breathe the fumes (hydrocyanic gas). Insects may 
be left in it overnight without injury to them. 

Butterflies or dragon-flies too large to drop into the killing-bottle may 
be killed by dropping a little chloroform or benzine on a piece of cotton, 
to be placed in a tight box with them. Larve (caterpillars, grubs, etc.) 
and pup (chrysalids) should be dropped into the vials of alcohol. 

When the collected insects are killed they may be “pinned up” or 
papered” in the field; or if not many have been taken, may be brought 
home in the killing-bottle and cared for after arriving. 

To “‘paper” specimens—and only insects with large wings, as butterflies, 
moths, dragon-flies, etc., are papered—they should have the wings folded 
over the back and the specimen then laid on one side on a rectangular piece 
of smooth paper, not too soft, which is then folded so as to form a triangle 
with the margins narrowly folded over to prevent its opening. A very success- 
ful professional collector of my acquaintance “papers,” in a sense, small 
insects in the following way: In the bottom of a small tin, wooden, or paste- 
board box he puts a thin layer of glazed cotton; over it he lays a sheet of 
paper, and on this a layer of small insects just as they are poured out of the 
cyanide bottle; then a covering sheet of paper, and over this a layer of cotton, 
another sheet of paper, a layer of insects, and so on. In this way he rapidly 
cares for hundreds or thousands of specimens in the field. When these 
specimens are brought home he either pins them up immediately while 
fresh and flexible, or stores them away to be worked over and pinned up 
at leisure. Before dried insects can be pinned, however, they must be re- 
laxed. This may be effected by steaming them, or simply by putting them 
for a day or two into a closed glass jar with a soaked sponge. In my lab- 
oratory we keep one or two jars with a layer of wet sand in the bottom; 
into these relaxing jars dried insects can be put at any time, and made ready 
for pinning. 


ae 


658 Collecting and Rearing Insects 


To “pin up” specimens special insect pins are used. These pins can 
be bought of any dealer in naturalists’ supplies at from ten’ to fifteen cents 
a hundred. Order Klaeger pins No. 3 or Carlsbaeder pins No. 5. These 
are the most useful sizes. For larger pins order Klaeger No. 5 (Carls- 
baeder No. 8); for smaller order Klaeger No. 1 (Carlsbaeder No. 2). 
Pin each insect straight down through the thorax (Fig. 80r) (except beetles, 
which pin through the right wing-cover near the middle of the body (Fig. 
802)). Oneach pin below the insect place a small label with date and locality 
of capture. If many specimens are going to be collected in one locality, small 


Fic. 8or. Fic. 802. Fic. 803. 

Fic. 801.—Insect properly pinned up. (After Jenkins and Kellogg.) 

Fic. 802.—Mode of pinning beetle. (After Packard.) 

Fic. 803.—Pinning a bug. (After Packard.) 
“locality and date” labels printed in diamond or agate type on paper not 
too stiff for the pin and yet not so thin and weak as to fold on the pin should 
be got. The following is the kind of label in use by the students in my 
laboratory: SYnU For each specimen the day of the month and 
year is filled in. We have such labels for each month in the year: Insects 
too small to be pinned may be gummed on to small slips of cardboard, which 
should be then pinned up. 

The box for pinned specimens which is to be carried on the collecting 
trip should be small: a cigar-box with its bottom covered with sheet cork 
or compressed cork is excellent. Corn pith can be used; on the Pacific 
coast the pith of the flowering stalk of the century-plant is much used, under 
the name of pita-wood, and is unusually good for the purpose. For con- 
taining the specimens permanently cigar-boxes are only to be used when 
more carefully made boxes cannot be afforded. Certain small insects, 
especially beetles of the family Dermestide, have a particular liking for 
dried insects and work their way into any but the tightest of specimen boxes. 
If cigar-boxes have to be used, a small naphthaline cone fastened on a pin 
should be kept in each box. It will be much safer to obtain tight boxes 
or trays, either of the glass-topped sort used for display collections, or of 
the book-shaped sort, used by the National Museum and many other museums 


Collecting and Rearing Insects 659 


and collectors. These boxes may be bought of dealers in naturalists’ sup- 
plies. 

Butterflies, dragon-flies, and other larger and beautiful-winged insects 
should be “spread,” that is, should be allowed to dry with wings expanded. 
To do this spreading—or setting—boards (Figs. 804 and 805) are necessary. 
Such a board consists of two strips of wood 
fastened a short distance apart so as to 
leave between them a groove for the body 
of the insect, and upon which the wings 
are held in position until the insect is dry. 
A narrow strip of pith or cork should be 
fastened to the lower side of the two strips 
of wood, closing the groove below. Into 
this cork is thrust the pin on which the 
insect is mounted. Another strip of wood 
is fastened to the lower sides of the cleats 
to which the two strips are nailed. This 
serves as a bottom and protects the points 
of the pins which project through the piece 
of cork. The wings are held down, after 
having been outspread with the hinder 


LI MAEELLIELELELSEEMLITDLLSUSLEL LIED 
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CEUMETTA 


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———————————— 
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GLEE LLL. 


Fic. 804. Fic. 805. 


Fic. 804.—Setting-board with butterflies properly spread. (After Comstock.) 
Fic. 805.—Setting-board in cross-section to show construction. (After Comstock.) 


margins of the fore wings about at right angles to the body, by strips of paper 
pinned down over them. 

“Soft specimens,” such as insect larvae, myriapods, and spiders, should 
be preserved in bottles of alcohol (85 per cent.). Specimens which the 
collector may desire to preserve in condition fit for future dissecting should 
be killed in boiling water, into which they should be dropped and allowed 
to remain for a minute or two until thoroughly stiffened, and then removed 
to 50 per cent. alcohol for six hours, and finally to 85 per cent. alcohol for 


660 Collecting and Rearing Insects 


preservation. Nests, galls, stems, and leaves partly eaten by insects, and 
other dry specimens can be kept in small pasteboard boxes. 

Where and how to collect.—The principal points about where and how 
to collect will be obvious even to the veriest novice. Go where the insects 
chiefly congregate, and collect them in the most effective way. But some of 
the insect haunts may not be known to the beginner nor at first catch his 
eye, and there are little tricks about collecting in the most effective way. 
“The most advantageous places for collecting are gardens and farms, the 
borders of woods, and the banks of streams and ponds. The deep, dense 
forests and open, treeless tracts are less prolific in insect life. In winter 
and early spring the moss on the trunks of trees, when carefully shaken 
over a newspaper or white cloth, reveals many beetles and Hymenoptera. 
In the late summer and autumn, toadstools and various fungi and rotten fruits 
attract many insects; and in early spring, when the sap is running, we have 
taken rare insects from the stumps of freshly cut hard-wood trees. Wollaston 
says: ‘Dead animals, partially dried bones, as well as the skins of moles 
and other vermin which are ordinarily hung up in fields, are magnificent 
traps for Coleoptera; and if any of these be placed around orchards and 
inclosures near at home, and be examined every morning, various species 
of Nitidule, Silphide, and other insects of similar habits, are certain to be 
enticed and captured.’ 

“Planks and chippings of wood may be likewise employed as successful 
agents in alluring a vast number of species which might otherwise escape 
our notice; and if these be laid down in grassy places, and carefully inverted 
every now and then with as little violence as possible, many insects will be 
found adhering beneath them, especially after dewy nights and in showery 
weather. Nor must we omit to urge the importance of examining the under 
sides of stones in the vicinity of ants’ nests, in which position, during the 
spring and summer months, many of the rarest of our native Coleoptera 
may be occasionally procured. Excrementitious matter always contains 
many interesting forms in various stages of growth. 

“The trunks of fallen and decaying trees offer a rich harvest for many 
wood-boring larve, especially the Longicorn beetles; 
and weevils can be found in the spring, in all stages. 
Numerous carnivorous coleopterous and dipterous 
larve dwell within them, and other larvae which eat 
the dust made by the borers. The inside of pithy Fis. 806.—Water - net. 

: (After Packard.) 
plants, like the elder, raspberry, blackberry, and 
syringa, is inhabited by many of the wild bees, Osmia, Ceratina, and the 
wood-wasps, Crabro, Stigmus, etc., the habits of which, with those of their 
Chalcid and Ichneumon parasites, offer endless amusement and material for 
study. 


Collecting and Rearing Insects 661 


“Ponds and streams shelter a vast throng of insects, and should be diligently 
dredged with the water-net, and stones and pebbles should be overturned 
for aquatic beetles, Hemiptera, and Dipterous larve.” 

Much collecting may be done at night. Many nocturnal moths and 
beetles are attracted by bright lights: the city’s lamp-posts or your own 
brilliant bicycle-lamp of acetylene gas may be relied on. “Sugaring” 
for moths on warm nights, a favorite trick of moth-collectors, consists of 
smearing a mixture of stale beer and sirup in patches a foot square on the 
trunks of various trees, and then making repeated rounds of these trees 
with a dark lantern. Throw the light on the smeared spot and any feed- 
ing moth there will tarry long enough to be covered with a wide-mouthed 
bottle or swooped up with the net. 

Numerous small insects may be found in galls, in rolled-up leaves, and 
in bored canes. Where a plant shows leaves ragged or full of holes, there 
look for the hole-makers. In this kind of insect-hunting one is likely to 
get the immature stages of insects rather than the adult. So much the better. 
A collection should not be limited to grown-up insects alone, but should 
include eggs, larvae, chrysalids, cocoons, nests, and specimens of insect archi- 
tecture and industry, and specimens showing the character of the injuries 
to plants caused by insects. Any specimen which illustrates anything of 
the life, the biology, of insects should go into the collection. And everything 
should be labeled, accurately and fully. Locality and date, notes telling 
of such evanescent conditions as color or of such ecologic relations as character 
of the surroundings should be put on the specimen, or written into a “ collec- 
tions” book under a number corresponding with one on the specimen. The 
collecting of immature stages of insects leads naturally to attempts to rear 
these caterpillars, etc., at home or in the schoolroom or laboratory. 

Rearing insects.—While in ordinary collecting the insects are killed 
immediately after being caught, the collector going afield to obtain specimens 
to keep alive and rear must bring back his trophies unharmed. It is neces- 
sary that he modify his field equipment somewhat. He needs empty boxes 
and little jars, more than killing-bottles and cork-lined pinning-boxes. Do 
not trouble to punch air-holes in box-lids; enough air will get in through 
cracks and loose-fitting covers. Aquatic specimens, however, are easily 
suffocated by filling the water-jar too full and then screwing a tight cover 
on to prevent splashing. The jars and pails should be carried uncovered 
if possible, and they should be broad and shallow rather than narrow and 
deep. Do not try to bring too many water-insects back in one jar; crowd- 
ing is always fatal to them. With log-burrowing grubs and larve bring in 
some chips and dust of the home log; with underground larve bring in 
some soil. Simply because you find such larve in a certain place is sufficient 
proof that their surroundings are of the right sort for them. 


662 Collecting and Rearing Insects 


When brought home the live specimens must be transferred to ‘‘cages”’ 
or rearing-boxes or jars in which proper food is kept and which enables. 
the insect to live as nearly as possible in its normal way. We want our 
caterpillars not merely to provide us with fine ‘‘unrubbed” fresh moths and 
butterflies for our collection, but want them to go through under our eyes 
their usual life-history: we wish to see them eat and crawl and moult 
and spin and transform. We wish to get acquainted with the details of 
their living; to watch them grow and develop; and to see them display 


————————S—SS—=— —' ULL) m —— 
 —e 
Fic. 807.—Breeding-cage. (After Packard.) 


their instincts and insect wits. We may go so far in our scientific curiosity 
as to be led to experimenting with them: to note how they react or behave 
toward light and darkness, toward moisture or dryness, heat or cold; to 
see if they may be induced to modify their inherited instincts to the extent 
of doing new and unusual things, or old things in new ways; to see if their 
life is pure mechanism or in a simpler and more generalized way something 
like ours, in which consciousness and memory and choice play so important 
a part. 

Particularly available and interesting kinds of insects to rear in home 
cages and aquaria are the larve (caterpillars) of moths and butterflies, various 
leaf-eating, wood-boring, and ground-burrowing beetle larvae, honey-bees 


Collecting and Rearing Insects 663 


and ants, and many still-water insects, as water-beetles and bugs, mosquitoes, 
May-flies, dragon-flies, etc. For these various kinds of insects with their 
various kinds of habitat and habit several different kinds of cages are neces- 
sary. 

For moths and butterfly larve very simple cages are sufficient. It is 
only necessary that they admit light and air, that they keep the insects in, 
and that food, green leaves of the favorite food-plant, may be kept fresh 
in them, or readily repeatedly supplied. For small, or a few, caterpillars an 
excellent rearing-cage is shown in Fig. 808. It is made by combining a 
flower-pot and a lamp-chimney or lantern-globe. When practicable, the 
food-plant of the insects to be bred is planted in the flower-pot; in other 
cases a bottle or tin can filled with wet sand is sunk into the soil in the flower- 
pot, and the stems of the plant are stuck into this wet sand. The top of 
the lantern-globe is covered with Swiss muslin. These breeding-cages 
are inexpensive, and especially so when the pots and globes are bought in 
considerable quantities. 


Fic. 808. Fic. 809. 


Fic. 808.—Lamp-chimney and floor of breeding-cage. (After Jenkins and Kellogg.) 
Fic. 809.—Bell-jar live-cage. 


In our laboratory we have made much use of bell-jars of the kind with 
a hole in the top for a cork, which can be closed with netting instead of a 
cork, so that the air may enter (Fig. 809). Small branches of the food- 
plant are kept in glass bottles of water, whose mouth is closed around the 
branches by loose cotton so as to prevent the caterpillars from getting in 
and drowning. For larger, airier cages in which many caterpillars or trans- 
forming pup can be kept we make much use of common wire-screened 


664 Collecting and Rearing Insects 


meat-safes (Fig. 810), which can be got at the grocer’s for about a dollar apiece. 
Comstock describes a good home-made cage built by fitting a pane of glass 
into one side of an empty soap-box. A board, three or four inches wide, 
should be fastened below the glass so as to admit of a layer of soil being 


Fic. 8ro.—Meat-safe live-cage. 


placed in the lower part of the cage, and the glass can be made to slide, so 
as to serve as a door (Fig. 811). The glass should fit closely when shut, 
to prevent the escape of the insects. 

We have even made use in our laboratory of pasteboard shoe-boxes 
with the middle part of the cover cut out (leaving but an inch or so around 
the edges), and mosquito netting pasted 
over the hole. Into such a box fresh 
leaves must be put often, but beyond 
the trouble it serves very well. Specially 
made rearing-cages (Fig. 807) of various | 
kinds can be bought of dealers in natural- 
ist’s supplies, but they are mostly rather 
expensive. 

For larve that live underground 
cages with soil in must be provided. 

The principal difficulty of rearing such ie: Sri — Step Bae, breeding seaee 
insects is to keep the right degree of (After Comstock.) 
moisture in the soil. If too damp, fungi 

grow and envelop the insects; if too dry, the larve soon die. For the study 
of insects that live on the roots of live plants Comstock has devised a special 
form of breeding-cage known as the root-cage. ‘‘In its simplest form this 
cage consists of a frame holding two plates of glass in a vertical pos:tion 


Collecting and Rearing Insects 665 


and only a short distance apart. The space between the plates of glass 
is filled with soil in which seeds are planted or small plants set. The width 
of the space between the plates of glass depends on the width of two strips 
of wood placed between them, one at each end, and should be only wide 
enough to allow the insects under observation to move freely through the 
soil. If it is too wide, the insects will be able to conceal themselves. Im- 
med-ately outside of each glass there is a piece of blackened zinc which slips 
into grooves in the ends of the cage, and which can be easily removed when 
it is desired to observe the insects in the soil.” 

Many caterpillars and other larvae which live above ground in the larval 
stage when ready to pupate crawl down to the ground and burrow into it. 
For these soil must be provided in the rearing-cages, or the larva when 
ready to pupate must be removed from the meat-safe and bell-jar cages 
to boxes containing soil. This soil must not be allowed to dry out entirely, 
nor yet must it be too moist. Experience is the only teacher that will deter- 
mine for the novice the “just right” condition. 

It may be necessary to keep pupe, in cocoons or in underground cells, over 
winter, for many insects, especially in the eastern and northern states, pass 
the winter in the pupal stage. “Hibernating pupe may be left in the breed- 
ing-cages or removed and packed in moss in small boxes. Great care should 
be taken to keep moist the soil in the breeding-cages, or the moss if that 
be used. The cages or boxes containing the pupe should be stored in a 
cool cellar, or in an unheated room, or in a large box placed out of doors 
where the sun cannot strike it. Low temperature is not so much to be feared 
as great and frequent changes of temperature. Hibernating pupe can 
be kept in a warm room if care be taken to keep them moist, but under such 
treatment the mature insects are apt to emerge in midwinter.’’ Eggs of 
insects, laid in the fall, may also be kept over winter, but one must be careful 
to preserve them in a cold place—as an unheated attic or cellar. 

Directions for making and maintaining observation beehives and 
formicaries (artificial ant’s nests) are given on pp. 532 et seq. and pp. 548 
et seq. of this book. 

Aquarium.—Many accounts of how to make and keep up aquaria have 
been published. The following directions have been written by Miss Isabel 
McCracken, an assistant in my laboratory, who has made and successfully 
maintained many small aquaria in schools: 

To make the aquarium get a board 171314 inches thick, grooved all 
around about 1 inch from the edge with a half-inch groove, and painted 
white. This is for the base. Get two pieces of double-thick glass 15X9 
inches for sides and two pieces 11 Xg inches for ends. Set the glass into 
the grooves of the wooden base, bind the corners where the edges of the 
glass come together with strips of coarse muslin or cambric glued on the 


666 Collecting and Rearing Insects 


outside. (Bicycle-tape is good.) Place an oblong strip of glass 8} <1 inch 
across the inside of each corner. Fill the space, thus formed, with cement. 


Fic. 812.—Battery-jar aquarium. (After Jenkins and Kellogg.) 


Fill in the grooves of the bottom board with cement before pressing down 
the panes of glass. Where the glass sides join the bottom board use cement 
carefully both inside and out, filling all the cracks. 

The cement should be made according to the following formula: 


Niners San ccapsoacad.oldaodayoogngd 5. I part. 
PlASter OLR aUI Sore areresterttetttriterieierestetels iter 
Wath are: cress ieler deve eleteiisteeieerteneeteten tl terets Tp ee 
Powdered! Tesiniy. sce eect eerie ee 


Make into a stiff paste with boiled linseed-oil. Use as little oil as possible 
and take proper care in mixing. Leave for several days to harden the 
cement. ‘Then fill slowly and pour off the water several times before using. 

Place an inch and a half of sand on the bottom of the box. This sand 
should be previously baked or boiled to rid it of bacteria. Its main purpose 
is as an anchorage for growing plants. Over this place a layer of variously 
sized pebbles treated in the same way. These form hiding-places for the 
aquatic fauna. Fill with water to the depth of five or six inches. Stock 
with water-plants, the streams or ponds of the neighborhood to determine 
the kind. Watercress, water-crowfoot, Potamogeton, Chara, and eel- 
grass are good kinds. Parrot’s-feather can usually be obtained at nurseries 


Collecting and Rearing Insects 607 


Tradescantia (wandering-jéw or inch-plant) is also useful. Avoid the 
use of algee (pond-scum). The function of the plants is chiefly to oxygenate 
the water. The roots of cress will furnish food for some vegetable-feeding 
animals. 

