iii^..i

mum

For Reference

NOT TO BE TAKEN FROM THIS ROOM

• "^'- I CALF

LIBRARY OF

1885- IQ56

PLATE I

nfarr U'eUmnv, del.

PLATE T.
SPHINX-MOTHS.

1 = Pholus pandorus.

2 = Smerinthus geminatus.

3 = Ainpelophaga versicolor.
4=Marumba modesta.

5 = Hemaris thysbe.
6=Thyreus abbotti.

American j^aturr Series;

Group I. Classification of Nature

AMERICAN INSECTS

VERNON L KELLOGG

Professor oj Entomology and Lecturer on Bionomics
in Leliind Stanford Jr. University

WITH MANY ORIGINAL ILLUSTRATIONS
BY

MARY WELLMAN

NEW YORK

HENRY HOLT AND COMPANY
1906

Copyright, 1904

BY

HENRY HOLT AND COMPANY

ROBERT DRUMMOND, PRINTER, NEW YORK

TO
JOHN HENRY COMSTOCK

PREFATORY NOTE

If 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. But
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 etTort

vi 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 accounts
of the habits and kinds of insects than in their structure and physiology
will be inclined lo 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 obhged 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.

CONTENTS

CHAP. PAGE

I. The Structure and Special Physiology of Insects i

II. Development and Metamorphosis of Insects 35

III. Classification of Insects 52

IV. The Simplest Insects (Order Aptera) 58

V. May-flies (Order Ephemerida) and Stone-flies (Order Plecoptera). 65

VI. Dragon-flies and Damsel-flies (Order Odonata) 75

VII. The Termites or White Ants (Order Isoptera) 99

VIII. Book-lice and Bark-lice (Order Corrodentia), and Biting Bird-lice

(Order Mallophaga) iii

IX. The Cockroaches, Crickets, Locusts, Grasshoppers, and Katydids

(Order Orthoptera) 123

X. The True Bugs, Cicadas, Aphids, Scale-insects, etc. (Order Hemip-

tera), and the Thrips (Order Thysanoptera) 163

XI. The Nerve-winged Insects (Order Neuroptera), Scorpion-flies

(Order Mecoptera), and Caddis-flies (Order Trichoptera) 223

XII. The Beetles (Order Coleoptera) 246

XIII. The Two-winged Flies (Order Diptera) 301

XIV. The Moths and Butterflies (Order Lepidoptera) 358

XV. The Ichneumons, Gall-flies, Wasps, Bees, and Ants (Order Hymen-

optera) 459

XVI. Insects and Flowers 562

XVII. Color and Pattern and their Uses 583

XVIII. Insects and Disease 615

Appendix: Collecting and Rearing Insects 635

Index , 649

AMERICAN INSECTS

CHAPTER I

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 and hizarrerie, 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.

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 external 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), etc. 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-

antennae

•ovipositor

femuT'
tibia''

tarsal segments

Fig. I. — 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 (tracheje) 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-

FiG. 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

Fig. 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, antennae

and mouth-parts, and other parts. The small

portions of chitinized cuticle thus isolated or

made separate by the thin interspaces or sutures

4. ■ Fig. 5.

jri(;_ ^_ — Diagram of cross-section through the thorax of an insect to show leg and wing

muscles and their attachment to body-wall, h., heart; al.c, alimentary canal; v.n.c.

ventral nerve-cord; w., wing; /., leg; w., muscles. (Much enlarged; after Graber.)
PiQ J — 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.

Fig. 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. I and 7), which may be pretty distinct and similar, as in a caterpillar
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 segments of the abdomen retain their independence and are more or

compound eye,
antennae^
prothorax^ '

labial
palpi

proboscis''

tarsal segments

Fig. 7. — Body of the monarch butterfly, Anosia plexippiis, 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

antennae and three pairs of mouth-parts,
known as mandibles, maxillae, 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
may be wholly lost, as is true of the mandibles
in the case of all the butterflies. The head
bears also the large compound eyes and * the
smaller simple eyes or ocelli (for an account of
the eyes see p. 30). Attached to the thorax are
three pairs of legs, which are jointed appendages,
homologous in origin and fundamental struc-

FiG. 8. — Dorsal aspect of head
of dobson-fly, Corydalis cor-
nuta, female, showing mouth-
parts. Ih., labrum, removed;
md., mandible; mx., maxilla;
li., labium; gl, glossae of la-
bium; St., stipes of maxilla;
mxp., palpus of maxilla; ant.,
antenna.

ture with the mouth-parts and antennas, 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 jomted ventra
appendages. The thorax usually has its first or most anterior segmentl
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. 9. Fig. lo.

Fig. 9.— Head, much enlarged, of mosquito, Culex sp., showing piercing and sucking
mouth-parts. (After Jordan and Kellogg.) , tvt . .u u . * „,»i

Fig 10— 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
tracheae 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 Hkes
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 :ugs
and woolens, while the cigarette-beetle has
the depraved taste of our modern vouth.

Fig. II.

Fig. II. — Mouth-parts, much enlarged, of the house-fly, Musca domestica. mx.p., maxil-
lary palpi; ih., labrum; li., labium; la., labellum.

Fig. 12. — Head and mouth-parts, much enlarged, of thrips. ant., antenna; lb., labrum;
md., mandible; mx., maxilla; mx.p., maxillary palpus; li.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. 10 and 16), and another a broad lapping tongue (Fig. n).
Just this variety of structure actually exists, and in it the classific entomolo-
gist 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 18 16, have been able
to trace the fundamental three pairs of oral jointed appendages, the mandi-
bles, maxillae, 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 9

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

-mxp.

Fig. 13. Fig. 14.

Fig. 13. — Seventeen-year cicada, Cicada septcndecim, sucking sajj from twig. (After

Quaintance; natural size.)
Fig. 14. — Section of twig of Carolina poplar showing beak of cicada in position when

sucking. (After Quaintance; much enlarged.)
Fig. 15. — Mouth-parts, much enlarged, of net-winged midge, Bibicocephala doanei,

female, md., mandible; mx., maxilla; tnx.L, maxillary lobe; mx.p., maxillary

palpus; //., labium; hyp., hypopharynx; pg., paraglossa of labium; l.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

lo The Structure and Special Physiology of Insects

^

strongly chitinized lines called veins. 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. After the wing is
expanded and dry, the tracheae mostly die out, and
the veins are left as firm thick-walled branching
tubes which serve admirably as a skeleton or
framework 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
class. The more important and constant veins have
been given names, and their branches numbers
(Fig. i8). 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

Fig. i6. — Sphinx moth, showing proboscis; -^ ^ r ■

at left the proboscis is shown coiled up larger groups, as orders, of msects,
on the under side of the head, the nor- ^nd the first classification, that of
mal position when not in use. (Large _ . , \ j- -j i.i. i

figure, one-half natural size; small fig- Lmnsus (1750 app.), divides the class
ure, natural size.) 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 Lianaean ordinal names is given on p, 223.

Fig. 16.

The Structure and Special Physiology of Insects 1 1

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

Ik \

Fig. 17. Fig. li

Fig. 17. — Wing of cabbage-butterfly, Pieris rapa, in early sac-like stage, tr., trachea;

//., tracheoles; l.v., lines of future veins. (After Mercer; greatly magnified.)
Fig. 18. — Diagram of wings of monarch butterfly, Anosia plexippits, showing venation.

c, costal vein; s.c, subcostal vein; r., radial vein; cii., 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

I 2 The Structure and Special Physiology of Insects

knobs and horns. The rhinoceros-beetle (Dynastes) (Fig. 19) and the sacred
scarabeus are famihar 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
.nsects, and measure less than a millimeter in length, to the giant Phasmids

«£r

Fig. 19. — Rhinoceros-beetle, Dynastes tityriis, 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 e.xoskeleton 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 (e.xcept
perhaps in the terminal segments), and the modification of these append-
ages into antennae 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 i 3

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-

s.ijl.

Fig. 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 tracheje and fat body; I to III, segments
of the thorax; i to g, segments of the abdomen. Alimentary Canal and Appen-
dages: ph., pharynx; sd. and sgl., salivary duct and gland of the right side; oe.,
oesophagus; f.r., food -reservoir; St., stomach; i., small intestine; c, colon; r., rec-
tum; a., anus; m.v., Malpighian tube. Haemal System: h., heart or dorsal vessel;
ao., aorta; a.c, aortal chamber; Nervous System (dotted in figure): br., brain;
g., subcesophageal ganglion; l.g., compound thoracic ganglia; fl,g.,, ag.^, first and
fourth abdominal ganglia. Female Reproductive Organs: cp., copulatory pouch;
v., vagina; o., oviduct, and oo., its external opening; r.ov., base of the right ovarian
tubes turned down to expose the underlying organs; l.ov., left ovarian tubes in posi-
tion, and ov.c, their termination and four cords; sp., spermatheca; a.gl.^, part
of the single accessory gland; a.gl.^, one of the paired accessory glands; only the
base of its mate is shown. Head: a., antenna; mx., proboscis, p., 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 larvae,
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 Fig. 21. — Bit of muscle of a biting bird-louse,
them being composed of finely Eurymetopus tatcrus. (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
from 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

Fig. 22. — Diagrammatic figures of bits of insect muscle, variously treated.
Gehuchten; greatly magnified.)

(After Van

Fig. 23. — Alimentary
canal of a locust. At
upper end the oesoph-
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.)

contracted elsewhere to be oesophagus or intestine.
One or two pairs of saHvary 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 ca?ca.

Two striking peculiarities
about the reproductive system
of insects are the possession
by the female of one or more
spermathecce (Fig. 66, r.s.) in
which the male fertilizing
cells, the spermatozoa, are re-
ceived and held, and the com-
pletion of all the envelopes of „ t^- .. r
^ .... , Fig. 24. — Dissection of
the egg, mcludmg the outer cockroach to show {al.c.)
hard shell, before its specific alimentary canal. (After
. ... . , , T^ Hatschek and Cori: twice
fertilization takes place, rer- natural si^e.)

The Structure and Special Physiology of Insects i 5

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

sff.

ml.

int.

Fig. 25. Fig. 26.

Fig. 25. — Alimentary canal of larva of harlequin-fly (Chironovius sp.). oes., oesophagus;
s.g., salivary gland; ca., cardiac chamber of stomach; mt., Malpighian tubules; ch.,
intestinal chamber; si., small intestine; col., colon. (After Miall and Hammond;
much enlarged.)

Fig. 26. — AUmentary canal of two species of thrips; at left Trichothrips copiosa, male,
at right Aelothrips fasciata. sal.g., saHvary gland; oes., oesophagus; prov., proven-
triculus; vent., ventriculus; m.t., Malpighian tubules; int., 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

1 6 The Structure and Special Physiology of Insects

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

proTi-

FiG. 27. — Alimentary canal of dobson-fly, Cor)'(fa/wconi?</a. A, larva; B, adult; C, pupa;
oes., oesophagus; prov., proventriculus; g.c, gastric coeca; vent., ventriculus; r.g.,
reproductive gland; vi.t., Malpighian tubules; int., intestine; iut.c, intestinal
coecum; 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

Fig. 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

Fig. 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 estabhsh communi-
cation between the body-cavity and heart- Fig. 30. Fig. 31.
The blood receives no more oxygen than Fig. 30.— Diagram of circulatory
it needs for its own use, and thus does ^^^gX t mrchimS'dis'al
not play nearly so complex a function in vessel, or heart, with single artery.
the insect's body as in ours. And this Ar^ws^mdicate^direc^on „, blood-

simplicity of function probably explains pj^ 31.— Dissection showing dorsal

in some degree the extreme primitiveness vessel, or heart, of locust, Dis-
,^ . , . ,^ , sostezra Carolina. (After Snodgrass;

of the make-up of the circulatory system. ^^j^^ natural size.)

It will be seen that the respiratory

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

I 8 The Structure and Special Physiology of Insects

Fig. 32.

Fig. 33.

Fig. 32. — Portion of dorsal vessel and pericardial membrane of locust, Dissosteira caro*

Una. (After Snodgrass; greatly magnified.)
Fig. 33. — Cross-section of dorsal vessel or heart in pupa of tussock-moth, Hemerocampa

leiicostigma, showing valves. (Greatly magnified.)

:;^sp

Fig. 34.

Fig. 35.

Fig. 36.

Fig. 34. — Diagram of tracheal system in body of beetle, sp., spiracles; tr., tracheae.

(After Kolbe.)
Fig. 35. — Diagram showing main tracheae in respiratory system of locust, Dissosteira

Carolina. (After Snodgrass; twice natural size.) •

Fig. 36. — Diagram showing respiratory system in thripf. St., spiracles. (After Uzel;

much enlarged.)

The Structure and Special Physiology of Insects 1 9

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

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 euarded 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
tracheae 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 _^^^m.

numerous branches arise, these going to iS^^!

particular regions of the body (Fig. 38) Fig. 39— i'lcce of trachea (air-tube),
, , , , . » . ji .M greatly magnified, showing spiral

and there branchmg \epeatedly until e^^^^j (t^nidia). (Photomicro-

even individual cells get special tiny graph by George O. Mitchell.)

Fig. 37

Fig. 37. — Diagram showing respiratory system of pupa
of mealy -winged fly, Akyrodes sp.; only two pairs
of spiracles are present. (After Bemis; much
enlarged.)

Pig 28. — Diagram of trachese in head of cockroach.
Note branches to all mouth-parts, and the an-
tennae. /., tracheae, or air-tubes. (After Miall
and Denny.)

20 The Structure and Special Physiology of Insects

respiratory capillaries. The tracheae 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 w^all 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. Gillcd
insects do not, of course, have to come to the
surface to breathe. The gills may be thin plate-
like flaps on the sides or posterior tip of the
body, or may be tufts of short thread-like tubes
variously arranged 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 tracheae
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 thin walls of air-tube
and giU-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

Fig. 40. — Young (nymph) of
May-fly showing {g.) tra-
cheal gills. (After Jenkins
and Kellogg.)

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

^h.

ant.

%

ibxes,
saLgl . "-,,
i.b.wg.- •-//
br. _ I'

...A

i.bjnsi. -E

"''' i.b.h.-::.:::ff

^J^\

i.b.mt.l.-//W\]

^'^'"^^

prov. iw^

^iM

susp. /fl- --

9'C- - |-|^

P'^"^

vent jfl

£-3

ir. 11/

ad.tis yF\

ma I. tub. yi^:^---

FiG. 41. — Larva of giant crane-fly, Holorusia riibiginosa. A, entire; B, dissected, show-
ing all organs except the muscles and ventral nerve-chain, h., head; ant., anterina;
i.b.res., imaginal bud of pupal respiratory tube; i.b.wg., imaginal bud of wing;
i.b.ms.L, imaginal bud of mesothoracic leg; i.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); sal.gl., salivary gland (the other salivary gland is removed);
br., brain; ces., oesophagus; prov., proventriculus; susp., suspensorium; g.c, gastric
coecum; vent., ventriculus; tr., trachea; ad.tis., adipose tissue; mal.tub., Malpi-
ghian tubule; d.v., dorsal vessel; w.m., wing-muscles of pericardium; sm.int.,
small intestine; tes., testis; ini.c, intestinal csecum; v.d., vas deferens; Lint., large
intestine; sp., spiracle; term.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

Fig. 42. Fig. 43. Fig. 44.

Fig. 42. — Diagram of ventral nerve-cord of locust, Dissosteira Carolina. (After Snod-

grass; twice natural size.)
Fig. 43. — Diagram of the nervous system of the house-fly. (After Brandt; much

enlarged.)
Fig. 44. — Nervous system of a midge, CJuronomus 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 larvae 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 oesophagus. From this
ganglion (or fused pair) circumoesophageal commis-
sures run up around the oesophagus to an important
ganglion (also composed of the fused members of a
pair) lying just above the oesophagus and called the
brain, or supraoesophageal ganglion (Figs. 45, 46, and
47). From this proceed the nerves to those impor-
tant organs of special sense situated on the head, the
antennae and eyes. From the suboesophageal gan-
lion nerves run to the mouth-parts, from the thoracic ganglia to the

Fig. 45. — Brain, com-
pound eyes, and part
of sympathetic nerv-
ous system of locust,
Dissosteira Carolina.
(After Snodgrass;
greatly magnified.)

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

Fig. 46.

Fig. 46. — Brain, circumcesophageal commissures, and subcesophageal ganglion of the
red-legged locust, Melanophis jemur-rubrum. oc, ocellus; op.n., optic nerve; a.n.,
antennal nerve; m.oc, middle ocellus; op.I., optic lobe; a.L, olfactory lobe; a.s.g.,
anterior sympathetic ganglion; p.s.g., posterior sympathetic ganglion; f.g., frontal
sympathetic ganglion; Ibr., nerve to labrum; oe.c, circumoesophageal commissure;
g*, subcesophageal ganglion; md., nerve to mandible; mx., nerve to maxilla; l.n.,
nerve to labium; «., unknown nerve, perhaps salivary. (After Burgess; greatly
magnified.)

Fig. 47. — Cross-section of brain, oesophagus, circumcesophageal commissures, and
subcesophageal ganglion of larva of the giant crane-fly, Holoriisia rubiginosa.

nervous system by commissures which meet the brain just at the origin
from it of the circumoesophageal 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
gangha 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

Fig.

Fig

48. riG 49.

Fig. 48. — Part of sympathetic nervous system of larva of harlequin-fly, Chironomus
dorsalis. oes., oesophagus; j.g., frontal ganglion; r.n., recurrent nerve; d.v., dorsal
vessel; n*, nerve passing from brain to frontal ganglion (Newport's fourth nerv-e);
hr., brain; rn., point of division of recurrent nerve; tr., tracheae; pg., paired ganglia;
d.v.Ji., nerve of dorsal vessel; d.v.g., ganglia of dorsal vessel; g.n., gastric nerve
to cardiac chamber. The course of the recurrent nerve beneath the dorsal vessel is
dotted. (After Miall and Hammond; greatly magnified.)

Fig. 49. — Stages in the development of the nervous system of the honey-hee, Apis nielli-
fica; I 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 condit'on 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 iheir sense-organs, and we reahze on even the most superficial
examination of the structure of these organs, and casual observation of the

Fig. 50. — Stages in the development of the nervous system of the water-beetle, ^cilins
sulcatus; i 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.

2 6 The Structure and Special Physiology of Insects

Insects certainly have the senses of touch, hearing, taste, smell, and sight.
If they have others, v^e do not knovv^ 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 antennas or
" feelers," and often on certain pro-
cesses called cerci, projecting from
the tip of the abdomen. They may
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 papillae, usually two-segmented, or in certain pits, which

Fig. 51. — Diagram showing innervation of a
tactile hair, sh., tactile hair; ch., chitinized
cuticle; hyp., hypoderm, or cellular layer
of the skin; s.c, ganglion cell; c.o., gan-
glion of the central nervous system. (After
vom Rath.)

Fig. 52. Fig. 53.

Fig. 52. — Nerve-endings in tip of maxillary palpus of Locusta viridissima. s.h., sense-
hairs; i'.c, sense-cells; 6.c., blood-cells. (After vom Rath; greatly magnified.)

Fig. 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 papillte seated usually and especially abundantly
on the antennae, but probably also occurring to
some extent on certain of the mouth-parts. The
fact that the antennae are the principal, and in
many insects the exclusive, seat of the olfactory
organs has been proved by many experiments in
removing the antennae 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
ruder contact with obstacles against which the
antennae 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
of June-beetles nearly 40,000 olfactory pits occur.
Some of the results of experimentation on smell
indicate a delicacy and specialization of this sense
hardly conceivable. A few examples will illustrate
this. It is believed that ants find their way back
to their nests by the sense of smell, and that
they can recognize by scent among hundreds of individuals taken from

Fig. 54. —Antenna of a
carrion-bcctle with the
terminal three segments
enlarged and flattened,
and bearing many smell-
ing-pits. (Photomicro-
graph by George O. Mit-
chell; much enlarged.)

2 8 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
elaborately branched
or feathered anten-
nae, affording area
for very many smell-
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 w^re 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

Fig. 55. — Auditory organ of a locust, Melanoplus sp. The
large clear part in the center of the figure is the thin tym-
panum with the auditory vesicle (small, black, pear-shaped
spot) and auditory ganglion (at left of vesicle and connected
with it by a nerve) on its inner surface. (Photomicrograph
by George O. Mitchell; greatly magnified.)

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 antenna;
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- Fig. 56.— Male mos(|uito,
strated bv experiment. The fact, too, that manv f o^i"g '^«-^'-) antennal

,'. , . ■' hairs. (After Jordan

msects have special sound-makmg apparatus and and Kellogg; three times
do make characteristic sounds is a kind of proof natural size.)
that they can also hear. The auditory organs of insects, curiously enough,
are of several kinds and are situated on different parts of the body, in

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 tibiae of the fore
legs in the katydids and crickets.
Associated with each tympanum is a
small liquid-filled vesicle and a special
auditory ganglion from which an
auditory nerve runs to one of the
ganglia of the thorax. Among the
Fig. 57.— Diagram of longitudinal section midges and mosquitoes the antennae-
through first and second antennal seg- those all-important sensitive Structures

ments of a mosciuito, Mochlonyx ciilici- , , ,, • i i • i

formis, male, showing complex auditory ~^^^ abundantly provided With cer-

organ composed of fine chitinous rods, tain fine long hairs, the auditory hairs
nerve-fibers, and nerve-cells. (After /tt- _/:\ u* u ^ i tu ' j

Child; greatly magnified.) ^^^S- S6), 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). From
this segment runs a principal auditory nerve to the brain. 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
a microscope, and had a series of tuning-forks of
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
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 antennae 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

Fig. 58. — Longitudinal sec-
tion through ocellus of the
honey-bee, Apis mellifica.
/., cuticular lens; i.e., cell-
ular layer of skin; c.b.,
crystalline layer; r.c, ret-
inal cells; o.n., optic
nerve. (After Redikor-
zew; greatly magnified.)

Fig. 50. — OccUar lens of larva of a saw-fly, Cimhex 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 Ut4, 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

The Structure and Special Physiology of Insects 3 i

Fig. 60. — Part of corneal cuti-

-V~V~VV3.

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

simple ones. The larva; 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
cle, showing facets, of the ^ small convexly thickened clear part of the
fl^?^^rt/.S5fp.^Photo- chitinized cuticle of the head-wall (Fig. 59)
micrograph by George O. and a group of modified skin-cells behind it
Mitchell; greatly magnified.) gp^.j^^y 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 y(|lir~--OIl

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

or retinal element called rhabdom (Fig. 61). Each f^tion through a few

. • 1 1 • r 1 facets and eye-elements

of these ommatidia perceives that bit of the external (ommatidia) of the

object which is directly in front of it; i.e., from which compound eye of a

light is reflected perpendicularly to its corneal facet. "j°. ' /^' ^°crysulHne

All of these microscopic images, each of a small part cones; p., pigment; r.,

of the external object, form a mosaic of the whole ^erve * ^"(ffter' ExSJ-'j

object, and thus give the familiar name mosaic 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,

OS

FiG. 62.

Fig. 64.

F!G.

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

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

Fig. 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). (.\fter
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 hght 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

Fig. 65. — A section through the compound eye, in late pupal stage, of a blow-fly, Calli-
phora sarracenicp. 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.)

•t

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, UexkuU, 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.

fMsmij

CHAPTER II

DEVELOPMENT AND META-
MORPHOSIS

HAT animals are born or hatch from eggs in
an immature condition is such famihar 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 re:emble 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
alive is the exceptional experience of the young
of but few kinds, and even this is a sort of
pseudo-birth. Such hatch alive, one may better
say, for they begin life in eggs, not laid out-
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

Fig. 66. — Ovaries and oviducts
of a thrips. o./., ovarial tubes;
o.d., oviduct; r.s., seminal
receptacle, or spermatheca;
d.r.s., duct of the seminal re-
ceptacle. (After Uzel; much
enlarged.)

Development and Metamorphosis

37

either the germinal or the food part of the eggs. There seems to exist no
dififerentiation 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, i.e., reserve foodstufi^. 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

.^

^y

Fig. 67. — Insect eggs and parts of eggs, showing micropyle. a, egg of Drosophila cel-
laris; h, upper pole of egg of robber-fly, Asilus crabriformis; c, upper pole of egg
of hawk-moth, Sphinx popiili; d, egg of head-louse, Pediculus capitis; e, egg of
dragon-fly, Libellida depressa; /, upper surface of egg of harpy-moth, Harpyia
vinida; 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

</r.

Fig. 68. — Early stage in development of egg of water-scavenger beetle, Hydrophilus sp.
A, first division of nucleus; B, migration of cleavage-cells outward; C, beginning
of blastoderm; D, blastoderm; y., yolk; dc, cleavage-cells; yc, yolk-cells; bl.,
blastoderm. (After Heider; greatly magnified.)

developing embryo begins soon to show that fundamental structural charac-
teristic of insects, a segmental condition (Fig. 6gD). 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. 6gE). The appendages of the
head and thoracic segments continue to develop and begin soon to assume
their definitive character of antennae, 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, tracheae, 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

r7=?==^^

Fig. 69. — Early stages in the development of the egg of saw-fly, Hylotoma beriheridis.
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, ant., antenna; nid., mandible; mx., maxilla; li., labium; /', P, l^,
legs; sg., salivary glands; St., spiracles; ab.ap., abdominal appendages; n.c, nerve-
centers; a., anal opening; lb., labrum; sd., oesophageal invagination; y., yolk;
b.s., abdominal segments; pd., 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 lea-
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-

FiG. 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 removed from egg at time of readiness to hatch.
y., yolk; emb., embryo; ser., serosa; am., amnion; ant., antenna; lb., labrum;
md., mandible; mx., maxilla; mx.p., maxillary palpus; //., labium; H.p., labial
palpus; /'.. P, P, legs; pr., proctodaeum, or intestinal invagination; cer., cerci; 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,
hatch 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

41

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 Y\
(order Hemiptera) and all the locusts, katydids, crickets,
and cockroaches (composing the order Orthoptera), as well
as the May-flies, dragon-flies, white ants, and several other
small groups of unfamiliar forms, agree in having their
young hatched in a condition strongly resembling the
parents, although lacking wings, and in some cases, particu-
larly those in which the young live on different food and in a different habitat
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 antennas, and, usually, char-
acter of mouth-parts, the young and parent agree. During postembryonic

I . — Young
and adult of Po-
dura sp., one of
the simplest in-
sects, showing
development
without meta-
morphosis.
(Much enlarged.)

42

Development and Metamorphosis

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

Fig. 73. — Stages in development of the wings of a locust. /., developing rudiment of
fore wing; h., 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).
After each moulting the young
locust appears markedly larger and
with its wing-pads better developed
(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. In the case of all the thousands of
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. Familiar examples of such young are the caterpillars
and "worms" of the moths and butterflies, the grubs of beetles, the mag-

FiG. 74. — Metamorphosis, incomplete, of an
assassin-bug (family Reduviidae, order
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.)

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 larva?, and the stage or life of the insect passed as a
larva is known as the larval stage. In almost all cases these larvae have
mouth-parts fitted for biting and chewing, while most of the adults have
sucking-mouth parts; the larvae have only simple eyes and small inconspicu-

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

ous antennae; the adults have both simple and compound eyes and well-
developed conspicuous antennae; the larvae 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 larvae 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

Fig. 76. — Larva, pupa, and adult of

the flesh-fly, Calliphora crytJiroce-
phala, with complete metamor-
phosis. (Two times natural size.)

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 larvae
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 larvae
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
hatching. But after its last moult it ap-
pears suddenly in the guise of a partially
formed adult in (usually) quiescent mummy-like form, with the antennae,
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
larva, just before pupation, has spun a
protecting silken cocoon about itself, or
has burrowed below the surface of the
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

Fig. 77. — Adult worker {a) and larva
{b) of honey-bee. (Adult natural
size; larva twice natural size.)

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 (larvae) (Fig. 75) with biting
mouth-parts, simple eyes, short antennae, 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

Fig. 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 antennal 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 antennae, 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 put a 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-fiy (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 larva: (maggots), footless, eye-
less, wingless, nearly headless, with a single pair of curious extensile hooks
for mouth-parts. For ten to fourteen days these larva; 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

knitl. ■hm.l. h.p.1,
B

Fig. 7q. — Dipterous larvae showing (through skin) the imaginal discs or buds of wings,
these buds being just inside the skin. A, larva of black fly, Simulium sp.; B, anteiior
end of larva of midge, Chironomus sp.; C, anterior end, cut open, of larva of giant
crane-fly, Holorusia ruhiginosa; h.pr., bud of prothoracic respiratory tube; h.pl.,
bud of prothoracic leg; h.mw., bud of mesothoracic wing; h.ml., bud of mesothoracic
leg; h.mtb., bud of metathoracic balancer; h.tntl., 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 httle
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 le^^ rudi-

FiG. 80. — Stages in development of wing-buds in the larva of the giant crane-fly,
Holorusia riibiginosa (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; tr., trachea; irl.,
tracheoles; p.m., peritrophic membrane; w., developing wing; t.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, tracheae, 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

.•^

r*

^

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
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,
disintegrating tissue, to the develop-
ing centers of the imaginal parts.
Much investigation remains to be
done on this interesting subject
of histolysis and histogenesis in
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

Fig. 8i. — A cross section of the body of the
pupa of a honey-bee, showing the body-cavity
filled with disintegrated tissues and phago-
cytes, and (at the bottom) a budding pair
of legs of the adult, the larvK being
wholly legless. Photomicrograph by George
O. Mitchell; greatly magnified.)

50

Development and Metamorphosis

to the ancestral fish-like ancestors of all vertebrates. Do then the larvae
and pupae 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
nor eat and which had no in-
ternal organs except a nervous
system, heart, and rudimentary
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

Fig. 82. — A bit of degenerate muscle from tussock
moth, Hemerocampa leucostigma. Note phago
cytic cells attacking muscle at the margins
(Greatly magnified.)

Fig. 83. — Degenerating muscle from pupa of giant crane-fly, Holorusia ruhiginosa, 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

5'

successfully a crawling, squirming, worm-like life. That those insects which
hatch as worm-like larvae 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-

FiG. 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
breaking down and building anew. It is an inter-
polated stage in the development of the butterfly
corresponding to nothing in the phyletic history;
an adaptation to meet the necessities of its life-
conditions. To my mind, this is the interpretation of the phenomena of
complete metamorphosis.

Fig. 85. — Cross-section
of newly developing
muscle in pupa of
honey-bee, Apis mel-
lifica. (Greatly mag-
nified.)

CHAPTER III
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 with 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. IVIost
entomologists of the present incline toward this latter position, so that whereas
Linnasus, 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 Classilication of Insects 53

mology recognizes nineteen distinct ones. This does not mean, of course, that
twelve new orders of insects have been found since Linnaius'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 Linnaeus simply as famihes
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 Linnaean
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 beheves 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 Prof. 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; month-parts well developed, hut all except the apices oj the
mandibles and maxillcB 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. Month-parts, when developed, with both mandibles and maxillce 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 tmjointed 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 fan;
when wings are absent, prothorax small.
F, Antennce 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; posteiior end of

abdomen without many-jointed filaments.

(Dragon-flies and damsel-flies.) Odonata.
FF. Antennce conspicuous.

G. Tarsi less than five-jointed; labium cleft in the
middle.

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

(Stone-flies.) Plecoptera.

The Classification of Insects ^^

HH. Hind wings, when present, not broader than fore
wings, not jolded in repose; protliorax 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; ahvays
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 emarginate.

H. Wings, when present, naked or slightly hairy;

hind wings with or without jolded 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 jolded 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 (i) 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.
C. Prothorax jree; 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; maxillae 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.

CC. 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 jour {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.) Lepidoptera.
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

side (Flies.) Diptera.

FF. Prothorax well developed, distinctly visible from dorsal

side; wings never present (Fleas.) Siphonaptera.

DD. Mandibles well developed, fitted for biting; wings four {sometimes
two or none), naked or with scattered 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 1000 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 ^J

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
speciahsts 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)

ERTAIN household pests which are
not moths and do not look like
fish, but which are com '^^^_Jg 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 larvae 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.

Besides the fish-moths other not unfamiliar Aptera are
the tiny "springtails" (Fig. 87), which sometimes occur
in large numbers on the surface of pools of water or on
snow in the spring. Others may be easily found in damp
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
insect class. Also, as might be expected, these most
primitive insects are simplest in point of bodily struc-
ture; but in this respect they are nearly approached
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

Fig. 86.— The fish-
moth, Lepisma
saccharina. (After
Howard and Mar-
latt; twice natural
size.)

Fig. 87. — The pond-sur-
face springtail, Smyn-
thurus aquations.
(After Schott; much
enlarged.)

The Simplest Insects

59

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

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 Uve 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

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-
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. 90
and 94) are almost exactly like the parents

Fig. 89.— Diagrammatic figures show- except in size. They have simply to grow
ing the respiratory system in three larger and to become mature. In internal
Apteran genera. A, Machilis; B, ^ ^ ^1 • 1 a .l 1

Nicoletia; C, Jcipyx. (After Tar- Structure the smipler Aptera show some
gioni-Tozzetti; much enlarged.) 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

6o 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 tracheae
(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; antennae 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.

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

Body covered with scales Lepismid.e

Body not covered with scales.

Tip of abdomen with forceps-like appendages jAPYGiDiE.

Tip of abdomen with slender many-segmented appendages Campodeid^.

To the last family in the above key belongs the interesting creature
Catnpodea staphylinns (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

6i

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

The Campodeidte contain another
genus, Nicoletia (Fig. 91), one species of
which, A^. iexensis, 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 Japygidae 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 siihterraneus is a species
first found under stones at the mouth of
a small grotto near the Mammoth Cave
(Kentucky). Japyx (Fig. 92) is larger Fig. go
than Campodea,^being about one-half inch
long, and is readily recognized by its caudal

Young and adult of Cam-
podea slaphylinus (from California),
the simplest living insect. (Natural
size indicated by line.)

forceps. Like Campodea its body is white and soft.

The Lepismidae 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 antennae and legs, and is from one-third to two-

p V Z /■ c fifths of an inch long. The three long caudal appen-

ensis, from Califor- dages, characteristic of the genus, are conspicuous. It

ma. (Eight times nat- fg^^jg chiefly on sweet or starchy materials, sometimes

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

Fig. 92. — Japyx sp., from back. Both saccharina and domestica are common
California. (Five times jj^ England, and saccharina probably came to this
natural size.) r 1

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.