An aquarium, to be in good condition, must be kept aerated, must be 
kept clean, and its temperature must not be suddenly changed. Sufficient 
air is sometimes maintained by plant-life alone. Unless this proves to be so, 
shown by the healthy condition of both plants and animals, dip up a few 
cups of water every day and let it fall back into the aquarium. All uneaten 
food, dead animals, or decaying leaves must be removed at once. An 
apparatus for removing such is described in a later paragraph. 

The aquarium should be in the light to enable the plants to produce 
oxygen, but not in direct sunlight. If it stands in a sunny window, it should 
be screened from the sun. Water lost by evaporation must be replaced, 
but the fresh water must not differ materially in temperature from that in 
the aquarium. If a film appears on the surface of the water, it is due to 
bacteria and dust. It prevents absorption of air at the surface of the water. 
It may be removed by absorbent paper (newspaper or blotting-paper). It 
may be prevented by thorough cleanliness and by using a coarse cheese- 
cloth cover when not under observation. Never give more food than is 
eaten. 

Implements for use in connection with the aquarium are the following: 
A small dip-net made by twisting a wire about a bottle for the ring and the 
ends about each other for a handle,—the net to be made of coarse cheese- 
cloth or bobinet, used for removing certain objects; a piece of flannel wrapped 
about a stick for cleaning the sides of alge, which are bound to accumulate. 
For removing small particles from the bottom, a 4-inch glass tube long 
enough to reach to the bottom is useful. Close the upper end with the finger, 
hold the other end over the object to be removed, lift the finger, and the 
water will rush up the tube, carrying out the object. Replace the finger on 
the upper end and lift the tube out of the water. For removing a quantity 
of sediment, a long narrow chimney tightly fitted at each end with a cork 
is required. Insert through the center of the corks a short piece of glass 
tubing, and use as described for the simple glass tube. 

To stock the aquarium choose animals that are adapted to life in still 
water, and keep cannibals by themselves. A wire netting will keep in flying 
insects. 

Of the insects that may be kept in an aquarium some spend their entire 
life in the water, while others are aquatic during one stage of existence only. 
Among the insects easily kept in aquaria are the predaceous diving-beetles, 
the young of which are known as water-tigers and feed on small earthworms 
and other insects, as mosquito-wrigglers, May-fly nymphs, etc.; the water- 


668 Collecting and Rearing Insects 


scavenger beetles; back-swimmers; water-boatmen; dragon-fly and May-fly 
nymphs; mosquito larvae, etc. 

Other animals may of course be kept in the aquarium. Common pond- 
snails will live easily, feeding on green slime, roots of water-plants, bits of 
cabbage, etc.; minnows will eat bits of fresh meat, and also the insects; 
quarrelsome little sticklebacks will eat the pond-snail eggs and small crusta- 
ceans, as cyclops, etc.; frog and salamander larvee feed at first on vegetable 
matter, later on bits of meat, tiny earthworms, mosquito larve, etc. 

Remember that an aquarium needs daily care to keep it in good condition. 

The foregoing account of collecting, preserving, and rearing insects has 
been made short and only a general course of procedure indicated, with the 
hope in mind of avoiding the confusion to the beginner likely to result from 
a longer account, including many “‘specialties’’ and refinements in collect- 
ing methods. Numerous excellent extended directions for collecting, pre- 
serving, and rearing have been published. Two such accounts are those 
by Comstock in ‘Insect Life’ (Appletons), pp. 284-335, and by Packard in 
“Entomology for Beginners” (Holt & Co.), pp. 224-288. 


INDEX 


Illustrations are indicated by an asterisk. Page references in black face 


type are to definitions of technical terms. 


order, suborder, superfamily, and family names. 
derived from the Greek, the Greek is followed by the transliteration (in 
italics) of the Greek letters into Latin letters, and that by the English 
meaning; in those derived from the Latin, the Latin (in italics) and the Eng- 
lish meaning are given; in those derived from other languages, the nativity 
of each word is specifically indicated. Each of the family names has been 
derived by adding -ide (having the force of a patronymic) to the name of 
the type-genus, which, in the index, immediately follows the family name. 
The family termination is not repeated throughout the etymologies and 
should be supplied by the reader. 


Abbott-sphinx, larva of, 
*437; tufted-bodied, 437 

Abdomen, parts of, 7 

Acalyptrate Muscidae, 341 

Acanthaclisis, 232 

Acanthia hirundinis, 206 

Acanthiide, Acantha 
(axava, acantha, thorn), 
195, 205 

Achemon — sphinx - moth, 
larva of, *431 

Achorutes nivicola, *64 

Achurum brevipenne, 142 

Acoloithus falsarius, 387 

Acridiide, Acridium 
(axpid.ov, acridium, dim. of 
axpic, locust), 126, 1333 
auditory organ of, *134, 
135; impaled by shrike, 
*134; life-history of, 
136; key to subfamilies 
of, 136; migratory spe- 
cies of, 133; sounds of, 
134 

Acridiinz, 136. 

Acronycta americana, 404; 
impressa, *405; occiden- 
talis, *404; occidentalis, 
larve of, *404 

Adalia bipunctata, 287 

Adephaga (dn, aden, 
enough; gaye, phagen, 
eat), 251 

Admiral, red, 454 

Zcilius sulcatus, stages in 
development of nervous 
system of, *25 

ZEschna constricta, head 
of, *93 


ZEschnide, 7Eschna (prob. 
aioxpoc, aischrus, ugly), 
91, 92 

Agamic, 173 

Agaristide, Agarista 
(etym. uncertain), 407 

Agenius, 499 

Aglais milberti, 456 

Agonoderus pallipes, 255 

Agrilus, 266; ruficollis, 
267 

Agrionidz, Agrion (aypr6c, 
agrius, wild), 89, 90 

Agrotis ypsilon, 402; vena- 
tion of, *404 

Ailanthus-worm moth, 421 

Air-bush bug, 205 

Akidoproctus, 118 

Alaus oculatus, *268 

Alder-blight, 180. 

Aletia argillacea, 404 

Aleyrodes, respiratory sys- 
tem of, *19 

Aleyrodes iridescens, *192; 
merlini, enlarged details 
of pupa, *193; pupa-case 
of, *193; pruinosa, *192; 
tentacu latus, *192 

Alevrodide, Aleurodes 
(aAevpidne, aleurodes, 
floury), 166, 190 

Alimentary canal, 13 

Alimentary canal of cock- 
roach, *14; of dobson- 
fly, *16; of harlequin- 
fly, *15; of locust, *14; 
of thrips, *15 

Allantus basillaris, *464 

Allorhina nitida, 276 


Etymologies are given for the 
In etymologies of names. 


Alternation of generations 
of gall-flies, 469 

Alulet, 327 

Alypia 8-maculata, *408 


Amber-wing  dragon-fly, 
* 

Amblychilia cylindri- 
formis, 253 , 

Amblycera (@m“3Avc, am- 


blys, blunt; *épac, ceras, 
horn), key to genera of, 
118 
Amblycorpha oblongifolia, 
*151; rotundifolia, 151 
Ambrosia-beetle, 299 
Ambush-bugs, 105 
American blight, 179 


American locust, *139, 
141 
American __ tortoise-shell, 


455 ° 
Ammophila, nest-building 
of, *494; nest-burrow of, 
*404; nesting-ground of, 
*492; nesting habits of, 
492; putting inchworm 
into nest-burrow, *493 
Amnion, 38 
Ampelophaga myron, 434, 
435; versicolor, 435 
Amphibolips coccinee, 
471; spongifica, 471 
Amphicerus bicaudatus, 271 
Amphientomum, 112 
Amphigerontia, 113 
Amphion nessus, *438 
Anal veins (see venation) 
Anabrus purpurascens, 
*156, 157 


670 


Anea andria, 455 

Anaphothrips striatus, 221 

Anarsia lineatella, 374 

Anasa tristis, *213 

Anatis 15-punctata, 287 

Anatomy, internal, 13; of 
larva of giant crane-fly, 
*21; of monarch butter- 
fly, *13; of silkworm, 430 

Anax junius, head of, *033 
stages in development of, 
#83 

Ancistrona, 119; gigas, 
*I21, 122 

Ancyloxypha numitor, 443 

Andrena, 517; nest of, 


*516 

Andrenide, Andrena 
(avdphvn, andrene, bee), 
SII 


Andricus californicus, 472; 
gall of, *473 

Androconia from wings of 
butterflies, *592, 445 

Angerona crocotaria, 308, 


300) || 
Angle-wings, 452 
Angoumois — grain-moth, 
375 


Angular-winged  katydid, 
*I51 

Anisolabis annulipes, 162 

Anisomorpha, 133 

Anisoptera (avicoc, anisus, 
unequal; 7Tepov, pterum, 
wing), 89; key to fami- 
lies of, 91 

Anisopteryx pometaria, 


397 ; 
Antsota rubicunda, 427; 
senatoria, *428, 420; 


stigma, 428; virginiensts, 
428 
Anobium, 113, 271 
Anomiopsyllus nudatus, 


356 
Anopheles, 305, 307; ma- 


culipennis, *308;  sp., 
eggs of, *306 
Anosia plexippus, *451; 


arrangement of pharynx, 
cesophagus, etc., in head 
of, *361; complete meta- 
morphosis of, *44; cross- 
section of sucking pro- 
boscis of, *361; devel- 
opment of color-pattern 
in pupal wings of, *596; 


Index 


development of scales of 
wing of, *595; external 
parts of, *6; internal 
anatomy of, *13; larva 
of, *605; mimicry of, by 
viceroy butterfly, *610; 
part of maxillary pro- 
boscis of, showing ar- 
rangement of muscles, 
*361; part of wing of, 
showing scales, *360; 
venation of, *11; vena- 
tion of wings of, *371 
Ant, California black, 
*535; driver, 543; honey, 
545; little black, *536; 
red, 541; slave, 547; 


slave-maker, 547; velvet, | 


497; Western agricultu- 
ral, mound-nest of, *542 

Antelope-beetle, 273 

Antenna, *3; of carrion- 
beetle showing olfactory 
pits, *27; of beetles, *250 

Ant-guests, *553 

Anthidium, 514 

Anthomyiine, 341, 345 

Anthonomus grandis, 206; 
quadrigibbus, 296; sig- 
natus, 296 

Anthophora, 515; pilipes, 
mouth-parts of, *512; 
stanfordiana, 516 

Anthophoride, Anthophora 
(av§0¢6poc, anthophorus, 
flower bearing), 515 

Anthrax, 334;  fulviana, 
venation of wing of, 
*333 

Anthrenus museorum, 263 ; 
scrophularie, *263, 264; 
varius, 263 

Ant-lions, 55, 30 

Ants, 56, 463, 533; and 
rose-aphids, *174; arti- 
ficial nests for, 548; com- 
munal life of, 537; dia- 
grams of lateral aspect 
of abdomen, *540; in- 
stincts of, 554; key to 
families of, 540; relation 
to aphids, 175 

Apanresis virgo, 413 

Aphidiide, Aphis ( adecdeic, 
aphides, lavish), 166, 
171 

Aphids, 171; as ants’ cat- 
tle, 175; honey-dew of, 


| Apide, 


175, 180; killed by Hy- 
menopterous parasites, 
*173; wax of, 175 
Aphis-lion, 228, 229, 230 
Aphis mali, 174 
Aphodius fimetarius, 274; 


oblongus, 275;  termi- 
nalis, 275 

Aphoruride, Aphrophora 
(dgpogopoc, aphrophorus, 


foam-bearing), 63 

Aphrophora 4-notata, 171; 
signoreti, 171 

Apis (apis, bee), 
pat 

Apina, (see Apide), 463 

Apis florea, comb of, *520; 
mellifica, 520, 521; melli- 
fica, hind leg of, *521; 
mellifica, stages in devel- 
opment of nervous sys- 
tem of, *24; mellifica, 
varieties of, *521 

Apoidea (see Apide), 511 

Apple aphids. 174, 179 

Apple bucculatrix-moths, 
376; pupal cocoons of, 
*375, *376 

Apple tent-caterpillars, 
*350 

Apple-tree borer, *266, 
*285 

Aphodius; 274 

Aptera (4, a, without; 
mTEpoV, pterum, Wing), 52, 
58; ovarial tubes of, *50; 
respiratory system of, 

Aquarium, _ battery-jar, 
*645; for dragon-fly 
nymphs, *88; how to 
make and maintain, 
644 

Aquatic muscid, *348, *350 

Arachnida, 3 

Arachnis picta, 413 

Aradide, Aradus (4padoc, 
aradus, rumbling), 195, 
207, 208 

Aradus cinnamomeus, 208, 

Aramiges fulleri, 205 

Arctiide, Arctia (arktos, 
bear), 370, 411 

Areoles, 232 

Argia putrida, 84 

Argynnis cybele, 456 

Arista (antennal bristle) 


Aristolochia clematitis, 
flower of, *575 
Aristolochia, specialization 


Index 


Acridiide, *134, 135; of 
locust, *28; of Locus- 
tide, 150 


of, for insect pollination,’ Australian lady-bird bee- 


575 


Army-worms, 325, *403,, 


404; ichieumon parasite 
of, *482 

Arphia sulphurea, 
tenebrosa, *144 

Arthasia galleata, *169 

Arthropoda, classes of, 2; 
defined, 2 

Arums, specialization of, 
for insect pollination, 
575 

Ascalaphine, 232; key to 
genera of, 233 

Asclepias, catching cab- 
bage-butterfly, *574; cor- 
nuti, specialization of, 
for insect pollination, 
573; incarnata, visited by 
insects, 571; verticillata, 
visited by insects, 569, 
571; visited by honey- 
bee, *574 

Ash-tree borer, *392 

Asilide, Asilus (asilus, a 
gad-fly, a horse-fly), 330 

Asparagus-beetle, 278 

Aspidiotiphagus  citrinus, 
*479 42 

Aspidiotus aurantii, 188, 
*189, *190; ficus, 188; 
perniciosus, *181, *182, 
*184 

Assassin-bugs, 195, 203; 
incomplete metamorpho- 
sis of, *43 

Astata, 499; unicolor, nest- 
burrow of, *500 

Aster paniculatus, visited 
by insects, 571 

Ateuchus sacer, 274 

Athous scapularis, 268 

Atlanticus dorsalis, 
pachymerus, *155 

Atropide, Atropos(Arporoc, 
atropus, one of the 
Fates), 112; key to gen- 
era of, 113 

Atropos divinatoria, 113; 
sp., *112 

sIttagenus *263, 
264 

Auditory organ in antenna 
of mosquito, *29; of 


*1445 


156; 


piceus, 


tle, 186, *187 

Automeris io, 424, *425; 
larva of, 426; pamina, 
424; selleri, 424; sephy- 
rid, 424 


Bacillus, 132 

Back-swimmers, 194, 198 

Bacunculus, 133 

Bag-worm, 360, *388; 
moth, 386, *387; moth, 
venation of wing of, 
*3 

Balancers, 302 

Balaninus caryatrypes, 
*295, 296; nasicus, 206; 
quercus, 296; restus, 296 

Baltimore butterfly, 456 

Banded footman, 410; pur- 
ple, 452 

Bark-lice, 111 

Barren-ground locust, *146 

Basilarchia archippus, 452; 
arthemis, 452; astyanax, 
452; astyanax, venation 
of, *440; floridensis, 452; 
lorquini, 452 

Basilona imperialis, 426 

Battery-jar aquarium, *645 

Bat-tick, 351, *352 

Beak of mosquito, *302 

Bean-weevil, 277, *281 

Bedbugs, 195, 205, *206; 
hunter, masked, 203 

Bee-flies, 332, 333 

Bee-fly, *334; mouth-parts 
of, *334 

Beehive, observation, *531, 
*532 

Bee-lice, 351 

Bee-louse, *352, 353 

Bee-moth, 379 

Bees, 56, 463, 510; carpen- 
ter, 513; gregarious, 516; 
long-tongued, 511; ma- 
son, 514; mining, 513; 
mining, nest-burrows of, 
*516; potter, 514; short- 
tongued, 511; social, 
517; solitary, 513 

Beetles, 55, 246; antenne 
of, *250; development 
of, 250; eyes and tarsi 
of, *250; mode of pin- 


671 


ning, *637; tracheal sys- 
tem of, *18 
Bell-jar formicary, *550; 
live-cage, *642 
Belostoma americana, *200 
Belostomatide, Belostoma 
(BéAoc, belus, dart; oréua, 
stoma, mouth), 194, 200 
Bembecia marginata, 391 
Bembecide, Bembex(3eu325, 
bembix, buzzing insect), 
500 
Bembex spinoloe, 500 
Benacus griseus, 200 
Berytide, Berytus (Bery- 
tus, a seaport town of 
Pheenicia), 195, 214 
Bibio albipennis, *326; ve- 
nation of wing of, *326 
Bibio femorata, 326; fra- 
ternus, 326; tristis, 326 
Bibiocephala —_comstocki, 
heads of male and fe- 
male of, *316; larva of, 
*315; pupa of, *315; ve- 
nation of wing of, *3173 
doanei, head of larva of, 
showing formation of 
adult head-parts, *318; 
doanei, mouth-parts of, 
*9, *316; doanei, mouth- 
parts of larva of, *317; 
elegantulus, female, *316 
Bibionide, Bibio (brbis, 
an insect, from  bibo, 
drink), 304, 325 
Bilateral symmetry (halves 
of body similar) 
Bill-bugs, 204 
Bird-lice, 55, 113; biting, 
III; remedies for, 114 
Bird-ticks, 351 
Biston ypsilon, *3098 
Bittacus, 236; apterus, 238; 
strigosus, *237 
Black beetle, *128 


Black-bordered orange, 
446 

Black-flies, 313 

Black-fly, *312; female, 
mouth-parts of, *313; 


head of larva of, show- 
ing developing mouth- 
parts of, *314; mouth- 
parts of larva of, *313; 
venation of wing of, 
*312 


Black scale, 187 


672 


Black swallowtail, 450 

Blastoderm, *38 

Blastophaga = grossorum, 
* 


497 

Blattide, Blatta (blatta, 
insect that shuns light), 
126 

Blepharocera capitata, 
cross-section of eyes of, 
+207 

Blepharoceride, Blepharo- 
cerus (probably SArgapor, 
blepharus, eye;  épac, 
ceras, divided), 304, 
314. 

Blissus leucopterus, 211, 
* 21 


Blister-beetle, 288 


Blood, 17 
Blow-flies, 343 
Blow-fly, *344; complete 


metamorphosis of, *45; 
compound eye of, *33; 
larva, pupa, and adult 
of, *302 
Bluebottles, 343 
Blue-striped looper, *398 
Body-louse, *216 
Body-wall, section of, *4 
Boleototherus bifurcus, 
289; larva of, *289 
Boll-worm, cotton, 404 
Bombidz, Bombus (36ufoc, 
bombus, a_ buzzing 
noise), 518 
Bombus, 518; affinis, 519; 
californicus, 519; ed- 
wardsti, 519; ferviotus, 
519; sp., nest of, *519; 
sp., worker and queen, 
*518; terricola, 519 
Bombycide, Bombyx 
(bomby-x, silk), 3690 
Bombyliidez, | Bombyllius 
(Bousvrcde,  bombylius, 
humble-bee), 332, 333 
Bombylius, 333; mayor, 
*334; sp., mouth-parts 
of, *334 
Bombyx mori, 429; larve 
of, 428; venation of, *420 
Book-lice, 55; III 
Book-louse, *112 
Book-worm, 271 
Boreus brumalis, 236; cali- 
fornicus, 236; nivoriun- 
dus, 236; unicolor, 236 
Bot-flies, 232, 337 


Index 


Bot-fly, larva of, *337; of 
horse, *338 
Box-elder bug, *213 
Brachycera (payve, bra- 
chys, short; *épac, ceras, 
horn), 303, 327; division 
into groups, 327; keys 
to families of, 327, 332 
Brachynemurus, 232 
Braconide, Bracon (Fa- 
bricius, etym. uncertain), 
463 
Brain of locust, *22 
Braula ce@ca, 353; sp., *352 
Braulide, Braula (3pavda, 
braula, louse), 351, 353 
Breathing of aquatic in- 
sects, 20 
Breeding-cage, *641 ; lamp- 
chimney, *642; soap- 
box, *643 


Breeding-cages how to 
make, 642 

Broad-winged katydid, 
DRO; SUSE 


Brood-comb of honey-bee, 
with young stages, *46 
Bruchide, Bruchus 


(Bpovxoc, bruchus, a lo- 
cust without wings), 
277, 281 

Bruchus obtectus, *281; 
pisi, *281 

Brush-footed butterflies, 
450 


Bucculatrix pomifoliella, 
*376; pupal cocoons of, 
*375 

Buckeye butterfly, 455 

Bud-moth, 381 

Buffalo-gnats, 304, 313 

Buffalo-moth, *263 

Buffalo tree-hopper, 169 

Bug, pinning a, *637 

Bugs, 55, 163 

Buprestide, Buprestis 
(Boic, bos, ox, mpHben, 
prethen, swell), 265, 266 

Buprestis, 267 

Burrower-bugs, 105, 215 

Burying-beetle, *261 

Bumblebee, at clover-blos- 
som, *518; guest, 519; 
nest of, *519 

Bumblebee-like robber-fly, 
*331 

Bumblebees, 517 

Butterflies, 358, 439; key 


to families of, 441; 
scales of, their structure 
and arrangement, 589 

Butterfly, part of wing of, 
*500 


Cabbage-bug, 
214, *215 
Cabbage-butterfly, caught 
by Asclepias, *574; Eu- 
ropean, 445; northern, 

445; southern, 445 
Cabbage maggot-fly, 345 
Cac@cia _ cerasivorana, 

*380; venation of, *380 
Cacecia parallela, *380; 

pervadana, 380; rosa- 
ceana, 380; obsoletana, 
larva of, *364; obsole- 
tana, pupa and adults of, 

*365 
Cecilius, 113 
Caddis-flies, 23, 55, 240; 

keys to families of, 244 
Caddis-worms, case-build- 

ing of, 240; fishing-net 

of, *243; habits of, 241; 

pupation of, 242; cases 
of, *241; key to families 

of, 244 


harlequin, 


Cenonympha californica, 
457 ; 

Calandra granaria, 297; 
oryz@, 207 


Calandride, Calandra (F. 
calandre, weevil), 294, 
207 

Calephilis cenius, 444 

California _ flower-beetle, 
270, *280; parasitic fun- 
gus of, *346; tachinid 
parasite of, *346 

California honey-ant, un- 
derground nest of, *546 

California oak-worm moth, 
*406 

California ringlet, 457 

California _ shield-backed 
grasshopper, *155 

Caligo sp., *612 

Callimorphas, 414 

Calliphora erythrocephala, 
344; complete metamor- 
phosis of, *45; com- 
pound eye of, *33; larva, 
pupa, and adult of, *302 

Callosamia angulifera, co- 
coons of, *423; prome- 


~s 


thea, 422, *424; cocoons 
of, *423; development of 
color-pattern in pupal 
wings of, *597 
Calocalpe undulata, *399 
Calopterygide, Calopteryx 
(Katéc, calus, beautiful ; 
mrépvs, pteryx, flight), 


9 
Calopteryx, 89; maculata, 
* 


, “90 

Calosoma calidum, *254; 
frigidum, *254; larva of, 
*253; scrutator, 254 

Calotermes, 102; casta- 
neus, 104 

Calyptrate Muscide, key 
to subfamilies of, 341 

Camel-crickets, 155 

Camnula pellucida, 
*145 

Campodea sp., *61; staphy- 
linus, 60 

Campodeide, Campodea 
(xauzn, campe, caterpil- 
lar; eldoc, eidus, form), 
60 

Camponotide, Camponotus 


133, 


(kau™n, campe, curve; 
varoc, notus, back), 540, 
545 
Camponotus pennsylvant- 
cus, 545 
Canker-moths, _ lime-tree, 
*307 


Canker-worms, *395, 397 
Canthon, 274 - 
Capitate, *250 
Capnia, 73; pygme@a, 74 
Caprification, 488; figures 
showing effect of non- 
caprification and, *489 
Capside, Capsus (prob. 
kanrew, capten, gulp 
down), 195, 207, 209 
Carabidae, Carabus 
(xapaBoc, carabus, 
horned beetle), 252 
Carneades scandens, 402 
Carolina locust, *141, 143 
Carpenter-bees, 513; nest- 
tunnel of, *513 
Carpenter-moths, 369, 385 
Carpenter-wasps, nest-tun- 
nels of, *502 
Carpocapsa pomonella, 
381; larva or worm of, 
*382; pup of, *383 


Index 


Carpocapsa saltitans, 382, 
* 


Carrion-beetle, *261; larva 
of, *262; smelling-pits 
on antenna of, *27 

Cases, for insect collec- 
tions, 637 

Cassida bicolor, #280, 281 

Castes, 503 

Cat- and dog-flea, 356 

Caterva catenaria, 399 

Catocala epiore, 401; gry- 
nea, *400, 401; nupta, 
ommatidia of, *32; pala- 
ogama, *400;_ relicta, 
401; ultronia, *400, 401 

Catopsila eubule, 446 

Caudal (tailward) 

Cave-crickets, 156 

Ceanothus americanus, vis- 
isted by insects, 569 

Cecidomyia destructor, 323 

Cecidomyiide, Cecidomy- 
ia (xykic, cecis, gallnut; 
kvia, myia, fly), 304, 
322 

Cecropia-moth, 418, *419 

Celery leaf-hopper, *170 

Celithemus epomina, *96 

Cell of wing (space bound- 
ed by veins) 

Cephalic (headward) 

Cephus, grain, European, 
467 


Cephus pygmaeus, 467 
Cerambycide, Cerambyx 
(Képausvé, cerambyx, 


beetle), 277, 282 

Cerasa bubalus, 169 

Ceratocampide (prob. 
kepac, ceras, horn; xaurh, 
campe, a bend), 426 

Ceratophyllus stylosus, 356 

Ceratopogon sp., mouth- 
parts of, *311 

Cerceris deserta, locality 
study of, *501; tubercu- 
lata, dragging weevil to 
nest, *495 

Cerci, 73 

Cercopide, Cercopis (kepxoc, 
cercus, tail; &w, ops, ap- 
appearance), 166, 170 

Cercyonis alope, 457; pe- 
gala, 457 

Cerococcus ehrhorni, *191 ; 
quercus, *192 

Ceruchus piceus, 273 


673 
Cerura, 304; sp., larva of, 
*60 


7 
Ceutophilus 
*155; maculatus, 
155 
Cherocampa tersa, 435 
Chalcedon, 457 
Chalcid fly, *479 
Chalcididz, Chalcis (xaAxic, 
chalcis, copper), 463 
Chalcidoidea (see Chal- 
cidide), 477 
Chalcophora liberta, 267; 
virginiensis, 267 
Chauliodes, 224; serricor- 


lapidicolus, 
*154, 


nis, adult depositing, 
*225 
Chauliognathus margina- 


tus, 270; pennsylvanicus, 
270 

Checkered beetles, 265, 270 

Cheese-skipper fly, *348 

Chelymorpha argus, 281 

Cherry aphis, 174 

Cherry-bug, 214 

Cherry-fruit fly, larva of, 
*340; puparia of, *350 

Cherry-tree leaf- roller, 
*380 

Chicken-flea, 355 

Chickweed geometer, 144, 
399 

Chigoe, 355 

Chilocorus bivulnerus, 287 

Chinch-bug, 211, *212; 
family, 195 

Chionaspis pinifolie, 188 

Chironomide, Chironomus 
(yetpovopuoc, chironomus, 
one who moves hands in 
gesticulation [symmetri- 
cal spreading of feet 
when at rest] ), 304, 310 

Chironomus, alimentary 
canal of, *15; dorsalis, 
part of sympathetic ner- 
vous system of, *24; 
nervous system of, *22; 
pupa of, *311; sp., *310; 
larva of, *311 

Chitin, 4 

Chloealtis conspersa, *140, 
142 

Chloroperla, 73, 74 

Chlorops similis, 350 

Chorion, 37 

Chortophaga viridifasciata, 
144, *145 


674 


Chrysalid, 44 

Chrysidide, Chrysis (xpvace, 
chrysis, a vessel of 
gold), 463, 498 

Chrysobothris — femorata, 
*2600 

Chrysochus auratus, 280; 
cobaltinus, 280 

Chrysomelide, Chryso- 
mela (xpvoounrordvicov, 
chrysomelolonthium, lit- 
tle golden beetle), 277, 
286 

Chrysopa sp., *228 

Chrysophanus thoe, 
venation of, *440 

Chrysophila thoracia, ve- 
nation of wing of, *330 

Chrysopide, Chrysopa 
(ypvse", chrysops, gold- 
en eyes), 224, 228 

Chrysops sp., venation of 
wing of, *328 

Cicada, mouth-parts of, 
*9; septendecim, mouth- 
parts of, *9; septende- 
cim, 166, *167; tibicen, 
167; seventeen-year, 166, 
167 

Cicida-killer, 500 

Cicadide, Cicada (cicada), 
166; sound-making or- 
gan of, *167 


444; 


Cicadula exitiosa, 170; 4- 
lineata, *170 

Cicindela hybrida, larva 
of, *252 


Cicindelide, Cicindela 
(candela, light), 252 
Cicuta maculata, visited 
by insects, 571 
Cigarette-beetle, 271 
Circotettix verruculatus, 
*146 
Circulatory system, 16; of 
young dragon-fly, *17 
Cisthene unifascia, 410 
Citheronia regalis, 426, 
*427; larva of, *366, 
*427 
Class, 2 
Classification, 52 
Clastoptera pini, 171; 
teus, 171 
Clavate, *250 
Clavicornia (clava, club; 
cornu, horn), 251 , 264; 
key to families of, 258 


pro- 


Index 


Claytonia virginica, visited 
by insects, 569 
Clear-winged moths, 368, 
388; sphinxes, 438 
Cleride, Clerus  (kAjpos, 
clerus, mischievous in- 
sect, so named by Aris- 
totle), 265, 270 
Clerus dubius, 270; nigri- 
fons, 270; nigripes, 270; 
sanguineus, 270 
Click-beetle, 265, 267; 
larva of, *268; snapping 
apparatus of, *267 
Climacia, 229 
Clistocampa —_ americana, 
415; larva of, *359; ve- 
nation of, *418; disstria, 
stages of, *417 
Close-wings, 377 
Clothes-moth, *373, 
case-bearing, 374 
Clothilla, 113 
Clouded locust, *145, 146 
Clouded-sulphur, 446 
Cobea scandens, visited by 
insects, 567 
Coccide, Coccus (kéxkoe, 
coccus, berry or kermes 
insect), 166, 180 
Coccinella abdominalis, 
*286; californica, *286; 
californica, stages of, 
*287; novemnotata, 287; 
oculata, *286; sanguinea, 
*286; trifasciata, *286 
Coccinellide, | Coccinella 
(dim. of coccinus, scar- 
let garments), 282, 286 
Coccotorus scutellaria, 206 
Cockroach, alimentary ca- 
nal of, *14; egg-case of, 
*127; trachez in head of, 
*19; wood, *128 
Cockroaches, 53, 126 
Cockscomb gall-louse, 180 
Codlin-moth, 381; larva or 
worm of, *382; pupz of, 
*383 
Cenis dimidiata, *69 
Coleoptera  (KoAedc, co- 
leus, sheath ; 7Tepdv, 
pterum, wing), 55, 246; 
genuina, 251; key to sec- 
tions and tribes of, 251 
Collecting insects, direc- 
tions for, 635 
Collecting-net, *635 


374; 


Collembola (xéA2a, colla, 
glue; ¢430An embole, in- 
sertion, i.e, closely 
joined, well framed), 60, 
62; key to families of, 


3 
Colletes, 513 
Colobopterus, 233 
Colopha ulmicola, 180 
Colorado potato - beetle, 
*278 
Coloration, directive, 607 
Color-pattern, de velop- 
ment of, in giant wood- 
boring beetle, *508; de- 
velopment of, in pupal 
wings of monarch-but- 
terfly, *500 ; develop- 
ment of, in pupal wings 
of promethea-moth, *597 
Colors, analytical table of, 
of insects, 588; chemical, 
how produced, 586; hy- 
podermal, 587; of flow- 
ers, developed for at- 
traction of insects, 566; 
of insects, advantages 
of, 584; of insects, de- 
velopment of, 506; of in- 
sects, their causes and 
uses, 583; physical, how 
produced, 586; produced 
by scales, 504; warning, 
604; cuticular, 587 
Colpocephalum, 119 
Comma-butterfly, *453 
Communal life of ants, 
537; of the honey-bee, 
521 
Compsomyia 
344 
Compton tortoise, 456. 
Cone-nose, blood-sucking, 
203, *204 
Coniopterygide, Conio- 
pteryx Gaus conis, 
dust; 7Tépv, pteryex, 
wing), 224, 235 
Conocephalus, 154; en- 
siger, *153 
Conopidz, Conops (K@vcn), 
conops, gnat), 332, 336 


macellaria, 


Conops, 337 

Conorhinus sanguinisugus, 
203, *204 

Conotrachelus nenuphar, 


*206; crategi, *207 
Copris carolina, 274 


Coptocyla 
281 

Coral-winged locust, *142, 
144 

Corbiculum, 514, *521 

Cordate (heart shaped) 

Cordulegaster, 92 

Cordulegasteride, Cor- 
dulegaster (prob. 
xopdvan, cordyle, a club; 


clavata, 


yaotnp, gaster, belly), 
92 
Coreide, Coreus (xépec, 


coris, bedbug), 195, 207 

Corethra sp., *309; pupa 
and larva of, *309 

Corimelena publicaria, 215 

Corimelenidz, Corimelena 
(Képe, coris, bedbug; 
pedavia, melaina, f. of 
melas, black), 195, 207, 
215 

Corisa sp., *199 

Coriscum cuculipennellum, 
moth and leaf rolled by 
larva of, *378 

Coriscus subcoleoptratus, 
204 

Coriside, Corisa (képec, 
coris, bug), 194, 198 

Corn-bill bug, 297 

Cornroot-louse, and shep- 
herds of, 175 

Corn-worm, 404 

Corrodentia, (corrodere, 
gnaw to pieces), 55, III; 
life-history of, III; ce- 
sophageal sclerite of, 
112; structure of, III, 
112; table of families of, 
112 

Corydalis, 224 

Corydalis cornuta, *226; 
alimentary canal of, *16; 
development of mouth- 
parts of, *227; habits of, 
227; head of, showing 
mouth-parts, *6 

Corymbetes hamatus, 268; 
hieroglyphicus, 268 

Corythuca, sp., *208; ar- 
cuata, 208 

Cosmopepla carnifex, 214 

Cosmosoma auge, 410 

Cossid, venation of a, *385 

Cosside, Cossus (cossus, 
a larva under bark of 
trees), 369, 385 


Index 


Cossus populi, 385 
Costa (see venation) 
Costal, 460 
Cotalpa lanigera, 276 
Cotton-stainer, 210 
Cotton-worm, 404 
Cow-ants, 408 
Cow-killer, *497, 498 
Goxa, *3> 46; 247 
Crab-louse, *217; egg of, 
*217 
Crabro stirpicola, 502 
Crabronide, Crabro (cra- 
bro, hornet), 502 
Crambide, Crambus 
(xpauBoc, crambus, dry, 
shriveled), 377 
Crambidia cephalica, 410; 
pallida, 410 
Cranberry leaf-roller, 
*380; spittle insect, 171; 
worm-moth, *381 
Crane-flies, 304, 321 
Crane-fly, giant, anatomy 
of larva of, *21; degen- 
erating muscle from pu- 
pa of, *50; development 
of wing-buds of, *48; 
salivary glands of, be- 
fore and after degenera- 
tion, *51; stages of, 
*322; venation of wing 
of, *321 
Cremastogaster lineolata, 
544; shed-nest of, *543 
Creophilus villosus, *260 


Crepidodera cucumeris, 
281 

Crickets, 53, 126, 157; 
ant-loving, 161; burrow- 
ing, 161; degenerate 


forms, 162; sound-mak- 
ing file of, *157; wing- 
less striped, chirping of, 
150 
Crioceris asparagi, 278 
Cross-pollination, 564; of 
flowers by insects, how 
developed, 581 
Croton-bug, 128, *128 
Crustacea, 3 
Ctenocephalus canis, *354, 


356 
Ctenucha multifaria, 410; 
ruberoscapus, 410; ve- 
nosa, 411;  wirginica, 
410; venation of, *411 
Cubitus (see venation) 


675 


Cuckoo-flies, 463, 408 
Cucujide, Cucujus (Bra- 
zilian cucujo, a bu- 
prestid beetle), 258, 262 
Cucujus flavipes, 263 
Cucumber-beetle, 279, *280 
Cucumber flea-beetle, 281 
Culex, 305, 307 
Culex fatigans, scales on 
wings of, *310; head of, 
*7; incidens, eggs of, 
306; life-history of, 
*305; mouth-parts of, 
*301 
Culicide, Culex 
gnat), 304, 305 
Curculionide, Curculio 
(curculio, weevil), 204, 
205 
Curculios, 294 
Cucullia, 402 
Currant-angerona, *399 
Currant-borer, 390 
Currant endropia, *399 
Currant-slug, *465 
Currant-stem girdler, *465 
Currant-worm, imported, 
466; native, 466 
Cuterebra cuniculi, 
larva of, *337 
Cuticle, 4; chitinized, *5 
Cutworm, *402; climbing, 
402 
Cyantris pseudargiolus, 443 
Cybister, 255, 257 
Cydnide, Cydnus (xvdvdc, 
cydnus, famous), 195, 
207, 216 
Cyllene pictus, 284 
Cymatophora pampinaria, 
* 


Cynipide, Cynips («vap, 
cnips, name of several 
insects), 463, 467; al- 
ternation of generations 
of, 460 


(culex, 


338; 


Cynipoide (see Cynipi- 
dz), 478 
Cynips  quercus-saltatrix, 


*474; galls of, *473 
Cyrtophyllus concavus, 
*150, *I51 


Dagger-moth, gray, *404; 
larve of, *404; rasp- 
berry, *405 

Damsel-bug, 195, 204, *205 

Damsel-flies, 53, 75, *78 


676 


Damsel-fly, nymph of,. *84; 
ruby-spot, *90 

Dance-flies, 332, 334 

Dance-fly, mouth-parts of, 
*335; venation of wing 
of, *335 

Darkling ground-beetles, 
288 

Dasyllis sacrator, *331 

Datana angusti, 394; min- 
istra, 393 

Datura stramonium, spe- 
cialization of, for insect 
pollination, 571 

Daunus swallowtail, 449 

Dead-leaf butterfly, *6o1 

Death’s-head sphinx-moth, 


*438, *613 
Death-watch, 271; beetles, 
265 
Deer-flies, 328 
Degeneration, among 


scale-insects, 180, 188 
Deilephila lineata, 435 
Dejeania corpulenta, *346 
Dendroctonus valens, 299 
Dendroleon, 232 
Dermatobia cyaniventris, 