Fig. 94.

Fig. 93. — The fish-moth, Lepisma domestica. (After Howard and Marlatt; a little

larger than natural size.)
Fig. 94. — Young and adult of Lepisma sp., from California. (Twice natural size.)

CoLLEMBOLA. — 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

63

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
into 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,
enabhng 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) :

Fig. 95. — Machi-
lis sp., from Cali-
fornia. (Three
times natural
size.)

A. Spring wanting Aphorurid.i;.

AA. Spring present.

B. Spring arising from ventral side of
antepenultimate abdominal segment.

PODURID.E.

BB. Spring arising from ventral side of penultimate abdom-
inal segment.
C. Abdomen elongate, cylindrical, much longer than

broad Entomobryid^.

CC. Abdomen globular, but little larger than broad.

D. Terminal segment of antennas long, ringed.

Smynthurid.e.

DD. Terminal segment of the antennae short, with

* a whorl of hairs Papiriid^.

Fig. 96. — The spotted
springtail, Papirius
7naci(losus,with spring
folded underneath
body. (Natural
length, 2 mm.)

Of these five families the members of one, the Aphorurida?, in which
the spring is wanting, are non-saltatorial. In all of
the others leaping is a characteristic habit. The
Smynthuridae and the Papiriidae 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 "upon the Fig. 97.— The spotted
leaves of young cabbage, turnip, cucumber, and £™,^;^i|; 3%'Se3ei
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 antennae 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 Poduridae and Entomobryidae

are represented in North America by

twelve and fourteen genera respec-

>^am: tively. Many of the Podurids are

illf I f \w\Vi||'j|iM >^^H^ covered with scales and are often

mWmhJm ,^SSsL prettily colored and patterned. The

scales (Fig. 98) are very minute and
bear many fine lines and cross-lines,
regularly arranged. On this account
Fig. 98. Fig. 99. they are much used as test objects

Fig. 98.— Scales from a springtall. (After ^^^ microscopes, the quality of the

Murray; greatly magnified.) '■ • , , •

Fig. 99.-^The snov^-fita, Achorutes nivicola. lens being determined by its capacity
(After Folsom; much enlarged.) ^-q reveal their extremely fine mark-

ings. One of the most interesting Podurids is
the snow-flea, A chorutes nivkola (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-
bryidae is the house springtail, Lepidocyrtiis anieri-
canus (Fig. 100), said by Marlatt to be "not
infrequently found in dweUings in Washington."
It is about one-tenth of an inch long, silvery
gray, with purple or violet markings. In Europe
also one species of springtail is common in
houses. As these insects live on decaying vege-
table matter, they probably do no special harm
in the house. They especially frequent rather moist places, and may often
be found in window-plant boxes and conservatories.

Fig. 100. — The American
springtail, Lepidocyrtus
americanus, ventral aspect,
showing spring folded un-
derneath body. (After
Howard and Marlatt ;
much enlarged.)

CHAPTER V

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 famihar 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

lllii)»"ja

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,

If however, break up while sinking, so that the released

Fig. ioi. — May-flies about an electric lamp.

The May-flies and Stone-flies

67

eggs reach the bottom separately. From each egg hatches soon a thiy
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 aquarivim with
amazing quickness. Almost all other insects
require some little time after the final moulting
for the gradual unfolding of the wings, and dry-
ing and strengthening of the body-wall, before
flight or other locomotion. Most of the May-
fly species go through another moulting after
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

Fig. 102. — Young (nymph) of
May-fly, showing (g) tracheal
gills. (After Jenkins and
Kellogg; three times nat-
ural size.)

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
tracheae and of the sac — car-
bonic dioxide passing out, and
air from that held in solution
in the water passing in. If a
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 wihged 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-
FiG. 103. — May-fly, from California. (Natural size.) ^ork 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 awl-like antennte. 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) tl^^t 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
outhne. 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, Canis
,. 1 , , , , ,, r 1-1 , /,,. 1 dimidiata, possessing only

hghted water below the surface, while the light p -

one pair of wings.
enlarged.)

(Much

eyes" are for special use at the brilliantly lighted
surface. I have noted similar conditions in the eyes of both male and
female net-winged midges (Blepharoceridae), small, two-winged flies of
particularly interesting hfe (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

f^^^T^ ///^ ' — ^"^^K ■ ^'^^^ body, as the legs, wings, mouth-parts,
%^>^^^^'^^^^—^^^M^M antennae, eyes, spiracles, etc., or exact-
^'^ ^"^W^ \y Qj^ ^]^g middle line, as the heart,

alimentary canal, and ventral nerve-
cord. That is, the typical insect body
is bilaterally symmetrical, and the
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

FiL.. 105. — Section through head of
male May-fly, Potamanihus hriinneus,
showing composition of compound
eye and two sizes of eye-elements
(ommatidia). (After Zimmer; greatly
magnified.)

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-fiies are an ancient group of insects, and there is httle 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 hves. 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 accomphsh 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 httle 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, v. 26, 1894, pp. 239-259.

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, 1901.

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 IVIay-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 Fig 106.— Young(nymph)
; f .,, .,, , -11 ,-r- 1 01 stone-flv, from Cali-

vessel of still water will be seen with claws arnxed, 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.
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, weU 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
probably not nearly as many times as is common among
May-flies. When ready for the final moulting, the nymph

Fig. 107. — Exuvia
of nymph of stone

fly. (Natural size.) 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 exuviae (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 He 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 antennae 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-

FiG. io8. — 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 ICO 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:

T.\BLE 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.

S

Fig. 109. — Diagram of venation of wing of a stone-fly; /, costal vein; 2, subcostal vein;
3, radial vein; 4, medial vein; 5, first anal vein; 6, radial sector, P, pterostigma;
A, arculus: Op a^, a^, 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.

F. With three ocelli Perla (in part).

FF. With only two ocelli 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 AI 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

hind wings not expanded Isopteryx.

AA. With the cerci rudimentary or wanting.

B. Second segment of the tarsi equal in length to the others; rudimentary cerci
present T.eniopteryx.

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.

Leuctra.

The genus Perla (Fig. io8) 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 pygnma, which is grayish black. The
female is 9 mm. (about f in.) long, with an expanse of wings of 16 mm.
(about I in.), while the male is but 4§ 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-

■l^-^^-lAlel l-n^ar

ming over the surface in zigzag Hnes or sweeping curves, stopping still
in midair, and starting again, seeming never to rest, nor even to tire. Poised

75

76

Dragon-flies and Damsel^flies

in the air, with the sunUght dancing on its trembhng 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

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-
fly that is making short dashes in different
Fig. 1 10.— 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

the weed-choked slimy depths of the pond, Fig. m

he would see the dragon-flies in another

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,

The young (nymph) of
a dragon-fly. (From Jenkins and
Kellogg; twice natural size.)

Dragon-flies and Damsel-flies 'j'j

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

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

prey, consistmg of water-bugs, May-fly larvae, small crustaceans, mol-
lusks, and any of the numerous aquatic insect larvae, 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.
113) are known in North America, about two thousand having been found
in all the world. In any single locality where conditions are at aU 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
salt 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 which regularly passes the winter in adult stage, and

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 and along the shores of a pond may
be imaginarily divided into zones one
above the other, each zone characterized
by the presence 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

Fig. 113. — Damsel-flies
winged dragon -flies),
size; from life.)

(narrow-
(Natural

Dragon-flies 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, cHnging 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 sahent 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 ahke indeed in the damsel-flies. The venation
is of the general type known as net-veining (Fig. 114b), 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

8o 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 i8o°, 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
antennae, 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 difl'erent 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 ii8 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-flies and Damsel-flies 8 1

the thorax is transkicent 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 Hve 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 lanai (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 hunting 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 role 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

Fig. 114a.

Fig. 1 146.
Stages in the development of the giant dragon-fly, Anax Junius, a, youngest stage; b,
c, and d, older stages, showing gradual 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-flies

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 A rgia 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
the larger nymphs, Needham having seen the
nymphs of one species seize and devour young
brook-trout as long as themselves.

The young of different species differ consider-
ably in size, shape, and duration of their nymphal
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

Fig. 115. — The young
(nymph) of a damsel-
fly (narrow-winged dra-
gon-fly), Lestes sp. The
three leaf -like processes
at the tip of the abdo-
men are gills (Twice
natural size.)

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 Ught
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
gifls are in six longitudinal bands, each consisting of two thin rows of small
plates or tufts of short slender papillae. 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 Libelluhds 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
crawl out among the weeds and grass
of the shore for some distance before
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. ii6). 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

Fig. ii6. — The issuance of an adult white
tail, Plathemis trimaculata. (After Need-
ham; natural size.)

Fig. 117. — Adult and last exuvia of the whitetail, Plathemis 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

Adult and last exuvia of the damsel-
fly, Lestes uncata. (Natural size.)

cast nymphal skins or exuvicX, clinging here and there to stones and plant-
stems. Attached to these exuvice 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 Fig. 118
and capturing of prey, and often
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:

"If 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
-A home-made water- the apparatus required,
collecting dragon-fly "A rake will bring ashore those other
(After Needham.) ^y^^^is 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

Fig. iiq.-
net for
nymphs.

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
Fig. 1 20.— a simple aquarium for rear- ^ymphs to maturity. Place them in a
ing dragon-fly nymphs. (After Need- •' ^ •'

ham.) wooden pafl 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 dried 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 lip of the abdomen. A couple ot 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.

i %v / /■ / ■■■ A. P

Fig. 121. — Diagram of venation of wing of dragon-fly. a, antecubitals; b, postcubitals;
N, nodus; P, pterostigma; A, arculus; t, 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 Zygopter.a.
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. 121).

Family Calopterygid^.
Wings with not more than three, usually two, antecubitals (Fig. 121).

Family Agrionid,e.
Key to Families (Nymphs).

Basal segment of the antennae extremely elongate Family Calopterygid.e.

Basal segment of the antennae short, subrotund Family Agrionid^.

The family Calopterygidae 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 Hetaerina, 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,

90

Dragon-flies and Damsel-flies

Fig. 122.

-The black wing, Calopteryx
macula ta.

(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 fiat
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-
cessfully, to tear and damage
his wings."

The best known representative of the other genus is a perfect master-
piece of insect beauty and grace. Entomologists know it as Hetcerina
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-fiy 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
them come together and chng in
graceful festoons to the drooping willow branches. Then they look like
strings of rubies, or of warm red flowers or seeds.

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

Fig. 123. — The ruby-spot, Hetcerina
americana.

Dragon-flies and Damsel-flies 91

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
09- 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.E.

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.

JESCUNIBM.

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

ridges 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).

Antennae 7-segmented, tarsi 3-segmented, climbing nymphs. ..(Eschnid.e.
AntenucB 4-segmented, the fourth segment rudimentary; fore tarsi 2-seg-

mented; burrowing nymphs Gomphid^.

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

Two stout teeth with a notch between them on the middle lobe of the under-
lip (labium) '. Cordulegasteridj!:.

A single median tooth on the middle lobe of the under-lip LibelluliDjE.

92 Dragon-flies and Damsel-flies

The family Cordulegasteridae 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 Gomphidae 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 (Libellulidoe, 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 Gomphidae. 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 brevistyliis
is a large black-and-yellow species common in the East, South, and Middle
West. The nymph has an unusually wide, flattened body.

The /Eschnidse 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 ceaseless
warfare on the mosquito hosts. It
can be recognized by its clear wings,

large size (wings over two inches long),

, , . , , , , , , Fig. 124a. Fig. 1240.
and bright-green thorax and head, the

, ^. , . ,1 r . Fig. 124a. — Top of head, showing charac-

latter bearmg on the upper front a ^^^.^^ mark in front of eyes, of Anax

round black spot surrounded by yellow, Junius. (Enlarged.)

the yellow encircled by a dark-blue Fig. 1 24^. -Top of head, showing charac-
•' •' teristic mark in front of eyes, of ALSckna

ring (Fig. 124(7). A still larger member constricta. (Enlarged.)

of this family is the great "hero"

dragon-fly, Epiccschna 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 .Eschna
constricta, about the size of Afiax Junius, reddish brown marked with bright
green, and with a black T spot on the upper front of face (Fig. 124^). 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 Libellulidai 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, ^Eschna
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-

94

Dragon-flies and Damsel-flies

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

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

and well-marked species of Libellula are L. hasalis, 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

Fig. 126. — Libellula semi-Jasciala. (After Needham; natural size.)

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

Dragon-flies 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. semi-jasciata, whose complex wing-markings are

Fig. 127.

-The water-prince, Epicordnlia 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
laceyata is a familiar species. The water-prince, Epicordulia princeps (Fig.

5. — 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

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

Fig. iT,o.—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. WiUiamson 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

<s

Fig. 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 VII

THE TERMITES, OR WHITE ANTS (Order Isoptera)

NCE when camping in the King's River
Canon, one of the great vertical -walled, flat-
floored canons 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 Californ'a 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

lOO

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.

Fig. 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 Httle, 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, setthng 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

lOI

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
termites in the popular mind. The termites
not only are not ants, but are neither nearly
related 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
ol' individuals. The termites are either blind
or have only simple eyes, have slender an-
tennae 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 ihe
extraordinary development of their jaws,
which are long and scissor-like; their heads
are also much enlarged and strongly chitin-
ized. The food of all consists mainly of
dead wood, and of curious pellets excreted
from the intestine and called "proctodeal

food." In addition some species attack live wood and even soft plants,
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

Fig. 1.33. — Termite shed on
cocoanut-palm in Samoa. From
the shed note numerous tunnels
leading down to the ground, in
which is the main nest of the
community; a few tunnels (only
one visible in the picture) lead
up the trunk of the tree. (Pho-
tograph by the author.)

I02 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 absent 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

without veins 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 flavipes (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.
Fig. 134. — T. flavi- Jt makes its nest in or under old logs and stumps.

Marlatf natural Sometimes it mines a nest in the beams and rafters of
size indicated by old houses. Howard records the serious injuries done
^"^■■' 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 Uving 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 T. 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. 135c) 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 I in. in length. The four wings are of about
equal size, and when the insect is in flight expand about f 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 fl3'ing
some time and to some distance, the insects alight on the ground and shed
their wings (Fig. 1356). 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 oS, 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
females pair, and each pair
probably founds a new colony.
Perhaps some of the pairs
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 caUed com-
plemental males and females. These are forms which, in case of the loss
of the real king or queea, can develop into substitute royalties. Whether such
forms exist in all flavipes colonies does not seem to be certainly known.
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, afl of which are limited to the
southern, southwestern, and Pacific states, three, representing all of the

Fig. 135a. Fig. 135&.

Fig. 135a. — T. flavipes, winged male. (After Mar-

latt; natural size indicated by line.)
Fig. 135&. — T. flavipes, complementary queen.

(After Marlatt; natural size indicated by line.)

I04

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 castaneiis, 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 angusticollis 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 f in. long, the soldiers
(Fig. 136) § in., and the kings and queen (Fig. 137) a little less, while the
wings expand i\ 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

Fig. 136. Fig. 157.

Fig. 136. — The large termite of California, Termopsis angusticollis; workers, young,

and a soldier. (From life; natural size.)
Fig. 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 Cafion 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- 47-63.

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 notecT 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 oft' 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

io6

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 hve 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 heUicosus, 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
inches long. A similar specimen is to be found
in the natural-history museum of the University
of Kansas.
The enormous number of individuals in a great village of nests cannot

Fig. 138. — Worker and
queen of Termes red-
mani. (After Nassonow;
natural size.)

* 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 sahva. 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:
"Instead 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

io8 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 tibiie 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 lucijugus 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 loo 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 stomoda^al 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 larva? 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 larvae 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-
coUis Heath has experimented by feeding members of
various colonies, both with and without primary royal
pairs, "on various kinds and amounts of food — procto-
deal 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 p ^ , .

Embiida?, of doubtful affinities, is represented by not iexana. (After
more than twenty hving species, of which but four Melander; en-
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 iexana, is about one-quarter

1 1 o 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 VIII

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-hce, or
dust-hce. 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 antennae, 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

1 1 2 Book-lice and Bark-lice ; Biting Bird-lice

there is a peculiar little chitinized structure, which may be called the
oesophageal sclerite (Fig. 145). This structure is situated in the floor of
the pharynx (forward end of the oesophagus), and has some special function
in connection wfth the peculiar food-habits. It was first described by Bur-
gess, and was for a long time supposed to be peculiar
''J^T } to the book-lice alone. But, in a study of the mouth
structure of the biting bird-lice (Mallophaga) , I found
an almost identical oesophageal 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
Fig. 140. — A wingless order,
book -louse, Atropos sp. -pj^g Q^der Corrodentia as at present known con-
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). . .PSOCID.E.
Wings wanting or present as small scales or pads; ocelli absent . — Atropid.^.

The winged Corrodentia or Psocidae (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 ^^^ i4i._a winged
general color. The small white eggs are laid on the bark-louse. (Thirteen
surface of the bark in small patches, and in a cluster ^^™^^ '^^^"'"^^ ^'^^-^
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.

2. Tarsi 3-jointed 3.

Tarsi 2-jointed 4-

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

3. Discoidal cell closed Myopsocus.

Discoidal cell open , .' Elipsocus.

4. Discoidal cell closed 5.

Discoidal cell open 6. 2

5. Discoidal cell four-sided. Psocus. t ^.<;)>i'''ZI^^^^^--'^ " ^^ >^\ «?"

Discoidal cell five-sided.

Amphigerontia.

6. Third posterior cell elliptical.

C.ECILIUS.

Third posterior cell elongated.

PoLYPSOCUS ^'*^' ^4^' — Diagram of venation of a Psocid.
„, . , , . 11 . , ' d, discoidal cell; \a, 2a, -la, posterior cells.

Third posterior cell absent. ^^^^^^ g^^^^ -,

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

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

1. Meso- and metathorax united, no wings Atropos.

Meso- and metathorax separate, rudimentary wings 2.

2. Wings with veins Dorypteryx.

Wings veinless, in form of squamte or tubercles 3.

3. Squamas small, hyaline Clothilla.

Squamae in the form of scars Lepinotus.

Small tubercles in the place of squamas 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. Atropos divinatoria is the species usually
found in books. It is about i 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
found on mammals, and vice versa.

The injury done to the hosts by these parasites
consists not in the character of the food-habits, but
chiefly in the irritation of the skin caused by the
scratching of the sharp-clawed little feet of the insects
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 in a few weeks reach

Fig. 143. — A biting bird-
louse, Nirmiis prce-
stans, from a tern,
Sterna maxima. (Pho-
tomicrograph by
George E. Mitchell;
natural size, one-twelfth
inch.)

Book-lice and Bark-lice; Biting Bird-lice 115

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 antennae are short and in one suborder (see classifica-
tion key) are wholly concealed in pits or grooves on the under side of the

Fig. 144. — Immature and adult stages of the biting bird-louse, Lipeuriis forficidatiis,
taken from a pelican, i, adult female; 2, adult male; 3, very young stage; 4,
older immature stage. (Natural size of adult specimens ^s in.)

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

Perhaps the oddest thing about the structure of the Mallophaga is the
presence in the throat of the curious oesophageal 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 oesophagus! The bark-
lice and book-lice, which have a similar oesophageal sclerite, also bite off
and swallow small bits of hard, dry organic substance.

I 1 6 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 puzzHng problem of their
distribution. The problem in its largest phase is this: the species of Mal-
lophaga are, in a 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 oiT 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

sclente, lateral aspect, from a biting _ .

bird-louse, Euryjnopetiis taurus, from mating and nesting, and when gregarious
an albatross. (Greatly magnified.) |^jj.^g ^^^^^ ^^ p^j-^j^ 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. Docophoriis
lari has been found on thirteen species of sea-gulls, and Nirmiis lineolatiis
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 iderodes 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 platystomiis is
common to several hawk-species, D. cursor to several owl-species, D. excisus
to several swallows, D. californiensis to several woodpeckers, and Z). com-
munis to several passerine birds. In the other genera of Mallophaga are

Fig.

-Bonnet-shaped pharyngeal

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
Hving European birds to this country, and the few species of cicumpolar
range, there remain to be accounted for about 100 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,
Docophorns pertusus is common to the European coot {Fulica atra) and
the American coot {Fulica americana); Nirmus pileus is common to the
European avocet {Reciirvirostra avocetta), and to the American avocet
{Recurvirostra amcricana) ; Lipeurus jorficulatus is common to the European
pelican {Pelecanus onocrotalus) and to the American pelicans (Pelecanus
erythrorhynchus and P. calif ornicus), 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;» tra-

1 1 8 Book-lice and Bark-lice ; Biting Bird-lice

hecula, triangular membranous processes projecting laterally from the head and situated
one in front of each antenna; temples, 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; lahral
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 antennae; no palpi; mandibles

vertical Ischnocera.

With short clavate or capitate, 4-segmented antennae concealed in shallow cavities
on under side of head; 4-segmented palpi; mandibles horizontal.

Amblycer.'V.
Key to Genera of the Suborder Ischnocera.
A. With 3-segmented antennae; tarsi with one claw; infesting mammals only (family

TrichodectidcE) Trichodectes.

AA. With 5-segmented antennae; tarsi with two claws; infesting birds only (family
Philopterida).
B. Antennas alike in both sexes.

C. Front deeply angularly notched Akidoproctus.

CC. Front convex, truncate, and rarely with a curving emargination, but never
angularly notched.
D. Body broad and short; head with large movable trabeculae.

E. Forehead with a broad, transverse membranous flap, project-
ing beyond lateral margins of the head in the male, barely

projecting in the female Giebelia.

EE. Without such membranous flap Docophorus.

DD. Body elongate, narrow; head with vers'- small or no trabeculae.

NiRMUS.

BB. Antennae differing in the two sexes.

C. Body wide, elongate oval to suborbicular.

D. Temples rounded; tip of abdomen with shallow, curving emargina-
tion; antennae 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. Antennae and legs long; a semicircular depression in front of

moutli LiPEURUS.

DD. Antennae and legs short; depression in front of mouth narrow and
elongate, e.xtending as a furrow to the anterior margin of the head.

Oncophorus.
Key to Genera of the Suborder Amblycera.

A. Tarsi vrith one claw; infesting mammals only (family Gyropidce) Gyropus.

AA. Tarsi with two claws; infesting birds only (family Liotheidce).
B. Ocular emargination distinct, more or less deep.

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

C. Forehead evenly rounded, without lateral swellings; antenna; 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 L^mobothrium.

BB. Ocular emargination absent or very slight.

C. Sides of the head straight or slightly concave, with two small laterally

projecting labral lobes 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 coxje with very long lobe-like append-
ages 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
I mm. (^ig- in.) to 1.5 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 Lipeiirus
variabilis, 2 mm. (y^g- in.)
long and slender, with dis-
tinct black markings on
the otherwise smooth,
white body.

Ducks are infested by
several species. Com- ^^^ ^^^ p^^ ^^^

mon among them is the Fig. 146.— The biting chicken-louse, Menopon pallidum.
little Docophoriis icterodes _ (After Piaget; natural size, i to 1.5 mm.)

(Fig. 147), I mm. (uV i"-)
long, with head curiously
expanded and rounded in front, darkish-red head, and thorax with darker

icterodes. (Natural size indicated by line.)

I20 Book-lice and Bark-lice; Biting Bird-lice

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

Fig. ISO.

Fig.

Fig. 152.

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

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

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

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

Fig. 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,
Lipeuriis 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 i 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 ^4flonkeys are troubled
by two or three species, of which T. pilosiis, a hairy form with antenna? rising
near the front of the head, and T. pariim pilosiis (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

153- Fig. 154.

Fig. 153. — A biting louse of gulls, Nirmus felix, male. (Natural size indicated by line.)
Fig. 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
most 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, Lcemobothnum 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 Nirmns
jelix (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)

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 shriUing 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

I 24 Cockroaches, Locusts, Grasshoppers, and Crickets

keep up
offers its

the chorus. At home, in house and garden, the domestic cricket
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

Fig. 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

Fig. 156. — The immature stages of a locust, Melanoplus jemur-rubrum. a, just hatched,
without wing-pads; h, c, d, and e after first, second, third, and fourth rnoultings
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 AcridiidEe, locusts and
grasshoppers with short antenna;; Locustidae, meadow green grasshoppers

126 Cockroaches, Locusts, Grasshoppers, and Crickets

and katydids, all with long thread-like antenna?; and Gryllidae, the crickets.
The three silent and walking or running families are the Blattidae, cock-
roaches; Mantidae, praying-horses and soothsayers; and Phasmidas, 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.e.

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; antennae usually shorter than
body; pronotum usually longer than any other body segment; anal cerci

jointed (Praying Mantes.) Mantid^.

Fore legs not fitted for grasping; antennae usually longer than body; pronotum

short (Leaf -insects and Walking-sticks.) Phasmid.i:.

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.
Antenna; 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.) ACRIDIIDvE.

Antennaj much longer than the body, delicately tapering; tarsi 3- or 4-segmented;
auditory organs usually near the base of the fore tibise; 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.) Locustid^.
Tarsi 3-segmented; ocelli variable; ovipositor usually exserted and forming a
nearly cylindrical straight needle, the tip somewhat expanded.

(Crickets.) Gryllid.e.

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-evadint^
guests. From Mazatlan, Mexico, a naturalist sent me quarts of large native
American roaches (Periplaneki 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 Blattida^, 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 ^^^- ^S7- — £gg-case of
'-T'l- ii- i. c^^ J r i-'i.- 1 1 cockroach. (Three times

wmgs. 1 he mouth-parts are fitted tor bitmg hard natural 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 i| 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 qusrter 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,
Ectohia gennanica (Fig. 158), about half an inch long, and pale yellowish
brownish with a pair of distinct black longitudinal stripes on the pro-

Fig. 158. Fig. 159. Fig. 160.

Fig. 158. — The croton-bug, or German cockroach, Ectohia gennanica. (Twice natural

size.)
Fig. 159. — The black beetle, or Oriental cockroach, Periplaneta orientalis. (One and

one-half times natural size.)
Fig. 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 di.stribution. 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 plains. It is the
commonest cockroach in England and Europe. The native outdoor species
most familiar in this country is the common wood-cockroach, Ischnoptera

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-

FiG. 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 locale for the insects, but the abundance of prey here
in summer-time makes it a good feeding-ground.

The family Mantidc-e 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 2^ inches long.

Slingerland has collected a num-
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 five hundred

years ago, says: "They are called

Mantes, that is, Joretellers, 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 Fig. 163. — Egg-case of praving-mantis,

famine, as Cslius the Scoliast of ^^'""'' ''^TT' "'"' T""' rST'"f
' ■^'^ ^^ arrangement of eggs inside. (Natural

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-

FiG. 162. — Egg-cases of the praying-
m-antis, Mantis religiosa. (After
Slingerland; natural size.)

Cockroaches, Locusts, Grasshoppers, and Crickets i 3 1

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 Fig. 164. — The walking-stick, Diaphe-

H-. ■ ■ ■ romera jemorata.

it mjures you ni any way,

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

tell 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-
midse. 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 jemorata (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. Fernorata 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 Phasmidae occurring in the United States may be distin-
guished by the following key:

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

Bacillus.

Cockroaches, Locusts, Grasshoppers, and Crickets 133

Antcnnre with many segments, and longer than the fore femora.

Mcsothorax twice as long as prothorax Anisomorpha.

Mesothorax no longer than prothorax Tinema.

Tibias without groove at tip, as above described.

Hind femora with one or more distinct spines on the median line of the under side

near the tip Di apheromera.

Hind femora without such spines.

Head, especially in female, with a pair of tubercles or ridges on the front between

the eyes 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 Acridiidae, which
are known in the United States but three or four can be fairly called
migratory, and of these the Rocky Mountain locust, Melanopliis sprelus, is
the most conspicuous. The lesser migratory locust, Melanopliis atlanis,
does much injury in New England and other eastern states, while the
pellucid locust, Camnula pellncida, is a migratory species that often does
much harm in CaHfornia 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 Acridiidae, 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-

„ . T w 1.1 WW. • pearance and habit. The body

Fig. 105. — Locust from lateral aspect (left wings f •'

removed), showing (ao.) auditory organ, is rather robust, the head is set
(Natural size.) ^,^1-]^ j^g joj^g g^^is 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 antennae 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 pj^^g^^Locust impaled on
across a thickened and ridged longitudinal vein thorn by shrike (butcher-
on the outer surface of the wing-covers. When ^^''^^- (Natural size.)
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-

FiG. 167. — The red-legged locust, Melanoplus jemiir-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 Acridiidae 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 Tettigin^.

Pronotum not extending back over abdomen or only slightly; tegmina usually well
developed (sometimes short or wanting).
Prosternum (ventral aspect of prothorax) with a prominent thick conical or cylindrical

spine AcRiDiiNiE.

Prosternum not spined (sometimes a short, oblique, inconspicuous, obtuse tubercle).

Face very oblique Tryxalin^.

Face nearly or quite vertical (Edipodin^.

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

Cockroaches, Locusts, Grasshoppers, and Crickets 137

Melanopliis spretiis. 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

Fig. 168. Fig. 169.

Fig. 168. — The lesser migratory locust, Melanopliis atlanis, female. (After Lugger;

natural size indicated by line.)
Fig. 169. — The differential locust, Melaiioplus 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 milUons 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

Fig.

170. — The two-striped locust, Melanophis hivittatus, 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
voung "hoppers" appeared in the spring they could be crushed by heavy

Fig.

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. Fig. 175.

Fig. 172. — The emarginate locust, Schistocerca emarginata, male. (After Lugger; nat-
ural size.)

Fig. 173. — The pale-green locust, Hesperotettix pratensis, female. (After Lugger;
natural size indicated by line.)

Fig. 174. — The short-winged locust, Stenobothrus curtipennis, female. (After Lugger;
natural size indicated by line.)

Fig. 175. — The sprinkled locust, Chloealtis 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-riihrum
(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 tibiae 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. allanis (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. difjerentialis (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. bknttatus (Fig.
170), nearly as large but readily distinguished by the pair of longitudinal

Fig. 176. Fig. 177. Fig. 178.

Fig. 176. — The short-winged green locust, Dichromorplia viridis, female. (After Lugger;

natural size indicated by line.)
Fig. 177. — The spotted-winged locust, Orphida pelidina. (After Lugger; natural size

of male 16-19 mm., of female, 20-24 mm.)
Fig. 178. — The Carolina locust, Dissoskira 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 bivittatiis ranges far to the north, being one
of Minnesota's destructive species.

Among the other genera of the subfamily Acridiinae 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,

Fig. 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. rubiginosiim, with light dust-red body and opaque tegmina, are
the common eastern representatives of this genus. Both are large and
striking forms.

The subfamily Tryxalin^e 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,
Stenohothrus 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
Fig. 180.— Young coral-winged locust, and dodging usually save it from
Hippiscus tuberculatus. (After Lugger; capture despite its poor flying and
natural size indicated by line.) , . ^, 7 , , ,

leaping powers. The sprmkled

locust, Chlivaltis 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 Achtinim 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 obhque. 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 (Edipodina^ is well represented in the United States,

Fig. 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 1^-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

Fig. 182. — The yellow-winged locust, Arpltia
sulphiirea. (After Lugger; natural size of
male 23-26 mm., of female 28-30 mm.)

"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,
tuherculatiis (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
the air. The genus Arphia,
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-
thopiera, 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
in the West. The green-
striped locust, Chortophaga

Fig. 183. — Arphia tenebrosa. (After Lugger; nat-
ural size indicated by line.)

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

Fig. 1S4. — The green-striped locust, Chortophaga viridifasciata, form virginiana, female.
(After Lugger; natural size indicated by line.)

Fig. 186.

Fig. 187.

Fig. 185. — The green-striped locust, Chortophaga viridifasciata, form virginiana, male.
(After Lugger; natural size indicated by line.)

Fig. 186.— The clouded locust, Encoptolophus sordidus, male. (After Lugger; nat-
ural size indicated by line.)

Fig. 187. — The pellucid locust, Camnula pelliicida, female. (After Lugger; natural
size indicated by hne.)

146 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 i inch (male) to i^
inches (female) long, and have a distinct sharp little median crest on the

Fig. 190.

Fig. iqi.

Fig. 188. — Barren-ground locust, Spharagemon holli, male. (After Lugger; natural size
of male 20-22 mm., of female 27-33 rnn^-)

Fig. 189. — Spharagemon collare, race scudderi, male. (After Lugger; natural size in-
dicated by line.)

Fig. 190. — The long-horned locust, Psinidia jenestralis, male. (After Lugger; natural
size indicated by line.)

Fig. 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 famihar 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)
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 Trimero-
tropis sp. in Colorado
showing this whole
range of ground
coloration.

Fig. 193.
(After Lugger; natural size indicated by line.)

Fig. 192. — Mestohregma cincta, male

Fig. 193. — The maritime locust, Trimerotropis maritima, female
ural size indicated by line.)

(After Lugger; nat-

The subfamily Tettiginae includes the strange little Acridiids known as
"grouse-locusts.". They are all under f inch in length, and most of
them are less than h 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. 105. Fig. 196.

Fig. 194. — Nomotetlix parvus. (After Lugger; natural size indicated by line.)
Fig. 195. — Tettigidea lateralis. (After Lugger; natural size indicated by line.)
Fig. 196. — Tettix granulatus, and pronota of two varieties, (.\fter Lugger; natural size
indicated by line.)

infrequently seen except by persistent students. They vary much in colora-
tion and sHght 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 Tettix
gramdatus (Fig. 196), slender, length about
\ inch, and with the narrow pointed pronotum
extending beyond the abdomen. This species
hibernates among rubbish and loose bark, but
is more or less active on warm winter days.
It is plentiful all through the rest of the year
on its feeding-grounds. T. ornatiis (Fig. 197) is a shorter, more robust
species, and is marked with black spots and indefinite yellow blotches as

Fig. 197. — Tettix omatus. (After

Lugger; natural size indicated

by line.)
Fig. 198. — Paratettix cucullatus.

(After Lugger; natural size

indicated by line.)