3390; no-xialis, 339 
Dermestes lardarius, *264 
Dermestide, Dermestes 

(dépua, derma, skin; 

éahiew, esthien, eat), 258, 

263 
Desmia maculalis, 378 
Desmocerus palliatus, 284 
Development, 35; of bee- 

tles, 250; of color-pat- 

tern in giant wood-bor- 
ing beetle, *508 ; of color- 
pattern in pupal wings of 

monarch butterfly, *596; 

of color-pattern in pupal 

wings of promethea 
moth, *597; of egg of 
fish-moth, *40; of egg 
of saw-fly, *39; of egg 
of water scavenger-bee- 
tle, *38; of honey-bee, 

522; of malaria-produc- 

ing Hemameeba in hu- 

man__ blood-corpuscle, 

*618; post-embryonic, of 

locust, *42; of scales on 

wing of Anosia plexip- 
pus, *595; of scales on 
wing of Euvanessa anti- 
opa, *594; of wing-buds 


Index 


of giant crane-fly, 
of wings of locust, *42 


*48; Diverse-land geometer, 


*309 


Devil’s darning-needle, 76. Dixa-flies, 304 


Dexia, 346 

Dexiine, 341, 346 

Diabrotica 12-punctata, 
279; longicornis, 279; 
soror, 279, *280; vittata, 
279 

Diapheromera _ femorata, 
*131, 132, *603 

Diaspis rose, *190 

Diastrophus nebulosus, 
473 


Dicerca divaricata, 267 

Dichelia sulfureana, *380 

Dicromorpha viridis, *141 

Dictyopteryx, 73 

Diedrocephala mollipes, 
170 

Diestrammmena marmorata, 


155 
Differential 

141 
Digestive epithelium, cells 

of, of crane-fly, *17 
Digger-wasps, 463 
Dimorphic, 469 


locust, *137, 


Dineutes emarginata, *257 | 


Diopside, Diopsis (4% di, 
two; duc opsis, eyes), 
347 

Dioptide (prob. de, 
dis, twice; 6yuc, opsis, 
seen, referring to the 
two generations per year 
in some forms), 407 

Diplosis pini-radiata, *324 


Diptera (dt, di, two;) 
mTepév, pterum, wing), 
56, 301; genuina, 303; 
life-history of, 302; 


mouth-parts of, 302 

Dipterous larve, histo- 
blasts or imaginal discs 
of, 47 

Directive coloration, 607 

Discal area or spot or cell 
(near center of base of 
wing) 

Diseases, insects in rela- 
tion to, 615 

Dissosteira carolina, *141, 
143; brain of, *22; ner- 
vous system of, *22; 
pericardial membrane of, 
*18; respiratory system 
of, *18 


| Dixa sp., 


*319; larva of, 
*318; mouth-parts of, 
*319; pupa of, *319; ve- 
nation of wing of, *320 

Dixide, Dixa (prob. 4diséc, 
dixus, double, or dciéc, 
dixis, a showing, dis- 
play), 304, 319 

Dobson-fly, *326; alimen- 
tary canal of, *16; head 
of showing mouth-parts, 


Dobsons, 55 

Docophorus californiensis, 
116; communis, 116, 
*120, 122; cursor, 116; 
excisus, 116; icterodes, 
116, *119; lari, 116; per- 
tusus, 117; platystoy- 
mus, 116 

Dog- and cat-flea, *354 

Dog-day locusts, 167 

Dog-louse, sucking, *217 

Dolichopodid, venation of 
wing of, *336 

Dolichopodide, Dolicho- 
pus (doAcyérovc, dolicho- 
pus, with long feet), 332, 


335 
Dolichopus lobatus, *335 
Dorcus parallelus, 273 
Dorsal (backward, oppo- 
site of ventral) 
Dorsal vessel, valves of, 
*18; of locust, *17 
Doryphora ro-lineata, *278 


| Dorypteryx, 113 


Double-eyed sphinx, *435, 
437 

Dragon-flies, 53, 75; col- 
lecting nymphs of, 87; 
colors of, 80; distribu- 
tion of, 78; egg-laying 
of, 82; food of, 81; life- 
history of, 84; preserv- 
ing adults, 88; rearing 
nymphs of, 87;  struc- 
ture of, 79; table for 
classification, 89 

Dragon-fly, *76; circula- 
tory system of, *17; 
giant, stages in develop- 
ment of, *83; hero, 93; 
nymph of, *76, *77; ve- 
nation of wing of, *890; 


water-prince, *95; wind- 
sprite, *96 

Drosophila ampelophila, 
349 

Drosophilide, Drosophila 
(dpisoc, drosus, dew ; 
gidoc, philus, loving), 
349 

Dynastes grantii, 276; her- 
cules, 276; tityrus, *12, 
*276, *277 

Dysdercus suturellus, 210 

Dyspepteris  abortivaria, 
*307, 398; venation of, 
* 


Dyticus, *255, *256 

Dytiscide, Dytiscus 
(durixoc, dyticus, fond of 
diving), 252 

Dyticide, 252 


Earwigs, 53, 162, *162 
Echocerus maxillosus, 289 
Ecitomyia wheeleri, *553 


Eciton c@cum, *543; opa- 
cithere, 543; schmitti, 
*543 


Ecitoxenia breviples, *552 
Ecpantheria deflorata, 413; 
musina, 413 
Ectobia germanica, 
*128 
Egg, development of, of 
water scavenger-beetle, 
*38; fertilization of, 14; 
of fish-moth, develop- 
ment of, *40; of saw- 
fly, development of, *39; 
tubes, *248 
Egg-case of cockroach, 
*127; of Hydrophilus 
triangularis, *259 
Eggs, micropyle of, *37; 
of Anopheles sp., *306; 
of Culex incidens, 306 ; 
of katydid, *149 
Elaphidion villosum, 
stages of, *284 
Elater acerrimus, larva of, 
*268; nigricollis, 268; 
rubricollis, 268;  san- 
guinipennis, 268 
Elateride, Elater (#Aarnp, 
elater, driver), 266, 267 
Eleodes, *288 
Elephantiasis 
quitoes, 633 
Elm-leaf beetle, 278 


128, 


285 ; 


and mos- 


Index 


Elipsocus, 113 

Elytra, 249 

Embia texana, *109 

Embiide, Embia (é8z0c, 
embius, living, viva- 
cious), 109 

Embryo, 37 

Emesa longipes, 204, *205 

Emeside, Emesa (Emesa, 
city of Syria), 195, 204 

Empidide, Empis (é7c, 
empis, mosquito), 332, 
334 of, * 

Empis, venation Be we 

Empodium (appendage be- 
tween two tarsal pul- 
villi) 


Enchenopa binotata, 168; 
gracilis, *169 

Encoptolophus  sordidus, 
*145, I 


Endropia armataria, *399 
Ennonos subsignarius, 398 
Ensign-flies, 463 
Entomobryide, Entomo- 
brya (prob. évte“ov, en- 
tomum, insect; pvor, 
bryum, moss), 63 
Entomophilous flower, 566 


Epargyreus tityrus, 442; 
venation of, *440 

Ephemerida, Ephemera 
(€onuEpoc, ephemerus, 


for a day), 53, 54, 65 
ree kuehniella, *377, 


Barcdia, 347 
Ephydride, Ephydra 
(é¢vdpoc, ephydrus, liv- 
ing on the water), 348 
Epieschna heros, 93 
Epicauta cinerea, 203; 
pennsylvanica, 293; vit- 
tata, *290, 293 
Epicwerus imbricatus, 295 
Epicordulia princeps, *95 
Epidapus scabies, 325 
Epimartyria, 371 
Epimenis, grape-vine, 400 
Erax cinerascens, mouth- 
parts of, *331; venation 
of wing of, *331 
Erebia, 457 
Erebus odora, 401 
Eretmoptera brownt, 
Ergates spiculatus, 
284 
Eriocampa cerasi, 466 


*35T 
*282, 


677 


Eriocephala, 371 
Eriocephalide, Erioce- 
phala (prob. 7piov, eri- 
um, mound ; xkegady, 
cephale, head), 368 
Eristalis sp., mouth- “parts 
of, *340; tena-x, *339, 
340 
Erynnis sassacus, 443 
Erythroneura comes, *170; 
vitis, 170; vulnerata, 
*170 
Eubyia cognataria, *398 
Euclea del phinii, 384; 
penulata, 384 
Eucleide, Euclea (edxAea, 
euclea, glory), 384 
ee proteus, 442 
Pantie tones 381 
Eudryas grata, *400, 410 
Eugonia californica, 456; 
j-album, 456 
Eumacaria brunneraria, 
*308 
Eumenes, 498; vase mud- 
nest of, *499 
Eumenide, Eumenes (¢?, 
eu, good; evoc, menus, 
disposition), 408 
Euphoria inda, 276, *277 
Euphydryas phaeton, 456 
Euplectrus comstocku, 485 
Euplexoptera = ( «t, 
well; wAexo, pleco, fold. 
ed; 7Tepov, pterum, 
wing), 53, 162 
Eurymetopus, 118 
Eurymus eurytheme, 446; 
philodice, 446 
Eustigme acraa, 415 
Euthrips tritici, 221 
Euvanessa antiopa,~455 
Evaniide, Evania (evavic, 
euanius, taking trouble 
easily), 463 
Exoprosopa sp., *334 
Exoskeleton, 4; attach- 
ment of muscles to, *4 
Exuvia, 186; of stone- 
fly nymph, *71 
Eye, of horsefly, *31; of 
moth, *31; of Lasio- 
campa quercifolia, *32; 
of Catocala nupta, *32; 
of May-fly, *32; of 
blow-fly, *33; spots, Pl. 
Koya 
Eyed grayling, 457 


678 


Eyes, compound and sim- 
ple, 30; of May-flies, 
*69; of net-winged 
midges, *316 

Eye - spotted bud - moth, 
*381 


Fabre, J. H., on instinctive 
behavior, 643 

Fall canker-worm, 397 

False crane-flies, 327 

Family, 56 

Feather-wings, 376 

Femur, *3, *6 

Feniseca tarquinius, 444 

Fermenting fruit-flies, 349 

Fertilization of egg, 14; 
of plants, 564 

Fig-insect, *487 

Figitide (figo, to attach by 
piercing), 475 

Figs, caprification of, 487; 
on a branch, *488; show- 
ing effect of non-caprifi- 
cation and of caprifica- 
tion, *489 

Filariasis and mosquitoes, 
632 

Filiform, 364 

Fireflies, 265, 269 

Fish-moth, *58, *62; de- 
velopment of egg of, *40 

Flannel-moths, 369 

Flat-bug, 195, 208, *209 

Fleas, 56 

Flesh-fly, 343, *344 

Flies, 56; life-history of, 
302; mouth-parts of, 
302; two-winged, 301 

Flower-bug, 195, *209; in- 
sidious, 206 

Flower-fly, 332, *339 

Flower, pistil and ovary, 
showing pollen tube, #564 

Flowers and insects, 502; 
colors of, developed for 
attraction of insects, 
566; cross-pollinated by 
humming-birds, 573; en- 
tomophilous, 570 

Food-habits of Hemiptera, 
164, 165; variety of, 8 

Footman, banded, 410; 
painted, 409; pale, 410; 
striped, 400 

Footman-moths, 370, 409 

Foot of house-fly, *341 

Forest-fly, *352 


Index 


Forest-moths,  eight-spot- 
ted, *408 

Forest _ tent-caterpillar 
moth, *417 


Fork-tailed katydid, *152 

Formica exsectoides, 545; 
nitidriventris, 547; san- 
guinea, 547; schaufussi, 
547; suba@nescens, 547; 
subsericea, 547 

Formicina (see Formi- 
coidea), 463, 539; key to 
families of, 540 

Formicoidea, Formica 
(formica, ant), 539 

Frenate (frenum, that 
which holds things to- 
gether), 368 

Frenulum, *376 

Fritillaries, 456 

Frog-hoppers, 170 

Froth production of frog- 
hoppers, stages of, *171 

Fruit-worms, parasite of, 
*485 

Fulgoride (Fulgora, god- 
dess of lightning), 166, 
168 

Fungus attacking chinch- 
bugs, 212 

Fungus, parasitic, of Cali- 
fornia  flower-beetle, 
*346 

Fungus-gnat, 304, 324, 
*325; venation of wing 
of, *325 


Gadflies, 328 

Galerucella luteola, stages 
of, *278 

Galgulide, Galgulus (gal- 
gulus, a small bird), 194, 
202 

Galgulus oculata, *202 

Gall, blackberry, 473; fi- 
brous, of the California 
live-oak, *472; of the 
California white oak, 
*4733; Tose, 473 

Galleria mellonella, 379 

Gall-flies, 56, 463, 467; al- 
ternation of generations 
of, 469 

Gall-fly, *468; ovipositor 
of, *468 

Gall-forming aphids, 180 

Gall-gnats, 304 

Gall-midge, 322 


Galls, 467; growth of, 474 ;, 


jumping, of the oak, 
*473;, made by a Cynipid 
gall-fly, *469; on leaf, 
*471; on leaf of Califor- 
nia white oak, *470; on 
twigs of California white 
oak, *471; trumpet, on 
leaves of California 
white oak, *470; variety 
of, 470 
Ganglia, 21 
Gastropacha 
416, *418 
Gastrophilus equi, 337, 
*338; nasalis, 338 
Gelechia cerealella, 
galle-solidaginis, 
pinifoliella, 376 
Genus, 56 
Geometer-moths, 396 
Geometra iridaria, 398 
Geometrid moth, larva of, 
*395, *306; larva of, in 
protective position, *603 


Geometrid, venation of a, 
* 


americana, 


375; 
350; 


Geometrina, Geometra (77, 
ge, earth ; wérpov, me- 
trum, measure), 370, 


306 

Geotrupes, 275 

Geotrupes excrementi, 
275; Opacus, 275; splen- 
didus, 275 

Ghost-moths, 372 

Giant-skippers, 441 

Giebelia, 118 

Gills of young May-fly, 
68 ; tracheal, 20; of May- 
fly, nymph, *20 

Girdler, currant-stem, *465 

Gloveria arizonensis, base 
of scale of, *591; scales 
from wing of, *593 

Glow-worm, 269 

Goatweed-butterfly, 455 

Golden-eyed fly, *228 

Gomphide, Gomphus 
(yougoc, gomphus, a fast- 
ening), 92 

Gomphus exilis, 92 

Goniodes, 118 


Goniocotes, 118; holo- 
gaster, 119 
Goniotaulius dispectus, 


2430 
Gopher crickets, 155 


} 
is 
: 


Gossamer-winged _ butter- 
flies, 443 

Gnophela latipennis, 407 

Grain-cephus, European, 
467 d 

Grain-weevil, 297 

Granddaddy-long-legs, 321 

Grape-berry moth, 381 

Grape-phylloxera, 172,176; 
various forms of, *176, 
177 

Grape-vine amphion, *438; 
flea-beetle, larva of, 
*280; roots infested by 
phylloxera, *178; 
sphinx-moth, *434; root- 
borer, 391 

Grapholitha sebastiane, 383 

Grapta sp., part of wing 
of, showing insertion 
pits of scales, *590 

Grasshoppers, long- 
horned, 126, 149 

Grass-stem flies, 350 

Grass-thrips, 221 

Green fly of gardens, 172 

Green-fruit worms, *402; 
parasitized, *486 

Greenhead, *328 

Green-leaf insect, *602 

Green-striped locust, 144, 
*345 

Grouse-locusts, 136, 147 

Gryllide, Gryllus (gryllus, 
cricket), 126, 157 

Gryllatalpa borealis, 161; 
columbia, 161 

Gryllus abbreviatus, *158; 
assimilis, 158; domesti- 


cus, *158; luctuosus, 
158; pennsylvanicus, 
*157 


Guest bumblebee, 519 

Gypsy-moth, 405 

Gyrinide, Gyrinus ( yupives, 
gyrinus, a circle, a whirl- 
pool), 252, 255 

Gyrinus marinus, larva of, 
*257. 

Gyropide, Gyropus (yupos, 
gyrus, crooked; 7ovg, 
pus, foot), 118 

Gyropus, 118, 121 


Hzemameeba, malaria-pro- 
ducing, development of, 
in human blood-corpus- 
cle, *618 


Index 


Hematopinus acanthopus, 
218; antennatus, 218; 
asin, 218; eurysternus, 
217, *218; ovis, *219; 
pedalis, 218;  piliferus, 
*217; sciuropteri, 218; 
spinulosus, 218; sutu- 
ralis, 218; urius, *218; 
ventricosus, 218; vituli, 
217 

Hadenucus subterraneus, 
156 

Hagenius brevistylus, 92 

Hag-moth, 384 

Hair-streaks, 444 

Hair, tactile, innervation 
of, *26 

Halesus ind stinctus, *241 

Halictus, 517 

Halis:dota argentata, 414; 
carye, *414; lobecula, 
414; maculata,*414; sp., 
larve of, *411; tesselata, 
*414; tesselata, cater- 
pillar of, *413; tesselata, 
venation of, *416 

Halobates, 198; wiillers- 
dorfi, *197 

Halteres, 302 

Haltica chalybea, larva of, 
*280 

Handmaid-moths, 392 

Haploa clymene, 414; 
contigua, *415;  fulvi- 
costa,- *415;  lecontei, 


414 

Harlequin-fly, alimentary 
canal of, *15; part of 
sympathetic nervous sys- 
tem of, *24 

Harpalus pennsylvanicus, 
255 

Harrisina americana, 387; 
coracina, 387; metallica, 
387 

Harvester, 444 

Harvest-flies, 167 

Hawk-moth, 360, 431; 
posed before jimson- 
weed, *572 

Head, interior of, of Mon- 
arch butterfly, showing 
arrangement of pharynx, 
cesophagus, etc., *361; 
of dobson-fly, parts of, 
*6; of locust, showing 
anatomy, *124; parts of, 


679 


Head-louse, *216 
Hearing, sense of, 29 
Heart, 16; of locust, *17; 
valves of, *18 
Heel-flies, 338 
Heliconia sp., scales from 
wing of, *594 
Heliothis armigera, 404 
Hellgrammite, 226 
Hemaris brucei, 439; dif- 
finis, larva of, *438; 
thysbe, 438 
Hemerobiidz, Hemerobius 
(jHepoioc,  hemerobius, 
ephemeral), 224, 229 
Hemerobius sp., 229, 230; 
sp., larva of, *230 
Hemerocampa leucostigma, 
degenerating muscle of, 
*so; head of,*363; larva 


of, *405 
Hemileuca electra, 425; 
maia, 425; mnevadensis, 
425 a 
Hemiptera (74, hemi, 
half; xrépov, pterum, 


wing), 55, 163; as pests, 
163, 165, 169, 172, 176, 
180, 194; classification 
of, 165; food habits of, 
164, 165; key to sub- 


orders of, 165; meta- 
morphosis of, 164; 
mouth-parts of, 164; 


section through head and 
beak, *164 

Hen-flea, 356 

Heodes hypophleas, 444 

Hepialide, Hepialus 
(jrlados, hepialus, ghost- 
moth) 368, 379, 372 

Hepialus gracilis, venation 
of wing of, *372; mog- 
lashani, scale of, *589 

Hesperia tessellata, 442 


Hesperid, venation of, 
*440 

Hesperide, Hesperia 
(Hesperus, evening 
star), 442 

Hesperotettix pratensis, 
*140 

Hessian fly, 323; parasite 
of, *478 


Hetzrina, 89; americana, 
*90 

Heterocampa _guttivitta, 
*393; larva of, *304 


680 


Heterocera (érepoc, hete- 


rus, different; «épac, 

ceras, horn), 364 
Heteromera (repos, he - 

terus, different; époc, 


merus, part), 252; key 
to families of, 288 
Heteroptera (étepoc, he- 
terus, different; 7Tépov, 
pterum, wing), 166, 194; 
key to families of, 194 
Hexapoda, 3 
Hibernia _ tiliaria, 
larva of, *396 
Hilara, 335 
Hippiscus tigrinus, *143; 
tuberculatus, 144;  fe- 
male of, *142; young of, 
¥] 
Hippobosca 
*352 
Hippoboscide, Hippobosca 
(ixxo, hippo, horse ; 
Buoxés, boscus, feed), 
351 
Hippodamia 


*207%5 


equina, 351, 


convergens, 


2 
Histoblasts of Dipterous 
larve, *47 
Histogenesis, 49 
Histolysis, 49 


Hives, observation, for 
studying honey-bee, *531, 
*532 


Hematobia serrata, 
*343 

Hog-louse, *218 

Holcaspis centricola, 471; 
globulus, 472; inanis, 
471 : 

Holorusia rubiginosa, 
anatomy of larva of, 
*21; degenerating mus- 
cle from pupa of, *50; 
development of wing- 
buds of, *48; salivary 

» glands, before and after 
degeneration, of larva 
of, *51; salivary gland 
of, *16; stages of, *322 

Homolomyia  canicularis, 


342, 


345 ‘ 
Homoptera (6ué6c, homus, 
same; 7Trpov, pterum, 
wing), 165; key to fam- 
ilies of, 166 
Honey-ant, 545 
Honey-bee, *521; alimen- 


Index 


tary canal of, *529; 
brood-comb with young 
stages, *46; comb, brood 
cells, *523; building 
comb, *527; developing 
muscle in pupa of, *51; 
development of mouth- 
parts, *460; East Indian, 
comb of, *520; first tar- 
sal segment of hind legs 
of, *528; gathering pol- 


len and nectar, *522; 
head and mouth-parts 
of, *7; honey-making 


by, 528; larva and adult, 
*45; leg of, *521; life- 
history of, 521; nervous 
system of, *24; mouth- 
parts of, *459; section of 
body of pupa, showing 
histolysis and histogen- 
esis, *49; section of 
ocellus, #30; sting of, 
460, *461; swarming of, 
525; swarming reflex of, 
639; ventral aspect of 
abdomen of worker, 
#527; visiting Asclepias, 
*574; Wwax-making by, 
526 

Honey-dew of Aleyrodide, 


192; of aphids, 175, 180; | 


of black scales, 187 
Honey-making by honey- 
bee, 528 
Hop-merchants, 454 
Horn, caudal, *432 
Hornet, bald-faced, 506; 
nest, single-comb, *508 
Horn-fly, 342, *343 
Horn-tails, 463, 466 
Horse-fly, 327, *328; cor- 
neal facets of compound 
eye of, *31; mouth-parts 
of, *329; venation of 
wing of, *328 
Horse-louse, 218 
Horse-stinger, 76 
Horse-tick, 351, *352 
Host, 479 
House-crickets, 157 
House-flea, *354 
House-fly, *341, 342; foot 
of, *341; larva of, *342; 
mouth-parts of, *8, *301; 
nervous system of, *22; 
pupa in puparium of, 
*342 


Hover-flies, 339 
Human flea, 356 
Humming-bird moth, 431 
Humming-birds, cross-pol- 
linating flowers, 573 
Hyaliodes vitripennis, 210 
Hydrobatidez, Hydrobates 
(idap, hydor, water ; 
Bartnc, bates, one that 
treads), 195, 106 
Hydrocharis obtusatus,260 
Hydrophilide, Hydrophi- 
lus (idwp, hydor, water; 
gitoc, philus, loving), 
256, 258 
Hydrophilus, development 
of egg of, *38; external 
anatomy of, *247; inter- 
nal anatomy of, *248; 
triangularis, *259; trian- 
gularis, eg g-case of, 
*259; triangularis, larva 
of, *259 
Hydropsychide, Hydro- 
psyche (idwp, hydor, 
water; wx, psyche, 
butterfly), 244, 245 


Hydropsyche, 243; sca- 
laris, *242 

Hydroptilide, Hydroptila 
(idep, hydor, water; 


arisov, ptilum, feathers), 

|__244, 245 

Hygrotrechus, 196, *197 

Hylotoma berberidis, de- 
velopment of egg of, *39 

Hymenoptera (tum, hy- 
men, membrane; TTFpov, 
pterum, wing), 56, 459; 
aculeate, 490; key to 
groups of, 463; mouth- 
parts of, 460; parasitic, 
476; sting of, 460 

Hyperites, 113 

Hypermetamorphosis, 200; 
of Epicauta vittata, 290 

Hyperparasitism, 482 

| Hyphantria cunea, 412 

Hypoderma bovis, 338; 
lineata, 338 

| Hypoprepia fuscosa, 409; 
miniata, 409 

Hydroporus, 255 


Icerya purchasi, *187; 
male and female, *186 

Ichneumon-flies, 56 

Ichneu.ronide, Ichneu:non 


(ichneumon, ichneumon 
fly), 463 | 

Ichneumonoidea (see Ich- 
neumonide), 477 

Ichneumons, 463 

Imaginal discs of Dipter- 
ous larve, *47 

Imago (adult) 

Imperial-moth, 426 

Inchworm, in protective 
position, *603 

Inchworms, 395 

Indian Cetonia, 276; meal- 
moth, 378 

Inocellia, 233 

Inquilines, 475 

Insect, pinned up, *637 

Insecta, 3 

Insect-killing bottle, #635 

Insects, simplest, 52 

Instinct, defined, 636; ex- 
amples of, 641, 642, 651 

Instincts of ants, 554 

Intelligence, defined, 637; 
of solitary wasps, 653 

Io Emperor, 424, *425; 
larva of, #426 

Iphidicles ajax, 449; mar- 
cellus, 449; telamonides, 


449. 

Iris versicolor, 568 

Isabella tiger-moth, 412 

Ischnocera (prob. ‘axvoc, 
ischnus, thin, thread- 
like; xépac, ceras, horn), 
key to genera of, 118 

Ischnoptera pennsylvanica, 
*128 

Isoptera (iooc, isus, equal; 
mrépov, pterum, wing), 
55, 99 

Isopteryx, 73 

Isosoma hordei, 487 

Ithobalus acauda, 450; 
polydamas, 450 


Janus integer, *465 

Japanese locust, *155 

Japygide (Japyx, mythical 
progenitor of Japyges of 
southern Italy), 60, 61 

Japyx sp., *62; subter- 
raneus, *61 

Jasside, Jassus (Jassus, a 
town in ancient Caria), 
166, 169 

Jennings, trial and error 
theory of behavior, 635 


Index 


Jerusalem cricket, *156, 
157 

Jigger-flea, 355 

Jimson-weed, hawk-moth 
posed before, *572 

Jugatee (jugum, yoke), 
6 


3 
Jugum, 368 
Jenene plant-lice, 171 
une-bugs, 273, #275 
Junonia cena, 455 


Kallima sp., *601 
Katydid and eggs of, #149 
Key, 53 
Killing-bottle, for collect- 
ing insects, 635 
Kissing-bug, 203 
Labels, for collected in- 
sects, 637 
Labellum, *8 
Labeo longitarsis, *479 
Labia minor, *162 
Labidura riparia, 162 
Labium (see mouth-parts) 
Labrum (see mouth-parts) 
Lace-bug, hawthorn, 208 
Lace-bugs, 195, 207 
Lace-wing fly, *228 
Lachnosterna fusca, *275 
Ladybird - beetle, *286 ; 
Australian, 186, *187 
Lemobothrium, 119; loo- 
mist, 122 
Lertias philenor, 450 
Lagoa crispata, 383 
Lake-flies, 65 
Lamellate, *250 
Lamellicornia (lamella, 
thin plate; cornu, horn), 
251, 272 
Lamp-chimney 
cage, *642 
Lampyride, Lampyris 
(Aaurovpte, lampuris, a 
glow worm), 265, 260 
Lance-tailed grasshopper, 
*154 
Lantern-flies, 168 
Laphria, 331 
Lappet-moth, 
*418 
Lappet-moths, 416 
Largus succinctus, *210 
Larridx, Larra (Fabricius, 
—derivation unknown), 
500 


breeding- 


American, 


681 


Larva, 44; coarctate, 291; 
of a phorid fly attached 
to the larva of the ant, 
*553 

Lasiderma serricorne, 271 

Lasiocampa —_quercifolia, 
ommatidia of, *32 

Lasiocampide, Lasio- 
campa (Adowoc, lasius, 
hairy; xaurn, campe, a 
caterpillar), 370, 415 

Lasius brunneus, 175, 545 

Lateral (to right or left) 

Leaf-beetles, 277 

Leaf-bug, four-lined, *209; 
predaceous, *206 

Leaf-bugs, 195 

Leaf-chafers, 273, 275 

Leaf-cutter bee, nest of, 
*51 

Leaf-hoppers, 169 

Leaf-insects, 132 

Leaf-miners, 375 

Least skipper, 443 

Leather-jackets, 321 

Lebia grandis, 255 

Lecanium ole@, 187 

Lecanium scales attacked 
by Cordyceps clavulata, 
*188 


Leg, section of, showing 
muscles, *5 

Legs of beetles, *250 

Leistotrophus cingulatus, 
261 

Lema trilineata, 278 

Lemonias virgulti, 444 

Lens of ocellus of larva of 
saw-fly, *30 

Leopard-moth, 413 

Lepidocyrtus americanus, 
* 


4 
Lepidoptera (Aezic, lepis, 
a scale; mrTepév, pterum, 
wing), 56, 358; life-his- 
tory of, 360; mouth- 
parts ‘of, 350, *362; 
scales of, their structure 
and arrangement, 589 

Lepinotus, 113 

Lepisma saccharina, *58, 
61, domestica, *62; sp.. 
*62; sp., development of 
egg of, *40 

Lepismide, Lepisma 
(Aémioua, lepisma, scaly), 
60; key to genera of, 61 

Leptide, Leptis (AetTov, 


682 


leptus, thin, fine, deli- 
cate), 327, 330, 332 


Leptoceride, : 
(Aexroc, leptus, thin, 
fine, delicate; xépac, 


ceras, horn), 244 
Leptocerus resurgens, *240 
Leptocoris trivittatus, *213 
Leptogenys elongata, 540, 

*541 
Leptoglossus — oppositus, 

214; phyllopus, 214 
Leptoterna dolobrata, 210 
Leptothorax emersoni, 544 
‘Lesser migratory locust, 

133, *137, I41 
Lestes sp., nymph of, *84; 

uncata, *87 
Leucania unipuncta, 404; 

larva of, on corn, *403 
Leuctra, 74 
Libellula basalis, 94; pul- 

chella, 93, *04; quadri- 

maculata, 94; semifasci- 

ata, *94, 95 
Libelluliide, Libellula 

(libellulus, a tiny book), 

QI, 93 
Liburnia lentulenta, para- 

site of, *479 
Lice, 216 
Lightning-bugs, 260 
Ligyrus rugiceps, 276 
Lime-tree canker-moths, 

*397; inch-worm, *596 
Limnephilide, Limnophi- 

lus (Aiuyn, limne, a pool; 

di2o¢, philus, loving), 244 
Limnobates lineata, *197, 

198 
Limnobatide, Limnobates 

(Aiuen, limne, a pool; 

Barn, bates, one that 

treads), 194 
Lioderma ligata, 214 
Liotheide (Acioc, linus, 

smooth ; Get, then, run), 


118 
Lipeurus, 118; 


Index 


Live-cage bell-jar, *642; 
meat-safe, *643 


Leptocerus | Live-oak moth, 407; scale, 


California, *191 

Locust, alimentary canal 
of, *14; auditory organ 
of, *28; brain of, *22; 
development of wings 
of, *42; development 
stages of, *42; external 
parts of, *3; head, ner- 
vous system of, *23; 
head of, showing anat- 
omy, *124; heart or dor- 
sal vessel of, *17; ner- 
vous system of, *22; per- 
icardial membrane, *18; 
respiratory system, *18 

Locusta viridissima, nerve- 
endings of, *26 

Locustide, Locusta (/o- 
custa, locust), 126, 149; 
wingless, 154 

Locusts, 53, 126, 133; au- 
ditory organs of, *135; 
impaled by shrike, *134; 
life-history of, 136; key 
to subfamilies of, 136; 
migratory species of, 
133; sounds of, 134 

Locust-tree carpenter- 
moth, 385, *386 

Loeb, tropism theory of 
behavior, 635 


Long-horned locust, *146 
Long-legged flies, 332, 335 
Long-tailed skipper, 442 
Loopers, 395 

Lopidea media, 210 
Lorquins Admiral, 452 
Louse, sheep-foot, 218 


Lucanide, Lucanus (lu- 
cere, shine), 272 
Lucanus dama, 273; 


elaphus, *273; placidus, 
273 

Lucilia cesar, 344; vena- 
tion of wing of, *344 


baculus, | Luna-moth, 420, *422 


*120, 121; ferox, 122; | Lycena, 443; sp., part of 


forficulatus, 117; for-| wing of, *590 

ficulatus, development | Lycenid, venation of, 
stages of, *115; vari-| *440 

abilis, 119 Lycenide, Lycena 


Lipoptena cervi, 352 
Lithosia bicolor, 410 


(Avcawa, lycena, a she 
wolf), 443 


Lithosiid, Lithosia (Adoc,| Lycomorpha constans, 


lithus, a stone), 370, 409 


scale of, *592; grotei, 


410; miniata, 410; pho- 
lus, 410 
Lyctocoris fitchi, *206 
Lyda, 466 
Lygeidex, Lyzus ( Avyaioc, 
lygeus, shadowy), 195, 
207, 211 
Lygeus turcicus, *211 
Lygus pratensis, *209 
Lymantriide (Avuavtqpioc, 


lymanterius, destruc- 
tive), 370, 404 : 
Machilis, 62; polypoda, 


nerve-endings in tip of 
labial palpus of, *26; sp., 
*63 


Macrodactylus 
sus, *275 

Maia moth, 424 

Malaria-carrying 
quito, *308 

Malaria, mosquitoes and, 
617 

Malaria-producing Hama- 
moeba, development of, 
in human blood-corpus- 
cle, *618 

Mallodon, 284 

Mallophaga (ua%Aé6c, mal- 
lus, hair, wool; ¢ayeiv, 
phagen, eat), 55, 111; 
distribution of, 116, 117; 
keys for classification, 
118; life-history of, 114; 
cesophageal sclerite of, 
115; pharyngeal sclerite 
of,*116; structure of, 115 

Malpighian tubules, 14 

Mandible (see mouth- 
parts) 

Mantide, Mantis (u“avric, 
mantis, a prophet), 126, 
129; ancient beliefs con- 
cerning, 130 . 

Mantis religiosa, *129, 130, 
131; egg-cases of, *1 
*165 

Mantispa styriaca, 234 

Mantispide, Mantispa (ir- 
regular, mavtic, mantis, 
an insect; Sy, ops, face), 
224, 234 

Maple-scale, *188 

Maple-tree borer, 
of, *284 

Maracanda, 232 

March-flies, 304, 325 


subspino- 


mos- 


stages 


March-fly, *326 

Margarodes formicarum, 
190 

Maritime locust, *147 

Marsh-treader, *197, 198 

Marsh-treaders, 194 

Marumba modesta, 437 

Masaride, Masaris 
(“acdouat, masaome, to 
chew), 498 

Mason-bees, 514 

Mason-wasps, 498 

May-beetles, 275 

May-flies, 53, 65; about 
electric lamp, *66; gills 
of nymph of, 68; life- 
history of, 67 

May-fly, *68; compound 
eye of, *32; nymph of, 
showing tracheal gills, 
*20; section through 
head of male, *69; young 
nymph of, *67 

Maxille (see 
parts) 

Meadow-browns, 457 

Meadow — grasshopper, 
*153, *154 

Mealy-winged flies, 166, 
190, *193; respiratory 
system of, *19 

Meat-safe live-cage, *643 

Mecoptera (“ijxoc, mecus, 
length; zzepév, pterum, 
wing), 223, 235; key to 
genera of, 235 

Media (see venation) 

Mediterranean flour-moth, 
*377, 379 

Megachile, 514; anthra- 
cina, nest of, *514 

Megachilide, | Megachile 
(uéyac, megas, great; 
yethoc, chelus, lip), 514 

Megalopyge crispata, 
scales, from wing of, 
*593; opercularis, 383 

Megalopygide (prob. 
péyag, megas, great; 
aa pyge, rump), 369, 
393 

Megathyma yucce, 441 


mouth- 


Megathymide (prob. 
Héyac, megas, great; 
Guudc, thymus, spirit), 


441 
Megilla maculata, *286; 
vitigera, *: 


Index 


Melanactes piceus, 268 

Melanoplus atlanis, 133, 
*137, 141; bivittatus, 
*138, 141; differentialis, 
*137,141; femur-rubrum, 
*135, 140; development 
of, *42; nervous system 
of head of, *23; postem- 
bryonic development of, 
*125; spretus, 133, 136 

Melipona, 520 

Melissodes, 515 

Melittia ceto, 301 

Melitea chalcedon, 457 

Meloe angusticollis, 293 

Meloide, Meloe (Lin- 
nzeus,—etym. uncertain), 
288, 289 

Melophagus ovinus, 
*352 

Membracide, Membracis 
(uéuGpas, membrax, a 
kind of cicada), 166, 168 

Membrane of wing (outer 
half of fore-wing, He- 
teroptera, *196) 

Memythrus  polistiformis, 


351, 


391 
Menopon pallidum, *119 
Merisus destructor, *478 
Merope, 236 
Mesochorus agilis, para- 
sitizing Nylina sp., *486 
Mesothemis simplicicollis, 


97 
Mesobregma cincta, *147 
Meso-thorax, 7 
Metal-marks, 444 
Metamorphosis, 35; com- 
plete, 41; complete, of 
blow-fly, *45; complete, 
of honey-bee, *46; com- 
plete, of monarch but- 


terfly, *44; complete, 
significance of, 51; in- 
complete, 41; incom- 


plete, of a dragon-fly, 
*83; incomplete, of as- 
sassin-bug, *43; incom- 
plete, of Melanoplus fe- 
mur-rubrum, *125; of 
Hemiptera, 164 

Metapodius femoratus, 
214 

Meta-thorax, 7 

Meteorus hyphantrie, 
*485; parasitizing Xy- 
lina lacticinerea, *487 


683 


Mexican jumping bean- 
moth, 382, *383 

Microcentrum laurifolium, 
*I51, 152; retinervis, 152 


Micropterygide, Microp- 
teryx (ixpdc, micrus, 
small; 7répvé pteryx, 


wing), 368, 370, 371 

Micropteryx sp., venation 
of wing of, *372 

Microdon mutabilis, *340 

Micromus sp., *229 

Micropyle, 15; of various 
eggs, *37 

Midaide, Midas (yidac, 
midas, a destructive in- 
sect in leguminous 
plants), 330 