Cockroaches, Locusts, Grasshoppers, and Crickets 149

indicated in tlie figure. In the genus Tettigidea the antennas have from
15 to 22 segments, while in Tettix they have only 12 to 14 segments. Tet-
tigidea lateralis (Fig. 195) is a common species yellovi^ish brown in color,
more yellowish underneath. It is rather robust and the pronotum extends
beyond the tip of the abdomen.

Included in the family Locustidae 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-
diidae, but not to any of the
members of the family whose
scientific name is Locustidae.
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 r? t, ji ■ j 1 ,■ 1 1 . r • 1

-' riG. igg. — 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 antenna?, 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,
the commonest and most wide-spread species
being Crytophylliis concavus (Fig. 200).
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"

Fig. 200. — Broad-winged katydid,
CyrtophyUits concavus, male.
(After Harris; natural size.)

Cockroaches, Locusts, Grasshoppers, and Crickets 151

Fig. 201. — Cyrtophyl-
liis concavus sp.

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

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. oblongi folia (Fig. 202),

is 2 inches long to tips of folded
wings, while the round - winged
species, A. rotundijolia, is i\ in-
ches or less in length. These
katydids prefer bushes and tall
weeds or even grass-clumps to
tree-tops. Oblongijolia is said by
McNeill to make a "quick shuf-
fling sound which resembles
' katy ' or ' katydid ' very slight-
ly," while the song of rotun-
dijolia 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.

Fig. 202. — The oblong leaf-winged katydid,
Amblycorypha oblongijolia, female. (After
Lugger; natural size.)

Fig. 203. — Angular-winged katydid, Microcentrum laiirifolium, 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. laurijoliiim (Fig. 203) is said to sound like tic repeated from
eight to twenty times, at the rate of four a second. The eggs, of which each
female lays from 100 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 fiat eggs overlap each other in their own row. The young
hatch in spring and, slowly growing, moulting, and developing wings, reach
full size and maturitv by the middle of the summer.

Fig. 204a. Fig. 204&.

Fig. 204a. — The fork-tailed katydid, Scudderia jiircala, female. (After Lugger; nat. size.)
Fig. 2046. — The fork -tailed haXydid, Scudderia jnrcata,Tadi\e. (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 i^
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. Fig. 206.

Fig. 205. — Scudderia pistillala, female. (After Lugger; natural size )
Fig. 206.— Scudderia pistillala, 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-

FiG. 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.

Fig. 208. Fig. 209.

Fig. 208. — The sword-bearer, Conocephalus ensiger, male. (After Lugger; nat. size.)
Fig. 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 antennae longer than the body. These antennae readily distinguish
them from any of the locusts (Acridiidae) 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
Fig. 210.— a common meadow grasshop- long, slender, straight or angled, sword-
per, Orchelimum vulgare, male. (After like ovipositor; Orchehmum (Figs. 209

Lugger: natural size indicated by line.) a \ ^-i ^ ^ j v.

^^ ^ 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

Fig. 211. — The lance-tailed grasshopper, Xiphidium attenuatiim, 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. Fig. 213.

Fig. 212. — Udeopsylla robusta, female. (After Lugger; nat. size indicated by line.)
Fig. 213. — The spotted wingless grasshopper, Ceuiophilus macidatiis, female. (After
Lugger; natural size indicated by line.)

The family Locustidae includes numerous wingless forms, some with
no remaining trace of wing-covers or wings, some with rudimentary or scale-

Cockroaches, Locusts, Grasshoppers, and Crickets irr

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

Fig.

214.

-Diestrammena mannorata, 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,

Fig. 2JS.— 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,

Fig. 216. y^^ _,^^

Fig. 216.— The shield-backed grasshopper, Allanlicus pachymerus, male. (After Lue-

ger; natural size indicated by line.)
Fig. 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 bhnd or have the eyes much reduced. One of these cave-crickets,
Hadoenuciis siibterraneus, 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 duU-

FiG. 218. — The western cricket, Anabrus pttrpurascens, 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 .4. 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

(

Fig. 219. Fig. 220.

Fig. 2I(). — The western cricket, Anahriis purpurascens, female. (After Lugger; nat-
ural size.)
Fig. 220. — The Jerusalem cricket, Stenopelmahis 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, Anahrus

piirpurascens (Figs. 218 and 219), often occurs in

such numbers as to be very destructive to crops.

The body of this cricket is i^ inches long and

h 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

"baby-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-

lidae, that live in trees and are pale greenish white, fig. 221. -A common

and others that burrow into the ground and have cricket, Gryllus pennsyl-

broad shovel-like lore fee,, and still other curious I™; '™»|.l, i^"

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 ofTshoots of this
type, both in habit and structure. In all the
antennae 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
the wing-covers.

In the familiar black, bright-eyed, loud-voiced
house- and field-crickets the wing-covers when
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 curiously changed in course and specially thickened and roughened
to make a sound-producing organ. This organ is illustrated in Fig. 222.

Fig. 222. — Cricket and file
(part of the sound-making
apparatus). (Cricket nat-
ural size; the file greatly
magnified.)

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 dwellings, 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 luctiiosus and G. assimilis
are two native crickets which are common in houses;
they are black with brownish-black wing-covers, larger
and nifire 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
with such liquids, into which the crickets will fall and
drown in their attempts to get at the food. The most
abundant and wide-spread outdoors cricket is Gryllus
abbreviatus (Fig. 224), the short-winged field-cricket.
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 ver}-
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, Fig. 224.— The short-winged cricket, Gry/n^
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

Fig. 223. — The Euro-
pean house - cricket,
Gryllus domesticus,
female. (After Lug-
ger; natural size in-
dicated by line.)

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 Hving. 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 hve 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 ^'s^tri ed'^TouTd^!

the noonday sun along the beaten roadway, mature speci-
mens may be seen by hundreds during the days of early

autumn." They are powerful jumpers and readily evade

attempts to capture them. They feed on living vegetation

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
The observed while singing to its mate. At first the song was
mild and frequently broken; afterwards it grew impetuous,
forcible, and more prolonged; then it decreased in volume
(Natural size.) ^^^ 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

cricket, Nemobius
jasciatus; form vit-
tatus, female. (After
Lugger; about
twice natural size.)

Fig. 226. —
snowy tree-
cricket, CEcan-
thus niveus.

Fig. 227. — (Ecanihus jasciatus, female. (After
Lugger; natural size indicated by line.)

i6o 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.
X-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, (Ecantheics 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 antennae 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
destroyed. Several other species
of (Ecanthus are found in this
country; one, O. jasciatiis (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 larvae of various insects. Its eyes are also like those of the mole,

Fig. 228. Fig. 229.

Fig. 228. — (Ecanthus fasciati4S, rrnde. (After

Lugger; natural size indicated by line.)
Fig. 229. — Orocharis saltator, fermle. (After

Lugger; natural size indicated by line.)

Cockroaches, Locusts, Grasshoppers, and Crickets 1 6 1

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 Fig. 230. — The Porto

become seriously destructive because of their attacks ^ican molc-cncket,

bcapteriscus didacty-
on plant-roots. In Porto Rico a mole-cricket, Scap- lus. (After Barrett;

teriscus didadylus (Fig. 230), called "changa," dam- natural 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, T. apicalis (Fig. 231), is about

J 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

Fig. 27,1 —Tridactylus ^]^g oreneric name. They can leap amazingly, so that
apicahs. (After'' . . ■' ^ ^^'

Lugger; natural size 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.

i62 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 -j\ 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

T?Tp 2 2 2 A^ V f fft C"

cophila nebrascensis, a hemispherical wings compactly folded, both longitudi-
degenerate cricket nally and transversely, underneath them. Earwigs are
times "^ot often seen because they are nocturnal in habit,
but in some places they are rather abundant. They
are ve<^etable feeders, being especially fond of ripe fruit, flower corollas, etc.,
which they bite off and chew with the well-developed jaws and maxilla?.
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.

The commonest representative of the order in the
northern and eastern states is the little earwig.
Labia minor (Fig. 233), measuring to tip of forceps only about J 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 Httle more and a little less than | inch respectively.

that inhabits
nests. (Five
natural size.)

Fig. 233. — An earwig,
Labia minor. (Six times
natural size.)

CHAPTER X

THE TRUE BUGS, CICADAS, APHIDS, SCALE-
INSECTS, ETC. (Order Hemiptera), AND THE
THRIPS (Order Thysanoptera)

W

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 lavages 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

I

I

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
maxillae). 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
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-
tial characteristics except size and the presence of wings. 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

Fig. 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; •y., valve; 5., stop-
per; m., muscle of stopper;
s.d., salivary duct; Ir., la-
brum; b., 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.)

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 meadov^s 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 v^^orld 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
hiicopterus, 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 Jose 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 Hkely
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, unsegmentcd sucking-beak, living as parasites on

man and other mammals 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
head Homoptera.

1 66 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 m.ore or less distinct neck Heteroptera.

Of these three suborders the Parasita, or sucking-Hce, 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 fiat 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 Woodworth.) *

Proboscis seeming to rise from the middle of the sternum, or proboscis wanting; insects
less than J inch long.

Hind femora much larger than other femora (Jumping plant-lice) Psyllid.e.

Hind femora not much larger than the others.

Legs long and slender (Plant-lice.) Aphidiid.?;.

Legs short, or wanting.

Feet of one joint, or wanting (Scale-insects.) Coccid^.

Feet of two joints (Mealy wings.) Aleyrodid.^:.

Proboscis plainly arising from the head.

With three ocelli, sometimes (nymphs) with large front tibiae and no wings.

(Cicadas.) Cicadid^.
With two ocelli or none, and the front tibiae not enlarged.

Antennae inserted on head below the eyes (Lantern-flies.) Fulgorid.e.

Antennae inserted in front of and between the eyes.

Prothorax extending back over the abdomen (Tree-hoppers) Membracid^. ^

Prothorax not extending back over the abdomen.

Hind tibiae with few spines (Spittle-insects.) CERCOPiD.aE. <3

Hind tibse with two rows of spines (Leaf-hoppers.) Jassid^. ^

Perhaps no other insect-species has any single characteristic of its hfe-
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
Cicadidae, 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 Fig. 235. — The seventeen-year cicada,
.,, . • r . J J. -. Cicada septendecim; specimen at left

a tm pan with a strmg fastened to its growing sound-making organ, v.p.,
center. These sound-making organs ventral plate; /., tympanum. (Natural
of the cicadas, confined to the males — ^^^^''

"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)
black and green dog-day harvest-fly, Cicada
tibicen. The life-history of this species is not
fully known, but the insect requires, accord-
ing to Comstock, two years to t^ecome mature.
The really famous cicada is Cicada septen-
decim, the seventeen-year locust, or periodical cicada (Fig. 235). It is
about li inches long, 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

Tig. 236. — Diagram of section
of body of cicada, showing
attachment of muscles to inner
surface of sound-making
organ. (Enlarged.)

I 68 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 juices 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 igo6 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 (Membracidae) and lantern-flies (Fulgoridse)

(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

FiG_ 237. A fulgorid, Stohera by amateurs. Among the commonest of our forms

tricarinata. (After Forbes; are the candle-heads, species of Scolops, small

natural length 1 inch.) . . t • j u u -i-i. 4.u u j

msects livmg on grass and herbage, with the head
bearing a long slender upcurving projection. The tree-hoppers (Mem-
bracidae) 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. E. hinotata 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 Httle white waxen frothy masses.
A curiously humpbacked 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

.n^.

::■ ,nw^

Fig. 238. Fig. 239. Fig. 240.

^ Fig. 238. — The black-backed tree-hopper, Arthasia galleata. (After Lugger; natural

length I inch.)
' Fig. 239. — A tree-hopper, Enchenopa gracilis. (Three times natural size.)
^ Fig. 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 ^ 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 smiiU and active insects are sap-sucking leaf-hoppers, of the family
Jassidas, 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 J 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 Httle 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,"^ CicaJn/a exitiosa, i 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
oi^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,
.1 or at least to burn up in the winter any accumulated

rubbish. The rose leaf-hop-
per, ' Tr^/z/or^'Zja rosa, 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
and fall, hibernating as
adults under leaves or rub-
bish.

A common leaf-hop-

FiG. 241. Fig. 242.

Fig. 241. — The celery leaf -hopper, Cicadula 4-Uneata.

(After Lugger; natural size indicated by line.)
Fig. 242. — Two vine-hoppers, at left Erythroneura _

viilnerata, on right^£. comes. (After Forbes; much per of grass-fields is' Diedro-

en arge . j cephala molHpes, ^ 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 -j\ 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 Cercopidae.
The spittle is a viscid fluid expelled from the alimentary canal of the insects,
and beaten up into a froth by the 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 -3- inch long which occasionally occur in sufficient

numbers to do some injury to grapes,

cranberries, or pasture grasses. A grape

frog - hopper, ^yl/j/^ro/'/zora ^-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-

insecf; Clastoptera protens, 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.

Looking like miniature cicadas, but
belonging to a diiTerent family, and really
more nearly related to the aphids or true
plant-lice, are the Psyllidae, or jumping
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 Aphidiidae,
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,

■'^iigC.

Fig. 243. — The spittle-insect, ApJiro-
phora, showing stages of froth
production. (After Morse; en-
larged.)

172 Bugs, Cicadas, Aphids, and Scale-insects

^ __ are

Fig. 244;-The southern grain plant- ^f ^^ plant-lice which infest

louse, loxoptera gramineum, winged ^
migrant. (After

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

plant
ingec
Pergande; much crop-plants, the extraordinarily ruinous
enlarged.) grape-phylloxera, for example, the apple-

tree root-lou.se, 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-
stantly eaten in spring and summer by
eager predaceous insects, such as lady-
bird beetles, certain syrphid-fly larva;
and aphis-lions (larvae 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

Fig. 245. — The southern grain-louse,
Toxoplera gramineum, wingless. A,
female; B, young nymph; C, older
nymph. (After Pergande; much en-
larged.)

Bugs, Cicadas, Aphids, and Scale-insects 173

mm. in width, an easy calculation shows that these conceivably possil)le 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 remarkable 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 (i.e., 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 generations. But toward the end of the
season, when the first cold 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. 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.

Fig. 246. — Bodies of
aphids which have been
killed by Hymenoptcr-
ous parasites, the adult
parasitic flies having
emerged from the small
circular holes. (En-
larged.)

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-
ing variation as regards wings
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. Aphis 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

Fig. 247. — Rose-aphids visited by ants,
size; from life.)

(Natural

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 deUcate 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 Httle 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 brnnneus, 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 Card,
the other in the southwest near Bordeaux. In 1868, when the nature of
the pest was understood, it had already invaded considerable areas. The

Fig. 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 Riibsaamen; 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 177

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 tirst 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: (i) 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

1 78 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

Fig. 249. — Roots and rootlets of grape-vine infested by the phylloxera. (After Ritter
and Riibsaamen; 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 -j'-g- 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 tw^o 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 sHght as to be
imperceptible. The European vine, Vitis vinifera 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

I 80 Bugs, Cicadas, Aphids, and Scale-insects

scrubbed with a carbolized solution of soft soap (soap 10 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 Coccidae, 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 Aphididas, 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, antennae, 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 18 i

tunily to make easy acquaintance with one or two species at our breakfast-
tables; the t^attish, 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 extremie 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-
tennae, 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 Jose
scale, Aspidiohis 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

^, . r . J 1 . Fig. 2t;o. — San Tose scale on bark of fruit-

or China,— was first made known to ^^^^/ (After Slingerland; natural size.)

science, and named, by Prof . J. H. Com-

stock in 1880. Professor Comstock's specimens were collected in the Santa
Clara Valley near San Jose, 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 w'ell-
advised — legislation. This legislation has been directed toward restricting
its spread by (a) quarantining it at the states' borders, and {h) inspecting
orchards and nurseries for it within the state and attempting to stamp it

I 82 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 -^j 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 exuviae 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
creature, the insect itself (Fig. 252).
If adult, this degenerate female will be
seen (by examination with magnifier)
to have no distinct head, no eyes nor
antennae, 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, antennae, 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 antennae 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

Fig. 251. — The San Jose scale, Aspi-
diolus perniciosus, females and young,
on bark of fruit-tree. (From living
specimens; at left, natural size; at
right, considerably enlarged.)

* The following long quotation is made from Howard and Marlatt's " The San Jose
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, a) are rather larger than
the females, and have large purple eyes, while the females have lost their
eyes entirely. The legs and antennje 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.

"Eighteen days from birth the males change to the first pupal condition
(propupa), and the male scales assume an elongate oval, sometimes shghtly
curved shape, characteristic of the sex, the exuvia or cast larval skin show-
ing near the anterior end. The male propupas are very pale yellow, with
the legs and antennae (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 spHts 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 exuviae 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

184 Bugs, Cicadas, Aphids, and Scale-insects

Fig. 252. — The San
Jose scale, Aspidiotiis
perniciosus. a, male;
/), a d u 1 1 female.
(Much enlarged.)

with the natural reddish green of the uninjured bark. With the second
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
the scale. The scale, after the second moult, pre-
sents on the inside two longitudinal ridges run-
ning from one end to the other, touching the sides
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, antennae, 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 fuU generations are reguhirly developed,
with the possibiUty 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 Jose) scale. The females of some species
retain the eyes, antennae, 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 antennae, 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 antennae through life, but have them in reduced condition when adult,
and although capable of feeble motion, usually lie quiescent; they commonly

1 86 Bugs, Cicadas, Aphids, and Scale-insects

Fig. 253. — The fluted or cottony
cushion-scale, Icerya purchasi,
winged male and wingless
female with fluted waxen egg-
sac {es). (After Jordan and
Kellogg, much enlarged.)

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 antennae,
eyes, and legs, thus being incapable of
locomotion; they form a flatfish or convex
dorsal scale of secreted wax and of the cast
skins or exuviae 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
a single pair of wings, a pair of long antennae,
and a plump, soft, little body, usually
terminating in a single needle-like process or
in a pair of long waxen hairs. Males are
not yet known for some of the species.
Familiar examples of the first group are the mealy-bugs {Dadylopiits 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 cardinaJis (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 locaHties any injury at all.

Fig. 254.— The fluted scale, Tcerya pitrchasi, 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 figiire 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. olece, 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, antennae, 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

J 88 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, Pith'inaria inmimerahihs (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 as a shining
example. There is a host of these
armored scale-insects, and few trees or

Fig. 255.

Fig. 256.

Fig. 255. — The maple-scale, Pulvinaria innumerahilis. 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.)

Fig. 256. — Lecaniiim scales attacked by the fungus Cordyceps clavidata. (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 aiirantii (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 exuviae at one end; these belong to the widely spread species
Chionaspis pinifolice. On apple-trees often occurs a roughened shining

Bugs, Cicadas, Aphids, and Scale-insects 189

Fig. 257. — The red orange-scale, Aspidiotus
aiirantii. a, females, natural size, on leaf; b,
female, much enlarged, removed from under
waxen scale; r, the scale, composed of wax
and exuviae, much enlarged; d, just hatched
young, much enlarged; e, male, much enlarged.
(After Jordan and Kellogg.)

blackish narrow elongate curved scale, resembling a little an oyster-shell

in miniature; this is the sometimes serious apple-pest, Mytilaspis poniorum.

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
tree is made, and with this in
place hydrocyanic gas is gen-
erated under it by pouring
about 50 oz. of water into 5 oz.
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 10 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 lbs., sulphur 50 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,
crude petroleum and kerosene emulsion are the best. For use, undiluted
crude petroleum should be entirely untreated and of specific gravity of 43°
or over on the Beaume 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 J lb. of hard soap in i gal. of water and then adding 2 gals.

190 Bugs, Cicadas, Aphids, and Scale-insects

Fig. 258. — Female red orange-scale, Aspi-
diotus aiirantii. (Photomicrograph by
George O.Mitchell; much enlarged.)

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
are, when first met with, difficult to
recognize 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
(Fig. 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 jormicarum, a scale-insect. Taken alto-
gether, probably no other family of insects exceeds
the Coccidae in the extremes of strange specializa-
tions.

Closely related to the plant -lice and scale-
insects are the mealy- winged flies, constituting the
family Aleyrodidae. The adults (Fig. 262), except
of two or three of the most abundant species, are
rarely seen even by professional entomologists, but
careful search will reveal in almost any locality the
curious little box-like elliptical bodies of the young
(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

•;

Fig. 259. — Female rose-
scale, Diaspis r o see.
(Photomicrograph b y
George O. Mitchell;
much enlarged.)

Bugs, Cicadas, Aphids, and Scale-insects 191

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

Tig. 260. — The California live-oak scale, Ccrococcus ehrhonii.

Patterson; natural size.)

(,l'huK)graph by Rose

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 antenna. After a second
moulting, however, minute new legs and antennas are again to be seen, and
later the wing-pads appear, and wings, legs, and antennae 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.

Fig.

261. — The Southern California oak-scale, Cerococcus qiiercus.
(Photograph by Rose Patterson; natural size.)

All of the pupas 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

j'.-frA&i^

..^

Fig. 262.

Fig. 263.

Fig. 262. — A mealy-wing, Aleyrodes pruinosa, adult. (After Bemis; much enlarged.)
Fig. 263. — Pupa of Aleyrodes tentacidatus. (After Bemis; much enlarged.)

Fig. 264. Fig. 266.

Fig. 264. — Pupa of Aleyrodes iridescens. (After Bemis; much enlarged.)
Fig. 265. — Pupa-case of Aleyrodes merlini. (After Bemis; much enlarged.)
Fig. 266. — Vasiform orifice and Hngula 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,
Fig. 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.)

Antcnnse shorter than the head: aquatic or shore insects.

With two ocelli (Toad-bugs.) Galgulid^.'

With no ocelli.

Hind feet without claws; aquatic insects.

Prothorax overlapping the head above (Back-swimmers.) Notonectid^.

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

a tube (Water-scorpions.) Nepid^.

Without abdominal processes, or if any, short flattish retractile ones.

Hind legs broad and flat (Giant water-bugs.) Belostomatid^.

Hind legs slender Naucorid^.'^

Antennae at least as long as the head: a few aquatic forms, but mostly terrestrial.
Head as long as the whole thorax (Marsh-treaders.) Limnobatid^.'^

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 Veliid^.

Last segment of foot not divided, and the claws at the tip.
Antennae 3- or 4-segmented.

Proboscis (or beak) with three joints.

Body very long and slender (Thread-legged bugs.) Emesid.e.

Body not long and slender.

Femora of fore legs very wide (.\mbush-bugs.) Phymatid.-e.

Femora of fore legs not very wide. ^

Antennas of three segments (Assassin-bugs.) Reduviid^.

Antennae of four segments.

Feet of two joints, and body very flat (Flatbugs.) Aradid^. v

Feet of three joints.

Body flat on top (Bedbugs.) Acanthiid.e. '

Body not flat on top (Shore-bugs.) Saldid.e.

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, i).

(Leaf- and flower-bugs.) Capsid.e. ''
No 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.) Nabid^.
Fore legs not very different from the others.

Body very narrow (.Stilt-bugs.) Berytid.e.

Body not very slender.

Feet of two joints; wing-covers (of adults) resembling lace network.

(Lace-bugs.) Tingitid.e.
Feet of three joints.

Antennae 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, ,5) . . (Chinch-bug family.) Lyg.5:id.e.
Antennae 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.) C0REID.E.
Antennae 5-segmented.
Body flat above.

With few or no spines on the tibias (Stink-bugs.) Pentatomid.«.

With rows of spines on the tibiae (Burrower-bugs.) Cydnid.e."

Body strongly convex above.

Prothorax round in front and nearly straight behind.

(Negro-bugs.) Corimel^nid^. '
Prothorax hexagonal (Shield-backed bugs.) Scutellerid.t..

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

Fig. 268. — Wings of Heteroptera, showing disposition of veins in membrane character-
istic of various families: i, Capsidae; 2, Pyrrhocoridae; 3, Lygasidas; 4, Coreida:
5, Nabidae; 6, Acanthiidae. (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 Hydrobatidse, 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-

FiG. 269. Fig. 270.

Fig. 269. — Water-strider, Hygrotrechus sp., adult. (Twice natural size.)
Fig. 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

Fig. 271. Fig. 272. Fig. 273.

Fig. 271.— Broad-bodied water-strider, Stephania picta. (After Uhler ; natural

size.)
Fig. 272. — An ocean water-skater, Halobates wiil/ersdotffi, from near Galapagos Islands.

(Three times natural size.)
Fig. 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 Veliidae, 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 ^ inch long, with thin long
legs and hair-like antennae 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 Limnobatidae known
in this country.

Swimming and diving about beneath the surface are the water-boatmen
(family Corisidas) and back-swimmers (family Notonectidae). The water-
boatmen (Fig. 274) are oval, finely mottled, greenish gray and black, and
swim with back uppermost. They are all small, some only \ 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 ahke, 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 ^^^ ^^^ _^ wat^oatman, Corisa
knowledge to entomological science. Both sp. (After Jenkins and Kellogg;
water-boatmen 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 Naucoridae,
only five species of which are known in this country. The single species
found in the eastern states is known as Pelocaris jemorata, and is about
J 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 no member of the family is known.

Occasionally there will be seen resting, or swimming slowly about, at the
bottom of the pool a veritable giant bug, 2f inches long and i J 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

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 Belostomatidae. 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. The two largest 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 diJatatus, the toe-biter.

Fig. 275.

Fig. 275. — The giant water-bug or electric-light bug, Belostoma americana. (Natural

size.)
Fig. 276. — The western water-bug, Serphus sp.; male with eggs deposited on its back

by female. (Natural size.)

which is i\ to j\ inches long and f to |^ inch wide. In the East a still
smaller form, Zaitha fluminea, is common. This is a little less than i
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 Serplnis 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 Serphits 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 Nepidae, 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 halves 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

Fig. 277.

Fig. 278.

Fig. 277. — A water-scorpion, Ranatra jiisca. (One and one-half times natural size.)
Fig. 278. — Eggs of the water-scorpion, Ranatra jusca. (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.

20 2 Bags, 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 (Galgulidae) and
the smaller, soft, long-oval, long-legged, running shore-bugs (Saldidae).
One species of toad-bug, Galgidiis ocidatiis (Figs. 279 and 280), is common
all over the country and may often be found in considerable nimibers 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

-nw-

Fig. 279.

Fig. 280.

Fig. 279. — The toad-bug, Galgulus oculatus. (Three times natural size.)
Fig. 280. — Three toad-bugs, Galgulus 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 (Saldidae) are
represented by but one genus, Salda (Fig. 281), of
thirty or more species, in our country. The insects are
about y\- inch long, smooth-bodied, and narrower than
the toad-bugs, blackish with white or yellow markings,
and have long slender antennae. They prefer stream
or pond banks which are weedy or grassy and offer
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-

FiG. 281. — A shore-
bug, Salda sp. (Six
times natural size.)

good hiding-places.

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 Reduviida;. 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 it, 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 ^ to f 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, Hnt, 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, Conorhiniis sanguisugus (Fig. 282), which comes

204 Bi-igs, 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
antennae. It roams about over plants
from early summer to late autumn,
Fig. 282.-The blood-sucking cone-nose benevolently assimilating the blood
Conormnus sangmsugiis. (After Howard ■' _ °

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, Emesida. The few known species have the body very
slender and long, and the legs and antennae 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 i^ inches
long, each middle and hind leg a little more than ij 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 (Nabida?) 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 Corisciis siihcoleoptrahis. 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
^ inch long. The air-bush bug, Phyniata wolfii, a rough, horny-bodied,
yellowish-green insect with brown or blackish band across the abdomen,

is about i 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

Fig. 283.

Fig. 284.

Fig. 283. — A thread-legged bug, Emesa longipes. (Natural size.)

Fig. 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 Acanthiidae, 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

2o6 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.

Fig. 2

Fig. 286.

Fig. 28s. — The bedbug, Acanthia lectularia; young at left and adult at right. (After

Riley; natural size indicated by line.)
Fig. 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 is Lyctocoris fitchii
(Fig. 286), which preys on the larvae of certain destructive wood-bormg
beetles.

The remaining famihes, 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 foui

Bugs, Cicadas, Aphids, and Scale-insects 207

sharp stylets or lancets (maxillae 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:

Antennae 4-segmented.

Fore wings reticulated and of uniform thin substance throughout Tingitid.e.

Fore wings of various forms or absent, but not reticulated, and not of uniform thin
substance throughout.

Beak 3-segmented ; body greatly flattened Aradid.e.

Beak 4-segmented; body not greatly flattened.

Membrane (apical area) of fore wings with one or two closed cells at base, but

otherwise without veins (Fig. 268) 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) Pyrrhocorid^.

Ocelli present.

Head with a transverse incision in front of the ocelli Berytid^.

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 the base (Fig. 268) Lyg.eid^.

Membrane of fore wings with many usually forked veins springing from

a transverse basal vein (Fig. 268) Coreid.s:.

Antennae 5-segmented.

Scutellum nearly flat, narrowed behind.

Tibiae unarmed or furnished with very fine short spines Pentatomid^.

Tibiae armed with strong spines in rows Cydnid^.

Scutellum very convex and covering nearly the whole of the abdomen.

Small, black (sometimes with bluish or greenish tinge) CoRiMELiENiDyE.

Not black Scutellerid^.

The first of the families in the above table, the Tingitida?, includes the
curious small lace-bugs (Fig. 287), readily recognized by the dehcate 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

2o8 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. Th'e 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
exuviae (cast skins) stick to the leaf. The
adults hibernate under the fallen leaves
on the ground beneath the bushes. In
Cahfornia a similar lace-bug, Corythuca sp.,
(Fig. 287), infests the Christmas berry,
Heteromeles arhiitijolia, a plant whose clusters
of bright red berries take the place in Cali-
fornian Christmas-tide decorations of the
holly of the East. The eggs (Fig. 287) are
deposited in the same way as the hawthorn
lace-bugs', and the life-history is practically
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 Aradidae. 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 cinnamomens (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 all the adult flatbugs
have wings, while all the bedbugs are wingless.

Fig. 287. — The lace-bug, Cory-
thuca sp., of the California
Christmas berry, Heteromeles
arbiitijolia; at bottom, eggs on
small tubercles on leaf; above,
just-hatched young, intermediate
stage, and adult. (Eight times
natural size.)

Bugs, Cicadas, Aphids, and Scale-insects 209

The flower-bug family, CapsicUe, contains two hundred and fifty known
North American species, almost all of which, however, are small and incon-
spicuous. They mostly five 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

Fig. 288

Fig.

290.

Fig. 288.— a flalbug, Aradits cinnamomeus. (After Lugger; enlarged about six times.)
Fig. 289. — The tarnished plant-bug, Lygus prate.nsis. (Five times natural size.)
Fig. 29c. — The four-lined leaf-bug, Pmcilocapsus 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 outhne 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, Lygiis pnitensis (Fig. 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, Poecilocapsus hneatus (Fig. 290), a small bright-yellow bug with head

2 1 o 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 sHts 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 (y^j 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 Pyrrhocoridae 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 succindus (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

Fig. 291.— Redbug, Lar- young are steel-blue with a small bright-red dash on
eus succinctus. (Twice , - ,, , , , , .11, ,

natural size.) DQ.'&e. 01 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, Dysderciis 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 211

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 Lygseidae, 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 Lygaeids 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 antennae rise rather from the under
than the upper side of the head, and all of the members \'W^^fJ/ \^

of the family have ocelli (simple eyes). While most
of the Lygaeids are small and inconspicuous, a few fig. 292. — LygcBus turci-
are comparatively large and bright-colored. The ^"•^- (After Lugger;
milkweed-bug, Oncopelius 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 f 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, \
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, Blissiis leucopterns
(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 ^ 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

jTjg 2 , 'pj^g chinch- remain in the wheat until harvest (last of June to

bug, Blissus leucopterus. middle of July), when the destructive host moves into

(Nine times natural .1 r- u r j • Ti

gj^g X the fields of young and growmg 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, Sporotrichiini globtdijerum, 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 2 1 3

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 Coreidoe, 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 antennae 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 f— iiiigKai-^- % mnw n .n

about two weeks and at first are green,
but soon turn brown and grayish.
They suck the sap from the growing Fig. 294. Fig. 295.

vine, and soon stunt them or even kill Fig. 294.— A squash-bug, Anasa tristis.
^, ™, ■, ■ . . 4. 4.U (Natural size.)

them. The remedy is to protect the p^, ap^.-The box-elder bug, Leptocoris
young plants by means of frames cov- 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 femoralus, 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 tibite have a
blade-like expansion. The leaf-footed plant-bug, Leptoglossus oppositiis,
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 Coreidse is the family Berytidse, or stilt-bugs, of which but a
few species are known in this country. One of these, Zalysus spinosiis,
is common all over the country east of the Sierra Nevadas. It is about ^
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) antennae (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 Pentatomidae, 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 f inch
long, flattened, with grass-green body margined with a light yellow Une,
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 \ 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, Miirgantia

B

PROPERTY OF

ugs, Cicadas, Ajmrds^ and Scale-insects 2 1

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-

-■^liv

Fig. 296.

Fig. 297.

.ni^

Fig. 296.— The harlequin cabbage-bug, Mur:^anlia histrionica. (Twice natural size.)
Fig. 297.— The spined tree-bug, Podisus spinosus. (After Lugger; natural length,

I inch.)
Fig. 298.— a stink-bug, Pentatoma jtiniperina. (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 m 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,
Corimelcena pulicaria (family Corimelffinidffi), 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 burro wer-bugs

21 6 Bugs, Cicadas, Aphids, and Scale-insects

(family Cydnidie) 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 Pediculidse, the single
family of the suborder represented in this country. The only other family,
Polycterridae, 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. 299.

Fig. 300.

Fig. 299. — The head-louse of man, Pediciilns capitiis. (After Lugger; natural size

indicated by line.)
Fig. 300. — The body-louse of man, Pediculus vestimenii. (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

gi\-e 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 aj)pearance, 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

Fig. 301.

Fig.

Fig. 30J

Fig. 301. — The CTa.b-\ouse.oi ma.n, Phthirius inguinalis. (.'\fter Lugger; much enlarged.)
Fig. 302. — Egg of crab-louse, Phthirius inguinalis. (After Lugger; much enlarged.)
Fig. 303. — Sucking dog-louse, HcBmatopinus pilijerus 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, Hasma-
topinus, but are very similar in appearance and structure to the head-lice
of man. H. pilijerus (Fig. 303), of dogs, is about yV inch long, reddish
yellow, and with the abdomen thickly covered with fine hairs and minute
tubercles; H. eiirysternus (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. viiuli, long-nosed ox-louse.