Midas-flies, 330 


Midge, larva of, *311; 
male, *310; pupa of, 
¥311 


Midges, 304, 310 

Migratory locusts, 133 

Milkweed-bug, 211 

Milkweed-butterfly, ar- 
rangement of pharynx, 
cesophagus, etc., in head 
of, *361; cross-section 
of sucking proboscis of, 
*361; part of maxillary 
proboscis of, showing 
arrangement of muscles, 
*361 

Milyas cinctus, 204 

Mimesidae, Mimesa 
(uiunotc, mimesis, imi- 
tation), 502 

Mimicry, 609; of monarch 
butterfly by viceroy, 
*610; of wasps by moths, 
*608 


Mining-bees, 513 

Mochlonyx  culiciformis, 
auditory organ in an- 
tenna of, *29 

Mode of pinning beetle, 
*637 

Modest sphinx, 437 

Mole-cricket, long-winged, 
161; northern, 161; Por- 
to Rican, *161 

Monarch butterfly, *451; 
complete metamorphosis 
of, *44; development of 
color-pattern in pupal 
wings of, *596; external 
parts of, *6; internal 


684 


anatomy of, *13; larva 
of, *605; mimicry of, by 
viceroy butterfly, *610; 
part of wing ot, show- 
ing scales, *360; vena- 
tion of wings of, *371; 
venation of, *11 

Moniliform, 258 

Monobia quadridens, 502 

Monohammus, 285 

Monomorium — minutwm, 
*536; pharaonis, 541 

Monostegia rose, 466 

Monterey-pine midge, *324 

Morpho sp., base of scale 
of, *591 

Mosquito, auditory organ 
in antenna of, *29; beak 
of, *302; female, mouth- 
parts of, *301; head and 
mouth-parts of, *7; life- 
history of, *305; mala- 
ria-carrying, *308 

Mosquitoes, 304; and ele- 
phantiasis, 633; and fila- 
riasis, 632; and malaria, 
617; and yellow fever, 
630; eaten by dragon- 
flies, 81; methods of 
fighting, 309 

Moth, ommatidia of, *31 

Moth-fly, 319, *320; larva 
anid ip wpa ots *320:: 
mouth-parts of, *320 

Moth-like flies, 304 

Moths, 56, 358; and but- 
terflies, single scale 
from, *589; and wasps, 
showing mimicry, *608; 
key to superfamilies and 
families of, 367; scales 
of, their structure and 
arrangement, 589; wood- 
nymph, 407 

Moulting, 43 

Mourning-cloak, 455 

Mouth-parts, 6; head of 
larva of net-winged 
midge showing forma- 
tion of adult, *318; head 
of larva of  black-fly 
showing developing, 
*314; developing, of tus- 
sock-moth, *363; devel- 
opment of, of Corydalis 
cornuta, *227; of bee- 
fly, *334; of dance-fly, 
*335; of Cicada, *9; of 


Index 


Dixa sp., *319; of dob- 
son-fly, *6; of Eristalis 
sp., *340; of female 
black-fly, *313; of fe- 
male net-winged midge, 
*316; of a female mos- 
quito, *301; of a female 
punkie, *311; of Hemip- 
tera, *164; of honey-bee, 
*7, *459; of honey-bee, 
development, *460; of 
horse-fly, *329; of house- 
fly, *8, *301; of Hymen- 
optera, 460; of larva of 
black-fly, *313; of larva 
of net-winged midge, 
*317; of larva of wasp, 
*461; of Lepidoptera, 
*362; of a long-tongued 
bee, *512; of mosquito, 
*7; of moth-fly, *320; 
of mud-wasp, *460; of 
net-winged midge, *9; 
of robber-fly, *331; of a 
short-tongued bee, *511; 
of sphinx-moth, *10; of 
thrips, *8, *220; variety 
of. 8; of wasp, devel- 
opment of, *460, *461 

Mud-nest, vase, of Eume- 
nes sp., *499 

Mule-killer, 76 

Murgantia histrionica, 214, 


*215 
Musca domestica, *341, 
342; larva of, *342; 


mouth-parts of, *8, *301 ; 
pupa in puparium of, 
*342 
Muscardine, 412 
Muscid, aquatic, *348 
Muscide, Musca (uvia, 
myia, a fly), 332 
Muscine, 341, 342 
Muscle, degenerating, 
from pupa of giant 
crane-fly, *50; degen- 
erating, of tussock-moth, 
*50; developing, in pupa 
of honey-bee, 51; struc- 
ture of, *13, *14 
Muscles, arrangement of, 
in maxillary proboscis 
of milkweed butterfly, 
*361; attachment of, to 
body-wall, *4; of leg, 
*5; of wing, *5 
Muscular system, 13 


Mutillide, Mutilla (mu- 
tilo, to crop short), 497 
Mycetophilidez, | Myceto- 
phila (“ixno, myces, a 
fungus; gidoc,  philus, 
loving), 304, 324, *325; 
venation of wing of, *325 
Mydas luteipennis, 330 
Myodocha serripes, 211 
Myopa, 337 
Myopsocus, 113 
Myriapoda, 3 


Myrmecocystus  melliger, 
545 

Myrmecophila, 161; ne- 
brascensis, *162 

Myrmecophily, 552 

Mrymeleon, 232; adult, 
*231; sp., larva and 


sand-pit of, *230 


Myrmeleonide, Myrme- 
leon (“ipunt, myrmex, 


ant; Aéwr, leon, lion), 
224, 230; key to subfam- 
ilies of, 231 
Myrmica brevinodes, 544 
Myrmicide, Myrmica 
(ubpunt, myrmex, ant), 
540, 541 
Mystacides, 243 
Mytilaspis pomorum, 189 
Myzus cerasi, 174 


Nabide, Nabis (nabis, 
camelopard), 195 

Nabis fusca, *205 

Nathalis iole, 446 

Naucoride, Naucoris 
(vate, naus, ship; Kxdpic, 
coris, a bug), 194, 199 

Necrobia rufipes, 270; vio- 
lacea, 270 

Necrophorus marginatus, 
*261 


Nectar, 566 

Nectar-drinking, adapta- 
tion of insects for, 569 

Negro-bug, flea-like, 215 

Negro-bugs, 105 

Nematocera (vjua, nema, 
thread; xépac, ceras, 
horn), 303; key to fam- 
ilies of, 304 

Nematus erichsonii, 466; 
ventricosus, 466; larva 
of, *465 

Nemobius fasciatus, form 


vittatus, *159; chirping 
of, 150 

Nemoura, 74 

Neophasia menapia, 445 

Nepa, 201 

Nepide, Nepa (nepa, a 
scorpion), 194, 201 

Nerve endings in labial 
palpus of Machilis poly- 
poda, *26; in maxillary 
palpus of Locusta viri- 
dissima, *26 

Nerve-winged insects, 223 

Nervous system, 20; in 
head of locust, *23; of 
house-fly, *22; of locust, 
*22; of midge, *22; 
stages in development 
of, of honey-bee, *24; 
stages in development 
of, of water-beetle, *25; 
sympathetic, 23; of larva 
of harlequin-fly, *24 

Nest, artificial, for ants, 
*550; communal, of yel- 


low-jacket, Vespa sp., 
*505; Fielde, for ants, 
*551; Janet, for ants, 


*550, *551; of Califor- 
nia honey-ant, 546; of 
Camponotus pennsyl- 
vanicus, *545; of bum- 
blebee, *519; of leaf-cut- 
ter bee, *514; of a mud- 
dauber wasp, *499; of 
Vespa crabro, *504; of 
western agricultural ant, 
*542; of yellow-jacket, 
Vespa sp., cut open to 
show combs within, *506 

Nest-building of wasps, 
508 

Nest-burrow of Ammophi- 
la, *494; of Astata uni- 
color, *500; of Oxybelus 
quadri-notatus, *491; of 
short-tongued mining- 
beetle, *516 

Nesting-grounds of Am- 
mophila, *492 

Nests, for rearing ants, 


54 

Nest-tunnel of carpenter- 
bee, *513 

Nest-tunnels of two car- 
penter-wasps, *502 

Net, for collecting insects, 
how to make, 635; wa- 


Index 


ter, for collecting drag- 
on-fly nymphs, *87 

Net-winged midge, cross- 
section of body of larva 
of, *315; cross-section of 
eyes of, *317; female, 
*316; female, mouth- 
parts of, *316; head of 
larva of, showing forma- 
tion of adult head-parts, 
*318; heads of male and 
female of, *316; larva of, 
*315; mouth-parts of, 
*g; mouth-parts of larva 
of, *317; pupa of, *315; 
venation of wing of, 
My) 

Net-winged midges, 304, 


314 
Neuroptera (vevpov, neu- 
rum, nerve, MTEépov, 


pterum, wing), 55, 223; 
key to families of, 224 
Nezara pennsylvanica, 214 

Nicoletia texensis, *61 

Nirmus, 118; felix, *121, 
122; lineolatus, 116; pi- 
leus, 117; pr@stans, *114 

Nitzschia, 119 

Noctuide, Noctua (noctua, 
a night owl), 370, 3990 

Nomadide, Nomada 
(véuac, nomas, nomad) 
455 

Nometettix parvus, *148 

““No-see-ums,’’ 310 

Notodonta stragula, *392 


Notodontid, venation of, 
$3023 1) 
Notodontide, Notodonta 


(voroc, notus, the back; 
ddove, odus, tooth), 369, 
302 

Notolophus  leucostigma, 
405; developing mouth- 
parts of, *363. 


Notonecta, 199 

Notonectide, | Notonecta 
(voroc, notus, the back; 
vyxTn¢e, mnectes, a swim- 
mer), 194, 198 

Notum (dorsal wall of a 
body segment) 

Number of insect species, 


56 , 
Nycteribiide, | Nycteribia 
(vuxteplc, nycteris, a 


685 


bat; Bioe, life), 
351, 352 

Nycteribia sp., 352 

Nymph (young of insects 
with incomplete meta- 
morphosis), *42, *67 

Nymphalid, venation of, 
*440 

Nymphalide, © Nymphalis 
(vongn, nymphe, a 
nymph), 450 


bius, 


Oak _ bucculatrix - moths, 


37 
Oak leaf-roller, 380 
Oak-apples, 471, *472 
Oak-scale, southern Cali- 
fornia, *192 
Oak-worm moth, orange- 
striped, *428 
Oblique-banded leaf-roller, 


380 

Oblong leaf-winged katy- 
did, *151 

Obsolete-banded strawber- 
ry leaf-roller, larva of, 
*364; pupa and adults 
of, *365 

Ocellar lens of larva of 
saw-fly, *30 

Ocellus, *3, 31; section of, 
of honey-bee, *30 

Odonata (ddove, odus,. 
tooth, applicability un- 
certain), 53, 75 

Odontomachus hematodes, 
340 

Odontomyia, venation of 
wing of, *329 

Odynerus, 499 

CEcanthus angustipennis, 
160; fasciatus, *159,. 
*160; niveus, *159, 160 

(Edemasia concinna, 304% 
eximia, *393; larva of, 


393 
CEdipodine, 136, 143 
(Eneis, 457 
CEstride, Gstrus (ozorpoe,. 
estrus, a gadfly, a 
sting), 332, 337 
Oiketicus abbotti, 386 
Oil-beetles, 289 
Olfersia americana, 351 
Ommatidium, *31, *32, *33 
Omus, 253 
Oncomyia, 337 


686 


Oncopeltus fasciatus, 211° 
Oncophorus, 118 
Onion-fly, 345 
Onion-thrips, 221 
Onychophora, 3 
Ophion purgatum, *482 
Opsicatus personatus, 203 
Orange-puppy, 450 
Orange-scale, 188, *180, 
*190 
Orange-sulphur, 446 
Orange-tips, 446 
Orchelimum vulgare, *153, 
*154 
Orders, key to, 52 
Orl-fly, smoky, immature 
stages of, *225 
Orneodes hexadactyla, 377 
Orneodide, Orneodes 
(6preov, orneum, bird; 
eldoc, eidos, form), 368 
Orphnephilide (prob. 
“opovn, orphne, darkness ; 
giroc, philus, loving), 327 
Orphnephila testacea, 327 
Orphula pelidina, *141 
Orthoptera (op§0c, orthus, 
straight ; trépov, pterum, 
wing), 5, 123; key to 
families of, 126; sound- 
-making by, 123, 134, 150, 
*I51, 152, 155, *157, 159 
©Orthosoma brunnea, 283; 
development of color- 
pattern in, *598 
Orchids, specialization of, 


for insect pollination, 
575 

Oscinide, Oscinis (La- 
treille, — etym. uncer- 
tain), 350 

Osmia, 514 


Otiorhynchide, Otiorhyn- 
chus (driov, otium, little 
ear; piyxyor, rygchus, 
snout), 204, 205 

Otiorhynchus ovatus, 205 

Ovarial tubes of Aptera, 
*50 

Ovaries and oviducts of 
thrips, *36; of queen bee, 
*521 

Ovipositor, *3, 7; of a gall- 
fly, *468 

Owl-butterfly, *612 

Owlet-moths, 370 

Ox-louse, long-nosed, 217; 
short-nosed, 217, *218 


Index 


Oxybelus quadri-notatus, 
nest-burrow of, *401 
Oxyptilus periscelidacty- 
lus, 377; tenuidactylus, 

*377 


Pach ycondyla harpax, 540, 


Painted beauty, 454 

Paleacrita vernata, 307 

Pale-green locust, *140 

Palmer-worm, larva of, 
*373; moth, *374 

Palpi (jointed processes 
attached to mouth-parts 
or terminal segments of 
abdomen) 

Palpus, nerve-endings in 
tip of, *26 

Pamphilas, 443 

Pamera longula, 211 

Panorpa, 236; rufescens, 
*236 

Panorpodes, 236 

Paonias excacatus, *435; 
myops, *435 


Papilio, 448 
Papilio cresphontes, 449; 
daunus, 449; Euryme- 


don, 449; glaucus, 449; 
polyxenes, 450; venation 
of, *440, rutulus, *447, 
449; sp., chrysalid of, 
*448; troilus, 450; tur- 
mus, 449 

Papilionid, 
*440 

Papilionide, Papilio (pa- 
pilio, a butterfly), 447 

Papilionina (see Papilion- 
ide) 

Papiriide (prob. tatupoc, 
paryrs, paper, reed), 
3 

Papirius maculosus, *63 

Parandra brunnea, 285 

Parasa chloris. 384 

Parasita (parasitus, a 
parasite), 165, 216 

Parasite, chalcid, 
ichneumon, of army- 
worms, *482; ichneu- 
mon, of the pigeon-tre- 
mex, *484 

Parasites, importation of, 
486; Hymenopterous, of 
a social wasp, *480; 
numbers of, 480; of 


venation of, 


*470; 


aphids, *173; of caterpil- 
lars, *476, *477 
Parasitic fungus of Cali- 
fornia flower-beetle, *346 
Parasitic Hymenoptera, 
478 
Parasitism, characteristics 
of, 478; of caterpillar, — 
*476, *477 
Paratettix cucullatus, *148 
Parnassian butterfly, *439 
Parnassians, 447 
Parnassius clodius, 447; 
smintheus, 447, *439 
Parnide, Parnus (Fabri- 
cius, 1792,—etym. doubt- 
ful), larva of, *264 
Parorgyia parallela, 405 
Parthenogenesis, 221; 
among aphids, 173, 175 
Passalus cornutus, 273 
Pastinmaca sativa, 569, 571 
Patagia, 408 
Patterns of insects, 584 
Peach-tree borer, 389; lar- 
va of, #391; cocoons of, © 
*391; moths of, *3903 
eggs of, #390 
Peacock butterfly, 455 
Pear-tree flea-louse, 171; 
slug, 466 
Pea-weevil, 277, *281 
Peckham, G. W.and E.G., 
on instinctive and intel- 
ligent behavior, 643, 650 
Pectinate, *250 
Pediculide, Pediculus 
(pediculus, a louse), 
216 
Pediculus capitus, *216; 
inguinalis, *217; vesti- 
mentt, *216 
Peduncle, ror, 534 
Pegomyia vicina, 345 
Pelecintde, Pelecinus 
(werexivoc,  pelecinus, a 
pelican), 463, 484 
Pelecinus polyturator, 
*485 
Pelidnota punctata, 275 
Pellucid locust, 133, *145 
Pelocaris femorata, 199 
Pelopeeus, 499 
Pemphigus tessellata, 180 
Pemphredonidz, Pemphre- 
don (teudpedav, pemphre- 
don, a kind of wasp), 
502 


Pentamera (méTe, pente, 
five; “époc, merus, part), 


251, 252 
Pentatomide, Pentatoma 
(wévte, pente, five; 
Taueiv, tamen, cut), 195, 
207, 2 
Pentatoma juniperina, 
215 


Pepper-and-salt — currant- 
moth, *398 

Pepsis formosa, *500, 501 

Pericardial membrane of 
locust, *18 : 

Pericoma californica, *3203 
larva and pupa of, *320 

Pericopide (epi, peri, 


around; kote, copten, 
cut), 370, 407 
Periplaneta americana, 
127; australasia, 128; 
orientalis, 128, *128 
Peripsocus, 113 
Perithemis domitia, *95, 
9 
Perla, 73; sp., *72 
Pernicious scale, females 


and young on bark of 
fruit-tree, *182; male 
and female (enlarged), 
*184; on bark of fruit- 
tree, *181; structure and 
life-history of, 182 
Petrophora diversilineata, 


*300 

Phagocytes, 49 

Phagocytosis, 49 

Phaneus carnifex, *274 

Phasmide, Phasma 
(gaoua, phasma, an ap- 
parition), 126, 132; key 
to genera of, 132; pro- 
tective resemblance of, 
132 

Pheidole commutata, sol- 
dier and worker of, *537; 
lamia, soldier and work- 
er of, *535 

Phigalia strigataria, *308 

Philopteride, Philopterus 


(oize, philen, love; 
mrépov, pterum, a feath- 
er), 118 


Philosamia cynthia, 421 

Phlegethontius sexta, 434; 
carolina, larva of, *432; 
celeus, larva of, *432; 
quinquemaculata, 434 


Index 


Phobetron pithecium, 384 

Pholisora catallus, 442 

Pholus achemon, *433, 
434; larva of, *431, *434; 
pandorus, *433, 434 

Phorbia brassice, 345; ce- 
parum, 345 

Phorothrips sp., *219 

Photinus angulatus, 269; 
modestus, larva of, *269; 
pyralis, 269; scintillans, 
*269 

Phryganea cinerea, *239 

Phryganeide, Phryganea 
(gpvyavov, phryganum, 
a dry stick), 244, 245 

Phryganidia californica, 
*406, 407 

Phyllium, 132, *602 

Phylloxera vastatrix, 176 

Phyllum, 2 

Phymata wolfi, 205 

Phymatide, Phymata 
(dina, phyma,atumor), 
195 

Physocephala, 337; affinis, 
*336 

Physonota unipunctata, 
281 

Physostomum, 119 

Phytophaga (gvTév, phy- 
tum, plant; gaye, pha- 
gen, eat), 252, 277 

Pierid, venation of, *440 

Pieride, Pieris (epic, 
pieris, sing. of uepidec, 
the Muses), 444 

Pigeon-tremex, *467; ich- 
neumon-parasite of, *484 

Pimpla conquisitor, *483; 
inquisitor, 483; sp., an 
ichneumon-fly, *481 

Pinacate bug, *288 

Pine-leaf miner, 
white, 445 

Pinning beetle, mode of, 
*637; bug, *637; insects, 
637 

Pioplila casei, *348 

Pipe-vine swallowtail, 450 

Pistil and ovary of flower, 
showing pollen-tube, 
*564 

Plagionotus 
*283, 284 

Planta, 522 

Plant - bug, leaf - footed, 
214; tarnished, *209 


376; 