21 8 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-

FiG. 304.

Fig. 305.

Fig. 304. — Short-nosed cattle-louse, Hamatopinus eiirysternus. (After Lugger; natural

length 1.5 mm.)
Fig. 305. — The hog-louse, HcBtnatopinus 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. spimdosus, of the rat, small, Hght yellow, and with the
head projecting very little in front of the antennae 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. aniennatus, of the
fox-squirrel, with long slender body and curious curved tooth-like process
on basal segment; H. sciuropteri, of the flying squirrel, with slender light-
yellow body, and head as broad as long, and with front margin nearly
straight; H. siituralis, 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 appUcation of a wash of tobacco-water or dilute carbohc 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-

FiG. 306.

Fig. 307.

Fig. 306. — The sheep-louse, Hamatopinus ovis, female and egg.

size of insect indicated by line; egg much enlarged.)
Fig. 307. — Thrips, Phorithrips sp. (Much enlarged.)

(After Lugger; natural

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 o^
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 -^-^ to \ of
an inch, and may be certainly known by their narrow fringed wings (when

2 20 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 tc 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
tvpe, with mandibles and maxilke 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-
phosis, but before reaching this stage well-
developed external wing-pads have appeared,
just as happens in the case of immature
insects of incomplete metamorphosis. Finally,
the peculiar character of the feet is due to the
presence of a small protrusile or expansile
membranous sac or bladder at the tip of the
tarsus, instead of claws or fixed pads, which seero,s 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

Fig. 308. — Head and mouth-
parts, much enlarged, of
thrips. ant., antenna; lb.,
labrum; tnd., mandible; 7nx.,
maxilla; mx.p., maxillary pal-
pus; li.p., labial palpus; m.s.,
mouth-stylet, (After Uzel;
much enlarged.)

Bugs, Cicadas, Aphids, and Scale-insects 221

to be expanded by becoming suddenly filled with blood, and contracted
l)y 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 (Aphidida;) , 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 tabaci), the wheat-thrips (Eiilhrips tritici), and the grass-thrips
(Anaphothrips striatus). The first of these is about ^j 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 larvae are full-

222 Bugs, Cicadas, Aphids, and Scale-insects

grown in five days, and the quiescent pseudo-pupal stage lasts icur 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

THE NERVE -WINGED INSECTS

(Order Neuroptera) SCORPION-FLIES
(Order Mecoptera), AND CADDIS-
FLIES (Order Trichoptera).

INN.'EUS, 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 et 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
Linnaean 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 Linnaean order
Neuroptera, the too aberrant ones have been gradually one by one removed,

* Aptera, from a, without, pteron, a wing; Diptera, from dis, double, pteron, a wing;
Lepidoptera, from lepis, a scale, pteron, a wing; Coleoptera, from koleos, a sheath, pteron,
a wing; Hymenoptera, from Intmen, a membrane, pteron, awing; Orthoptera, from orthos,
straight, pteron, a wing; Hemiptera, from hemi, half, pteron, a wing; Neuroptera, from
neuron, a nerve, pteron, a wing.

2 24 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 Mantispid^.

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.

CONIOPTERYGIDvE.

CC. Wings with numerous veins, and not covered with powder.

D. Antennae gradually enlarged towards the end, or filiform with a

terminal knob Myrmeleonid^.

DD. Antennse without terminal enlargement.

E. Some of the transverse veins between the costa and subcosta
forked (in all common forms), wings brownish or smoky.

Hemerobhd^.

EE. Transverse veins between the costa and subcosta simple,

wings greenish Chrysopid^.

While most of the Neuroptera are terrestrial in both immature and adult
life, one family, the Sialidse, includes forms whose larvae 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) Sialis.

Fourth segment of the tarsus simple, cylindrical; three simple eyes (ocelli).

Antennje with segments enlarged at the outer ends; hind corners of the head. rounded.

Chauliodes.

Antennae with segments cylindrical; hind corners of the head with a sharp angulation

or tooth CORYDALIS.

The larvs can be distinguished by the following key:
Tip of abdomen bearing a single long, median, laterally fringed tail-like process. .Si.^Lis.
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 infitmata, widely distributed over
this country, is a dusky brownish in-
sect about ^ inch long, often seen, with
wings closely folded, sitting on sedge-
leaves near quiet waters. The larvae
(Fig. 309), according to Needham, live
in marshy places tilled 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 crawls out of the water and at Fig. 309. — Larva (at right) and pupa (at

some little distance burrows into the Y!^} °L ^" ""^"^y- . ■^''^^" in/umata.

. (Alter JNeedham; twice natural size.)

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 i^ to 2^ inches long, and their wings

expand from 2^ to 4 inches. The wings are grayish or brownish with whitish

spots or bands, and the antennae are curiously feathered or pectinate. The

Fig. 310. — The saw-horned fish-fly, Chauliodes serricornis, laying eggs.
(After a photograph from life by Needham; natural size.)

larvae 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. corniita,

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
larvae (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-

FiG. 311.

Fig. 312.

Fig. 311. — Dobson-fly, Corydalis corniita, male, with head of female above. (Natural

size.)
Fig. 312. — Larva of dobson-fly, Corydalis corniita. (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 larvae live under
stones in the beds of streams. They are most abundant where the water

Nerve- winged Insects ; Scorpion-liies ; 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

fbnd „^„

I ant frf\-~^\ i ,f\^^y\^ p.an(.

Intjr

Ih'W

Fig. 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; H., labium; lb., labrum; ant., antenna; l.h., larval head-wall; p.h.,
pupal head-wall; ga., galea; li.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

22 8 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 larvae 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 ChrysopidcC. 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 Chrysopida; the
larvae are not aquatic as in the
family Siahdae, 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
aphis-lion (Fig. 314) has a pair
Fig. 314.— The golden-eyed or lace-winged fly, . , shirn-T^ointed slender

Chrysopa sp.; adult, eggs, larva, "aphis-lion," ^i long,^ snarp pomtea, sienoer
and pupal cocoons on the under side of leaf, jaws which are grooved on the
(Natural size.) -^^^^^ f^^g_ 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 larvae 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-Hies; Caddis-flies 229

half an inch high, fastened at the base to a leaf or twig (Fig. 314). When
the first larvae 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 Hemerobiidas are some insects whose larvae 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 larvae (about i inch long) living as parasites

Fig. 316.

Fig. 3156.

Fig. 315c.

Fig. 317.

Fig. 315. — Sisyra umhrata. a, adult; ft, larva; c, pupa. (All about five times natural size.)
Fig. 316. — Polystwchotes punctatits. (Natural size.)
Fig. 317. — Hemerobius sp. (Three times natural size.)

on or in fresh-water sponges (Spongilla). The largest members of the
family belong to the genus Polystoechotes, of which two species are known.
The commoner one, P. punctatus (Fig. 316), is about i\ 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 larvae are like the Chrysopa larvae, predaceous and
well equipped with big strong head and sharp, curved seizing and blood-
sucking mouth-parts. The larvae (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 rehcts. This is true of all the Hemerobius larvae 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 larvae are
the ant-lions, or Myrmeleonidae. The horrible pit of Kipling's story, into

Fig. 318.

Fig. 319.

Fig 320.

Fig. 318. — Larva of Hemerobius sp. covered with detritus. (From life; four times natural

size.)
Fig. 319. — Larva of ant-lion, Myrmeleon sp. (Three times natural size.)
Fig. 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-tiies ; 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-hons 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

Fig. 321. — Adult ant-lion, Myrmeleon. (Natural size.)

and the freshly-hatched larvae or ant-lions immediately dig little pits. When
the larvae 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 Myrmeleonidae includes eight genera, which are usually
grouped into two subfamihes as follows:

Antennae nearly as long as wings Ascalaphin^.

Antennae not one-third as long as wings Myrmeleonin^.

The subfamily Myrmeleoninae includes the true ant-lions with habits
in general as already described. The live genera in it may be distinguished
by the following key:

232 Nerve-winged Insects ; Scorpion-flies; Caddis-flies

Claws very stout, swollen 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) Myrmeleon.

Wings with a double row of costal areoles Brachynemurus.

The subfamily Ascalaphinse includes but three genera and six species,
the larvae 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 antennae,
knobbed at the tip, like the antennae 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 antennae 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.

Fig. 322. — An Ascalaphid, Ulula hyalina, male. (After McClendon; natural size.)
Fig. 323. — Larva of Ulula hyalina. (After McClendon; natural size, ^ 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 larvae (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 maxillae
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 Ascalaphinae may be determined by the follow-
ing key:

Eyes entire Ptynx.

Eyes grooved.

Hind margin of wings entire Ului.a.

Hind margin of wings excised 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, gauzv-
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 Raphidiida;,
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
oceUi. Twenty-four species are found scattered over Asia Minor, Syria,

^^

Fig. 324. — Raphidia sp., aduh, 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 larvae being notoriously voracious
insectivores. The larvae 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 larvae are said to find and eat many larvae of the codlin-moth,
one of the worst pests of apple-trees. Many of the codlin-moth larvae crawl
into crevices in the apple-tree bark to spin their cocoon, and there meet
the hungry snake-fly larvae.

The pupae (Fig. 324), which are not enclosed in silken cocoons like the
other terrestrial Neuroptera (ant-Uons, lace-winged flies, Hemerobians), lie

2 34 Nerve- winged Insects; Scorpion-flies; Caddis-flies

concealed in sheltered places. They are active, though, when disturbed, and
look much like the larvae, but are more robust-bodied and bear externally
the developing wings. The head, with eyes and antennae, 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 Mantispidae, 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 Mandspa has similar habits of catching hve
prey with them: it is a case of what is called by biologists "parallehsm 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 of 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 Mantispidae are known, and

^ ^ , . . ,„ these include but five American species.

Fig. 325. — Symphasts stgnata. (One . . . \ • r j •

and one-half times natural size.) Symphasts signata (Fig. 325) IS found m

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 larvae 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 Iarva3 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 ConiopterygidcT 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 larvae of a "dusty wing" species have been found feeding on
scale-insects. When full-fed these larvae 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-iiies; Caddis-flies

Simple eyes (ocelli) absent.

Wings well developed; antennae short and thick; body more than J inch long.

Me ROPE.

Wings rudimentary; antennae slender; body less than \ inch long Boreus.

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 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. calijornkus
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.
brnmalis, 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 J to f 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

Fig. 326.

Fig. 326.^A scorpion-fly, Panorpa rufescens.
Fig. 327. — Larva of scorpion-fly, Panorpa sp.

Fig. 327.

(Twice natural size.)

(After Felt; three times natural size.)

been seen to attack living injured and helpless insects. Panorpa riijesc

ens

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 larvas (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 in'o the ground, e.xcavates 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
California species is wingless) which do not resemble the scorpion-flies
much in general appearance, but have a 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 Fig.
within reach of the long, dangling legs imperils
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

,328. — Bittacus strigosus.
(Twice natural size.)

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, Bitiacus apteriis, 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-flies 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 great sheer cliffs of the flanks of the Range are only equalled

Fig. 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 larvae 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

Fig. 330. — Leptocerus 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
Mountains, 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 larvas, 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 the
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, s^-mmetrical
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 Ji^^^ \Ol? '-^t^

the worm in its ramblings, some Fig. 331. Fig. 332a. Fig. 3326.

are fastened to the boulders or Fig. 331.— Two cases of caddis-worms. (Natu-

rock banks or bed of the stream. fig'!^32.-Two 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 P'-oJecting. (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 hning is made.

Fig. 333. — Halesus indistinctus. (After Needham; enlarged.)

The larvae 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),

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 pupae 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 larvae. 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, aUhough 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 wino-s
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. 336.

Fig. 335. — Fishing-net of caddis-worm in stream. (After Comstock.)
Fig. 336. — Goiiiotatiliiis 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

Fig. 337. — TricBiiodes 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 observed. 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 larvae is known. For three California
species Geo. Coleman, a student of Stanford University, has obtained adults
by putting wire-screen cages over the larvae in the streams. In these cages
the larvae 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 (larvae) or caddis-flies (adults) to families:

KEY TO FAMILIES (ADULTS).

Spines on the legs, three simple eyes (ocelli).

Four spurs on tibiae (second long segment) of middle legs Phryganid^.

Two or three spurs on middle tibiae 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 Rhyacophilid^.

Palpi of males 4-segmented; ocelli absent.

No spurs on front legs Hydroptilid^.

Spurs on front legs Sericostomatid.e.

Last segment of palpi elongate and flexible; palpi hairy.

Basal segment of antennas long and thick, wings slender, no ocelli. . . .Leptocerid.e.

Basal segment of antenna shorter, wings broader, last segment of palpi composed

of numerous subsegments Hydropsychid.e.

KEY TO FAMILIES {^ARYJE). (After 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
stones Leptocerid.e.

Hind legs not more than twice as long as first pair.

Nerve-winged Insects; Scorpion-flies; Caddis-liies 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.e.

Lateral fringe slightly developed; cylindrical case of sand or small stones.

Sericostomatid.5.
arva 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

and parchment-like Hydroptilid^.

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.

Hydropsychid^.

CHAPTER XII
THE BEETLES (Order Coleoptera)

I 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 preserv^ation. 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
larvae 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-larvae 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
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

.A

PLATE II.

BEETLES.

i = Desmocerus palliatus.
2 = Tragidion armatum.
3=Chalcophora liberta.
4= Chrysochus auratus,
5 = Silpha amftrrivana.
6=GeotrupJes splendidus
7 = Chrysochus cobaltinus
8=Bupr'estis sp.
9= Calosoma scrutator
io= Tc-traopes tetraophthahnu;
ix = Cucujus platipes.
i2^Meloc sp.
i3=PeHdnota punctata.
i4=Parandra brunnea.
i5=Cyllene robiniae.
i6=RosaHa funebris.
i7=Cicindela genetosa.

PLATE II

!\rayy Jle/lmnn, ,iel.

Beetles

247

It would be reasonable to expect to find the insects of an order so pursued
bv collectors susceptible of ready classifying and determining. On the
contrary, no order presents more difficulty to the elementary and even

labial palpi

labium
compound eye-

mouth-parts

maxi^la'Ty palpi
^head
/intenna.

y

'prothorax

.mesothorax

metathorax

coxa-

trochanter—

femur'''%
tibia^'

tarsal segme7i{s

abdomen

Fig. 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 all 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
oesophagus-

elytron

..-go-nglia

r^Mlimentary
canal
^_ ventral nerve
chain

oviduct'^ ' ^99-ti
accessory glandi-' Yectuvi

Malpighian
intestine tubules

\receptaculum seminalis
Fig. 33Q. — Dissection of female great water-scavenger beetle, Hydrophihis sp.;
heart and air-tubes (trachea;) are cut away. (Three times natural size.)

the

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 whv 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 shghtest
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 bv
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

* If 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, ft 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-

FiG. 340. — The different forms of antennae of beetles, i, serrate; 2, pectinate; 3, cap-
itate (and also elbowed); 4-7, clavate; 8-9, lamellate; 10, serrate; 11, irregular
(Gyrinus); 12, 2-segmented antennse of Adranes ccbcus. (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 antennae.
To learn the range of these differences in the antennae, and the names applied
to the various kinds a careful inspection of Fig. 340 will do more than a
4

Fig. 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 "; 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

251

hatch larvae usually called grubs, with three pairs of legs (sometimes want-
ing), with biting mouth-parts, simple eyes, and inconspicuous antennae.
These larva2 are predaceous, as the water-tigers (larvae of water-beetles),
plant-feeders, as the larva? 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 (larvae of click-beetles), the white
grubs (larvs 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 Up) 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 antennae slender, thread-like, with distinct, cylindrical segments.

(Carnivorous beetles.) Tribe Adephaga (p. 252).
With the antennas thickened gradually or abruptly toward the tip.

(Club-horned beetles.) Tribe Clavicornia (p. 258).
With the antennae serrate or toothed.

(Saw-horned beetles.) Tribe Serricornia (p. 265).

With the antennae 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

Beetl

es

With four tarsal segments in each of the feet Section Tetramera (p. 277).

Mostly with slender cylindrical antennte, 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-seginented tarsi, and the hind legs with 4-seg-
mented tarsi 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.

Antennae inserted on front of the head above the base of the mandibles.

(Tiger-beetles.) Cicindelid^.

Antennce inserted on side of the head between the base of the jaws and the eyes.

(Predaceous ground-beetles.) Carabid^e.
Aquatic.

With two eves (Predaceous diving-beetles.) Dytiscid^.

With four eyes, two above and two below (Whirligig-beetles.) Gyrinid^.

The attractive tiger-beetles (Cicindelidae) 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"
elusiveriess 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
hunting; their big eyes and long sharp mandibles and the
whole seeming of the body some way betray their predatory
habits even before one sees the swift pounce on some
dull-witted, slow-footed insect, and the eager blood-
drinking immediately thereafter.
The egg-laying habit of the tiger-beetles is not yet known, but the larvae
and their habits are familiar. They are ugly, malformed, strong-jawed

Fig. 342. — Larva
of a tiger-
beetle, Cicindela
hybrida. (After
Schiodte ; three
times natural
size.)

PLATE III

TIGER BEETLES. (After Lcng and Bcutenmuller.)

Ig. I. Tctracha Carolina.

" 2. Cicindela unipunctata

" 3-

' celeripes.

" 4

' dorsal is.

" 5 • '

' scutellaris var. rugifrons.

" 6

' longilabris

7

' " var. pcrviridis

" 8

' scutellaris var. Lecontei

" 9

' sexguttata.

" lO '

' " var. patruela.

" II '

' purpurea.

" 12 '

" var limbalis.

" 13-

' formosa var. generosa.

" 14

' aneocisconensis.

" IS

' vulgaris.

" i6

' repanda.

" 17.

" 12. guttata.

" 18

' hirticollis.

" 19.

' punctulata.

"20 '

' marginata.

" 21 '

' puritana.

" 22 '

' lepida.

" 23

' rufiventris.

" 24

' Hentzii.

" 25.

' tortuosa.

" 26

' abdominalis.

" 27

' marginipennis.

PLATE

I |i I I I

H

( i

12

15l

I

IG IT

20

22

23^

25

I' I

Beetles

253

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 11.
In the East occurs, besides Cicindela, the genus Tetracha (PL III, Fig. i)
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 Carabidae, 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 larvae (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 larvtC burrow just beneath the

surface of the earth, feeding on various insects which enter

the ground to pupate or for other reasons. They destroy

large numbers of the destructive leaf- feeding beetles, whose ; 343-— Larva

° . ° ' 01 Lalosoma sp.

soft-bodied larvae leave the plants and burrow into the (After Lugger;

ground when ready to pupate. When full-grown the Carabid enlarged.)
larvae form small rough cells in the soil within which they change to pupae.
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 antennae, 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 (PI. 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. jrigidum (Fig. 344) and C. cahduni (Fig. 345), the latter
called the fiery hunter from its characteristic rows of reddish
or copper-colored punctures on the black elytra, are keen

Fig. 346.

Fig. 344. Fig. 345.

Fig. 344. — Calosoma frigidum. (After Lugger; natural size.)
•fiG. 345. — Calosoma calidum. (After Lugger; natural size.)
Fig. 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 yV 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

AGM^rq

,ri/j)

PLATE IV.

PREDACEOUS BEETLES, (After Wickham.)

Fig. I

Panagsus f

asciatus.

" 2.

Patrohus

longicornis.

" 3-

Pterostichus

rostratus.

" 4.

( (

honestus.

" 5-

( (

coracinus.

" 6.

<(

sculptus.

" 7-

((

lucublandus.

" 8.

4t

tartaricus.

" 9-

<C

mutus.

" lO.

<(

orinomum.

'* II.

**

erythropus.

PLATE IV

Beetles

^S5

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 larvoe. Most abundant of the Carabids are the numerous
dull-black medium-sized species of Pterostichus (PI. 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 larvae of the codlin-moth and plum-curculio, ravag-
ing fruit-pests. A few Carabids are not such good friends, Lugger record-

FiG. 347. — Predaceous diving-beetles (and back-swiramers, 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 Dyticidae, 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 Gyrinidae) (p. 257), by having
but one pair of eyes, and from the water-scavenger beetles (family Hydro-

■y

Beetl

es

philidae) (p. 258) by having slender thread-like antennae instead of clubbed
ones. All are oval and flatly convex in shape, w^ith 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 larvag (described in the next paragraph), and the
interesting active Hfe 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-
jv^ regularly on the water,
while those of others are
laid in slits cut by the
sharp ovipositor of the
female in the stems of
aquatic plants. The long,
slender, semi-transparent,
predaceous larvae (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

Fig. 349.

Fig. 348. — Water-tiger, the larva of the predaceous water-
beetle, Dyticus sp. (Natural size.)

Fig. 34Q. — The predaceous water-beetle, Dyticus sp., pupa
and adult. (Natural size.)

Beetles

257

another near the base. When a Hve 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
larvae 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 cfarp-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 larvae 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,
and readily recognized by their curious spin-
ning or circling, in companies, on the surface
of ponds or still pools in streams, are the
whirligig-beetles (Gyrinidffi), common all over
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

Fig. 350. Fig. 351.

Fig. 350. — Whirligig - beetle,
Dineutes emarginata. (Twice
natural size."!

Fig. 351. — Larva of whirligig-
beetle, Gyrinus marinus.
(After Schiodte; enlarged.)

258

Beetl

es

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 whirhgig-
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-smeUing whitish hquid.

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 pupae 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 antennae, show much variety
in the character of the terminal thickening of the antennae (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.) Hydrophilid^.

Terrestrial; legs not fitted for swimming.

Antennae moniliform, i.e., with segments bead-like; elytra usually covering only basal

half of abdomen (Rove-beetles.) STAPHYLiNiDiE.

Antennae moniliform or sub-moniliform; elytra covering most of the abdomen: brown

or reddish species (Grain-beetles, etc.) Cucutid^.

Antennas 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.) Silphid^.

Small insects, mostly less than one-half inch long; body thick and convex above.

(Larder-beetles, etc.) Dermestid^.

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

antennae (the long slender palpi may be at first glance mistakenly taken
for antennae) as members of the family Hydrophilidce, the water-scavenger
beetles. As the popular name indicates, these beetles feed, for the most
part, on decaying material, animal or plant, found in the water, although
they feed also on Uving water-plants, as Nitella; and living insects are cer-
tainly taken by some species. They can be distinguished from the Dyticida)
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 larvae (Fig.
354) are elongate, but thicker and less graceful than
the water-tigers (larvae of the Dyticidae), and, unlike
the adults, feed chiefly on living insects, snails, tad-

Fig. 352. Fig. 353. Fig. 354.

Fig. 352.^Great water-scavenger beetle, Hydrophilus triangularis. (Natural size.)
Fig. 353. — Egg-case of great water-scavenger beetle, Hydrophilus sp. (Twice natural

size.)
Fig. 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 larvae 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.

26o

iJeetles

About one hundred and fifty species of HydrophilidEe 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
larvae."

The rove-beetles, Staphylinidae, form a large family, numerous in species
and individuals over the whole country, and one whose members are readily
recognized 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 Silphidae
(p. 261) are almost sure to be found whenever a mass of
decaying flesh or e.xcrementitious 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 famihar 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 — 9000
species are known in the world — are very small. In
California great swarms of minute rove-beetles dance in
the air in April and May, and are a woful nuisance to
people driving or bicycling. They get into one's eyes,
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. 55^)-

The larvae (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 pupse 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 chrysahd.

Among the more familiar rove-beetles are species of the genus Creophilus.

Fig. 355. — Larva
of a rove-beetle,
X anthaliniis
lentus. (After
Schiodte; twice
natural size.)

Beetles

261

Fig. 356. — Rove-bee-
tle, Creophilus vil-
losus. (One and one-
half times natural
size.)

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; 5. maculosus, i inch long, is

dark cinnamon-brown with a row of squarish black

spots along the middle of the abdomen; S. cinna-

mopterus, J inch long, is cinnamon-colored, with

blackish abdomen ; S. lonientosus, \ inch long, is deep

dull black; 5. violaceiis, \ inch long, is black with

thorax and elytra violet. Not uncommon along sandy

seashore in CaHfornia is a curious light-brown wing-
less rove-beetle, Thinopimis picius, 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 Silphidae,

or burying-beetles. Both adults and larvae
feed almost exclusively on decaying flesh.
The antennae 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
carrion-beetles, and Necrophorus (Fig.
358), the burying-beetles. The charac-
teristic shape and appearance of these two
types are well shown in the figures. The
species of Silpha are short, broad-bodied,
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 larvce (Fig.
359) and adults are found in and underneath putrid flesh. The larvae
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

Fig. 357. Fig. 358.

Fig. 357. — Carrion-beetle, Silpha
noveboracensis. (One and one-half
times natural size.)

Fig. 358. — Burying-beetle, Necropho-
rus marginatus. (One and one-
half times natural size.)

262

Beetles

Fig. 359. — Larva
of can ion-beetle,
Silpha sp. (One

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 long, 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 in a
hole; it is then covered over and thus really buried.
The female lays her eggs on the corpse, and the larvae
hatching from them feed on the decaying matter. These
larvae have spiny plates on the back of the body and
are otherwise unlike the Silpha larvae. Some Necrophorus

and one-half times larvae are predaceous and others feed on decaying vege-
natural size.) ^^^^^ j^^^^^^

Most of the blind, pale cave-beetles found in caves in this country and
Europe are Silphidas.

The Cucujidae, 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
^ 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
infests dried fruits, nuts, .seeds, and dry
pantry stores of all sorts, as well as grain bins
and cribs. The larvae (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

Fig. 360. — Larva, pupa, and adult of
the saw-toothed grain-beetle, Sil-
vanus surinamensis. (After How-
ard and Marlatt; much enlarged.)

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 (PI. II, Fig. 11), about half an inch
long, with black eyes and antennae and the legs with dark tibiae and feet.

The Dermestidac 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 Dermestidae are small, oval, and plump-bodied, the largest
species being about ^ 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 larvae are the real pests of house-

FiG. 361. Fig. 362.

Fig. 361. — Carpet-beetle or "buffalo-moth," Anthrenns scrophularia, larva and adult.

(After Howard and Marlatt; much enlarged.)
Fig. 362. — Black carpet-beetle, Attagenus piceits, 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 CSj are fatal to the pests.
The carpet-beetle or " buffalo-moth " (Fig. 361) is another species, A. scrophu-
laricE, of this same genus. The beetle is about y\ 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 fioor-cracks. The beetles are common
outdoors on plants of the family Scrophulariaceae, 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, Attagenus 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 l^ 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,

(After

Fig. 363. Fig. 364.

Fig. 363. — The larder-beetle, Dermestes lardarius, larva, pupa, and adult.

Howard and Marlatt; much enlarged.)
Fig. 364. — Larva of a water-penny beetle of the Parnidce. (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
Parnidae, 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 larvae are curiously flattened, broadly
oval to nearly circular small creatures (Fig. 364), which cHng 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 Platypsyllidae has been estabhshed 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 ^-g- 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 httle
beetles of curious habits are the Pselaphidae and Scydmaenidse, 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 antennae slender,
with each segment projecting more or less inward so as to give the whole
antennae 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 antennae, 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 elhptical, and with unusually
hard cuticle.
Antennae finely serrate, the first two abdominal segments grown together on the ven-
tral side (Metallic wood-borers.) Buprestid^e.

Antennee often filiform; first two abdominal segments free.

(Chck-beetles.) Elaterid^.
Head free, but bent under the thorax.

Small insects usually less than \ inch long (Death-watch beetles.) Pjinid.^.

Head free, but often partly or wholly covered by the thin anterior margin of the thorax.
Wing-covers flexible; body elongate and flattened; antennae not enlarged at tip.

(Fireflies.) Lampyrid.e.

Wing-covers firm, thorax convex, body not much flattened; antennae often enlarged

at tip (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

Fig. 365.— a flat-
headed borer,
larva of Rha-
gium lineatum.
(Natural size.)

Buprestidse, of which over two hundred species occur in North America.
The adult beedes have an elongate body, trim and compact, with a rigid
and armor-plate-hke 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
antennae 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 Hke
jewels.

The larvae are mostly wood-borers, although those of
some of the smaller species mine in leaves or live in galls.
The wood-boring Buprestid larvae are characterized by the
strangely enlarged and flattened, legless, first thoracic
segment, on which the small head with its powerful jaws
sets in front, and the tapering, flattened, legless, meso-
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
larvs 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, Chrysohothris femoraia (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 antennae 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
about one year from the time of its hatching. This
pest attacks peach- and plum-trees and several forest-
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

Fig. 366. — Apple-tree
borer, Chrysohothns
femorata. (Twice
natural size.)

Beetles ■ 267

truncate in front, as if cut sharply off, and the body rather cyhndrical than
flattened, as with most other Buprestids. A. ruficollis, the red-necked black-
berry-borer, y%- 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 larvae bore into pines. C.liherta (PI. II, Fig. 3) is
a beautiful pink bronze with darker raised lines. Dicerca divaricata, f inch
long, is copper-colored, with the black-dotted elytra tapering behind and
separated at the tips. Buprestis (PI. II, Fig. 8) is a genus of rather large
brassy-green or brassy-black species often spotted with yellow on the elytra
and beneath.

Resembling the Buprestids much in general shape and appearance, the
click-beetles, Elateridae, are readily distinguished from them by their lack
of metaUic 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 ^^'^- 367- — Ventral
into which the point of a curved projecting process click-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 sLe")' ^ "^a

tip of the curved horn to the edge of the cavity, when,
by a sudden release of muscular tension this tip slips and the insect is
thrown into the air. The Elateridae 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 aUve in h'ttle 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 larvae (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 larvae soon
hatch, dig down into the soil, and feed
on roots and seeds for two or three
years, when they become full-grown.
They pupate in the ground in early
fall and the pupae transform to adults
before winter, but the beetles do not
issue from the ground until the fol-
lowing spring.

Among our largest click-beetles
is the eyed elater, Alaus oculatus
(Fig. 369), if inch long, blackish
with large uneven whitish gray dots,
a pepper-and-salt fellow, Comstock
well calls him, with a pair of large
white-rimmed velvet-black eye-spots
on the prothorax. The large larvae, about 2 inches long, live in decaying
wood and are often found in the trunks of old apple-trees. Elaier rubricollis,
i inch long, is black with light-red prothorax; E. sangmnipennis,
j\ inch long, is black with light-red elytra; E. nigricollis, f inch long, is
black with whitish elytra. Athoics scapidaris, f 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, i inch long, has two
bands; C. hamaius, rather smaller, has one band near the tip. Melanactes
piceus, I 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.

Fig. 368. Fig. 369.

Fig. 368. — Larva of a click-beetle, Elater

acerrimus. (After Schiodte; natural

size.)
Fig. 369. — An eyed elater, Alans oculatus.

(One and one-half times natural size.)

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, Lampyrida', 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-hke 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 Lampyridae 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 (tracheae) and nerves. From a stimulus conveyed
by these special nerves oxygen brought by the network of tracheae 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
pupae and larvae and even the
eggs emit light. The combustion
in the egg is of course accom-
plished wholly without tracheae
or controlling nerves.

The larvae (Fig. 370) of Lam-

pyrida; mostly burrow under- Fig. 370. Fig. 371. Fig. 372.

ground, where they feed on soft- ^'?- 37o.— Larva of firefly, Photinus modestus.
, . (Twice natural size.)

bodied msects, slugs, and oXhtr Yig. 7,-ji.~Tue^y, Photinus scintiUans. (Three
similar food. The adults, too, times natural size.)

,1 r 1 r Fig. 372. — Checker-beetle, Trichodes ornatus

are carnivorous, the diurnal forms, (Twice natural size.)

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. scintiUans (Fig. 371), similar in mark-
ing but smaller. P. angulatus, h 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. pennsylv aniens, which is yellow with
a black spot in the middle of the prothorax and one near the tip of each
wing-cover, and C. marginatiis, 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 larvae of T. hilineatiis, 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 larvae of the plum-
curculio."

Professor Comstock has given the name checkered beetles to the family
Cleridae; 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 antennae with a marked knob
at the end, and the body more or less cylindrical, either hairy or not.

"The larvae 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 larvae 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. diibins is ^ inch long, steel-blue with three
orange bands across the elytra; C. nigrifons is j 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 larvae
live in nests of bees, and T. apiarius is a pest in beehives in Europe.
Necrohia 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. Necrohia rnfipes, 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 larvae 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 Ptinidie 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.

^ 7 s), which we may well call the "drug- „ ^, , , , ^•

"^'^^' , ^■' . , ^'^ Fig. 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, gmger-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,
pups, and adults were side by side in most of the canisters. Ptinus brim-
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, gV 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 wovfld 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, Amphiceriis bicaiidahis, ^ 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 larvaj 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, | 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 antennas have conspicuous lateral prolongations in the shape
of teeth or plates (lamellas) (Fig. 340, s and 9). The families may be dis-
tinguished as follows:

Antennae elbowed, the club (terminal segments) composed of segments with fixed
transverse teeth; mandibles of the male often greatly developed.

(Stag-beetles.) Lucanid^e.
Antennae 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.) Scarab.eid.^.

The stag-beetles, Lucanidae, 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 larvae (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.

Beetl

es

'^IZ

The genus Lucanus contains four North American species, three of which
are familiar. L. elaphiis (Fig. 374), the giant stag-beetle, of the southern
states, varies from i^ to 2 inches in length, not including the mandibles,
which in the male are i inch long and branched; L. dama, the common
pinching-bug of the East, rich mahogany-brown in color, from i inch to
I J 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. placidits,
not quite an inch long, and black, is a third
common species. The antelope-beetle,
Dorcus paralleliis, is less than an inch long,
black, and with longitudinal grooves on the
elytra. Platycercus quercus, | inch long,
brownish black, is widely distributed.
Ceruchus piceus, J inch long and dark brown,
is occasionally common in rotten wood.
The horned Passalus, P. corniitus, large
and shining black, has a short horn bent
forward on top of its head.

The great family Scarabaeidae, com-
prising over five hundred species of North
American beetles, includes some of our most familiar kinds. Indeed
so many common, conspicuous, and interesting Scarabaeid 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
antenna? and heavy robust June-bug type of body make most of the members
of this family readily recognizable. In practically all, too, the anterior
tibiae are broad and flattened and fitted for digging. Depending on their
habits, the Scarabaeids are readily divided into two principal groups, the
scavengers, of which the tumble-bugs, dung-beedes, 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 Scarabaeids into several distinct families, but niost do not. The scavenger
Scarabaeids 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 Scarabasid larvae (Fig. 376) are thick, soft-bodied, whitish, six-footed
grubs, which usually lie curved and often on one side. They are found

Fig. 374. — Stage-beetle, Lucanus
elaphus male. (Natural size.)

2/4

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 Scarabasids the tumble-bugs are wide-spread and well
known. The species common in the East belong to three genera: Copris,
with middle and posterior tibiae dilated at the tip; Canthon, with these tibae
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 iinally buried in the ground. The female lays an egg in the ball,

Fig. 375.

Fig. 377.

Fig. 376.

Fig. 375. — Polyphylla crinita. (Natural size.)

Fig. 376. — Larva of a large Scarabeid beetle. (Natural size.)

Fig. 377. — Phaneus cartiifex. (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 tills the holes with this substance, on which the larvae,
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, Ateuchns 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 Eg}'ptian antiquities."

Common dung-beetles are the numerous species of Aphodius, ^ to ^
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 yl. fimetarius, ^ inch long, with red elytra;

Beetles

275

A. oblongus, ^ inch long, wholly black; and A. terminalis, \ inch long, black
with reddish legs and tips of elytra. The earth-boring dung-beetles,
Geotrupes, have ii-segmented antennse, 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 larvae, an egg being laid
in each hole." G. splendidus (PI. II, Fig. 6), f inch long, dark metallic
green to purple; G. excrementi, \ inch long, is bronze-black; G. opacus, J inch,
is deep black. Common on dried decaying animal matter, especially skins,
and on the hooves and hair of decaying animals are small (^ to + 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 Scaraba^id 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 larvas hve 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, however,
on the Pacific coast. The larvae are famiUar white
grubs that live underground and feed on the roots
of grasses, strawberries, etc. They often do much
damage to lawns. They live as larvae
for two or three years, and pupate in
an underground cell. The adult
beetles fly and feed at night, often
injuring the fohage of cherry, plum,
and other trees. The familiar rose-
chafer, Macrodactylus siibspinosus
(Fig. 379), I inch long, a slender
Pig. :;y8. Fig. 37Q. yellowish beetle with pale red legs,

Fig. 378. — The June-beetle, Lachnosterna does great damage to roses and grapes,
fusca. (One and one-half times natural ^^ppgaring in early summer and eat-

FiG. 379.— The rose-beetle, Macrodactylus ing flowers and foliage. The larvae
subspinosus. (Twice natural size.) jj^.g underground, feeding on the roots

of various plants, but especially grasses. The spotted vine-chafer, Pelidnota
punctata (PI. II, Fig. i^), i 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

2/6

Beetles

cell in the wood. The goldsmith-beetle, Cotalpa lanigera, of similar size
and shape, is gUstening, 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 lanigera, 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. titynis (Fig. 380), 2^ 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 larvae

Fig. 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 Scarabseids 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, it 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
larvae feed on decaying substances underground. The fig-eater, or "southern
June-beetle," AUorhina nitida, f inch to i 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 larva; 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

Fig. 381. Fig. 382

Fig. 381. — Larva and pupa of the rhinoceros-beetle, Dynasius tityrus. (After Chittenden;

one-half natural size.)
Fig. 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 Spondylidae) . The first
three tarsal segments are dilated and furnished with brushes of hairs on
the sole, the third segment being plainly bilobed (Fig. 341, 12). This
section is sometimes named Phytophaga, because of the voracious plant-
feeding habits of all its members. The three principal famihes of the
section can be separated by the following key:

Body short and more or less oval; antennae short.

Front of head not prolonged as a short broad beak; elytra usually covering the tip
of the abdomen; both larvce 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; larvae live in seeds.

(Pea- and bean-w^eevils.) Bruchid.e.

Body elongate; antennae almost always long, often longer than the body; larvae are

wood -borers (Long-horn beetles.) Cerambycid.^.

The leaf-beetles, Chrysomelidoe, are one of the largest of the beetle fami-
lies, 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 outUne, strongly convex above;

the head small, much narrower than the prothorax, and with the antennae

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 larvae, 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 lo-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

Fig. 383. — The Colo- gxtehded eastward until 1874, when it reached the
rado potato - beetle, . , . ^
Doryphora lo-lineata. Atlantic Ocean. Fmally 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 larvae 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-Hke 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 larvae 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 now "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, ^ 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 larvae
which when full grown are ^ 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.

Fig. 384. — The elm-leaf beetle, Galerucella liiteola; eggs, larvae, pupa, and adults. (After
Felt; eggs greatly magnified; larvae, pupa, and adults about twice natural size.)

Four species of the genus Diabrotica are common over the country and
very injurious: D. vittata, the striped cucumber-beetle, is greenish yellow
with two black stripes on each elytron, and feeds on cucumber-, pumpkin-,
squash-, and melon-vines, the larva also burrowing into the stems and roots
of the same plants; D. 12-piinctata (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

28o

Beetles

six black spots on the wing-covers (like l2-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.

Fig. 385. Fig. 386.

Fig. 385. — The cucumber-beetle, Diabrotica 12-punctata.
Fig. 386.— The California flower-beetle, Diabrotica soror.
Fig. 387. — Chrysomela digsbyana. (Twice natural size.)

Fig. 387.

(Three times natural size.)
(Three times natural size.)

Chrysochus auratus (PI. II, Fig. 4), f inch long, golden green in color,
found in the East, and C cobaltinus (PI. 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-

Fig. 388. Fig. 389.

Fig. 388.— Larvae of the grape-vine flea-beetle, Haltica chalybea. (After Slingerland;

much enlarged.)
Fig. 389.— a tortoise-beetle, Coptocyda 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 -^\ 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 aicimieris, the cucumber flea-beetle, ^V i^^ch
long, and black, attacks melons, cucumbers, and other vegetables. The
tortoise-beetles (Fig. 389) are curiously shaped, flat beloM^, convex above, and
with the prothorax and elytra thinly margined so as to give them a tortoise-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 argiis, | inch long, brick-
red with many black spots on prothorax and elytra, is found on milkweeds;
Physonota imipunctala, ^ inch long, the largest of our tortoise-beetles, yellow
with whitish margins, is common in midsummer on wild sunflowers.

The small familv Bruchidae contains two common and important beetles,
viz., the pea-weevil, Bntchus pisl (Fig. 390), and the bean-weevil, B.
obtectiis (Fig. 391). The adult pea-weevil is \ 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. 3QO. Fig. 391.

Fig. 390. — The pea-weevil, Bnichus pisi, and an infested pea. (Natural size of beetle

indicated by line.)
Fig. 391. — The bean-weevil, Bnichus ohtectus, 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 larvae 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 larvas.

The bean-weevil is a little larger than the pea-weevil and lacks the
white spot on the thorax. Its Hfe-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.

Fig. 393.

Fig. 392. — Prionus californiciis. (Natural size.)

Fig. 393. — Larva of Ergates spiculatiis. (Natural size.)

Fig. 392.
392. — Prionus californiciis.

The other principal tetramerous family besides the Chrysomelids is the
Cerambycidae, or family of long-horn wood-boring beetles: "long horn"
because of their long slender antennae, and "wood-boring" because their
larvffi 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 larvae, 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 et al., all causing much damage
to orchards and forests.

Beetl

es

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 Prionida? (Fig SQ2)
whose members have the sides of the prothorax sharply margined and
usually toothed. Prionus laticoUis, the broad-necked Prionus, varies from

Fig. 394.— The sugar-maple borer, Plagionotus speciosiis, larva; and adult beetle. (After

Felt; natural size.)

I inch to 2 inches in length, and is pitchy black or brown, the prothorax
with three sharp teeth on each lateral margin, and the antennae 12-segmented;
the larvffi, which live three years, are great footless white grubs, 2^ 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; OrtJiosoma brunnea, is long (li to 2* 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 Ergates (with a
single species, spiailatHs), both 2 J inches long, and with the lateral margins
of the prothorax with many fine sharp teeth. The larvae (Fig. 393) of
Ergates live in the giant sugar and yellow pines of the Sierra Nevada forests.
The cloaked knotty-horn, Desmocerus palliatus (PI. II, Fig. i), is a
beautiful species, dark greenish blue with the bases of the elytra orange-
yellow; the larvae bore in elder-pith. Cyllene robinicr, the locust-borer (PI. II,

Fig. 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 larvae live in locust-trees. A similar species, Cyllene pictus, attacks the
hickory. The red milkweed-beetle, Tetraopes tetraopthalmus (PI. II,
Fig. 10), brick-red with black spots, is a common species on milkweeds;
the larvae bore into the lower stems and roots. Two beautiful Cerambycids
of California are shown in Figs. 2 and 1 6 of PI. II.

The sugar-maple borer, Plagionotiis speciosus (Fig. 394), is a serious
pest of sugar-maples in New York and elsewhere in the East. The beetle,
I inch long, is black, brilliantly marked with yellow; the eggs are laid in

Beetles 28 c

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), f inch long, slender
grayish brown, lays its eggs on small twigs in maple-trees in July; the larvae
bore 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
larvae 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 antennc-e;
the larvae bore in sound pines and firs and do great injury to evergreen
forests.

One of the worst and most famihar orchard pests is the round-headed
apple-tree borer, Saperda Candida (Fig. 396). The beetle is f 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 F,o^3Q6.-The round -heLd

fallmg the outer part with sawdust and then apple-tree borer, Saperda cau-

retires to the inner end and pupates. Two f?/' ^^^^"^ .''"'^ '"^''^^ ^^'^t'^-

.1 1 r. . , . , (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
larvas 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, Spondylida?, called the aberrant long-horned beetles, is
represented in North America by four species, of which the most common
is Parandra brunnea (PI. II, Fig. 14), a beautiful polished mahoganv-
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 Coccinellidte. Their uniformly small size, the semispherical shape,
and the "polka-dot" pattern distinguish them readily from all other beetles
except perhaps the Chrysomelids, 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 Chrysomehdae, or leaf-eaters, both as larvse
and adults, attack our crops and trees and flowers; the CoccinelHdae, or
ladybirds, both as larvae 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 httle, 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

# i ^ $

Fig. 397. — Some Californian ladybird -beetles; beginning at left of upper row the species
are Megilla vitigera, CoccineUa caJijornica, C. ocidata, Hippodamia convergens;
beginning at left of lower row, CoccineUa trifasciata, C. sanguinea, C. ahdoniinalis,
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 vet 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 larva?
(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 larvae 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 bi punctata, reddish yellow with a

single black spot on each elytron, is 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

bivulnerits, is shining black with a large red

spot on each elytron. Anatis ij-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. i?,^ • o ^ 1 j i,- j u .1

Fig. 398. — A ladvbird-beetle,

In California the ladybirds are of great Coccinella caliloriiica ; larva,

importance to the fruit-growers, their steadv P'^''''^' ^"'^.^'^1'^ °'' Lawson's
, , , , . r 1 • , . ' cvprees. (Twice natural size.)

wholesale destruction of scale-msects bemg 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 estabhshment of the small red-and-
black ladybird, Vedalia cardinalis, which feeds exclusively on the fluted or cot-
tony cushion-scale (Icerya 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 u'idely 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.) Tenebrionid^.

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.) Meloid.c

The common ground-beetles of the North and East are the swift preda-
ceous Carabidae; 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 Tenebrionidae 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.

Yi(y ,gQ_ 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
^^^^■•^ 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 Hving or dead fungi, and a few are probably predaceous.
A common species in mills, stables, grocery-stores, and pantries is the meal-
worm beetle, Tenehrio nwlitor, ^ to f 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. T. 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 smafler brown species, Echoceriis maxillosiis, ^ inch long,
is common in the southern states in old and neglected flour.

Uloma impressa, J 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. 400. Larva of a Tene-

and east in and about the large shelf-fungi brionid, Boletotherus bifurcus.
/r> 1 \ iU i " iU -J r i (Twice natural size.)

(rolyporus) 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 larva; (Fig. 400)
live in the fungi.

The other of the two larger heteromerous families, the Meloidae, 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 svibstance 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 (PL 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 larvae (Fig. 402) with three pairs of long legs,
each terminating in three claw-like spines. These
larvse 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 triunguhn of Epicauta
Fig. 401. — The striped vittata, one of our common Meloid species, studied
potato-beetle, Epicauta ]^y Riley, explores cracks and burrows in the ground
^wLTnatimrsize^r'''' 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

Fig. 402. — Hypermetamorphosis of Epicauta vittata. A, young larva or triungulin;
B, caraboid larva; C, coarctate larva; D, scarabasoid 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-

Beetles 291

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 of 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 larvas 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
larva2 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 httle creature, which is
entirely unfitted for hving thereon. After this the triunguhn undergoes
a mouh 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-pupai and continuing the series of changes in
June of the following year; at that time the pseudo-pupa returns to a larval
form, dififering 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 bv
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 lias 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 larvae 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; E. vittata (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, i to f 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 Stylopidae, or wasp parasites. Indeed these
curiously modified beetles difl'er 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 bevond

a larval or grub-like condition. They live in Fig. 403.-A wasp Po//5/r5 sp.,
° -' parasitized by (x) Xeiws sp.

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
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 Hves 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 Ufe. 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 triunguHns. How the triungulins find their way to
their bee-larva hosts is not very clear, but they probably he in wait in flowers
and when a bee comes along they cHng to its leg and are thus carried to
the nest where the larvae are. There are two genera of Stylopidse 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 antennae 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 soHd and compact,
usually strongly rounded above, and many species are thinly or thickly cov-
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 larvae are soft, wrinkled, white, footless
grubs which mostly live in fruits, nuts, and seeds. The larvae and adults
of the important family Scolytidae, 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.e.

Mandibles without scar on the anterior aspect (Curculios.) Curculionid-i:.

Pygidium of both sexes undivided.
Pygidium vertical; tibis not serrate.

(Bill-bugs and gianary-weevils.) Calandrid^.
Pygidium horizontal ; tibiae usually serrate (B ark-beetles.) Scolytid^.

Beetles 295

The scarred snout-beetles, Otiorhynchidae, 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, Epiccerus imbricatiis, J 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 striae, 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, Araniiges 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 larvie 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 Curculionidae, 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- ^ ^,

^ ,. , , ^, , , Fig. 404.— The chest-

curculio, plum-gouger, apple-weevil, and strawberry- nut-weevil, Balani-

weevil, and such a destructive pest of cotton as the "'" caryatrypes.

boll-weevil (for the study and combating of which natural sizeT'

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

^ to I 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. quercns 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. qitadrigibbus, 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-
natiis, 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 larva? 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 Jose scale probably the most notorious
and destructive frviit-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

^ ^, , ,. green bark. When the plums have set, the

Fig. 40s. — The plum-curcuho, '^ . ... . ,

ConStrachelus nenuphar, females begm to deposit their eggs m them by

(After photograph by Slinger- driUing a. tiny hole and pushing an egg into

, en arge . 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 sciitellaris , another

destructive Curculionid pest of the plum, bores into the stone.) When

the larvae are full-grown the infested plums fall to the ground, and the larvae

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 of this country
it has wholly 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

Fig. 406. — Larva and pupa of the quince-curculio, Conotrachelus cratmgi. (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 larvae
within.

The family Calandridas includes about eighty North American species
of weevils, of which several are common and famihar 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 i to J 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 larvae 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-w^eevil, C. oryza, \ 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 multiphcation 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 sunHght
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 (Scolytidae). 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 Scolytidae. A common way of

„ . 1- /- making these tunnels is as follows: The

Fig. 407. — ^The quince -curculio, Cono- &

trachelus cratagi. (After photograph beetles (a male and a female together)
by Slingerland; natural size and en- burrow from the outside through the
larged.) , . , , , , „ T •

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 Uve sap-filled region, laying their
eggs in masses or scattered along a tunnel. Soon the larvae 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 finds its way out through 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
\ 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 larvK are white and footless little grubs
with very strong jaws. The family includes 1 50 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 J'orestry, has recently estimated the
annual forest losses caused by insects to be $100,000,000, and most of the
ravages are due to the Scolytidae.

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-

FiG. 408. — Galleries in Monterey pine, with larvas, pupae, and adults of the engraver-
beetle, Tomicus plaslographus. (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 (larvae, pupae, 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 plaslographus (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 larvae. 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 larvae nip off the tender tips of the fungus stalks "as calves crop the
heads of clover," but the older larvae and adult beetles eat the whole structure
down to its base, from which new hyphae 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 Hke, 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
gj—ju . name itself is derived from the most conspicuous

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

tiG. 409. Fig. 410.

Fig. 409. — Mouth-parts of a female mosquito, Culex sp. lep., labrum-epipharynx; md.,
mandible; mx.L, maxillary lobe; ntx.p., maxillary palpus; hyp., hypopharynx; li.,
labium; gl., glossa; pg., paraglossa.

Fig. 410. — Mouth-parts of the house-fly, Miisca domestica. lb., labrum; mx.p., maxil-
lary palpi; li., labium; la., labellum.

hind wings of other forms are replaced by a pair of strange little structures

301

302

The Two-winged Flies

Fig. 411. — Head, antennae,
and beak of mosquito, lat-
eral aspect.

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 diagno.stic 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 Hquid, or the juices of decaying animal or
plant substance. To take solid food as the
house-fly does from a lump of sugar, the solid
has 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 larvae (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
pupae 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
seed.

The Diptera include the famihar
house-flies, flesh-flies, and bluebottles

of the dwelling and stables; the horse-flies and greenheads, that make
summer hfe 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 faUen and fermenting fruit; the bot-flies, those disgust-

FiG. 412. — The blow-fly, Cclliphoraery-
throcephala. Larva, pupa, and adult.

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 cosmopolitian 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 larvae nearly ready to pupate.

Suborder Pupipara (see p. 351).
Not living on the bodies of other animals; young usually produced as eggs.

Suborder Diptera genuina (see p. 304).

Antennae with numerous (more than five) segments. .Section Nematocera (see p. 304).

Antennae 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

segments Section Brachycera (see p. 327).

Third segment of antennae annulated, showing it to be composed of several coalesced

segments (see p. 327).

Antennae consisting of four or five distinct segments (see p. 330).

Antennae with but three segments (rarely less), the third segment with or without a
style or bristle (see p. 332).

Of the two suborders the smaller one, the Pupipara, including certain
strangely speciahzed and degraded parasitic flies, will be considered last. Of
he first suborder, the Diptera genuina, the various famihes of small midge-
and mosquito-Hke flies composing the section Nematocera (flies with slender
several-segmented antennas) 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 sprawhng long-
legged crane-flies, or leather-jackets, are not unfamiliar members of this group.
In addition there belong here a few famiHes of flies httle 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. Antennae 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 9-1 1 longi-
tudinal veins, but no cross-veins except sometimes near the base of the wing.

(Moth-like flies.) Psychodid^.
BB. Not as above.

C. Wings with a network of line vein-like lines near the outer and hinder

margins in addition to the regular (heavier) venation.

(Net-winged midges.) Blepharocerid^.
CC. The margin of the wings and the veins fringed with scales.

(Mosquitoes.) Culicid^.
CCC. With a distinct V-shaped suture on the back of the thorax.

(Crane-flies.) Tipulid^,
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.) Cecidomyiid^.

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; hgs slender and with greatly elongate

ccxse (basal segment). . . (Fungus-gnats.) Mycetophilid^.

EE. Ocelli absent.

F. Wing-veins well developed in all parts of the wing.

(Dixa-flies.) DixiD^.
FF. Wing-veins much stouter near the costal (front)
margin of the wing than elsewhere.

(Midges.) Chironomid^.
AA. Antennse shorter than the thorax and rather stout.

B. OcelH present (March-flies.) Bibionid^.

BB. Ocelli absent; wings very broad (Buffalo-gnats.) Simuliid^.

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 larvae
and pupaj of all the members of the remaining three live in plants or in the
ground, none being aquatic.

Best known of the aquatic famihes, and indeed of the whole suborder,
is the mosquito family, the
Culicidc'e. 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 10 genera,
and new ones are being found
constantly. In the family Culi-
cida; 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
piercers and blood suckers (in
the female sex). Of these pierc-
ing genera three are of especial
importance and interest to us
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

Fig. 413. — The life-history of a mosquito,
Culex sp A small raft of eggs is shown on
the surface of the water, several larvae
("wrigglers"), long and slender, and one
pupa ("tumbler"), large-headed, are shown
in the water, and an adult in the air above.
(From life; much enlarged.)

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 hght
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
Fig. 414.— The eggs of permanent, pools are selected. I have found the
Anopheles sp. (After gggg of Culex incidens on the surface of a bubbhng
Giles; much enlarged.) g^^^^.^pj-jng jn CaHfornia, and of Stegomyia in water
held in sUght 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 larvs (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. Larva? of Culex have
lived in breeding-jars in my laboratory for three months. The larvae moult
twice, and on the third casting of the skin appear as active, non-feeding

The Two-winged Flies 307

pupae (Figs. 413 and 415) with thick, broad head end (the thick part includes
thorax and head) and slender, curving abdomen, bearing two conspicuous
swimming-iiaps 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 antennas provided with many long
fine hairs arranged in whorls and combining to give the antennae 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 Heu 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 Anopheles.

Palpi as long as proboscis in male, but only one-third as long in female.

Scales on the head narrow and curved Culex.

Scales on the head flat and broad 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

3o8

The Two-winged Flies

wide-spread and serious human diseases. The role 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 jasciata, 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

Fig. 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

3^9

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 fascia ta.

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, i{s 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,

Fig. 416. Fig. 417.

Fig. 416.— a short-beaked mosquito, Corethra sp. (From life; four times natural size.
Fig. 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 multipHcation 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;

3

lO

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
rhunicipal or county administration called on to take official action. But
when it is remembered that aboHshing 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.

Fig. 418. Fig. 410.

Fig. 418. — Scales on the wings of Culex fatigans. (After Theobald; greatly magnified.)
Fig. 419. — A midge, male, Chironomiis sp. (From life; much enlarged.)

Looking not unlike mosquitoes are the larger species of the family Chiro-
nomidae, whose members are popularly known as midges and punkies, the
name blood-worm being applied to the reddish aquatic larvae of certain
species. Like the mosquitoes, the males are distinguished from the females by
their very bushy or feathery antennae, 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 larvae (Fig. 420) of most species are aquatic, some of them forming
small tubular cases, as caddis-fly larvae do, and most oi 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 pupae
(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

The Two-winged Flies

311

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

compelled, as are the mosquito pupae, to come to the

surface for air. The larvae of the genus Ceratopogon

and its alhes, which include the fiercely biting and

blood-sucking httle punkies (Fig. 422), so irritating

to the fisherman and hunter in the north woods,

Fig. 420. Fig. 421.

Fig. 420. — Larva of a midge, Chironomus sp. (From life: natural length t inch.)
Fig. 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-

FiG. 422. Fig. 423.

Fig. 422. — Mouth-parts of a female "punkie," Ceratopogon sp. lb., labrum; md.,

mandible; «;x., maxilla; ?«:x:./., maxillary lobe; m^x;./)., maxillary palpus; //., labium;

p.g., paraglossa; hyp., hypothorax.
Fig. 423. — The tide-rock fly, Eretmoptera browni. (Natural length ^ inch.)

terey, California, may be seen in the winter months many small, long-legged,
spider-Hke flies (Fig. 423) whose wings are reduced to mere oar-like veinless
rudiments. The larvae and pups 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

312

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 larvae and pupje cling

Fig. 424.

Fig. 424.-
Fig. 425.-

FiG. 425.
(Four times natural size.)

-A black-fly, Simuliiim sp.

-Diagram of wing of black-fly, Simnliitm, 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 aknost
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

Fig. 426. — Larvae and pupas of Simidium sp. on edge of stream, May-fly on projecting

twig. (After Felt.)

The Two-winged Flies

313

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-Hne 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 Simuliidas, 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 larvae (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
of swift streams. The lip of a fall is a

favorite place for them. The swift- f^ }^[fp. \ \md.

running water constantly affords them
an abundant air and food supply. The
free or head end of the body is provided j^"" ^"^^ //

mjrp

Fig. 427- Fig. 428.

Fig. 427.— Mouth-parts of female black-fly, Simuliiim sp. lep., labrum; hyp., hypo-
pharynx; md., mandible; mx., maxilla; 7nxp., maxillary palpus; li., labium; pg.,
paraglossa. (Much enlarged.)

Fig. 428.— Mouth-parts of larva of black-fly, Simulium sp. lb., labrum; ep., epipharvnx;
md., mandible; mx., maxilla; mxp., maxillary palpus; mxl., maxillary lobe;' li.,
labium; hyp., hypopharynx. (Much enlarged.)

with a conspicuous pair of freely movable brushes which collect food from
the water. The cHnging to the rock is effected by means of silk spun
from the mouth, and by the skilful use of silken threads the larva? 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

3 1 4 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 httle 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

Fig. 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. /.OT(/., larval mandible; /.wix., larval maxilla; /./?., larval labium; /.c, larval
cuticle; /.a., larval antenna ; i.w J., adult mandible; i.wx., adult maxilla; i./i., adult
labium; i.d., adult hypoderm (cell-layer of skin); i.a., adult antennae; 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 larvae 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 Blepharoceridae. 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 larvce — 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

315

larvae squirm slowly around, feeding on diatoms and other microscopic water

\ A / .

Fig. 430. Fig. 431.

Fig. 430. — Larva of net-winged midge, Bihiocephala comstocki. At left, dorsal view;
at right, ventral view, ant., antennae; l.p., lateral processes; t.g., tracheal gills;
s., sucker. (Natural length, f to \ inch.)

Fig. 431. — Cross-section of body of larva of net-winged midge, showing anatomical
details of sucker and other parts, h., heart; al.c, alimentary canal; l.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; t., tendon at end of muscles.
(Much enlarged.)

organisms, and never suffering themselves to get into
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
back, and the delicate body pushes up through this
slit, and through the shallow swift water until the
wings can be outspread. All this is quickly done,
the fly being enchained by its long legs, which cling
to the pupal shell until it can fly away. But the

slow water. Trans-

FiG. 432. — Pupa, dorsal
aspect, of net-winged
midge, Bihiocephala
comstocki. Note re-
spiratory leaves on
dorsum of prothorax.
(Natural length, J inch.)

3i6

The Two-winged Flies

Fig. 433. Fig. 434.

Fig. 433. — Net-winged midge, Bibiocephala elegantuliis, female. (Natural length of
body, f inch.)

Fig. 434. — Mouth-parts of female net-winged midge, Bibiocephala doanei. l.ep., labrum-
epipharynx; ind., mandible; mx., maxilla; mxl., maxillary lobe; mxp., maxillary
palpus; li., labium; pg., paraglossa; hyp., hypopharynx. (Much enlarged.)

Fig. 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

Fig. 436. — Primarv venation of wing of net-winged midge, Bibiocephala comstocki.
R^, R^, etc., branches of the radial vein. (Much enlarged.)

these files 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 hfe; the family is probably becoming extinguished.
Because the few living species are so widely distributed over the world —

A

Fig. 437. Fig. 438.

Fig. 437. — Diagram of cross-section of head through compound eyes of net-winged
midge, Blepharocera capitata, female, o, ocelli; br., brain; o.l., optic lobes; /./., large
facets; s.}., small facets.

Fig. 438. — Mouth-parts of larva of net-winged midge, Bibiocephala doanei. md., man-
dible; mx., maxilla; l.ep., labrum-epipharynx; li., labium; hyp., hypopharynx.
(Much enlarged.)

theV 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

3i8

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 (larvae of the Chironomidae)
may perhaps be found a third kind of fly
larva (Fig. 440), a slender, pale-colored,
cylindrical Httle "worm," about one-
third of an inch long, which can be
distinguished from the other aquatic
larvae by its two pairs of short leg-like
processes borne on the under side of the

Fig. 439. Fig. 440.

Fig. 430. — Diagram of horizontal section through head of old larva of net-winged midge,
Bibiocephala doanei, showing formation of adult head-parts inside, l.md., larval
mandible; /.wx., larval maxilla; /.c, larval cuticle; i.wrd., adult mandible; i.mx.p.,
adult maxillary palpus; id., hypoderm (cell-layer of adult skin of head); i.e., adult
eye. (Much enlarged.)

Fig. 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-Hke flies of the genus Dixa
(Fig. 440), which is the only genus in the family Dixidae, 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 Psychodida% 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
moths (Fig. 445). The largest of these Fig. 441. — ^Pupa of Dixa sp.

flies are onlv about one-sixth of an -p^^^^f. '' n-

riG. 442. — Dtxa sp.

inch long, and are rarely distinguished
except by careful observers. I have found them especially common in gar-
dens near the seashore in CaUfornia, and also in the overhanging foliage

Fig.

442.

(Much en->

(Much enlarged.)

Fig. 443. — Mouth-parts of Dixa sp., female, l.ep., labrum-epipharynx; tnd., mandible;
OTjf., maxilla; wx./., maxillary lobe; wjc./)., maxillary palpus; /i., labium; /»^., 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 calijornica, which is, so
far, the only North American member of this family whose life-history is
known. The larvae (Fig. 446), which are Httle slug-hke 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

■n^

Fig.

Fig. 444. Fig. 445.

444. — Diagram of wing of Dixa sp., showing venation.

Fig. 445. — A moth-fly, Pericoma calijornica. (Much enlarged.)

wetted by the dashing water. When ready to pupate the larvae 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 pupae (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 pupae. After ^ ^-i^i lmuPS^

about three weeks the adults issue and fly

mxp.

tax.

Fig. 446. Fig. 447.

Fig. 446. — Larva, ventral surface (at left), and pupa, dorsal surface (at right), of the
moth-fly, Pericoma calijornica; also enlarged prothoracic respiratory tube of pupa.
(Much enlarged.)

Fig. 447. — Mouth-parts of moth-fly, Psychoda sp. Ih., labrum; inx., maxilla; inx.p.,
maxillary palpus; mx.l., maxillary lobe; li., 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
Tipulida;, whose long-legged, narrow-winged members are famiharly known as
crane-flies, leather-jackets, and " granddaddy-long-legs. " The granddaddy-
long-leg flies, which have wings, should not be confused with the often simi-
larly named harvestmen, which are alhes 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
Tipuhds bear a distinct V-
shaped mark (suture) on the Fig. 448.— Diagram of wing of crane-fly, Sim-

; . , , - ^ , plecta sp., showing venation,

back of the thorax. More than

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 viroods. The flight is uneven, slow, and weak, and
the ungainly fhes 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
larvae 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 ruhiginosa (Fig. 449), common in CaHfornia.
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 faUen leaves are decay-
ing and subdrainage water is always slowly trickling out from the soil. The
larvae (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 swaUowed, and, as it passes through the ahmentary
canal, the organic material digested out of it. The footless, worm-like
larvae 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 pupae (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 foHage 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, Cecidomyidae, 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

Fig. 449. Fig. 450,

Fig. 449. — The giant crane-fly, Holorusia rubiginosa, male. (Three-fourths natural

size.)
Fig. 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 antennae 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 larvae probably derive
most of their food by imbibing it through the skin. Lying with the body

The Two-winged Flies 323

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 larvai may be distinguished by their
possession of a strange little cliitin 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
larvae 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 100°, as well as in California. By the ravages of its larvae, 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 larva; 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 larvae. 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),

Fig. 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 larvae
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 Cahfornian 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 larvae, the
larvae of fungus gnats or members of the family Mycetophilidae. 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 antennae in most cases free from the whorls of long
hairs so characteristic of the Chironomidae, Culicidae, 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 larvae

The Two-winged Flies

325

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

Fig. 452. — A fungus-gnat of the family Mycetophilida; larva, pupa, and adult.

(Much enlarged.)

which to transform. Perhaps the most singular habits noted in the family
are those connected with the strong gregarious instinct which leads the
larv£e of many species to hve 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-
tenncT, the March-flies, Bibionida?, serve as a sort of transition family between
the long-legged, slender -bodied midge type of fly with its thread-like hairy
antennae, and the compact, heavy-bodied, short-legged type of fly with short
and club-Hke three-segmented antennae, 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-

FiG. 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-
tennae 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 larvae
feeding usually on decom.posing substances. With some species, however,
the larvas 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, Httle injury seemed to be done. B. jemorata, 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 CaHfornian 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.

Fig. 454. — March-fly, Bibio albipennis. (Three times natural size.)
Fig. 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. jraternus 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; Httle 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 famihes of nematocerous flies are not included in the key, and have

not heretofore been referred to. They are the Orphnephihdae, 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 antennae

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, Rhvphidae, or false crane- ^

.... . 1 ^ 1*10. 456. — Diagram of wing

flies, is represented in this country by two Rhyphus sp.

genera containing several species. The flies

are small and slender, with broad spotted wings veined in a character-
istic way (Fig. 456). The larvas 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 antennae
composed of few segments, in contrast with the many-segmented antennae,
usually slender and long, of the Nematocera, are separable into three groups
of famihes, as indicated in the key on page 303, based on a further analysis
of the structural character of the antennae. These groups are, first, one includ-
ing flies in which the antennae 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 antennae made of four or
five distinct segments; and third, and by far the largest, one including flies
with but three segments in the antennae.

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 famihes may be
distinguished as follows:

The branches of the radial vein (see Fig. 460) crowded together near the costal (front)

margin of the wing (Soldier-flies.) Stratiomyid.*;.

Venation normal.

Alulets, i.e., little whitish wing-like membranous flaps at the base of the true wings,

large (Horse-flies.) Tabanid^.

Alulets small (Snipe-flies.) Leptid^ (in part).

328

The Two-winged Flies

The most familiar and interesting flies in this group are the well-known
horse-flies, gad-flies, or deer-flies, Tabanidas. 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

Fig. 457. — Greenhead, or horse-fly, Tabanus lineola.

indicated by line.)

(After Lugger; natural size

the order. Many of the smaller horse-flies show gleaming metalHc 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.