Spectosus, 


687 


Plant-lice, 171 
Plants, fertilization of, 564 
Plathemis lydia, *97; tri- 
maculata, issuance of 
adult, *86 
Platycercus quercus, 273 
Platygaster herricki, larva 
of, *481; instricator, lar- 
va of, *481 
Platynota flavedana, *381 
Platypsylla castoris, 265 
Platypsyllide,  Platypsyl- 
lus (tAaric, p latys 
broad, flat; pvAda, psyl- 
la, flea), 265 
Plecoptera (aexréc, blec- 
tus, plaited ; 7repév, 
pterum, wing), 53, 65, 
70; table of genera, 73 
Plodia interpunctella, 378 
Plum-curculio, 296 
Plume-moth, California, 
*377 
Plume-moths, 368, 376 
Plum-geometer, *398 
Plusia, 402 
Podisus spinosus, *215 
Podura sp., *41 
Poduride, Podura (ove, 
pus, foot; ova, ura, 
tail), 63, 64; analysis of 
behavior of, 639 
Pecilocapsus lineatus, *209 
Pogonomyrmex barbatus 


var. molifaciens, 541; 
occidentalis, mound-nest 
of, *542 


Polistes, 294, 503, 506, 507; 
sp., nest and stages of, 
*508; parasitized by 
Xenos sp., *293 

Pollen, basket, 514, *521; 
gathering, adaptation of 
insects for, 569 

Pollination, 564 

Polybia, 503; favitarsis, 507 

Polyergus rufescens, 547 

Polygonia comma, *453; 
interrogationis, 454; 
chrysalid of, *455; larve 
of, *454 

Polymorphism, 526 

Polyphemus - moth, 
*421; larva of, *421 

Polyphylla crinita, *274 

Polypsocus, 113 

Polystachotes 
*220 


420, 


punctatus, 


688 


Pomace-flies, 349 4 

Pompilide, Pompilus 
(wourh, pompe, escort), 
499, 501 

Poneridz, Ponera ( zovnpéc, 
ponerus, bad, useless), 


540 : ! 
Pontia beckeri, 445; napi, 
445; occidentalis, 445; 


protodice, 445; venation 
of, *440; rap@, 445; si- 
symbri, 445 
Poplar carpenter-moth, 385 
Porthetria dispar, 405 
Potter-bees, 514 
Potato-beetle, 278 
Potter-wasps, 498 
Potomanthus brunnetus, 
section through head of 
male, *69 
Praying-mantes, 126; an- 
cient beliefs, 130 
Praying-mantis, *129, 130, 
131; egg-cases of, *162, 
#163 
Predaceous diving-beetle, 
252; ground-beetle, 252 
Prenolepis imparis, 547; 
underground nest of, 
*546 
Prionide, Prionus (piv, 
prion, a saw), 283 
Prionidus cristatus, 204 
Prionoxystus robinie, 385, 
386; scales from wing 
of, *594; venation of, 


Prionus californicus, *282; 
imbricornis, 283; laticol- 
lis, 283 

Pristophora 
466 

Proboscis, *7, 8, *10 

Proctotrypide, Procto- 
trypes (tpoxtéc, proctus, 
the anus; Tevar, trypan, 
to bore), 463, 477 

Proctotrypoidea 
Proctotrypide ) 

Prolimacodes scapha, 384 

Promethea- moth, 422, 
*424; development of 
color-pattern in pupal 
wings of, *597 

Prominents, 369, 392 

Pronotum, *3 

Pronuba moth laying eggs 
in ovary of Yucca, *577; 


grossularia, 


(see 


Index 


rubbing pollen down 
stigmatic tube of Yucca, 
a 

Pronuba yuccasella, as a 
cross-pollinator of yuc- 
cas, 576 

Prop-legs, 360 

Propolis, 530 

Prosopis pubescens, 
mouth-parts of, *511 

Prosternum, 136 

Protective resemblance, 
599; of Phasmide, 132; 
of Trimerotropis, 147 

Prothorax, 7 

Pselaphide, Pselaphus 
(yndagav, pselaphan, 
feel or grope about), 
265 

Pseudohazis eglanterina, 
426; hera, 426; shas- 
tensis, 426 

Pseudoperla, 73 

Psilopus ciliatus, venation 
of wing of, *336 

Psinidia fenestralis, *146 

Psithyride, Psithyrus 
(yiupéc, psithyrus, 
whisperer, warbler), 
520 

Psithyrus, 519 

Psocide, Psocus (payer, 
psochen, grind in 
pieces), 112; key to 
genera of, 112; venation 
of wing of, 113 

Psocus, 113 

Psyche, 386 

Psyche carbonaria, 386; 
confederata, 386; glo- 
vert, 386 

Psychide, Psyche (wvxn, 
psyche, a butterfly), 
369, 3 

Psychoda sp., mouth-parts 


of, *320 
Psychodide, Psychoda 
(puxn, psyche, butter- 


fly; eldoc, edus, form), 

304, 319 : 
Psychology of insects, 32 
Psychomorpha  epimenis, 


409 
Psyllide, Psylla (vada, 
psylla, a flea), 166, 171 

Psyllomyia testacea, *553 
Pteronarcys, 73 
Pterophoride, Pteropho- 


rus (7repév, pterum, 
feathers; ¢épew, pheren, 
bear), 368, 376 

Pteroptrix flavimedia, *479 

Pterostichus, 255; storiola, 
*254 

Ptinide, Ptinus (iro, 
phthino, decay, destroy), 
265, 271 


Ptynx, 233 

Pulex avium, 353; irritans, 
*354, 356 

Pulicide, Pulex (pulex, 


a flea), 355, 356 
Pulvilliform, 332 
Pulvillus, 102 


Pulvinaria innumerabilis, 
*188 
Punkie, female, mouth- 


parts of, *311 

Punkies, 310 

Pupa, 45 

Pupipara (pupus, a child; 
parere, bring forth), 303, 
351 

Puss-moth, larva of, *607 

Puss-moths, 392, 304 

Pyralid moth, venation of 
wing of, *376 

Pyralidina, Pyralis (zip, 
pyr, fire), 368, 374, 376 

Pyralis farinalis, 378; ve- 
nation of wing of, *376 

Pyromorpha dimidiata, 
388; venation of, *389 

Pyromorphid, venation of 


a *3 

Pyromorphide (prob. tt, 
pyr, fire; “0po7, morphe, 
form), 369, 386 

Pyrrharctia isabella, 412 

Pyrrhocoride, Pyrrhocoris 
(wuppéc, — pyrrus, red- 
dish ; xépec, coris, a bug), 
195, 207, 210 


Radius (see venation) 

Ranatra fusca, *201; eggs 
of, *201 

Raphidia sp., stages of, 
*233 e, 

Raphidiide, Raphidia 
(agic, raphis, a needle), 
224 

Raspberry geometer, 398; 
plume-moth, *377; root 
borer, 391 

Rat-fleas, 357 


Rat-tailed larva of a Syr- 
phid, *340 

Rearing insects, 640 

Redbugs, 195, *210 

Red-humped caterpillar- 
moth, see larva of, 
*393, 3 

Red- icgeed locust, *135, 
140 

Red-spotted purple, 452 

Red-tailed tachina-fly, *347 

Reduviide, Reduvius (re- 
an a hangnail), 195, 


Resets defined, 636; ex- 
amples of, 637, 638; of 
ants, 554 

Remedies, 189 

Reproduction among 
aphids, 173, 177 

Reproductive system, 14 

Reproductive organs, 38; 
of female thrips, *36 

Resemblance, protective, 


599 } 
Respiration, 19; of aquatic 
insects, 20 
Respiratory system, 19; of 
Aptera, *59; of locust, 
*18; of mealy-winged 
fly, *19; of thrips, *18 
Rhagium lineatum, larva 
of, *266 
Rhagoletts cingulata, larva 
of, *349; puparia of, *350 
Rhamnus lanceolata, vis- 
ited by insects, 560 
Rhamphomyia, 335; longi- 
cauda, *334; sp., mouth- 
parts of, *335; 
Rhinoceros - beetle, *12, 
*276 
Rhodites ros@, 473 
Rhopalocera (Aé7a/0v, rho- 
palum, a club; képac, 
ceras, a horn), 364 
Rhobotota vacciniana, *381 
Rhyacophilide, Rhya- 
cophila (tag, ryaxr,a 
stream; ge, philen, 
love), 244, 245 
Rhynchophora, 251, 204; 
key to families of, 294 
Rhyphide, Rhyphus ( fupde, 
rhyrus, curved), 327 
Rhyphus, diagram of wing 
of, *327 
Rice-weevil, 297 


Index 


Robber-flies, 330 


Robber-fly, *331; bumble- 
bee-like, *331; mouth- 
parts of, *331; venation 


of wing of, *331 
Rocky Mountain 
133, 136 
Rose-beetle, *275 
Rose-leaf hopper, 170 
Rose-aphids and ants, *174 
Rose-scale, *190 
Rose-slug, 466 
Rostrum, 251 
Rosy dryocampa, 427 
Rove-beetles, 260, *552 
Royal walnut-moth, larva 
of, *366 
Russet-brown tortrix, *381 


Saddle - back 
384 

Salda sp., *202 

Saldide, Salda (from a 
proper name), 195, 202, 
224 

Salivary gland, *15; sec- 
tions of, of giant crane- 
fly, *16; before and after 
degeneration, of larva 
of giant crane-fly, *51 

Salix cordata, visited by 
insects, 5690; humilis, 
visited by insects, 569 

Salvia-flower, *572 

Salvia officinalis, speciali- 
zation of, for insect pol- 
lination, 573 

Samia ceanothi, 419; ce- 
cropia, 418, *419; larva 
of, *420; moth and co- 
coon cut open to show 
pupa of, *367; columbia, 
419; gloveri, 419 

San José scale, *181, *182, 
*184 

Sand-cricket, *156, 157 

Sand-diggers, thread- 
waisted, 493 

Sanninoidea exitiosa, 380; 
larva of, *391; cocoons 
and empty pupal skins 
of, *391; moths of, *390; 
SS of, *390; pacifica, 


locust, 


caterpillar, 


Sener candida, *285 
Sarcophaga _ sarracenia, 
343, *344 


Sarcophagine, 341, 343 


689 


Sarcopsylla penetrans, 355 
Sarcopsyllide, Sarcopsyl- 


la (capé, sarx, flesh; 
widda, psylla, a flea), 
355 

Sargus, 330 


Saturnia, 370 

Saturniina, Saturnia (Sat- 
urn), 417 

Satyrs, 457 

Saw-fly, *464; develop- 
ment of egg of, *69; 
ocellar lens of larva of, 
*30 

Saw-flies, 463, 464 

Saw-horned fish-fly laying 
eggs, *225 

Scale of Hepialus megla- 
shani, *589 

Scale of Lycomorpha con- 
stans, *592 

Scale-insects, 180 

Scales, arrangement of, on 
wing of butterfly, *5901; 
base of, *591; develop- 
ment of, on wing of 
Anosia plexippus, *595; 
development of, on wing 
of Euvanessa antiopa, 
*594: single, from moths 
and butterflies, *589; 
from wing of Gloveria 
arizonensis, *593; from 
wing of goat-moth, 
*594; from wing of 
Heliconia sp., *504; 
from wing of Mega- 
lopyge crispata, *503; 
of moths and butterflies, 
producing color, 504; of 
moths and_ butterflies, 
structure and arrange- 
ment, 589; of springtail, 
*64; on wing of mon- 
arch butterfly, *360; on 
wings of Culex fatigans, 


*310 
Scallop - shell geometer, 
* 


Scapteriscus didactylus, 
*I61 

Scarabeid beetle, larva of, 
*274; leaf-chafers, 275 


Scarabzide, Scarabzeus 
(scarabeus, a_ beetle), 
272, 273 


Scatophaga sp., *348 
Scavenger-beetle, 272, 273 


690 


Scepsis fulvicollis, 411 
Sciara, 325 


Schistocerca americana, 
*130, 141; emarginata, 
*140 

Schizura, 395 

Sclerite, *5 

Scolytide, Scolytus 
(oKoAurtety, scolypten, 


to strip [bark]), 2094, 207 
Scorpion-flies, 55, 223, 236 
Screw-worm fly, 344 
Scudderia furcata, 

pistillata, *152 
Scutelleride, Scutellera 

(scutum, a small shield), 

195, 207 
Scutellum (dorsal trian- 

gular piece at the base 

of and between elytra or 
fore wings) 
Scydmenide, Scydmzenus 

(oxiduawoc, scydmenus, 

angry-looking, sad-col- 

ored), 265 
Seed-gall, jumping, 472 
Segment, 5 
Self-pollination, 564 
Senilia camelis, *169 
Sense of hearing, 20; of 

sight, 30; of smell, 27; 

of taste, 26; organs, 24; 

tactile, 26 
Senses, special, 24 
Sepedon fascipennis, *350 
Sericostomatide, Sericos- 

toma  (anptxéc, sericus, 

silken; oréua, stoma, 

mouth), 244, 245 
Sermyle, 133 
Serosa, 38 
Serphus dilatus, 200; sp., 

*200 
Serrate, *250 
Serricornia (serra, a saw; 

cornu, horn), 251, 265; 

key to families of, 265 
Sesia pictipes, *392; 

tipuliformis, 390 
Sestidz, Sesia (o7¢, ses, a 

moth), 368, 388 
Setting-board with butter- 

flies properly spread, 

*638; cross-section of, 

showing construction, 

*638; how to make, 638 
Seventeen-year Cicada, 

166, 167 


ese: 


Index 


Shad-flies, 65 

Sheep-louse, *219 

Sheep-ticky” 351, *352 

Shield-bytked bugs, 195, 
214; gfasshopper, *155 

Shore-big, 195, *202 

Short - beaked mosquito, 
$309 5 pupa and larva of, 


309 
Short-winged cricket, *158 
Short-winged locust, *140, 
*I4I, 142 
Sialide, Sialis (ovatic, si- 
alis a kind of bird), 
key to genera of, 224; 
key to larve of, 224 
Sialis, 224; infumata, ma- 
ture stages of, *225 
Sibine stimulea, 384 
Sight, sense of, 30 
Silkworm dissected, *430; 
mulberry, *428, *429 
Silkworm-moths, 369; 
mating reflexes of, 640 
Silpha americana, 261; 
lapponica, 261; novebo- 
‘racensis, *261, 262 
Silphide, Silpha (o/Adn, 
silphe, a beetle) ,258, 261 
Silvanus surinamensis, 
stages of, *262 
Silver-spots, 456 
Silver-spotted skipper, 442 
Silvius pollinosus, 329 
Simplecta sp., venation of 
wings of, *321 
Simuliide, Simulium 
(simulare, imitate), 304, 
313 
Simulium sp., *312; head 
of larva, showing mouth- 
parts, *314; larva and 
pupe, *312; mouth- 
parts, *313;  mouth- 
parts of larva, *313; 
venation of wing, *312 
Sinoxylon basilare, 272 
Siphonaptera (cigar,  si- 
phon, tube; arrepoc, ap- 
terus, wingless), 56, 353; 
key to families of, 355 
Siricicoidea (see Siri- 
cide), 464 
Siricide, Sirex (cetpnr, si- 
ren, a siren, wasp), 463, 


4 
Sisyra umbrata, stages of, 
*229 


Sitaris humeralis, life-his- 
tory of, 291 

Sitrodrepa panicea, 271 

Sium cicutefolium, visited 
by insects, 571 

Skipper-butterflies, 442 

Slave ants, 547 

Slave-maker ants, 547; 
shining, 547 

Slaves, 547 

Slug, pear-tree, 466; rose, 


4 
Smell, sense of, 27 
Smelling-pits on antenna 

of carrion-beetle, *27 
Smerinthus geminatus, 

*435, 437; larva of, *436 
Smoky-moths, 369, 386 
Smynthuridez, Sminthurus 

(cuirdoc, sminthus, 

mouse; ovpd, ura, tail), 


3 
Smynthurus aquaticus, 
*58; hortensis, 63 
Snake-doctor, 76 
Snake-feeder, 76 
Snap-dragon, specialization 
of, for insect pollination, 
572; visited by honey- 
bees, *563 
Snapping apparatus of 
click-beetle, *267 
Snipe-flies, 327, 330, 332 
Snout-beetles, 204 
Snow-flea, *64 
Snow-white Eugonia, 398 
Snowy tree-cricket, *159, 
160 
Social wasp, Hymenoptera 
parasites of, *480 
Soldier-beetle, 260 
Soldier-bug, banded, 204 
Soldier-flies, 327, 320 
Solenopsis molesta, 544 
Solidago canadensis, vis- 
ited by insects, 571 
Song of snowy tree- 
cricket, 160 
Sooty-wings, 442 
Sound-making by Orthop- 
tera, 123, 134, 150, *I5I, 
152, 155, *157, 159; file 
of cricket, *157; organ 
of the Cicadide, *167 
Southern grain-plant- 
louse, *172 
Span-worms, 395 
Species, 56 


Spermatheca, 14 

Spermatozoa (see Repro- 
ductive organs) 

Speyeria idalia, 456 

Spherophthalma  aureola, 
408 ; californica, 498; pa- 
cifica, *498; similima, 
* 


97 
Spharagemon bolli, 


*146; 
collare, *146 
Sphecina (c¢7&, sphex, a 
wasp), 463 
Sphecius speciosus, 500 
Sphecoidea (sec Sphe- 
cina), 464 


Sphenophorus, 297 

Sphex ichneumonea, 499; 
occitanica, *492 

Sphingicampa bicolor, 429 

Sphingide, Sphinx (cd/yé, 
spligx, sphinx), 369, 
431 

Sphinx, 437; chersis, larva 
of, showing threatening 
attitude, *606; gordius, 
*436 

Sphinx-moth, 431; front 
of head of, showing 
frontal sclerites and 
mouth-parts of, *362; 
mouth-parts of, *10; 
pen-marked, larva of, 
showing threatening as- 
pect, *606; sucking pro- 
boscis of, *360 

Sphyracephala 
MS, 347 } 

Spice- bush swallowtail, 
450 . . . 

Spilosoma virginica, 412 

Spiracles, 7, 19 

Spittle-insects, 170; stages 
of froth production, *171 

Spondylide, Spondylis 
(oxévdvioc, spondylus, 
a vertebra, a joint), 277, 
285 ; 

Sporotrichum — globulife- 
rum, 2123 Sp... *346 

Spotted-winged locust, 
*I4AI 

Spotted wingless 
hopper, *154 

Spreading-boards, how to 
make, 638 

Spring azure, 443 

Spring canker-worm, 397 


brevicor- 


grass- 


Index 


Springtail, American, 64; 
pond-surface, *58; scales 
of, *64; spotted, *63 

Sprinkled locust, *140, 142 


| Spur, 232 


Squash-bug, *213; family, 
195 

Squash-vine borer, 391 

Stable-fly, *342 

Stag-beetle, 272, *273 

Staphylinide, Staphylinus 


(aragvaAwoc, staphylinus, 
a kind of insect), 258, 260 
Staphylinus — cinnamopte- 


rus, 261; maculosus, 261 ; 
tomentosus, 261; viola- 
ceus, 261 

Stegomyia, 305, 307; fas- 
ciata, 308 

Stelide, Stelis (orTedic, 
stelis, a parasitical 


bee), 515 

Stenobothrus curtipennis, 
*140, 142 

Stenopelmatus sp., *156, 
157 


Stenopogon inquinatus, 


*331 
Stephania picta, *197 


Stephanide, Stephanus 
(crégavoc, stephanus, 
crown), 463 


Sternum (ventral wall of 
a body segment) 

Sthenopis argenteo-macu- 
latus, 373 

Stigma (opaque spot, 
costal area of wing) 

Stigmata, 19 

Stilt-bugs, 105, 214 

Sting of the honey-bee, 
460, *461 

Stink-bugs, 195, 214, *215 

Stobera tricarinata, *168 

Stomoxys calcitrans, *342 

Stone-crickets, 155 

Stone-flies, 53, 65, 70; life- 
history of, 71 

Stone-fly, *72; exuvia of 
nymph of, *71; young 
(nymph) of, *71 

Stratiomyia, 330 

Stratiomyide, Stratiomyia 
(otpatiwtnc,  stratiotes, 
a soldier; “va, myia, a 
fly), 327, 320 

Strawberry root - borer, 
*374 


691 


Strepsiptera  (orpége, 
strephen, twist; mrépov, 
pterum, wing), 293 

Striped ground-cricket, 
*159 

Stylopide, Stylops (orvAoc, 
stylus, a pillar; Gy, ops, 
eye, face), 293, 204 

Stylops, 204 

Subcosta (see Venation) 

Sugar-beet midge, 345 

Sugar-maple borer, *283 


Sulphur - colored _ tortrix, 
*380 
Suture, *5 


Swallow-tailed butterflies, 
446, *447; butterfly, 
chrysalid of, *448 

Swarming of honey-bees, 
525 

Swifts, 368, 372 

Sword-bearer, *153 

Sympathetic nervous sys- 
tem, 23; of larva of 
harlequin-fly, *24 

Symphasis signata, *234 

Symthurus aquaticus, 64 

Synchloé sara, 446; genu- 
tat, 446 

Synchlora glaucaria, 398 

Synhalonia, 515 

Syntomidz (prob. cvvrouia, 
syntomia, abridgment, 
shortness), 410 

Syritta pipiens, 340 

Syrphid, rat-tailed 
of, *340 

Syrphide, Syrphus (cipdoc, 
syrphus, a gnat), 332, 
339 

Syrphus, 340; . contumax, 
venation of wing of, 
*330 

Syrphus-flies, 3390 

Syssphinx heiligbrodti, 429 

Tabanide, Tabanus (ta- 
banus, a horse-fly), 327, 
328 

Tabanus, 320; lineola, *328 

Tachina-fly, 345, *346 

Tachinid parasite of Cali- 
fornia flower-beetle, *346 

Tachinine, 341,.345 

Tactile hair, innervation 
of, *26; sense, 26 

Tenidia, *19 

Tzniopteryx, 73 

Tapestry-moth, 374 


larva 


692 


Tarantula-killer, *500, 50I 

Tarsi, *6; of beetles, *250 

Taste, sense of, 26 

Tegmina, 134 

Tegule (cup-like scale 
over base of forewing), 


490 
Telea polyphemus, 420, 
*421; larva of, *421 
Telephorus bilineatus, 270 
Tenebrio molitor, 289; ob- 
scurus, 289 
Tenebrionide, 
(tenebre, 


Tenebrio 
darkness), 


2 
Tent-caterpillar, apple- 

tree, 415; forest, 415 
Tent-caterpillar moths, 


370 
Tenthredinide, Tenthredo 
(teripndav, _tenthredon, 
a kind of wasp), 463, 
464 
Tenthredinidoidea, (see 
Tenthredinide), 464 
Terias nicippe, 446 
Termes, 102;  bellicosus, 
106; depredation by, 
107; flavipes, comple- 
mentary queen, *103; 
habits of, 102, 103; 
winged male, *103; 
worker, *102; lucifugus, 
104; redmant, *106 
Termites, 55, 99; artificial 
distribution of, 108; 
food of, 101, 109; forms 
in a community, I01; 
key to genera of, 102; 
of Africa, 106; origin of 
castes of, 108; nests of, 
*100; sheds in Samoa, 
*ro1; structure of, Ior 
Termitogaster texana, a 
rove-beetle, *552 
Termitophiles, 108 
Termitophily, 108 
Termopsis, 102; angusti- 
collis, 99, *104; habits 
of, 104, 105, 106 
Texting appearances, 


Tetanocera pictipes, *348 

Tetracha, 253 

Tetragoneuria epinosa, *96 

Tetramera (Tetpa, tetra, 
four; pépoc, merus, 
part), 252, 277 


Index 


che lg tetraophthalmus, | Tolype velleda, 416 


284 
Tettigidea lateralis, *148, | 


149 
Tettigine, 136, 147 
Tettix granulatus, *148; 

ornatus, *148 
Thalessa lunator, *484 
Thecla halesus, 444 
Therioplectes, 320; 

mouth-parts of, *329 
Thinopinus pictus, 261 
Thistle-butterfly, 454 
Thorax, parts of, *6; sec- 

tion of, showing attach- 

ment of leg and wing 

muscles, *5 
Thread-legged bugs, 195, 

204, *205 
Thrips, 55, *219; alimen- 

tary canal of, *15; head 

and mouth-parts of, *8; 

mouth-parts of, *220; 

respiratory system of, 

*18; tabaci, 221 
Thyreus abbotti, 437; lar- 

va of, *437 
Thyridopteryx ephemere- 

formis, 386, *387; vena- 

tion of wing of, *389 
Thysanoptera ( 4icavoc, 

thysanus, a tassel ; *TEpdr, 

pterum, a wing), 55, 220 
Thysanura (@voavoc, thy- 

sanus, tassel; ovpa, ura, 

feu). 60; key to families 
or, 
Tibia, *3, *6 
Tide-rock fly, *311 
Tiger-beetles, 252 
Tiger-moths, 370, 411 
Tiger swallowtail, 449 
Tinea biselliella, 374; pel- 

lionella, *373, 374; 

tapetzella, 374 
Tineide (see 

374 
Tineina (tinea, a gnawing 

worm), 133, 368, 374 
Tingitida, Tingis (Fabri- 

cius, 1803,—etym. un- 

certain), 195, 207 
Tiphia inornata, 497 
Tipulide, Tipula (tipula, 

a water spider), 304, 321 
Tmetocera ocellana, *381 
Toad-bug, 194, *202 
Tobacco-worm moth, 434 


SP. 


Tineina), 


Tomato-worm moth, 434 
Tomicus _ plastographus, 
galleries and stages of, 
*209 
Tomognathus americanus, 
547; sublevis, male and 
ergatoid female, *535 
Tortoise-beetle, *280, 281 
Tortricina, Tortrix (fem. 
of tortor, tormentor), 
368, 374, 379 
Tortricid, venation of a, 
*380 
Toxoptera gramineum, va- 
rious stages of, *172 
Trachez, 7, 10; in head of 
cockroach, *19;  struc- 
ture of, *20 
Tracheal gills, 20; of 
May-fly nymph, *20 
Traces system of beetle, 
I 
Tramea lacerata, 95 
Tree-bug, bound, 2143 
green, 214; spined, *215 
Tree-hoppers, 168 
Tremex columba, *467 
Tremex, pigeon, *467 
Trienodes ignita, *243 
Trichodectes latus, *120, 
121; parumpilosus, *120, 
121; pilosus, 121; scala- 
ris, *120, 121; subro- 
Stratus, 121 
Trichodectide, T richo- 
dectes (Spit, thrix, hair; 
Onxrne, dectes, bite), 118 
Trichodes, 270; apiarus, 
270; ornatus, *269 
Trichoptera (4pig, thrix, 
hair; 7répov, pterum, 
wing), 55, 223, 239; key 
to families of, 244 
Tridactylus apicalis, *161 
Trigonalide, Trigonalys . 
(tpiyovoe, trigonus, 
three-cornered; dius, 
alos, disk), 463 
Trimera (rpeic, tris, three; 


népoc, merus, a part), 
252, 286 
Trimerotropis — maritima, 
*147 : 
Trimerotropis, protective 


resemblance of, 147. 
Trinoton, 119; Juridum, 
116, 120 , 


Index 


Triphleps insidiosus, 206 | Velvet-ants, 497 


Tripoxylon albopilosum, 
502; frigidum, 502; ru- 
brocinctum, 502 

Triprocris, 388 

Triungulin, 290 

Trochanter, *247 

Trochilium fraxini, *392 

“lropisms, 635, 636 

Tropizaspis sp., *155, 156 

Tropea luna, 420, *422; 
cocoons of, *423 

Trox, 275 

Trumpet-galls on leaves of 
California white oak, 
*470 

Trypeta longipennis, *349; 
ludens, 350; solidaginis, 
350 

Trypetide, Trypeta 
(tpiravov, trypanum, a 
borer), 350 

Tryxaline, 126, 142 

Tumble-bugs, 273, 274 

Turkey-gnats, 313 

Turnus butterfly, 4490 

Tussock-moth, degenerat- 
ing muscle of, *50; de- 
veloping mouth-parts of, 
*363; larva of, *405; 
parallel-lined, 405 

Tussock-moths, 370, 404 

Twig-insect, *603 

Two-striped locust, *138, 
I4I 

Typhlocyba rose, 170 


Udecopsylla robusta, *154 
Uloma impressa, 289 
Ulula hyalina, *232 
Underground nest of Cali- 
fornia honey-ant, *54 
Underwings, a group of 
red and yellow, *400 
Utetheisa bella, 413 


Valves of dorsal vessel or 
heart, *18 

Vanessa atalanta, 454; 
cardui, 454; cary@, 454; 
huntera, 454 


Vedalia cardinalis, 186, 
*187, 287 

Veins of wings, 10 

Veliide, Velia (perhaps 


Veha, a Greek colony in 
Southern Italy), 195, 
198 


Venation, 10; of a cossid, 
*385 ; of dragon-fly wing, 
*89; of a Geometrid, 
*306; of monarch but- 
terfly, *11; of social 
wing, *113; of a Pyro- 
morphid, *389; of a 
Tortricid, *380; wing 
of Anthrax  fulviana, 
*333; of wing of bag- 
worm moth, *389; of 
wing of Bibio albipennis, 
*326; of wing of black- 
fly, *312; of wing of 
Chrysophila thoracia, 
*330; of wing of crane- 
fly, *321; of wing of 
dance-fly, *335; of wing 
of Dixa sp., *320; of 
wing of a Dolichopodid, 
*336; of wing of fungus- 
gnat, *325; of wing of 
Hepialus gracilis, *372; 
of wing of horse-fly, 
*3028; of wing of Lucilia 
cesar, *344; of wing of 
Micropteryx sp., *372; 
of wing of monarch 
butterfly, *371; of wing 
of net-winged midge, 
*317; of wing of Odon- 
tomyia, *329; of wing of 
Pyralid moth, *376; of 
wing of robber-fly, *331; 
of wing of Syrphus con- 
tinuax, *339 

Ventral (bellyward) 

Ventral plate, 38 

Vertex, 142 

Vespa, 503, 506; crabro, 
nest of, *504; cuneata, 
506; germanica, 506; 
maculata, 506; sp., *505 

Vespide, Vespa (vespa, a 
wasp), key to genera of, 
503 

Vespina (see Vespide), 


463 
Vespoidea (see Vespide), 
464 
Viceroy, 452; butterfly 
mimicking monarch but- 
terfly, *610 
Vine-hoppers, *170 
Vine-loving pomace-fly, 349 
Violet-tip butterfly, 454, 
*455 


693 


Vitelline membrane, 37 
Volucella, 340 


Wallanese * 
Ghee stick, *131, 132, 


3 
Walking-sticks, 126; key 
to genera of, 132 
Walnut-moth, regal, 246, 
*427; larva of, *427 
Warble-flies, 338 
Warning colors, 604 
Wasp, development of 
mouth-parts of, *460, 
461; mouth-parts of, 
*460; mouth-parts of 
larva, *461 ; mud-dauber, 
nest of, *499 
Wasp-flies, 332, 336 
Wasp-like fly, *336 
Wasps, 56, 490; carpenter, 
*502; classification of, 
490; mason, 498; mim- 
icry of, by moths, *608; 
nest-building by, 508; 
potter, 498; social, 503; 
solitary, 491; solitary, 
Fabre’s experiments on 
instincts of, 643; soli- 
tary, Peckham's experi- 
ments on instincts of, 
650; classified by habits, 
497; habits of, 492; sting- 
ing prey, 495; structure 
of, 491; true, 463 
Water-beetle, #25. 
Water-boatmen, 194, 108, 
*199 
Water-bug, giant, 199, 
*200; western, *200 
Water-creepers, 199 
Water-net, *639 
Water scavenger - beetle, 
259; development of egg 
of, *38; external anat- 
omy of, *247 
Water-scorpion, 104, *201; 
eggs of, *201 
Water-skater, ocean, *197 
Water-striders, 195, 1096, 
*197 ; broad-bodied, *197 
Water-tiger, *256 
Wax-making of honey- 
bee, 526 
Wax secreted by aphids, 


175 
Webbing clothes-moth, 374 
Web-worm, fall, 412 
West-coast lady, 454 


694 


Western cricket, *156, 157 
Wheat-thrips, 221 
Wheel-bugs, 203 
Whirligig-beetle, 252, *257 
Whirligigs, 255 
White ants, 99 
White-lined sphinx, 435 
Wing, of butterfly, ar- 
rangement of scales on, 
*591; developing, of cab- 
bage-butterfly, *11; of 
monarch butterfly, part 
of, showing scales, *360; 
muscles of, *5 
Wing-buds, development 
of, of giant crane-fly, 
*48 
Wings, 9; of butterflies, 
androconia from, *592; 
of Heteropters, showing 
venation, *196; of locust, 
development of, *42 
Winthemia,  4-pustuluta, 


347 
Wood-boring beetle, giant, 
development of color- 
pattern in, *598 
Wood-borers, metallic, 


265 
Wood leopard-moth, 385 


Index 


Wood-nymph, *409, 410, 
457; moths, 370, 407 
Woolly apple-aphis, 179 
Woolly-bear caterpillars, 

FAIL 
Workers, 459 


Xenos, 294; sp., parasitiz- 
ing Polistes, *29 
Xestopsylla, 355; gallina- 
cea, 350 
Xiphidium, 
atum, *154 
Xylina antennata, *402; 
grotet, *402; lacticinera, 
parasitized larve of, *486 
Xylocopas, 513 


154; attenu- 


Yellow-fever, 
and, 630 
Yellow-jacket, communal 
nest of the, *505; nest 
of, Vespa sp., cut open 
to show combs within, 
*506; queen, nest of, 

*507 
Yellow-jackets, *505, 506 
Yellow-winged locust, *144 


mosquitoes 


Yolk, 37 

Ypsolophus —_ pomatellus, 
*374; larva of, *373 

Yucca-borer, 441 

Yucca filamentosa, specifi- 
cation of, for insect pol- 
lination, 576 

Yucca, pronuba moth rub- 
bing pollen down a stig- 
matic tube of, *578; pro- 
nuba moth laying eggs 
in ovary-tube of, *577 


Zaitha fluminea, *200 
Zalysus spinosus, 214 
Zebra swallowtail, 448 
Zerena cesonia, 446; eury- 
dice, 446 
Zeuzera pyrina, 385 
Zodion, 337 ; 
Zygenid, venation of, *411 
Zygenide, Zygena [Fabri- 
cius, 1775] (Svyawa, sy- 
g@na, supposed to mean 
the hammer - headed 
shark), 370, 410 
Zygoptera (prob. Cuydv, 
sygum, yoke ; 7Tépov, 
pterum, wing), 89; key 
to families of, 89 


THE AMERICAN NATURE SERIES 


In the hope of doing something toward furnishing a series where the 
nature-lover can surely find a readable book of high authority, the pub- 
lishers of the American Science Series have begun the publication of the 
American Nature Series. It is the intention that in its own way, the new 
series shall stand on a par with its famous predecessor. 


The primary object of the new series is to answer questions—those 
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But a collateral object will be to give some intelligent notion of the 

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This division will consist of three sections. 

Section A. A large popular Natural History in several volumes, 
with the topics treated in due proportion, by authors of unquestioned 
authority. 

The books so far publisht in this section are : 

FISHES, by Davin Srarr Jorpan, President of the Leland Stanford 

Junior University. $6.00 net; carriage, 50 cents. 

AMERICAN INSECTS, by Vernon L. Ke ttoae, Professor in the Leland 

Stanford Junior University. $5.00 net; carriage, 50 cents. 


NORTH AMERICAN TREES, by N. L. Brirron, Director of the New 
York Botanical Garden. 


Arranged for are: 
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Botany, Marine Biological Laboratory, assisted by other specialists. 


WILD MAMMALS OF NORTH AMERICA, by C. Harr Merriam, 
Chief of the United States Biological Survey. 


BIRDS OF THE WORLD. A popular account by Frank H. Know ron, 
M.S., Ph.D., Member American Ornithologists Union, President 
Biological Society of Washington, etc., etc., with Chapter on Anat- 
omy of Birds by Freprrick A. Lucas, Chief Curator Brooklyn Acad- 
emy Arts and Sciences, and edited by Rosert Ripeway, Curator of 
Birds, U. S. National Museum. 

Section B. A Shorter Natural History by the Authors of Sec- 
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its authority so far as that can be preserved without its fullness. 

Section C. Identification Books—‘‘ How to Know,”’ brief and in 
portable shape. By the authors of the larger treatises. 


AMERICAN NATURE SERIES (Continued) 
II. FUNCTIONS OF NATURE 


These books will treat of the relation of facts to causes and effects— 
of heredity in organic Nature, and of the environment in all Nature. 


Already publisht: 
THE BIRD: ITS FORM AND FUNCTION, by C. W. Beene, Curator 


of Birds in the New York Zoological Park. 8vo, 496 pp. $3.50 net; 
by mail, es 80. 
Arranged fi 


THE INSECT: ITS FORM AND FUNCTION, by Vernon L. Ke toca, 
Professor in the Leland Stanford Junior University. 

THE FISH: ITS FORM AND FUNCTION, by H. M. Smiru, of the 
U. S. Bureau of Fisheries. 


III. REALMS OF NATURE 


Detailed treatment of various departments in a literary and popu- 
lar way. 
Already publisht : 
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pp. xit+362. Price $3.00 net; by mail, $3.30. 


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THE SHELLFISH INDUSTRIES, by James L. Ke.ioce, Professor in 
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CHEMISTRY OF DAILY LIFE, by Henry P. Tarsor, Profess.x of 
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DOMESTIC ANIMALS, by Wittiam H. Brewer, Professor Emeritus in 
Yale University. 

THE CARE OF TREES IN LAWN, STREET AND PARK, by B. E. 
Fernow, Late Head of the Cornell School of Forestry. 


V. DIVERSIONS FROM NATURE 
This division will include a wide range of writings not rigidly system- 
atic or formal, but written only by authorities of standing. 
FISH STORIES, by Davin Srarr._ Jorpan and Cuartes F. Hotper. 
HORSE TALK, by Wiuiam H. Brewer. 
BIRD NOTES, by C. W. Beene. 
INSECT STORIES, by Vernon L. Kettoae. 


VI. MAN IN NATURE AND EVOLUTION 
A Series of volumes by President Jorpan, of Stanford Univer- 
sity, and Professors Brooks of Johns Hopkins, Tomson of Aberdeen, 
PrzipraM of Austria, zur Strassen of Germany, and others. Edited by 
Professor Kettocea of Leland Stanford. 


HENRY HOLT AND COMPANY, New York 


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