Fig. 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 larvae,
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 larva
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 briUiantly

^'''■«J^/~^°'^n^"P''ri°^ ^ horse-fly, Therioplectes sp. md., mandible; mx., maxilla;
mx.l., maxillary \ohy mx.p., maxillary palpus; hyp., hypopharynx; lb., labrum
ep., epipharynx; h., labium; la., labellum. ^ -'i' 1 ^ > .

colored eyes and black or brown and yellow bodies mostly belong to the
genus Chrysops. Silvius pollinosiis 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, Stratiomyidae, 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 larvc-e
being terrestrial, while others are
aquatic. The food seems to be mostly vegetable, although the larva of some
species are believed to be carnivorous. One or two species live in salt or
brackish water, and Sharp records that some Stratiomyid larva were found
in a hot spring in Wyoming with the water temperature only 20° to 30° F.
below boihng. They pupate within the last larval skin, which is long and

Fig. 460. — Diagram of wing of Odontomyia
sp., showing venation.

33° 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 subcyhndrical abdomen with the whole body metallic
green.

The snipe-flies, Leptidae, 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 larvae Hve

in the ground, in moss, or in decaying

wood, sometimes penetrating to the

Fig. 461.— Diagram of wing oi Chryso- burrows of wood-boring insects. The

phila thoracica (LeptiQEe), showing . k ^ • ^

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 lemain there themselves
and die. The larvae on hatching escape into the water."

In the second group of Brachycera, including flies which have their anten-
nae composed of four or five distinct segments, there are two famihes, the
Asilidae, or robber-flies, and the Midaidae, or Midas-flies. These latter resemble
the robber-flies in size and general appearance, but differ from them by having
the antennae rather long and clubbed at the tip. They are predaceous,
catching and devouring other flying insects, and the larvae of the few species
whose life-history is known are also carnivorous, and seem to have a special
fancy for the larvae of the great wood-boring grubs of the giant Prionus
beetles. Howard believes that the large species, Mydas luleipennis, found
in the Southwest, mimics in coloration and general appearance for protection
or aggression the tarantula-killer wasp found commonly in this country.

The Asilidae, or robber-flies, compose a considerable family — nearly 1000
species occur in this country — of large, swift, hairy, ferocious-looking flies
which hve 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

331

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

Fig. 462. Fig. 463.

Fig. 462. — A robber-fly, Stenopogon inquinatus. (Natural size.)
Fig. 463. — A bumble-bee-like robber-fly, Dasyliis 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.

Fig. 464. — ^Diagram of wing of robber-fly, Erax cinerascens, showing venation.

The larvae live chiefly in decaying wood or in soil containing decom-
posing vegetable matter, and are also predatory, feeding on grubs and other

Fig. 465. — Mouth-parts of robber-fly, Erax cinerascens. li., labium; hyp., hypopharynx;
lb., labrum; mx., maxilla; mxL, maxillary lobe; mxp., maxillary palpus.

underground or wood-boring insects. The pupje 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 Dasyliis (Fig. 463) look
astonishingly like bumble-bees and wasps, probably a case of protective

332 The Two-winged Flies

mimicry (see Chap. XVII). Erax is a gemis 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 famihes includes many
families, in all of which the antennae 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. Antennae 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.) LEPXiDiE (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

(see Fig. 466) (Bee-flies.) Bombyliid^.

DD. Second branch of cubital vein joining first anal far from the
margin of the wing (see lig. 471).

(Dance-flies.) Empidid^ (in part).
CC. Radial vein with not more than three branches.

D. Head with a curving suture immediately above the antennas.

(House-flies and allies.) MusciD^.
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 iust at or near
this sweUing (Fig. 474). .(Long-legged flies.) Dolichopodid^.
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; antennae with dorsal arista.

(Bot-flies.) CEsTRiD^.
GG. Proboscis not rudimentary; palpi present; antennae
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

antennae (Wasp-flies.) CoNOPiDiE.

GG. Front convex beneath the antennae; a spurious
vein usually present between radius and media
(Fig. 479) (Flower-flies.) SyRPHiD.E.

The famihes of flies named in the above key contain many hundreds of
species but few of which are at all popularly known. The bot-flies (CEstridae),
house-flies, flesh-flies, bluebottles and stable-flies (Muscidas calyptrata), and

The Two-winged Flies 333

the cheese-skippers and pomace-flies (Muscidae acalyptratae) are about the
only names in the Hst of these hundreds which seem at all familiar. The
flower-flies (Syrphida?) and bee-flies (BombyHidaj) 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 famihes
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 attempt
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 (Bombyhidas) 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

1, , , J , . Fig. 466. — Diagram of wing of Anthrax ful-

unusually long slender proboscis ^/a,°, 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 larvae of the bee-flies,
however, are carnivorous, Hving parasitically in the egg-cases of grasshoppers
or on the bodies of wild bees and various caterpillars. One of these bee-
fly larvas 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-Hke 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 speciaHzed 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 longisb

334

The Two-winged Plies

hair usually light brown or 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
black.

Fig. 467.
Fig. 467. — A bee-fly, Bombylius major
Fig. 468. — A bee-fly, Exoprosopa sp

Fig. 468.
(Twice natural size.)
(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 bicychng because of hosts of small slender blackish flies
in swiftly dancing swarms. These are dance - flies,
Empididas, 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-
midae, 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
antennae. All the dance -flies
are predaceous, sometimes
catching their prey in the air,
sometimes chasing it on the
ground. The larvae, slender cylindrical grubs living in the soil or under leaves

Fig. 469. Fig. 470.

Fig. 469. — Mouth-parts of a bee-flv Bombylius sp

(Much enlarged.)
Fig. 470. — A dance-fly, Rhamphomyia longicauda

(Three times natural size.)

The Two-winged Flies nor

or other vegetable matter, are also probably predaceous, feeding on smaller
insects 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. It is 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 Dohchopodidas, or long-legged
flies. They are found especially
in marshy or low places where
vegetation grows lush and rank.
They flit about searching for
lesser insects, which they catch
and devour. They often get their

• 471- — Diagram of wing of dance-fly,
Rhamphomyia sp., showing venation.

prey by swift chasing over leaves or ground or even on the surface of water.
Like the Empidids the larvas are also predaceous, living underground or in
decaying vegetable matter. Some have been found in the exuding sap of

wjrf

mjc

Fig.

Fig. 472. Fij, ^^^

472.— Mouth-parts of dance-fly, Rhamphomyia sp. lb., labrum; \,!x., maxilla;
Ftp "!^; ' "^^ r ^"I ""Yi f ^•/'•' "^^^^iHary palpus; li., labium; hyp., hypopharynx.
I'lG- 473-— Dohchopus lobatus. (Three times natural size.)

trees and elsewhere on or under bark. The larvae of certain species spin
little thin cocoons when ready to pupate, but with most the pupa is
naked.

33^

The Two-winged Flies

Dolichopus (Fig. 473) is the largest genus of the family, nearly 100 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

Fig. 474. — Diagram of wing of a Dolichopodid, Psilopics ciliatus, showing venation.

characters. Other ornaments, too, are found in various species, some occur-
ring on the face, others on the antennae 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-
na; like a fly. The puzzle is readily solved with
these clues: the insect is a fly, not a wasp; it simply
looks so much hke 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, Conopida;, thus save their lives by
an innocent deception; they are protected by their
curiously close mimicry of wasps. All of them are
narrow-waisted, and most have the abdomen spindle-
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
larvje are parasitic, living in the bodies of other insects, especially wasps,

Fig. 475. — A wasp-like
Qy,PhysocephaIa affinis.
(One and one-half times
natural size.)

The-Two-winged Flies 007

bumble-bees, and locusts. "The eggs," according to Williston, "are laid
directly upon the bodies of the bees or wasps during flight. The young
larvae 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 Hfe.

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 (CEstridae) 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 larvae, 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 larvoe
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. Fig. 476. — Larva

dogs, cats, and even man. The larvae of still other species ? "°^""7' yj''^''^-
° ' ' ^ bra cimtculi, from

burrow in the nasal passages of the sheep, the antelope, wood-rat, Neoto-
the horse, the camel, the buffalo, and various deer species, "f*^ ^P- (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 larvae 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 hcking, swallowed, and thus introduced
directly into the stomach, to whose walls the larvae 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, Gastrophiliis
equi (Fig. 477). This fly, which may be seen in open sunny places along
the roadways, is about ^ 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 larvae hatch in the mouth or stomach and attach themselves
to the stomach lining, living at the expense of the host. When many larvae
thus live in the stomach (and as many as several hundred have been found
in one animal) the horse suffers serious injury. The larvae live in the stomach

Fig. 477.-

-Bot-fly of horse, male, Gastrophilus eqiii, abdomen of female and egg.
Lugger; natural size of fly indicated by line.)

(After

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 nasahs, 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 larvae are found in
small tumors under the skin, also have their eggs swallowed, and the young
larvae may be found in the mouth and oesophagus. 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 larvae 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-

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 larvae 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 larvae are thick and broad
at one extremity and elongate and tapering at the other.

The family SyrphidiE, Syrphus-flies, flower-flies, or hover-flies, as the
Enghsh 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

Fig. 478. Fig. 479.

Fig. 478. — A flower-fly, Eristalis tenax. (One and one-half times natural size.)
Fig. 479. — Diagram of wing of Syrphus continuax, 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 larva? 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 larvae most often written about are the curious "rat-tailed
maggots" (Fig. 480), larvae 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-

34<

The Two-winged Flies

don, which live in ants' nests, look like little mollu^s, and when first found
were actually described as new molluscous genera. Their body is fiat.

Fig. 480. Fig. 481.

Fig. 480. — Rat-tailed larva of a Syrphid. (Twice natural size.)
Fig. 481. — Larva of Microdon miUabilis, dorsal view. (Four times natural size.)

broad, unsegmented, and looks Hke a fiat 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.

Fig. 482.

-Mouth-parts of Eristalis sp. li., labium; hyp., hypopharynx; Ih., labrum;
mx., maxilla; mx.l., maxillary lobe; mx.p., maxillary palpus.

The species of Volucella are bee-like in appearance and their larvae 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, subcyUndrical body, blackish
with reddish-yellow markings.

The Two-winged Flies

341

The abundant house-flies are the most famihar representatives of the
largest of all the Dipterous families: largest if the great heterogeneous
group of flies called Muscidae 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 subfamiHes (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 hght 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.)

Alulets small Acalyptrate Muscid.i;.

Alulets large Calyptrate Muscid.e.

First posterior cell widely open Subfamily Anthomyiin.e.

First posterior cell narrowly open or closed (Fig. 490).

Antennal bristle wholly bare Subfamily Tachinin.e.

Antennal bristle with some distinct hairs.

Antennal bristle bare near the tip Subfamily Sarcophagin^.

Antennal bristle plumose or pubescent to the tip.

Back of abdomen bristly, legs unusually long Subfamily Dexiin.e.

Back of abdomen not bristly, except sometimes somewhat so near tip.

Subfamily MusciN^.

The Acalyptrate Muscidae include a host of small, mostly unfamiliar,
flies, distributed among a score of subfamilies. We shall refer to a few

Fig. 483. Fig. 484

Fig. 483. — House-fly, Musca domestica. (After Howard and Marlatt; three times

natural size.)
Fig. 484. — Foot of house-fly, showing claws, pulvilli, and clinging hairs. (Greatly

magnified.)

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 Muscinas. 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.

Fig. 4S5.

Fig. 486.

Fig. 485. — Larva of house-fly, Musca domestica. (After Howard and Marlatt; three

times natural size.)
Fig. 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 larvae
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.

This stable-fly and another ally of the house-

moxys calcitrans. (Three fly^ called the hom-fly, are great pests of stock.

The horn-fly, Hcematobia 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

Fig. 487. — A stable-fly, Stp-

The Two-winged Flies

343

states so widely as o cause much alarm. By 1895 i^ ^^^ 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 larvcc 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

Fig.

-The horn-fly, Hcsmatobia serrata. (After Lugger; natural size indicated
by Hne.)

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 larvae on meat, and, with some other allied species which,
however, do not all restrict their egg-laying to animal substances, belong
to the subfamily Sarcophaginas, so named from the flesh-eating habits of the
larvae or maggots of the best-known species The most abundant flesh-
fly in this country is named Sarcophaga sarracenicc (Fig. 489), and looks like
an extra-large house-fly. It gives birth to larvae (hatched from eggs retained
in the body of the female) which are deposited on fresh meat, sometimes in
open wounds. The larvae (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 erythrocephala,
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

Fig. 480. — .

A blow-fly or flesh-fly, SarcopJiaga sarracenicB.
indicated by line.)

(After Lugger; natural size

larvae feed on the juices of the decaying meat and pupate after a few days.
The pupae enclosed in the thickened brown last larval skin look like
large smooth shiny brown elliptical seeds, as do indeed the pupa? of all
Calyptrate ^luscidie. The commonest bluebottle- or greenbottle-fly is Lucilia

ccBsar, 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
lays its eggs on flesh, manure, in
open wounds, and often in the

Fig. 490. — ^Diagram of wing of Lucilia casar,
showing venation.

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 lar\-a? 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. As a 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 larvae 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 maybe called the sugar-beet
midge. The eggs are laid on the leaves, and in three or four days the tiny
white larvae hatch and burrow into the soft leaf-tissue. When many of the
larvae 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 Anthomyiinae, to which Muscid group two
other well-known fly-pests belong, namely, the onion-fly, Phorhia ceparum,
and the cabbage maggot-fly, Phorbia brassicce. 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 larvae 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 caniailaris ,
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 Tachiniinae. The females fasten their
eggs to the skin of young caterpillars, the hatching larvae burrow into the
body of their crawhng host and feed on its body-tissues Sometimes the
caterpillar is killed before it can pupate, but usually not, spinning its cocoon

146

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.

Fig. 491. — A Tachina-fly, Dejeania corpulenta. (One and one-half times natural size.)
Fig. 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.

Resembhng somewhat in appearance the Tachina-flies are the so-called
nimble-flies, constituting the small subfamily De.xiince. Most of the species
in this country belong to the single genus Dexia and have been little studied.
The larvae 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 Muscidae (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

347

recognize some twenty distinct subfamilies (or families, if the group
Muscidse 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.

Fig. 493. — Red-tailed Tachina-fly, Winthemia 4-pustnluta, a parasite of the army-worm,
Leucania unipuncta. a, fly, natural size; b, 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 Diopsidae, which have the eyes on conspicuous elon-
gate lateral processes of the head. These eye-stalks bear also the antennae.
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 CaHfornia may be found, at certain seasons
of the year, innumerable larvc-e 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
Ephydridae occur abundantly in salt-water marshes, the flies living a preda-

FlG. 494.

Fig. 495.

Fig. 494. — Scatophaga sp. (Two and one-half times natural size.)
Fig. 495. — An aquatic muscid, Tetanocera pictipes, larva, pupa, and adult.
Needham; two and one-half times natural size.)

(After

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.
These flies would dart down and lay their eggs on the
smoked meat while actually in the wrapper's hands,
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 larvae 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.

Fig. 496. — The cheese-
skipper fly, Piophila
casei. (Five times
natural size.)

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, Drosophihdae, may be seen busily lapping up their
favorite food, the juices of fermenting fruits.
The most abundant and 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 larva or maggots hatch in
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

Fig. 497. — Trypeta longipennis. (Two
and one-half times natural size.)

Fig. 498 — Larva of cherry-fruit fly, Rhagoletis cingiihta, dorsal and lateral views.
(After Slingerland; natural size and much enlarged.)

35^

The Two- winged lilies

than two weeks. Thus e\'en in the short season of the fruit ripening and
gathering much injur}- can be and often is done by these little tipplers.

A much larger group of fruit-flies is the Trypetidas, whose larvae 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. — Pupari;i of cherry-fruit fly, Rliugoletis cingiilata. (After Slingerland; natural

size and much enlarged.)

of the thick white larvae 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, Gelechiq gallcE-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 liidens, whose
larvK infests Mexican oranges and may sometime
get a foothold in Cahfornia or Florida.

Another group of small flies whose larvae are
responsible for serious injury to growing grain,
meadows, and pasture grasses are the Oscinidae,
or grass-stem flies. The adults are commonly taken
by collectors when beating or sweeping in meadows
Fig. 500. — An aquatic and pastures. The flies are minute but plump,

muscid, Sepedon fasa- ^^^^ ^j.^ variously colored, sometimes blackish,

pennis, larva, pupa, and . .

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,

and are said to cause a prevalent disease of the

eyes in the South. The thick cylindrical little larvae of several species of

Oscinis hve 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 351

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 sj)ecimens 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 ofT 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 ^ 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 famihes, as follows:

With compound eyes; sometimes with wings.

(Bird-, sheep-, and horse-ticks.) Hippoboscid^.
Without compound eyes, always wingless.

Halteres present; on bats (Bat-ticks.) Nycteribiid^.

Halteres absent; on honey-bees (Bee-lice.) Braulid^.

Of the Hipposcida; 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. Oljersia 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.

(.-Xfter Lugger; natural

Fig. 501. — A horse-tick or forest-fly, Hippohosca equina.

length J to J 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.

Fig. 502. Fig. 503. pic. -03. Bat-tick, Nycterihia sp.

Fig. 502. — Sheep-tick, Melophagus ovinus. Nat. size \ in.

Fig. 504. — A bee-louse, Braula sp. (After Sharp; much enlarged.)

The bat-ticks, Nycteribiidse (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 353

upper were the under surface. The head is narrow and Hes back on the
dorsum of the thorax, and the pro thorax 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, jV inch long, found clinging to the thorax
of queen and drone honey-bees and known as the "bee-louse," Braula
ca'ca (Fig. 504), is the only species known of the family Braulidae. 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 (Pulicidae) 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
famihes of its own. Nearly 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 'pecuhar 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-
tenna 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 maxillae, 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

Fig. 505. — Dog- and cat-flea, Ctenocephalus canis. (After Lugger; much enlargeci.)

small-headedness is truly deceptive. However, our modern mechanical
theories of reflex action, negative phototropism (repulsion by light), etc.,

Fig. 506. — The house-flea, Pw/ex ^Vritew5. ^, larva; 5, pupa; C, adult.
(After Beneden; much enlarged.)

allow r.s to give the elusive flea little credit for its ingenuity; we must look
on it ..s 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 larva) (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 antenna) and biting mouth-parts, but no
eyes. The larvce 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 hfe 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 htter in which it hes,
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 larvae emerge), but in the burrowing
kinds hke the "chigoe" 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 SarcopsyUida) 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 chigoe, 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 Linnaeus 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,

35^ 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 swelhng 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, XestopsyUa 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 i8go
and is a common pest from Florida to Texas.

The second family, Pulicidae, includes all the other fleas, none of which
burrows into the skin. The various species range in size from ^^ inch (Anomi-
opsylhis niidatus, found on a mouse in Arizona) to \ inch {Ceratophyllus
stylos Its, 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, Piilex irritans, was described by Linnaeus 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, Ctenocephalns 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 larvae 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 larvae hatch,
in summer, in from four to six days, become pupae 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 larvae
live in the dust, feeding on whatever bits of organic substance they can find
there. Larvae 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-larvae will not develop successfully
in places where they are often disturbed, much sweeping and scrubbing

The Two- winged Flies 357

will keep them down. Mats and places where dogs and cats He 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 behef 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 XIV

THE MOTHS AND BUTTERFLIES (Order Lepidoptera)

OTHS and butterflies are the insects most
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 afluiities 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 sy-mmetrically 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,
e.xplaining 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 famihes. 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.

i = Junonia coenia.
2=Iphidides ajax.
3=Epargyieus tilyrus.
4= Cyan iris pseudargiolus.
5 = Ancy loxypha n umitor.
6=Papilio turnus.
7 = Nathalie iole.
8=Parnassiu3 smintheus.
9=Tlieda halesus.
io= Zerene ctesonia

PLATE V

Mary IVellman, del.

The Moths and Buttertiies

359

posed of the two greatly elongate maxillae, 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 hp
(labium) are greatly reduced and
are not movable and flap-like as in
most insects, while the mandibles
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 maxillae 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 Eriocephalidas, all the
usual parts of a typical insect
mouth are present and in a condi-
tion fitted for biting and chewing
and in all ways wholly comparable
with the condition in such biting
mandibles are movable

Fig. 507. — A trio of apple tent -caterpillars,
larvas of the moth Clisiocampa americana.
These caterpillars make the large unsightly
webs or tents in apple-trees, a colony of
the caterpillars living in each tent. (Photo-
graph from life by Slingerland; natural size.)

insects as the locusts and beetles; the
and truly jaw-like, the maxillas short and rlso
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

^

Fig. 508. — Bit of wing of monarch but-
terfly, Anosia plexippiis, showing scales;
some scales removed to show the inser-
tion-pits and their regular arrangement.
(Greatly magnified.)

stage. The immature staees of

and the extreme speciaUzation 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

adult or imaginal stage. 'I'he immature stages
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
and butterflies. The great silken cocoons found on
orchard-trees in winter-time are known to contain
the pupae 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 (larvae) 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 larvae 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-

FiG. 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.)

The Moths and Butterflies

3

6i

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 (larvae of the Geometric!
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. Fig. 511. Fig. 512.

Fig. 510. — Cross-section of sucking-proboscis of milkweed-butterfly, Anosia plexippus;

see tubular cavity, c, formed by apposition of the two maxillae, tr., trachea; n., nerve;

m., muscles. (After Burgess; greatly magnified.)
Fig. 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. in., muscles; tr., trachea;

71., nerve; c, groove.
Fig. 512. — Diagram of arrangement of pharynx, oesophagus, etc., in interior of head

of monarch butterfly, Anosia plexippus, showing means of producing suction in

the proboscis, oe., oesophagus; t?»?., dorsal muscle; /.w., 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 antenuce, legs, and
wings of the enclosed developing adult always indicated, are also hardly to
be mistaken for the pupae 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 pupae; some
are subterranean, the leaf-feeding larvae 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 larvae 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 brighdy 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 larvae 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. f ( /f ) niAii)])^-"'"'^'^'
Others attack fruits, as that ( ^^f\"^^' / y/%r^'^^
dire apple pest, the codlin-
moth larva ; while still others '" p^- '""''^ /ff\y\f)\' ^P-

Fig. 513.

Fig. 514.

Fig. 513. — Front of head, with scales removed, of sphinx-moth, showing frontal sclerites
and mouth-parts, f/^., epicranium; 5!(., suture; c/., clypeus; ^e., gena or cheek; />/.,
piUfer of labrum; md., mandible. Between the two pilifers the base of the sucking-
proboscis composed of the apposed maxillae is seen. (Much enlarged.)

Fig. 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; pj., 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; Im., labium; Ip., 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; lb., labrum; pj., pilifer
of labrum; md., mandible; ge., gena or cheek. In lower right-hand corner, ffont
of head, with scales removed, of monarch butterfly, Anosia plexippus lb., labrum;
g., gena or cheek; pj., piUfer of labrum. (Much enlarged.)

are content with dry organic substances, as the larvae 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 larvae 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 antennae
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 jesthetic ap-
preciation of the beauty
and attractive, apparently
care-free, flitting about of

ant

Fig. 517.

Fig. 518.

Fig.

Fig.

515. — Front of head of larva of tussock-moth, Notolophus leucostigma. ant., antenna;

md., mandible; vjx., ma.xilla; mx.p., maxillary palpus; li., labium. (Much enlarged.)
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, l.ant., larval antenna; ant., adult antenna; l.md , larval mandible;

l.mx., larval ma.xilla; i.nix., adult maxilla; lb., larval labrum; /./i, larval labium.

(Much enlarged.)
Fig. 517- — Developing adult head dissected out from head of larva of tussock-moth,

Notolophus leucostigma. ant., antenna; mx., maxilla; li.p., labial palpus. (Much

enlarged.)
Fig. 51S. — Head of tussock-moth, Notolopliw; leucostigma; showing adult antenna; and

mouth-parts, mx., maxilla; li.p., labial palpus. Note that the two maxilla; 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

3^4

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,

Fig. 519. — Larva of obsolete-banded strawberry leaf-roller, Cacoecia obsoletana. (Photo-
graph from life by SUngerland; natural size in lower corner and twice natural size
above.)

or moths, and the Rhopalocera, or butterflies. All butterflies have antennae

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 antennae variously formed, as wholly filiform, pectinate,

The Moths and Butterflies

365

Fig. 520. — Pupa of obsolete-banded strawberry leaf-roller, Cacoccia ohsoletana. (Photo-
graph from life by Slingerland; natural size a little more than one-half inch.)

Fig. 521. — Moths of the obsolete-banded strawberry leaf-roller, Cacoecia obsoletaiia,
male above, female below. (Photogt^aph from life by Slingerland; natural size.)

366

The Moths and Butterflies

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

Fig. 523. — ISIoth 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 butterfly families, the numbers represented in this country being
44 to 5. By reference to the following key adapted from Comstock aln ost any
North American moth can be traced to its proper family.

KEY TO THE SUPERFAMILIES AND FAMILIES OF MOTHS.
This key does not include 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 bright
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 sHdes with glycerine
jelly and thus be made available for inspection at any time.

A. Moths which have a thin lobe-Hke 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 Jugatse.)
B. Very small moths, not more than one-fifth inch long.

MiCROPTERYGiD^ and Eriocephalid.e.

BB. Moths from one-half to one inch long (The Swifts.) Hepialid^.

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 Frenatse.)
B. Hind wings with fringe on hinder margin as long as the width of the wing;

hind wings often lanceolate in shape Superfamily Tineina (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.) Pterophorid^ and ORXEODiD.i;.
CC. Wings not fissured.

D. Fore wings very narrow; part of the hind wings always, and of
the fore wings often, clear, i.e., without scales.

(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 Tineina (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.) Megalopygid.e.
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.) Psychid.^.

II. Anal veins not anastomosing.

J. Vein m^ of fore wings arising from the
discal cell nearly midway between
veins Wj and m^ (Fig. 603).

(Silkworm-moths.) Bombycid^.

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.) CossiD^.
EE. Hind wings with less than three anal veins.

F. 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).

Pyromorphid.e (part).

GG. The two anal veins partly fused and appearing like

a single branched vein (Fig. 552). PsYCHiDiE (part).

FF. 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 vwngs.
(Sphinx- or hawk-moths.) Sphingid^.
HH. Hind ^vings 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.) Notodontid.^.

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 dehcate fore wings.

Superfamily Geometrina.

II. Vein Wj 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.) Agaristid^ and Pericopid.e.
KK. Not such moths.

L. Ocelli absent; antennae pec-
tinate.
(Tussock-moths.) Lymantriid^.
LL. Ocelli present or, if absent,
with simple antennae.
(Owlet-moths.) Noctuid.e.
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 vnth only the tips
separate (Fig. 591). . .Zyg^nid.e
KK. Subcosta and radius of hind wings
united for about one-half their
length, of more, but usually
separating before the apex of the
discal cell (Fig. 597).
L. Ocelli present.

(Tiger-moths.) Arctiid^e.

LL. OceUi absent.

(Footman-moths.) Lithosiid.e.

GGo 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.E.
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 Micropterygida^ and
Hepialidae, both represented by but few species and these rarely met with

The Moths and Butterflies

371

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 (Cple-
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 maxillae, and short,
truly hp-like labium. All other moths
and butterflies have the mouth-parts
specialized for sucking, with the man-
dibles rudimentary or wanting, the max-
illje 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. Fig. 524. — Diagram showing venation
undoubtedly nearly alhed to the moth of wings in monarch butterfly, ^^mm
■' ■' plexippus. c, costal vein; sc, sub-

ancestors, instead of the specialized costal vein; r., radial vein; cm., cubi

frenulum as in other moths, is also evi-
dence of the ancestral type displayed by
the Jugatae.

The Micropterygidae, 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,

tal vein; a., anal veins. The base of
the medial vein (lying between radius
and cubitus) is obsolete, but its
branches still persist, lying between
branches of radius and cubitus.
(Natural size.)

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 larvae, 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 larvae burrow into the
ground to pupate, while the exposed feeders make a slight cocoon of silk and
debris above ground. The pupae are more like caddis-fly pupaj 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 Hepialidae, the ghosts or swifts, although an offshoot from the
Micropterygidae, or at least much more nearly related to them than to
any other moths, are very different in appearance, being from an inch to
2k 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 rjr3r3r4

~m — r. — '<^^r~p^mJ

a a ^''' y

Fig. 525. Fig. 526.

Fig. 525. — Diagram of wing venation of Micropteryx sp. cs, costal vein; sc, subcostal
vein; r, radial vein; m, medial vein; c, cubital vein; a, anal veins. (After Com-
stock; enlarged.)

Fig. 526. — Diagram of wings of Hepialus gracilis, showing jugum (7), 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-like and of the type of the
under hp 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

373

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

^^^- ^^"^ll^-^^n '^'l"*«^s-moth, -g^ p-eneral coloration of the moth, by a pale
I inea peUwnella; larva, larva ^ o j . r

in case, and adult. (After silvery appearance. Females have been seen
Howard and Marlatt; twice ^^ fly directly to the ghostly hovering males

natural size.) .. ' , _,, . i-. ,

as if strongly attracted. Ihe grub-like larvae
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-maadatus 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 pupce 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 Jugat£e 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 Frenatae. 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
elaborate means than the simple overlapping
of front margin of hind wing and hind
margin of fore wing, but never by a jugum,
the caddis-fly-like method common to the Micropterygids and Hepialids.

Fig. 528. — Larva of the palmer-
worm, Ypsolopliiis pomatellus,
lying under its web spun on a
leaf (After Lowe; natural length
\ inch.)

374

The Moths and Butterflies

Among the Frenatae there is a host of small obscure moths commonly
lumped by collectors and amateurs under the name Microlepidoptera, which

are little known because httle
studied, but which professional
entomologists recognize as in-
cluding all together eleven moth
families grouped into three dis-
tinct superfamiHes. Among these
microlepidoptera are probably the
most generahzed of the frenate
Fig. 529. Fig. 530. moths.

Fig. 529. — The palmer-worm moth, Ypsolophiis The three microlepidopteroUS
P^-^^atellus. (After Fitch; twice natural s^perfamilies are the Tineina,

Fig 530. — The strawberry root-borer> Anarsia including the clothes-moths, leaf-
Uneatella. (After Saunders; moth and larva miners, and Others, the Tortri-
both natural size and enlarged.) .

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 Tmeidae, 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 larvae, 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 small white larvae 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 T. 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 to transform. The moths, on issuing, rest during the day on the
garments or stuffs, but fly about at night, often coming to the lights in
rooms. They are all small, pellionella and biselliella expanding about -j
inch and tapetzella | inch; pellionella has grayish-yellow fore wings with-
out spots, and tapetzella has the 'fore wings black at base and creamy-

Z. p. mlz. I uALF*

The Moths and Butterflies

375

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 larvae bore into the kernels,
feeding on the inner starchy matter. I have seen ears
of corn in Kansas cribs with every kernel attacked.
The larvae 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 hke 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 larvae. 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-
appearance of the inner tissue. This is the work of
the tiny burrowing and feeding "leaf-miners," the
larvae of certain Tineid species. Often the miner,
a small white grub with the usual eight pairs of legs characteristic of Lepi-
dopterous larvae, 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

Fig. 531. — Pupal cocoons
of the apple bucculatrix,
Bucculatrix pomijoliella.
(Twice natural size.)

37^

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-
jolieUa, being abundant in the leaves of pitch-pine.

Interesting little Tineids are the apple and oak bucculatrix-moths, whose
larvae feed on the leaves and w\\tn ready to pupate crawl to a stem or branch

ff r2r.3 r4

'r-\--\ M \ ^^ C2

Fig. 532. . Fig. 533.

Fig. 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.)

Fig. 533. — Venation of a Pyralid moth, P>'ra/:'5 /ar/;ja/f5. C5, costal vein; 5C, subcostal
vein; r, 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
pupae hibernate, the tiny moth issuing the following spring and laying its
eggs on the leaves. The larva are miners at first, but after the first moulting
feed on the outer surface of the leaves under thin flat silken webs.

The PyraliJina include half a dozen famiUes, some of the moths
hardly properly called microlepidoptera, for they reach a wing expanse of
i^ inches. But most of the species are small and but few are at all
familiar to collectors. The larvae 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

377

ridte, the exception being a small moth with both wings deeply cleft into
six parts. It is called Orneodes hexadadyla and is considered to be the
sole representative, so far as known, of a distinct family, the Orneodidai.
Of the Pterophoridae several species are common in the North and East.

Fig. 534.

Fig- 535-

Fig. 534. A California plume-moth. (Natural size.)

Fig. 535. — The raspberry plume-moth, Oxyptilus tenuidactylus, moth and larva. (After
Saunders; moth natural size; larva much enlarged.)

Oxyptilus 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.

Tig. 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 larvae 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 larvae 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 jarinalis, is a common pest,
the larvae making long tubes of silk in the meal, and taking readily to cereals

^m^m^^^^m^

Fig. 537. — A curious hammock and its maker, Coriscum ciiculipennellitm, 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; hammock
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 inter punctella, 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 f 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 kiiehniella (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 larvae 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 tnellonella, whose larvae 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 larvae 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 pupai. 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 like 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 larvae 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-roUers are

38<

The Moths and Butterflies

Tortricids, but the majority of rolled-up leaves so commonly seen on shrubs
and trees are the homes of these larvae. 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
-^'-^ — iif ^ whose healthfulness is not

so important to us. The
larvae of Cacoecia rosaceatia,
the oblique-banded 1 e a f -
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
fore wings crossed by wavy
dark-brown lines and ochre-
yellow hind wings. Choke-
berries, and cultivated cher-
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 larvae change to pupae within
the nest; and the pupae when about to transform work their way out and
hang suspended from the outer portion of the nest." The moths expand
from -f to i^ inch, have bright ochre-yellow 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 larvae of C. parallela (Fig. 540),
a leaf-roller moth with reddish-orange fore wings crossed
diagonally by numerous fine Hnes of a darker red-brown,
and a pair of broad oblique red-brown bands. The hind
wings are pale yellow.

Notwithstanding the apparently sufficient protection afforded the leaf-
rolling larvae by their tightly rolled cylindrical cases and webby nests, birds

Fig. 540.

Fig. 538. — The cherry-tree leaf-roller, Cacoecia cera-
sivorana. (After Lugger; natural size.)

Fig. 53Q. — Venation of a Tortricid, Cacoecia cera-
sivorana. cs, costal vein; sc, subcostal vein;
r, radial vein; m, medial vein; c, cubital vein;
a, anal vein. (After Comstock; enlarged.)

Fig. 540. — The cranberry leaf-roller, Cacoecia paral-
lela. (After Lugger; natural size.)

Fig. 541. — The
sulphur-colored
tortrix, Dichelia
siiljureana. (Af-
ter Lugger; nat-
ural size.)

The Moths and Butterflies

381

Fig. 542. — The rus-
set-brown tortrix,
Platynota flavedana.
(After Lugger;
natural size.)

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 vi^ithdrawn 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 larvx^ 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

the grape-berry, cuts out of a grape-leaf a little flap which

it folds over and fastens with silk, thus forming a small

oblong case within which it pupates. The moth expands

finch, 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 larvae burrow into opening fruit- and leaf -buds on apple-
trees and eat them. The moth expands f inch and is
dark ashen-gray with a large irregular whitish band on
the fore wing.

By far the best known and most feared and hated
Tortricid is the codlin-moth, Carpocapsa pomonella (Figs.
545 and 546), the most important enemy of the apple-
grower. Distributed all over the United States, wherever
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)

in the calyx of the newly forming apple, or

sometimes, as recently observed in California,

on the side of the tiny fruit. The larvae, hatch-
ing in from three to five days, begin to feed on

the green fruit, soon burrowing into its center.

They become full-grown before the apples ripen, burrow out and crawl

Fig. 543, — The eye-
spotted bud-moth,
Tmetocera ocellana.
(After Lugger;
natural size.)

Fig. 544. — The cranberry
worm-moth, Rhopotota vac-
ciniana. (After Lugger;
natural size indicated by
line.)

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 larvae 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 pupae lasting over the winter and
the moths issuing about apple-blossoming time the following spring. The
pupae are protected by thin papery cocoons of silk spun by the larvae. 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

Fig. 545. — The larva or worm of the codlin-moth, Carpocapsa pomonella. (After
photograph by Shngerland; three times natural size.)

sacking at the time the larvae 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 larvae 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
hatchino- larvae 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 larvae inside act as if bewitched, twitching and jerking,
rolUng over and leaping shghtly clear of the table or desk on which they

The Moths and Butterflies

383

may rest. The larva; pupate within the beans, first gnawing a circuUu
thin place through which the moth may push its way out. Another Tor-
tricid moth, Grapholitha sebastiance, has similar habits. Most of the jump-
ing beans come from the Mexican province of Chihuahua.

Fig. 546. — Pupae, 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, Megalopygidae, 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 i 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 purpHsh- Fig. 547.— The Mexican jumping bean-moth,
brown hairs, is not uncommon in C<^rpocapsa saltitans; pupa croton-bean

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 pupae 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
Eucleidae (or Cochlidiida?). The moths themselves are small and stout,
mostly rather strikingly colored, with brown, apple-green, and cinnamon
prevailing. The larvte 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)
stimidea', 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 pcemdata 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
larvae is the hag-moth, Phohetron pitheciutn, 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 Cossidaj, or carpenter-moths, with slender,
smooth, spindle-shaped bodies and long, narrow-pointed, strong wings hke
those of the hawk-moths (Sphingidtc). The larva) 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 larvae burrowing into the hard wood, where they Hve
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 robinm (Fig. 549), or
goat-moth, so called from
its curious offensive odor,
expanding i^ inches (males)
to 2\ inches (females), has
gray wings with irregular
black lines and spots in
the female, and darker
fore wings and yellowish
hind wings in the male.
Its larvce feed on locust-
trees and are often abun-
dant enough to do much injury. The wood leopard-moth, Zeiizera pyrina,
is strikingly spotted with black on a white ground color, and is common in
certain eastern cities, its larvae infesting maples and other shade-trees. On
' the Pacific coast the poplar carpenter-moth, Cossus popidi, with whitish
fore wings shaded all over with blackish and irregular black Hnes, and hind
wings yellowish gray, growing darker at the outer margin, is common, its
larvae infesting poplars and cottonwoods. There are only twenty species
in North America belonging to this family.

FamiUar curiosities of entomology are the moving bags of silk and bits
of twigs and needles occasionally found in cedars, firs, and arbor vitae. The
"worms" which make these bags and carry them around, with all the body
inside except the projecting head and thoracic legs, are the larvae of the

Fig. 548. — Venation of a Cossid, Prionoxystus robinia.
cs, costal vein; sc, subcostal vein; r, radial vein;
m, medial vein; c, cubital vein; a, anal veins. (After
Comstock; enlarged.)

386

The Moths and Butterflies

bag- worm moth, Thyridopteryx ephemera; for mis (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 Psychids, as
represented in this country. In the Southern States a common species is
Abbott's bag-worm, Oiketicus abbotti, whose larvae make bags with the bits
of twigs fastened regularly transversely, the male moth expanding ij 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 ^ inch to | inch, P. conjederata, the best known, being all

Fig. 549. — The locust-tree carpenter-moth, Prionoxystus robittics, male and female
moths, young larva and empty pupal case. (After Lugger; moths and 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, Pyromorphidae, of which but fifteen species occur ,
in the United States, are small, expanding from -| inch to i inch (a single
Western species expands ij 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 larvai 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 larvae of Har-
risina americana, a common Eastern species, may often be found arranged

Pig. 550. — The bag-worm moth, Thyridopteryx ephemercejormis; 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
1 1 inches and is lustrous bluish green with orange prothorax. Acoloithus

The Moths and Butterflies

jaJsariiis, one of the smallest members of the family, expanding f inch, com-
mon in the East, is black with very narrow reddish collar. Pyromorpha
dimidiaUi, expanding i 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 Sesiidae. 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
moths of other families, as the clear-
winged sphinges and others, have simi-
larly partly clear wings, but the very
narrow fore wings and widely expanded
bases of the hind wings will distinguish the Sesians from the few other
scattered clear-winged moths. The larvae 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.

Fig. 551. — Bag-worm ; the larva of a moth
that builds a protecting case out of
silk and bits of sticks, in which its
whole body except homy head, thorax,
and legs is concealed. (Natural size-)

The Moths and Butterflies

389

rs

■:^*4f

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 larva; (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 a. Ieas,-and hibernate quies- ^'yil^ZTlt"Ti;T4!:^:'tf:-
cent, being now about half-grown. merajormis. cs, costal vein; sc, subcostal
In the spring they become active ^^in; r, radial vein; m, medial vein; c,

^ ° -^ 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
their burrows, come out to the
surface of the bark, spin about
themselves a thin silken cocoon
and change (Fig. 557). The
pupal stage lasts
weeks, when the
The clear-winged
expanding i inch, are deep
steely-blue, with small golden-
yellow markings on head and
thorax and abdomen; the larger,
heavier-bodied female, expanding
a a a "* i|inches,has a broad orange band

Fig. 553. —Venation of a Pyromorphid, Pyro- across the abdomen in the fourth
morpha dimidiata. cs, costal vein; 5C, sub- q^. f^^^]^ segments, and has the
costal vein; r radial vein; m, medial vein; . , . , , , 1 ■ 1

c, cubital vein; a, anal veins. (After Com- front wmgs 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

about three
moths issue,
male moths,

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.

Fig. 554. — Moths of the peach-tree borer, Sanninoidea exitiosa, the upper one and the
one at the right being females. (Photograph from hfe by Shngerland; natural size.)

The currant-borer, Sesia tipuliformis, expanding three-fourths of an
inch, has a robust body with a fan-hke tuft of scales at the posterior tip,

Fig. 555. — Eggs of peach-tree borer, Sanninoidea exitiosa. (After Slingerland; natural
size at n; one egg enlarged at I; 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 larvae burrow into the center
and then tunnel longitudinally in the pith. They hibernate in the cane
as larvae, not pupating until ihe following summer, when the moths escape

The Moths and Butterflies

391

through holes in the cane thoughtfully made by the strong-jawed larvae
before pupation. The grape-vine-root borer, Memythrus poUstijormis, looks
much like a large Polistes wasp, having a dark body with two bright* yellow

Fig. 556. — Larva of peach-tree borer, 5aKwmo/(/ea exitiosa. (After Slingerland; natural

size and much enlarged.)

narrow bands about the abdomen; the fore wings are brownish black, the
hind wings clear; the larvae bore in the roots of wild and cultivated grapes
and pupate underground. The raspberry-root borer, Bemhecia tnarginata,
is also very waspish in appearance, with its black body repeatedly banded

wr

«.

!^

jjimii

tfc..«>'

^|fcr

i

L

<*•

^BUM

Mi

1

\

1

L

"^^WlHi

BP

Fig. 557. — Cocoons and empty pupal skins of the peach-tree borer, Sannmoidea exitiosa.
(After Slingerland; natural size.)

with yellow and transparent fore and hind wings. The eggs are laid on
raspberry canes, and the larvae, first boring into the cane, finally work down
into the roots. Squashes are often badly injured by having their stems
tunneled by the larvae 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
larvae leave the stems and go into the soil to cocoon and pupate. The genus

Fig. 558.

Fig. 559.

Fig. 558. — The ash-tree borer, Trochiliiim fraxini. (After Lugger; natural size.)
Fig. 559. — Sesia pidipes, 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 Notodontidse, comprising the puss-moths, handmaid-moths,

and prominents, is represented in
this country by about ninety-five
species, all of medium siz.e, i.e., with
a wing expanse of from ij 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
famiUar species in this family are
the Datanas, or handmaid-moths;
certainly their larvae are more often
seen and are better known, under
the names of yellow-necked apple-
tree caterpillars and walnut cater-
pillars, than the larvae 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,

Fig. 560. — Venation of a Notodontid, Noto-
donta stragula. cs, costal vein; sc, sub-
costal vein; r, radial vein; m, medial
vein; c, cubital vein; a, anal veins.
(After Comstock; enlarged.)

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 larvie, 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

Tachina species the most good, that is, on

the body of these plump caterpillars, so

that the hatching Tachina grub can burrow into this well-nourished Ijody

and feed on its living tissues. When feeding in the tree-tops, too, the Datana

Fig. 561. — The red-humped cater-
pillar-moth, CEdemasia eximia^
(After Packard; natural size.)

Fig. 562. — Larva of red-humped caierpillar-moth, CEdemasia 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 larvce 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
100 by each female, on the leaves, all
cemented well together in neat patches.
When the larvae 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 ih inches, is reddish or yellowish brown, with the fore wings
crossed by from three to five darker brown lines, the outer margin and one

Fig. 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

Fig. 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, (Edemasia concinna (Fig. 561), a
darkish-brown moth expanding about i\ 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 larvae (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 (Noctuidas) with their brown and gray
and gray and blackish finely variegated fore wings and unmarked silky white
wings. Their brown or greenish larvae, 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,

Fig. 565. — Canker-worms, larvae 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

39^

The Moths and Butterflies

Fig. 566. — Lime-tree inch-worm, larva
of the geometrid moth, Hibernia
tiliaria. (After Pettit; twice natural
size.)

/v

as they are variously called, which are the larvae (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 larvae in lacking the front
three of the four pairs of prop-legs
normally belonging to the middle part
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.

The geometer-moths, of which we have
800 species in this country, while of course
presenting a great variety of coloration and
pattern yet possess a likeness of general
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 i inch expanse, and a few large,

Fig. 567. — -Venation of a geometrid,
Dyspepteris abortivaria. cs, cos-
tal vein; sc, subcostal vein; r,
radial vein; m, medial vein;
c, cubital vein; a, anal veins.
(After Comstock; enlarged.)

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 famiUes based on venational characters rather confusing and appar-
ently not surely indicative of natural relationships. We may content our-

5

Fig. 568. — Male and IriiKilc 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 {Anisopteryx 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' „ ^ r^ . .. •

° y r YlG. 50Q. — Dyspepterts

ink, refuse sorghum, or any slow-drying varnish is abortivaria. (After
equally effective. From the eggs laid in the spring by Lugger; natural
Paleacrita and in the fall by Anisopteryx hatch active
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 i
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 larvae crawl down the tree to the
ground, burrow into it and pupate in a 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

Fig. 570. . Fig. 571.

Fig. 570. — The pepper-and-salt currant-moth, Eubyia cognataria. (After Packard;

natural size.)
Yic. ;;7i. — Phigalia strigataria, the iemale 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

Fig. 572. Fig. 573. Fig. 574.

Fig. 572. — The large blue-striped looper, Biston ypsilon. (After Forbes; natural size.)

Fig. 573. — The common Cymatophora, Cymatophora pampinaria. (After Lugger;

natural size.)

Fig. S74. — The plum-geometer, Eumacaria hrunneraria. (After Lugger; natural size.)

has a grape-feeding larva. The raspberry geometer, Synchlora glaucaria,
has delicate pale-green wings with two transverse whitish lines; its larvse
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
tiny heap of debris. The snow-white Eugonia,
Ennonos suhsignarius, is pure white, expanding
an inch and a half; its larvae feed often de-
structively on the foliage of elms, lindens, and
apple-trees. Angerona crocotaria (Fig. 576) is
a beautiful sulphur - yellow Geometrid, ex-
panding i\ inches, with a number of irregular pinkish-brown blotches
on the wings; its yellowish-green larvae feed on currants, gooseberries.

Fig. 575. — The currant fruit-
worm moth, Enpithecia in-
trrruptofasciata. (After
Lugger; natural size.)

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 larva? 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, HcBmatopis grataria, with reddish-

FiG. 576. Fig. 577. Fig. 578.

Fig. 576. — The currant-angerona, Angerona crocataria. (After Lugger; natural size.)
Fig. 577. — The currant-endropia, Endropia armaiaria. (After Lugger; natural size.)
Fig. 578. — The scallop-shell geometer, Ca/oca//)e M«(fj</ato. (After Lugger; natural size.)

yellow wings and two transverse bands and the outer margins pinkish
The chain-dotted geometer, Caterva catenaria, expanding ij 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 larvae are pale straw-yellow
with two fine lines on the back and two on each side interrupted by two

Fig. 579. — The diverse-lined geometer, Petrophora diver silineata. (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 Noctuidse, 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
Noctuidae, 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 larva' ; 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

Fig. 580. — A group of red and yellow underwings; upper moth, Catocala palceogiima;
lower left-hand corner, Catocala iiltronia; lower right-hand corner, Catocala grymea.
(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 larvae are curious creatures, with body thick in the middle and

The Moths and Butterflies

401

tapering towards both ends. The lar\ie of Catocala nltronia (Fig. 581)
feed on plum-tree leaves; tlicy arc about ij 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

Fig. 581. — The plum-tree Catocala, Catocala iiUronia, 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 slimmer. 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 rr^argined
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

40:

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 curv-
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 Unes attacks
all sorts of garden products and other low-growing plants; it is the larva

Fig. 582. — Green-fruit worms, Xylina grotci, at left, and Xylina antennata at right.
(Photograph by Shngerland; natural size.)

of A gratis 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. Almost all the cutworms hide
in cracks 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 (PI. 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

403

Fig. 583. — Army-worms, larvae 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-
cania unipuncta, marked in the center

costal vein-^W °^ ^^^'^ ^°^^ ^^"S ^^^^ ^ distinct white
r, radial vein; m, spot. Perhaps as severe a sufferer as

medial vein; c cubital vein; a, anal ^ny other field product from the attacks

veins. (After Comstock; enlarged.) ■' ^

of Noctuid larvae is cotton. The cotton-
worm, Aletiaargillacea, 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 doUars-

FiG. 584. — Venation
A gratis ypsilon. cs,
subcostal vein

^NA \i I ■ 'iiiML ■'!>

. ^«»- ■!>.••• ^-*»4# v#"%i* ■-* ■*'n .

Fig. 585. Fig. 586.

Fig. 585. — Larvae of the gray dagger-moth, Acronycta occidentalis. (After Lugger;.

natural size.)
Fig. 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
larvae of the tussock-moths, Lymantriidae, one common species infesting our

PLATE VI.

MOTHS.

i = Catocala parta.
2=Basilona imperialis.
3 = Apanresis virgo.
4=Pseudohazis eglanterina.
5 = Automeris io.

PLATE VI

Mary Welhnan^ del.

The Moths and Butterflies

405

Fig. 587. — The raspberry dagger-
moth, Acronycta imprcssa. (After
Lugger; natural size.)

shade-trees in town and country and another, less common, attacking orchards
and forest-trees. The caterpillars (Fig. 588) of Notolophus leucostigma ,
the white-marked tussock-moth, which is the shade-tree species, are about
i\ 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
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 i^ inches, the fore wings with darker wavy
transverse bands, a small black spot near the tip, an obhque blackish stripe
beyond it, and a minute white crescent near the outer hinder angle. The

antennas 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 moths
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 10 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 Noctuidae is the gypsy-moth, Ocneria

Fig, 588. — Larva of the tussock-moth, Noto-
lophus leucostigma. (After Felt, natural size.)

4o6

The Moths and Butterflies

dispar, a European species brought to Massachusetts in 1868, and from
1890 to 1900 fought at the pubHc 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 189 1 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

Fig. 589. — The California oak-worm moth, Phryganidia californica. A, eggs on leaf;
B, just-hatched larva; C, full-grown larva; D, pupa, or chrysahd; E, 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 i^ 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 i| 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 2^ inches, and
creamy white in color, with irregular transverse gray or blackish hnes.

The Moths and Buttertiies 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 Dioptida:.
The larvs 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 calijornica (Fig. 589). The moths expand about i 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 larvae feed until October ist 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 ist. Thus each year about one-fourth of the eggs laid
by this species are wasted. The larvae 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 chrysaHds of the moth which I once gathered but 11 moths issued,
99 of the chrysalids giving forth ichneumon-flies and the rest dying from
other causes. I have found the caterpiUar most abundant on the live-oaks
{Q. agrijolia), but it occurs also on Q. lobala, Q. kelloggii, Q. diimosa, and
Q. doiiglassi.

A family represented in this country by only four species is the Peri-
copidae. 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 Gnophala 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, Agaristidae, of which about two dozen species

4o8

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 odo-
maciilata (PI. VIII, Fig. 5; also Fig. 590), is common in the Atlantic states;

Fig. 590. — Three eight-spotted forest-moths, Alypia 8-maculala, and one beautiful wood-
nymph, Eudryas grata (the lowest). (After Lugger; natural size.)

it expands about i^ 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 larvae,

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 V^irginia creeper, sometimes on the grape, and often
are so abundant as to injure the plants seriously. The caterpillar is nearly
i^ 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 Noctuidse), 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 muft'-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, Lithosiidae, in their
liveries of drab or slate, yellow or scarlet, and with their slender bodies
and trimly narrow fore wings. The larvae 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 i 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

41 o The Moths and Butterflies

is the pale footman, Crambidia pallida, expanding nearly i 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) unijascia, found
all along the Atlantic and Gulf coasts, expands f 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)
hicolor, found in the northern states and Canada, expands nearly ij 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 Zygasnidas,
or SyntomidiE, 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 Lithosiidce, the larvs 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 larvae 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 i inch.
Lycomoipha is a genus of small Zyga^nids 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. miiUijaria and C. ricberoscapus,
Pacific coast species which have a coral-red head and shoulder-lappets

The Moths and Butterflies

411

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 julvicoUis, 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 dilJerent
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. 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

C a

Fig. 591. — Venation of a Zygsenid, Ctenncha
virginica. cs, costal vein; sc, subcostal
vein; r, radial vein; ni, medial vein; c,
cubital vein; a, anal veins. (After Com-
stock; enlarged.)

Fig. 592. — Woolly -bear caterpillars, Halesidota sp., all three of the same species but
showing variations in extent of the black markings.

larvae 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 (PI. 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 comnionly 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 larv« 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, Hyphan-
tria cunea, which makes the large unsightly silken "nests" in plum-trees, both
wild and cultivated, so familiar in late summer and autumn. The eggs
are deposited in regular clusters of 400 or more on the plum-leaves, and the
hatching pale-yellow larvae spin small silky web-nests close together which
finally get included in one large one. The full-grown larvae 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 ij 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 (PI. VI, Fig. 3), a common species
in the Atlantic states, whose larva feeds on pigweed and other uncultivated
plants, expands 2^ 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.

1

^^^

^■l

k^ ^^Mi^^i^^M^

1

i

1

w^

1

k

y

■

^

H^^S^

m

1

.

-^M

■

i4j I (L*

WM

k:\

«^iiimmggg^___^

"

\

Fig. 593. — Caterpillar of Halesidota tesselata. (After Lugger; natural sj:c.)

Striking moths are Arachnis pida (PI. 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 in a single submarginal series on the hind wings; and Utethe-
isa bella (PI. VII, Fig. 7), a familiar little moth of the Atlantic states with

4H

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
larvae 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 larvae (see p. 404). The moths

(Fig. 504) have long narrow fore
wings, and hind wings only about
half as fong; in H. tesseUata 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

Fig. 594. Fig. 595.

Fig. 594. — Halesidota carya, above, and H. tesselala, below. (After Lugger; natural size.)
Fig. 595. — Halesidota maculata. (After Lugger; natural size.)

sprinkled with brown and blotched with creamy-white spots, the pale hind
wings being unmarked; H. lobeniJa 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 larvae 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 (PI. VII, F'g. 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

PLATE Vn.

MOTHS.

i = Anisota rubicunda
2=Geometra iridaria,
3=Pyrrharctia Isabella.
4=Tropoea luna.
5 = Haploa clymene.
6=Melittia ceto
7=Utetheisa bella.

PLATE VII

if

'.S

y^

¥

Mary Wellinaii, del.

The Moths and Butterflies 415

wings with six large white blotches; H. julvicosta 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 acrcea, expanse i^
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 Lasiocampida;, 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.

Fig. 596. — Haploa fitlvicosta (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

4.i6

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 larvae feed on the buds and young leaves of the
tree. The social larvte 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
Fig. 597.— Venation of Halesidota tessel- as 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 vein; «^ medial vein; ^^^ seventy-five thousand leaves are

c, cubital vein; a, anal veins. (Alter ■'

Comstock; enlarged.) devoured, a loss which no tree can long

endure." In about forty days the larvae
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 17 to if inches, has a white body with a black spot and dusky-
gray wings crossed by white lines; its caterpillar feeds on the fohage 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 i| inches, is so hke 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.

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.

Fig. 598. Fig. 599.

Fig. 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.)

Fig. 599. — The forest tent-caterpillar moth, Clisiocampa disstria, in its various stages.
m, male moth; /, female moth; />, pupa; e, eggs in a ring about twig; g, eggs after
hatching; c, 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

4i8

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

a a

Fig. 600. Fig. 601.

Fig. 600. — Venation of Clisiocampa americana. cs, costal vein; sc, subcostal vein;

r, radial vein; ;w, medial vein; c, cubital vein; a, anal veins. (After Comstock;

enlarged.)
Fig. 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 larvae 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 antennae 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-

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419

red on the second and third thoracic segments, bkie 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 i inch wide in the middle, composed of two layers,
an outer strong "brown-paper" layer and an inner loose fibrous one. The
pupaj may be easily found on trees when the leaves are off and brought

Fig. 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. 5. 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.

The polyphemus-moth, Telea polyphe-
miis (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
unsealed 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.

Fig. 603. — Venation of a Saturniid,
Botnbyx mori. C5, costal vein; sc,
subcostal vein; r, radial vein; m,
medial vein; c, cubital vein; a,
anal veins. (After Comstock; en-
larged.)

Fig. 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, Tropcea luna (Fig. 607), a marvel of delicate green tinting

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421

and exquisite symmetry of curving outlines. It expands 4^^ 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

Fig. 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

Fig. 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 pronielhea, 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 pohshed tubercles,
two of these tubercles on each of the second and third thoracic segments

Fig. 607.

-The luna-moth, or pale empress of the night, Tropcea 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.
angulijera is a moth slightly larger than promethea, but otherwise hardly
distinguishable from it except that the shape and markings of the wings,

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423

r

Fig. 608. — Cocoons: i, 2, 3. of Tropma hma; 4, 5, 6, of Callosamia angtdifera; 7, 8, 9, lo^
oi Callosamia promethea. (After Laurent; somewhat reduced.)

424

The Moths and Butterflies

which vary a httle in male and female of promethea, are identical in this. It
is found also only in the Atlantic states.

The lo emperor-moth, Automeris io (PI. VI, Fig. 5; also Fig. 610), ex-
panse 2^ 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 2^ inches long, and is pale green with a

Fig. 609. — The proinetliL-a-moth, Callusaiiiia 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 yl. pamina, expanse 2^ to 3 inches, with yellow around the white-
centered black eye-spots of the hind wings; and in New Mexico ^. se/'/zyr/a,
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. H.
maid, expanding 2^ inches, is subtransparent black with a broad middle
transverse band of white on each wing; in this band is a small blackish blotch

Fig. 610. — The lo 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, H.
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

Fig. 611. — Larva of lo emperor-moth, Automeris io. (After Dickerson; natural size.)

we may call the clown. An allied species, P. sJiastaensis, 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 Ceratocampidae. 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 antennae of the male to the basal half of the antenna.
The regal walnut-moth, atheroma 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 5I 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 larvae 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 larvae of both these

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427

great moths burrow into the ground to pupate, the rough brown naked
chrysalids wintering over.

Fig. 612. — The regal walnut-moth, Citheronia regalis. (Photpgraph 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. riibiciinda, rosy and

Fig. 613. — Larva of regal walnut-moth, Citheronia rcgaus.
(Photograph by author; natural size.)

yellow. This latter, called the rosy dryocampa, is shown in color in Plate
VII, Fig. I. Its larva, so:r:^t!n^es ca.led the green-striped maple-worm,

421

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 purpHsh red or brown, and the wings are nearly trans-

FiG. 614. Fig. 615.

Fig. 614. — The orange-striped oak-worm moth, Anisota senatoria, male. (After Lugger;

natural size.)
Fig. 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

Fig. 616. — Mulberry silkworms, larvae 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 /I. virginiensis, but lacks
the transparent place in the middle of the wing; the caterpillar is black with
four stripes. All these Anisota larvai feed on oaks, and that of A . senatoria
also on blackberries and raspberries. Sphingicampa (Adelocephala) hicolor
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 if inches, take no food at all, and
most of them cannot even fly despite
their possession of well-developed wings,
so degenerate are the flight-muscles from
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 larvae (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'etre.
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

Fig. 617. — Mulberry silkworm, show-
ing front view of head and thorax.
(From life; natural size.)

43°

The Moths and Butterflies

cocoon, composed of a single continuous silken thread averaging over looo 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

v^'^"!!^

days or longer. A fluid secreted by the moth softens one end of the cocoon
so that the dehcate creature can force its vi^ay out. But this is not the usual
fate of a silkvirorm pupa. The professional. grower must save the cocoon

The Moths and Butterflies

431

from injury by the moth, so he kills his thousands of pupae 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

Fig. 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 Sphingida?. Thus
the various adolescent stages of several hawk-moth species are known to

432

The Moths and Butterflies

many amateurs, and numerous different sphingid species will be found in
any collection of Lepidoptera. The uniformity of structural character in
larvae 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 exceptions, have long, nar-

FiG. 620. — Larva of the sphinx-moth, Phlegethontitis 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. 509). The colors and pat-
terns are extremely varied, but uniformly quietly beautiful and harmonious.

Fig. 621. — Larva of Phlegethontius celeiis. (After Soule; somevsrhat reduced.)

The larvae (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 fiattish, 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-Hke sheath
for the developing long imaginal proboscis. A few larvae pupate on the

Fig. 622. — Pholus achenion, 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 Linnaeus a century and a half
ago, is suggested by the curious attitude assumed by the larvae 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 of
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-
ihontius quinquemaculata (celeus) and P. sexta {Carolina) (PI. VIII, Fig. 3).

Fig. 623. — Larva of Pholus achemon. (After Soule; natural size.)

Quinquemaculata is the commoner in the north, sexta 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-
leaves or jimson-weed. The horn of sexta is red,
that of quinquemaculata green or blue-black.
The pupae 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. quinquemaculata
has ashy-gray wings, with zigzag markings, while
the wings of sexta are not thus marked. The
great pandorus sphinx, Pholus (Philampelus)
pandonis (PI. I, Fig. i), found in the eastern
and central states, is one of the most beautiful
of all moths. The larvas 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
Fig. 624. — Grape - vine each side; a shining black eye-like tubercle takes
spliinx - moth, Ampelo- ^j^g j^^^ ^f ^ caudal horn. It pupates under-
phaga myron. (Natural ^ /tt- < \ vu 1 •

size.) ground. P. achemon (rig. 022), 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.

JTIV .-1

PLATE VIII.

MOTHS.

i = Deilephila lineata.
2=Chser()campa tersa.
3 = Phlegethontius sexta.
4=Arachnis picta.
5 = Alypia octomaculata.
6=Anato]mis grotci.
7 = Plusia simplex.

PLATE VIII

niarv Welhnan^ del.

The Moths and Butterflies

435

The beautiful little Ampdophaga 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.

Fig. 625. — The double-eyed sphinx, Smerinthus geminatiis, above; Paonias excacatus,
in middle; and P. myops, below. (After Lugger; natural size.)

A. versicolor (PI. I, Fig. 3) is a beautiful cousin of myro7i with greenish
overlaid on the brown. An extremely slim, slender-bodied, and slender-
winged sphinx is Chcerocampa (Theretra) tersa (PI. VIII, Fig. 2), found in the
northern states. It is very swift. An abundant and familiar hawk-moth found
all over the United States is the white-lined sphinx, Deilephilalineata (PL VIII,
Fig. i). Its caterpillar feeds on various plants, as grape, apple, watermelon,
buckwheat, turnip, and purslane; the latter seems to be the preferred plant.

43^

The Moths and Butterfiies

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,

Fig. 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

P'iG. ()27. — Sphinx gordius. (After Lugger; natural ^izc.)

line edged above 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 geminatiis (PI. I, Fig. 2; also
Fig. 625), is a common species whose larvae 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 of them expanding more than three inches.

Fig. 628. — Larva of the abbott-sphinx, Thyreus abbotti. {Alitr 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
(PI. I, Fig. 4), found all over the country, is hairy, heavy-bodied, and

Fig. 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 larvae 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
larvae (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 nessiis (Fig. 630), of the same size and shape and colors and found

Fig. 630. Fig. 631.

Fig. 630. — The grape-vine amphion, Amphion nessus. (After Beutenmiiller; natural

size, i|-2 inches expanse of wings.)
Fig. 631. — Larva of clear-winged sphinx, Hemaris difflnis. (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 larvae are pale
yellowish green or chocolate-brown with various obscure darkish stripes.

Fig. 632. — The death's-head sphinx-moth; note skull-like markings on thorax between
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. thysbc (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 H. diffinis. 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 larvae
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 larvae of
H. thy she 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

Fig. 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

Fig. 638. Fig. 637.

Fig. 634. — Venation of a Hesperid, Epargyreus tityrus. (After Comstock; enlarged.)
Fig. 635. — Venation of a Papilionid, Papilio polyxenes. (After Comstock.)
Fig. 636. — \ena.\.\onoi s.'HymphsiMd, Basilarchia astyanax. (After Comstock; enlarged.)
Fig. 637. — Venation of a Lycaenid, Chrysophaniis thoe. (After Comstock; enlarged.)
Fig. 63S. — ^Venation of a Pierid, Pontia protodice. (After Comstock; enlarged.)
For all: cs, costal vein; sc, subcostal vein; r, radial vein; m, medial vein; c, cubital
vein; a, anal veins.

The Moths and Butterflies 441

KEY TO FAMILIES OF BUTTERFLIES (LEPIDOPTERA WITH THE
ANTENNA 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 antennae usually terminated by a

recurved hook (Skippers.) Supcrfamily Hesperiina.

B. Head of moderate size; club of antennas 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 antennce usually drawn out at the tip and with a

distinct recurved apical crook. If the crook is wanting, the species expand

less than 1} inches Hesperiid/E (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 antennae not terminated by a recurved hook.

(The butterflies.) Superfamily Papilionina.
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.e (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.) Nymphalid^ (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.) Lyc^nid^ (p. 443).
DD. Medial vein of the for^, 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.) Pierid^ (p. 444).

The family Megathymidse, 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, M. yucccr, whose larvae 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 larva? 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 connecting link
between the moths and the true butterflies.

The Hesperidae, or skipper-butterflies (PI. 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 weU-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, Epargyretis titynis (PI. 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-
minosae, especially wistaria and locust, and when full-grown is i| 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 cuiious 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. tessellaia, is found commonly all over
the country. It expands i^ 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 i 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 catidlus, common in the east, expands i inch
and has uniformly nearly black wings with a few distinct white dots on

PLATE IX.

SKIPPER BUTTERFLIES. (After Skinner.)
Fig. I

II

12

13

14

IS

16

17
18
19

20

21
22

23
24

25
26

27
28

Painphila lioboniok, male, upper side.
" " under side.

" " female, under side.

" upper side.
' ' zabulon, male, upper side.
" " " under side.

" " female, under side.

" " " upper side.

" scudderi, male, upper side (type).
" " female, upper side (type).

" bcUus, male, up{)er side.
" underside.
" panoquin, male, upper side.
" underside.
" stigma, male, upper side (co-type).

underside.
' ' pittacus, male, upper side.
" " under side.

' ' rhesus, male, upper side.
" " " underside.

' ' 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)
TEgiale .streckeri, male, upper side.
Archonias lyceas, upper side.

PLATE IX

The Moths and Butterflies

443

the fore wings. Several large species, known as dusty-wings, expanding
i^ to if 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 (PI. 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 (PI. X,
Fig. 5), common in the Atlantic states, is a good example of the group.
The least skipper, Ancyloxypha numitor (PI. V, Fig. 5), is the smallest
commonly seen and differs from other skippers in lacking the recurved
hook at the tip of the antennae 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 Lyca?nidai, 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 metaUic 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 dehcate
little tail-like processes projecting from the hinder margin of the hind wings.
The larvae 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 w^gs
almost white and conspicuously dotted with small black spots and with
white-ringed slender antennae; these are "blues," some species of the old
genus Lycaena 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 larvas, 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
(Comics), 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 PI. X shows the color, markings, and size
of a typical "copper," Heodes hypophlaas, "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 hypophlceas. A species patterned
and colored much like hypophlceas, but a half larger, is Chrysophanns thoe,
found in the Atlantic states and west to the Rocky Mountains. The har-
vester, Feniseca 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" (PI. 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 difiicult to classify to species; indeed professional
entomologists are not at all satisfied with our present systematic knowledge
of the Lycaenids.

In the extreme southwest are found rather rarely the few species of
"metal-marks," Lemonias and Calephelis, black and reddish checkered
Lycaenids, which occur in this country. Sometimes, as in L. virgiilti, 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 ccBnius, 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 Hesperida? or Lyca?nida?, but with numerous
better-known members, is the Pieridae, the whites, yellows, and orange-
tips. Because the larvae 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 famihar
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 ij to 2 inches, and
have white or yellow, from light sulphur to orange, as ground color, with
markings of black. The larva) 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 pupai 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. rapcz, the larvae of all three species being
voracious cabbage-eaters. P. rapce, the European cabbage-butterfly, is a
European butterfly which got to Quebec about i860 and since then has
spread over the whole country and is the most serious pest among all the
butterflies; it expands from if 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 i^ 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, E. 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 larvae 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 cmsonia (PI. V, Fig. 10), the Pacific coast species Z. eiiry-
dice. The caterpillars, which are green with a whitish longitudinal stripe and
a transverse dark line on each segment, feed on various Leguminosae. 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 euhule, the largest of the Pierids, expand-
ing 2^ 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, (PI. V, Fig. 7), the smallest member of the family, expanding
but I 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, Synchloe genutia (PI. 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 sara, is the commonest western species. The larvae of
the orange-tips, so far as known, feed on Cruciferae.

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 Papilionidte are two species of curious thinly scaled black- and red-
spotted white butterflies called parnassians, which live exclusively in high

Fig. 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-
siiis smintheus (PI. 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 fiower-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 larvae 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 Linnaeus, 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 larvae are large, cylindrical, fleshy, naked
caterpillars usually conspicuously banded or
spotted with green, black, yellow, orange,
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 larvae 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,

v'4- n^^

'%«..j^ '#"^

'"^•^fey^

rS\i.^

Fio 640. — Chrvbdhcl of a swal-
low-tailed buiierfly, Papilio sp
(Natural size.)

PLATE X.

BUTTERFLIES.

1 = Cercyonis alope.

2 = Vanessa atalanta.

3 = PapiIio cresphontes.
4=Heodes hypophloeas.
5 = Erynni3 sassacus.
6=Basilarchia arthemis.
7 = Euvanessa antiopa.

PLATE X

V Mary Weilntnn, del.

The Moths and Buttertiies 449

Iphidides 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
f inch long and tipped with white; another, telamonides, appearing in
late spring, a little larger, with tails -f 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 larvae 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 (PI. 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 Hlacs 6g 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. riitulus (Fig. 639) and P.
eurymedon of the same general pattern of turnus, the first being black
and yellow as turnus 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 PapiHo 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. troiliis, 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.,
Ithohahis acaiida, found in New Mexico, and I. 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 Nymphalidse, 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-Uke 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 family 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 Nymphalidae 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 (PI. XI, Fig. 4; also Fig. 641), sometimes called the milkweed-butter-

FlG. 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. i; 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 unHke that of 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 cornuli 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 (PI. 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 larvae 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 (PI. 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.

Fig. 642. — The comma-butterfly, Polygonia comma; two butterflies, a caterpillar, and
empty chrysalid on gooseberry branch. (After Lugger; natural size.)

The spiny greenish-brown larva:; 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. interrogationis, 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.

1

.^^^j^H^i

x7..:, ami

' i-S.

■**

iM

l^^ft^ ^^9

Kt

^oA

V ■^

r

'

Fig. 643. — The larva of the violet-tipped butterfly, Polygonia interrogationis, making its
last moult, i.e., pupating. (Photograph from Hfe 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 (PI. X, Fig. 2), the red admiral, V. huntera, the painted
beauty, and V. cardiii, the thistle-butterfly, are found all over the United
States, and in addition a fourth, V . carycc, 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; huntera may be dis-
tinguished from cardni by having but two complete eye-spots instead of
several, and caryce 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

PLATE XI.

BUTTERFLIES.

1 = Basilarchia archippus.

2 = Terias nicippe.
3=Synchloe genutia.
4=Anosia plexippus.
5 = Anasa andria.
6=Polygonia comma.

PLATE XI

Mary IVeUman, del.

The Moths and Butterflies

455

and cardiii 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 larvai feed on thistles by preference,
but on almost any composite if necessary: those of huntera on everlasting
and other Gnaphalieas; those of atalanta on nettles; vi^hile those of caryce
feed on Lavatera assiirgenliflora. All these larvae are spiny.

Tvi^o striking, widely distributed, and abundant butterflies are the mourn-
ing-cloak, Euvanessa aniiopa (PI. X, Fig. 7), and the peacock-butterfly,
or buckeye, Junonia cxnia (PI. V, Fig. i). Both are found over nearly
all of our country, and the mourning-cloak is common in Europe. The

Fig. 644. — Chrysalid or pupa of the violet-tipped butterfly, Polygonia intcrros^ationis.
(Photograph from life by author; sUghtly 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 Scrophulariaceae, 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 An(^a andria, the goatweed-butterfly (PI. 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, Aglais

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, Eiigonm 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
calijornica, 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 locahty, 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 2f 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 cyhele, 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 if to 2^ 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 snakehcad. 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 dope,
(PI. X, Fig. i), is the most familiar eastern and middle state species.
A larger similarly patterned form, C. pegala, is common in the south. The
larvae 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, Cceno-
nympha calijornica, 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 Hfe 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, CEneis 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."

P^^J5^F^

CHAPTER XV

THE SAW - FLIES, GALL - FLIES,
ICHNEUMONS, WASPS, BEES,

AND ANTS (Order Hymenoptera)

EES, ants, and wasps are the familiar Hymenoptera.
They are the "intelhgent" and the "social" in-
sects, and therefore seem, of all the insect hosts,,
those living the most speciaHzed 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
"ant and bee people." But in actual degree of
specialization of instinct
and behavior the perform-
ances of the soHtary 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. Of ^^^- 645 --Mouth-parts of a

honey-bee with maxilla
the structural characteristics common to the Hymen- and mandible of right side

optera the clear, membranous condition of the two removed, w J., mandible;

. . . mx., maxula.; mx.p., max-

pairs of wings gives the name to the order {hymen, juary palpus; mx.L, max-

membrane; pteron, wing). The front wings are iHary lobe; st., stipes of
1 ^1 ^1 1 • 1 1 11 • I J -^1 maxilla; cJ., cardoof max-
larger than the hind ones, and all are provided with jjj^. //. labium- sm. sub-
comparatively few branched veins, whose homologies mentum of labium; m.,

have not been fully worked out. The workers "^^ntum of labium; pg.,
•^ . . paraglossa; gl., glossa;

(infertile females) of all the ant species are wingless, H.p., labial palpus.

459

460

Saw-flies, 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
Fig. 646.— Lateral aspect of head of full- true first abdominal segment with
grown larva of honey-bee which has been ^j^^ thoracic mass, SO that the small
cleared so as to show the forming adult head ... , ,

within, ih., head of aduU; i.e., compound articulating segment between what
eye of adult; Ic, body-wall of larval head; ^^.g called thorax and abdomen if
i ant., antenna of adult; l.md., mandible of ,, ,, j i_ j • 1

larva; i.md., mandible of adult; l.mx., really the second abdominal seg-
maxilla of larva; i.mx., maxilla of adult; nient.
l.li., labium of larva; i.li., labium of adult.

The mouth-parts are 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 a sting. The sting
is possessed by the wasps, bees, and ants (rudi-
mentary in many ants), on which account these
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 (p.gl.) and stored in the

Fig. 647. — Mouth-parts of
mud-wasp, with mandible
and maxilla of right side
removed, md., mandible;
mx., maxilla; mx.l., max-
illary lobe; inx.p., maxil-
lary palpus; //., labium;
in., mentum of labium;
pg., paraglossa; gl., glossa;
li.p., labial palpus.

PLATE XII.
WASPS AND BEES.

1 = Spharophthalraus californicus.

2 = Polistes aurifer.
3=Stizus sp.
4=Psithyrus elatus.
5 = Bomb us vagans.
6=Agapostemon radiata.
7 = Xylocopa virginica.
8=Bembex spinolae.
9=Vespa germanica.

io= Bombus californicus.
11 = Anthophora pacifica.
i2 = Polybia flavitarsis.
i3=Chalybion ccjeruleura.
i4=Sphex ichneunionea.
15 = Pelopeus servilla-

Ma^V Wellni,<n. del.

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 larva? are, more than
in any other order, helpless and dependent for their
food and safety on the provision or care of the parents

"^ \mr.l.
Fig. 64S. — Frontal as-
pect of head of larva
of mud-wasp, md.,
mandible; mx., max-
illa; mx.l., maxillary
lobe; //., labium;
li.p., labial palpus.

With many

Fig.

Fig. 649. Fig. 650.

649. — Lateral aspect of head of full-grown larva of mud-wasp cleared so as to
show forming adult head within, i.h., head of adult; i.e., compound eye of adult;
I.e., body-wall of larval head; iant., antennae of adult; l.md., mandible of larva;
i.md., mandible of adult; l.mx., maxilla of larva; i.mx., maxilla of adult; i.mx.p.,
maxillary palpus of adult; I. It., labium of larva; i.li., labium of adult; li.lip., labial
palpus of adult.
Fig. 650. — Sting of the worker honey-1 ee. p-gl., poison-gland; p.s., poison-sac; d., dart;
/., levers; v., valve; s., sheath; p., palpus.

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 suflScient 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. Tibiae 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. Tibias of fore legs with one apical spur; female with elongate borer

instead of saw (Horn-tails.) Family SlRlciD^ (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 Evaniid^.
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 Chalcidid^ 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 Cynipid^ (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.e, 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 antennae also long and filiform.

Family Pelecinid^ (p. 484).
CC. Abdomen short, but little longer than head and thorax; antennae short

and elbowed (Cuckoo-flies.) Family Chrysidid^ (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 Formicina (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 Apina (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-flies, Gall-flies, Ichneumons,

relationship. For example, the Proctotrypiclie are held by Ashmead to be
more nearly truly related to the wasps and to the gall-flies (Cynipidae) than to
the other parasitic Hymenoptera, as the Chalcididae, Braconidae, and Ichneu-
monidae, 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 Tenthredinidae and Siricidae 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, Tenthredinidae, 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 ahke in
appearance, and the larvae 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 larvae. These larvae
are the familiar rose-, currant-, pear-, larch-,
and willow-slugs. They are soft bodied,
naked, slug-like or caterpillar-Iike 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
larvae 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
Fig. 651.— a saw-fly, Allantus instea,d of several. The eggs are laid by the
hasillaris. (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 larvae, 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 larvae ^ , ,^, , ,

. ,, , • , , 1 u 4. 4.U ^^'^- (^52-— The currant-sluf^, larva

live in gall which develop about them; one of the currant saw-fly, Nematus

such species is common on willows. The ventricosus. (Two and one-half

11, .11 xi i_ J u i times natural size.)

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

Fig. 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 roses, 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 ventncosus
(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 grossii-
lari(E, 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, Eriocampa 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 larch is 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 -| 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
larvae 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
svmimer on the new growth of needles on pines. The larvae 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 Siricidae. 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 ridges 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

467

Fig. 654. — The pigeon-tremex, Tremex
columba. (After Jordan and Kellogg;
natural size.)

and place an egg at the bottom of each. Ojae of the best-known horntails
is the pigeon-tremex, Treynex columba (Fig. 654), i^ inches long, with reddish
head and thorax and black abdomen with yellow bands and spots along
the sides. The females bore holes J
inch deep into elms, oaks, sycamore-
or maple-trees, the ovipositor, in boring,
being held bent at right angles with
the abdomen. The larvae 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, i^ inches long,
with short thoracic legs and a short anal
horn. They pupate in their burrows
within a cocoon made of silk and tiny
chips. The issuing winged adult gnaws
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 pygmcBUs, whose larvae
bore into wheat-stems. The adult is f 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 larvas 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 Cynipidae, 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 larvae of the

468

Saw-flies, Gall-flies, Ichneumons,

Cynipid gall-flies. These flies (Fig. 655) are all very smaU, the largest

species not being more than ^ 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

Fig. 655. — A gall-fly, species unde-
termined. (Much enlarged.)

Fig. 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 mucli 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 larvaj 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 larvae 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
and the fully developed flies are of the grand-
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-

FlG. 657. — Galls made by a
Cynipid gall-fly. (Natural
size.)

470

Saw-flies, 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 sweUings 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
r >y ^ R_^ something of

this variety.
In their interior
make-up they
also differ
much ; some
have a large
hollow central
space ; some

Fig. 658. Fig. 659.

Fig. 658.— Galls on leaf of California white oak. (Natural"^

size.)
Fig. 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 larvae.
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 Fig. 660.— Galls on leaf
a few Cynipid galls are known on other plants ^J^^^S'sizeO^'"' °^^'
than these. In the face of the host of species of Cyni-

pidjE 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. Corn-
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,
I to 2 inches in diameter, produced by the gall-fly Aniphiholips coccinece.

Fig. 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 bjack oak, made
by Am phiboli ps
spongifica, has the
space between kernel
and outer wall filled
by a porous, spongy
mass. In the "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, H. cent r kola, |
inch or less in diam-
eter, the space be-
tween kernel and
outer wall contains
only a few slender silky filaments which suspend the kernel in place

Fig. 663. Fia. 662.

Fig. 662.— Galls on twigs of California white oak; upper figure,

a gall split open longitudinally. (Natural size.)
Fig. 663.— Galls on leaf. (After Jordan and KeUogg; natural

size.)

The

472

Saw-flies, Gall-flies, Ichneumons,

common bullet gall, H. globulus, of the small twigs, | to f inch in diam-
eter, has the kernel surrounded by a hard woody substance.

I-'IG. 664. — An oak-apple, or fibrous gall of the Calilornia 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 Andriciis calijornicus, one of the largest of the Cyni-
pidae, 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 larvae. 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 oflf, when the

Fig. 665. — The giant gall of the California white oak, produced by Andricus calijornicus;
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
rosce, 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, Diastrophus
nehulosus, 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 i inch to ij inches.

Regarding the wonderful instinct of
the gall-fly, I quote the following from
Stratton, an English student of galls:

"It is impossible that inteUigence or

memory can be of any use in guiding the

Cynipidae; no Cynips ever sees its young,

and none ever pricks buds a second season,

or lives to know the results that follow Fig. 666.— Jumping galls of the oak

. produced bv Cynips quercus-saL'

the act. Natural selection alone has pre- tatrix. (Galls on leaf of natural

size ; at left

11 • r r • , , enlarged.)

seasonally recurrmg feelmgs, sights, or

single gall much

served an impulse which is released by
seasonally recurring feelings, sights, or
smells, and by the simultaneous ripening of the eggs within the fly.

474

Saw-flies, Gall-flies, Ichneumons,

Fig. 667. — Cynips qiiercus-
sallatrix, the gall - fly
which produces the
jumping galls. (Much
enlarged.)

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
Neuroteriis lenticiilaris 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-
tageous to the larva and sometimes described as
disinterested and self-sacrificing on the part of the
plant. We have just seen that, so far as the larva
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 larvae 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 fru.strate
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 larvae 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 bundle:; 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 ^yc

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;
i.e., 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 hfe 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, Cynipida\ 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 Ichneumonidae, Chalcididae, Braconidaj, 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 hst of commensals and parasites bred
from a common root-gall on oak, Biorhiza pallida: Commensals, the larvae
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
Cynipoidae, in the latest authoritative classification (Ashmead) of the Hymen-
optera, and divided into subfamilies, the Cynipidae including the gall-makers,
and the much smafler family, Figitidas, 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 larvae 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 bob! net
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 Cynipidaj 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 Cynipidae, 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 speciaUzed,

Fig. 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 Chalcididae, Braconidae, Proc-
totrypidae, Ichneumonidae, etc.

These parasitic Hymenoptera are only rarely collected by amateurs,

Fig. 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.

Fig. 670. — Hairy caterpillar killed by parasitic ichneumon-flies which have left the
body through small holes in the skin. (Natural size.)

The superfamihes 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 superfamihes 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
manuals. In the older books the para-
sitic habit has been looked to as in-
dicating an aflSnity of relationship
among them all ; in more recent books
and papers is adopted an arrangement
proposed by Ashmead which indicates a nearer relationship on the part of

Fig. 671. — Caterpillar killed by Hymen-
opterous parasites which have issued
from the cocoons attached to the skin
of the caterpillar; upper figure one of
the adult parasites. (After Jordan and
Kellogg; caterpillar and cocoons natu-
ral size; adult parasite much enlarged.)

4/8 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
Fig. 672. — A common parasite, Merisiis furnish the great majority of hosts
destructor, itva^l^, of the Hessian fly (After ^^^ ^^^ parasitic Hymenoptera. On
Lugger; natural size mdicated by line.) ^ r , 1 1

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

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 larvie, while degenerate in the same way as the footless,

Fig. 673. Fig. 674.

Fig. 673. — A chalcid fly, Pteroptrix flavimedia. (After Howard; much enlarged.)
Fig. 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 larvae undoubtedly furnish the majority of hosts
for the parasitic Hymenoptera, they are by no means the only ones. The
eggs and pupa of Lepidoptera as well as the larvae, Diptera, Coleoptera,
Hymenoptera in both egg and larval stages, some Hemiptera, especially

Pig. 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 (Coccidae) and plant-lice (Aphididae), 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-flies, 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

Fig. 676. — Hymenopterous parasites of a social-wasp. Fig. i, 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 i 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 nimibers 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 ^ 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 calijornica) in
years of its abundance in the vicin-
ity of Stanford University, and this
by the single ichneumon-fly, Pimpla
hehrendsii.

The success of any form of para-
sitism in any one locality in a given

Fig. 677. — Larvae of certain curious hymen-
opterous parasites; at left, Platygaster
instricator; at right, P. herricki, which
live in the alimentary canal of Cecidio-
myid flies, ant, antennae; lb, labrum;
wj, mandible; //, labium; /, 4/3, legs; kr,
clawed processes; /, lobe-like processes;
hj, 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

Fig. 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, Pitnpla 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
Fig. eyg.—Ophio,! purga- \ V' . . ,1 •

turn, an ichneumon-para- attack a smgle species of the primary parasites.

site of army-womis. (After Among these secondary parasites are not only
ugger, na ura size.; 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 (tracheae)
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 fa-tus to mother among viviparous
animals. Seurat's observations seem to indicate (for certain species at
least) that soHd 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 famiUar. P. con-
qidsitor (Fig. 680) is the commonest parasite of the tent-
caterpillars (Clisiocampa), is also the chief one of the de-
structive cotton-worm, Aletia argillacea, of the south and
has been bred from half a dozen other species of moths.
It lays its eggs not on the larvae of the tent-caterpillar
moth, but on the pupae (and perhaps on the cater- Fig. 680. — Pimpla
pillars after spinning and just before pupating) inside esg^^in Tocoorf ^ of
the silken cocoon (Fig. 680). P. inquisitor, a common American tent-cater-
parasite of the tussock-caterpillars, is an ichneumon- piske -^bout 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 larvae 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 2 J inches long and it
measures nearly 10 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-buriow, and, elevating her long ovipositor

484

Saw-flies, 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

Fig. 681.

Fig. 682.

Fig. 681. — Thalessa sp., ichneumon -parasite of the pigeon-tremex. (After Jordan and

Kellogg; natural size.)
Fig. 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-
cinidse, 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 i\ inches or more in length, while

Wasps, Bees, and Ants

485

that of the male is not more than { inch. The males, only about ^ 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.

Fig. 683.

Fig. 683. — Pelecinus polyturator, female. (Natural size.)
Fig. 684. — Pelecinus polyturator (?), male (Three and one-half times natural size.)

a half-dozen individuals perhaps in a single egg; needless to say they are
among our smallest insects. Some are wingless, some show a marvelous hyper-

FiG. 685.

-Meteorus hyphantrm, parasite of the green-fruit worms, Xylma 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 Ufe-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-fiies 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

Fig. 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-growers
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-
tionably considerable success has attended
some of these importations, although as
yet no other such signal overcoming of an
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),
enemv of the once dreaded fluted scale (see p. 189 for account of this).
Any discussion of the parasitic families of Hymenoptera would be incom-

FiG. 687. — A caterpillar of Xylina
lacticinerea, green-fruit worm, from
which the parasitic larva of Mcteoriis
hyphantricE has just emerged and
is spinning its cocoon, (.\fter Slin-
gerland; natural size.)

Wasps, Bees, and Ants

487

Fig. 688.— The fig-insect,
Blostophaga grossorum,
male. (After Howard;
much enlarged.)

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 larvae 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
food-figs. The male Blastophagas (Fig. 688) are
grotesque, wingless, nearly eyeless creatures which
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 larvae 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
through the puncture and fertilizing the
females. The fertilized winged female
gnaws out of the galls, and leaves the
fig through the smaU 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
egg-laying 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

Fig. 689. — The fig-insect, Blastophaga
grossorum, female. (After Howard;
much enlarged.)

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

FlG. 690. — Figs on a branch; the two lower ones are mammae, 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 role 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

Fig. 691. — Figs showing effect of non-caprification and of caprification. a, outside
appearance of non-caprified fig; b, 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 "mammae" 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 quahty 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 Asia Minor 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 ofJ,
strung on short raffia 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 grossonim, in CaUfornia 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, homtails, 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 multiphcity 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 superf amilies : one, the Sphe-
cina, or digger-wasps, including fourteen famihes; 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 Vespidae,
one family of solitary parasitic wasps, the Masaridae, and one other family of
solitary mason, carpenter, leaf-cutting, mining, and digging wasps, the
Eumenidae. The Sphecina include wasps all sohtary (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 tegulag 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
tegulae 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 ^_ ^ ^c~.
birth, insect food is brought by the ~^^^^^^i=i^=:.
mother or by sterile workers. The "^^^^^^^^^^^
parasitic wasps deposit their eggs on ^^^^^^^S^=s.

the paralyzed body of some insect, -^^^^^^^^^g^

while the guest wasps lay their eggs ^^t:^^^^^^-""^ — '- -

in the nests of other wasps or bees, ^-~ ~^^Mp-^^-^^

where the hatching larva can feed on ^^^^H^^H^^^

the food stored up by the host for its '^^^^^HU^^

own young. The larvae are white, "^^^^^gHMr s=^

footless, soft-bodied grubs, which lie ^^;-ssg^ssp^S.

in their cells feeding on the food stored Fig. 6q2. — Nest-burrow of Oxybelus
up or brought them and pupating in quadri-notatus. (After Peckham; one-

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 Mutillidae), and all the females and
workers have strong stings. The mouth-parts consist of strong toothed
jaws, of jaw-like maxillae 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 antennae 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 sohtarily. 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 sprmg
or summer. The males are irresponsible creatures, aiding little, if at all,

Fig. 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 sohtary

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

Fig. 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

Fig. 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 Httle 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 (gangha) so that
it is paralyzed. Finally, down she goes and lays a single egg, attaching

Fig. 696. Fig. 697.

Fig. 696. — Nest-burrow of Ammophila, with food for the young; paralyzed inchworms

in bottom and burrow nearly filled. (Natural size.)
Fig. 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 Hve 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-
ghng 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 hfe 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)

Fig. 698. — Cerceris tnherculata, dragging weevil {Cleonus 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, 1901.

49 6 Saw-flies, Gall-flies, 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 larvae. 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 quahties 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 ah 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 SoUtary Wasps,
Bull. 2, Wis. Geol. and Nat. Hist. Survey, 1898.

Wasps, Bees, and Ants

497

only in rare cases see even the commencement < f the hfe 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 civihzation that effects this destruction and toler-
ates this negligence."

Sharp divides the solitary wasps, according to their habits, roughly into
four groups: (i) 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 Tiphia inornaia,
f inch long, shining black, which paralyzes
white grubs, the larvas of June-beetles.
Other allied species, some yellow and black
and much larger, prey on other larvae of
Scarabaeid 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 Mutillidae, popularly known as velvet-ants, cow-

Fig. 699. — A cow-killer, or wingless
wasp, Spharophthalma similima,
female. (After Lugger; natural
size indicated by line.)

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. Sphce-
rophthalma caUjornica (PI. XII, Fig. i) is \ inch long,
with brick-red hair, black on bases of abdomen and
thorax; 6'. pacifica is similarly colored but much

Fig. 700. — Sphcerophthal- , t-ii o i ^ ■ t. ^ i.

ma pacifica (One and larger, f mch long; 5. aureola,^ i mch long, has
one-half times natural head, most of thorax, and posterior half of abdomen
^^^^■) with yellow hair, elsewhere black.

The brilHant metallic -green little bee-Hke cuckoo-flies (Chrysididae)
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 v/hose
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 saHva, there are numerous species belonging
to several different families. The daintiest mud-nests are the little vases
of Eumenes (Fig. 701), 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 Eumenidae, which is the only family of solitary wasps (besides the
rarely seen parasitic Masaridae) 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-

FiG. 701. Fig. 702.

Fig. 701. — A vase mud-nest of Eumenes sp. (Natural size.)
Fig. 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 Pelopoeus (PI. XII, Fig. 15) of the large family Sphe-
cidas. These cells are provisioned with paralyzed or dead spiders. Another
smaller kind of mud-dauber is Agenius, a genus of the Pompilidiae. 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 Amrnophila 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 (PI. 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 Ufe and habits

of two species of Astata, wasps
of the family Larridae, 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-
becidoe, distinguished by the pro-
jecting, even beak-like upper lip,
are all diggers, and include our
largest solitary-wasp species.
Bemhex spinolcB (PL XII, Fig.
8), a large black and bluish-
white banded form, shows an in-

FlG.

703. — Nest -burrow of Astata unicolor.
(After Peckham; natural size.)

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

Fig. 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, i\
inches long, rusty black with yellow-banded abdomen. The wasp, attracted

Wasps, Bees, and Ants

501

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,
PompiHdae, mostly black or steely-blue with bluish or light-bronzy wings
(PI. 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, Pepsis jor-
mosa (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 larvae. The Peck-
hams have made many interesting observations touching the problem, trac-
ing carefully the movements (Figs. 705 and 706) and behavior of individuals

Fig. 705.

Fig. 705. — Locality study of Cerceris deserta. (After Peckham.)
Fig. 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 Mimesidffi and Pemphredo-
nidK. The Mimesids have a petioled abdomen
and look like little Sphecids; the Pemphredonids
are shining black. The family Crabronidse, 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 jrigidiim; the cells are separated by mud
partitions. The Peckhams found two slender-
waisted, black species of Tripoxylon common near
Milwaukee, namely, T. albopilosum, f 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; albopilosum was found nest-

FiG. 707.— Nest -tunnels of ing in holes made by beetles in posts and trees,
two carpenter -wasps^ A, ^^^ never in straws; a third common species,
Monobia quadridens (Eume- i • 1

nidje); B, Stignms jraternes bidentatum, seemed to nest only m burrows tun-
(Pemphredonidse). (After ^gled by itself in the stems of plants. Another
Comstock: natural size.) ^ • i.-l. ^ ^ ^

carpenter-wasp, common m 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 Vespidae, 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 "soHtary" 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 (i) 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 Ufe-history of a community is in general outline
as follows: In the early spring fertiUzed 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 larvae throughout
their brief life by the queen. The larvae soon pupate in the cells and in a

Fig. 708. — Nest of Vespa crabro, found in hollow oak-tree on Long Island. (After
BeutenmuUer. 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

^./^

Fig. 709. — Vespa sp. a, worker; b, 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 -"(^j, ^-"^^^

through the summer several broods of Fig. 710. — Two workers of the yel-

workers are reared, until in the late sum- low-jacket, Vespa sp. (From life;

, . ,, , , . . , natural size.)

mer or early fall a brood contammg males

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
Fig. 7ii.-CommunaI nest of ^^^^ safely through the long winter found

the yellow- jacket, Vespa sp. the communities which live through the foUow-

(Much reduced.) jj^g g^^son.

The social wasps of the genus Vespa, the familiar yellow-jackets and

5o6

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. maculate, is the best-known builder of the globe nests. The smaller

Fig 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 Vespae, 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.

^'l^^

Fig. 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. fiavitarsis (PL XII, Fig. 12), is found only on the Pacific coast. It is
common in Cahfornia. 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 queea or workers. The queen brings food only for the larvae 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

5o8

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

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-

FiG. 714. — Pohstes sp. a. nest; b, young larva;
c, older larva; d, pupa; e, adult. (All one
and one-half times natural size except nest,
which is much reduced.)

Tig. 715. — The single-comb nest of a hornet, Polistcs 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 wliich 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 Httle and there
a httle, 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 wall, 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 Vespae 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.

5IO 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 larvae 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 larvas 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 fiower-fiies (Syrphidae), bee-flies (Bombyliidae), and certain robber-
flies (AsiHdae) 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 all these bee-mimicking flies.

Wasps, Bees, and Ants

511

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 hve 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-Hke 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 Andrenidae (short-tongued bees)
and the Apidas (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 Fig^ 716.— Mouth-parts of a
psychologic development, into three general groups,
namely, sohtary bees, gregarious bees, and com-
munal bees.

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 tegulae of the wings as is the case with the Sphecoid wasps,

short-tongued bee, Prosopis
piibescens. Note short,
broad, flap - Hke tongue
(glossa of labium). (After
Sharp; much enlarged.)

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 larvae 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 maxilla?
and labium are more or less intimately joined
by membranes and chitinous bars and are capable
of much variety of movement in the way of fold-
ing, retraction, and extension. The antennae are
elbowed and their terminal, smooth, cylindrical
segments are provided with numerous sense-pits
and papillae, 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
provided with a sting; in the social species
(bumble- and honey-bees) there are in addition
worker individuals (females of arrested sexual
development but with special structural develop-
ment) 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 larvae find stored up for them a suf-
ficient food-supply for their larval life, or they are brought food constantly
during this Hfe. These larvae 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 famihar 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.

-Mouth-parts of
a long-tongued bee, An-
thophora pilipes. Note
greatly extended tongue
(glossa of labium). (After
Sharp; much enlarged.)

Wasps, Bees, and Ants

513

F-

H

The hairy, medium-sized mining-bees of the short-tongued genus Col-
letes dig short vertical burrows in the ground which they hne 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 hke 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). Corn-
stock writes of the nest-building of the species, C. dupla,
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
the only case known to the writer where a solitary
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 (PI. XII,

15

Fig. 718. — Nest-tun-
nel of carpenter-
bee. (Natural size.)

5H

Saw-flies, Gall-flies, Ichneumons,

Fig. 7), They are as large as biiinblebees 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.

The long-tongued family Megachilidae includes a
number of common and interesting bees, most familiar,
perhaps, being the mason-bees (Osmia), the potter-bees
(Anth'dium), and the leaf-cutters (Megachile). The
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. 701), 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

cut out pieces of green leaves with which they line the

tunnel and partition in such a way as to form a series

of thimble-shaped cells each partially filled with a paste

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

Fig. 719. — Nest of
leaf-cutter bee, Me-
gachile anthracina>
(After Sharp; some-
what enlarged.)

Fig. 720. — Single cell
in nest of leaf-cut-
ter bee, Megachile
anthracina. (After
Sharp; somewhat
enlarged.)

Wasps, Bees, and Ants 5 1 5

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
(PI. XII, Fig. 11), the species of which are hairy and robust-bodied, looking
indeed much hke small bumblebees, Melissodes and Synhalonia with very
long antennae, rather like honey-bees in general appearance, and others
of the great family Anthophoridae. 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
sohtary 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 larvae 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, Nomadidae, mostly bright-
colored species, metallic blue or green with the abdomen spotted or banded
with yellow or white, and the Stelidae, differing structurally from the cuckoo-
bees by having only two, instead of three, submarginal cells in the wings.
Ashmead believes that the Nomadidae are descended from the Anthophoridae,
and the Stelidae from the Megachilidae, 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 larvae 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

5i6

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 hght on the possible line
of progression or specialization from strictly solitary to strictly communal
hfe. 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,

Fig. 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 stanjordiana, 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 5 1 7

few square yards of the many yards of exposed surface. The nest-tunnels
were capped by curious httle 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
2000 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 ^\ to j\ 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 v.^asps do in sheltered places, as crevices in stone walls, holes in the

5.8

Saw-flies, Gall-flies, Ichneumons,

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
larvae 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 larvae 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

Fig. ;y22. Bumblebee at irregular waxen cells, mostly containing brood (larvae

(From or pupae), but some containing pollen and a few
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 Bombidae) ,

long-tongued bees with two apical

spurs on the hind tibiae and with a

single submarginal cell in the front

wings. Their big velvety black-and-

yellow bodies and their deep-toned

buzz are the more familiar characters

which distinguish them. Over fifty species of bumblebees occur in this

countr)'; they differ in size and in the arrangement and relative amounts

clover-blossom,
life; natural size.)

Fig. 723. — Worker (A) and queen (B)
bumblebees, Bombus sp. (After Jordan
and Kellogg; natural size.)

Wasps, Bees, and Ants

519

of the black and yellow markings (PI. XII, Figs. 5 and 10). A common eastern

species is B. jerviotus (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. afjinis 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

third of the abdomen, and another

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 (PI. 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
bountiful table of their host, present
to us an interesting problem touching
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
Bombidae. Having given up the gathering and carrying of pollen, their tarsi

Fig. 724. — Nest of bumblebee, Bombtis sp.,
showing opening at surface of ground and
brood-cells in cavity underneath. (Adapted
from McCook.)

::20

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
Psithyridae, each species being represented by males and females only.

At the head of this line of speciahzation 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

Fig.

725. — Comb of the tiny East Indian honey-bee, Apis 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 famihar ones being the German or black race, the Italian
or amber race, and the Carniolan or striped race.

Wasps, Bees, and Ants

521

A community of the hive-bee, which may Hve, 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

Fig. 726. Fig. 727.

Fig. 726. — The honey-bee, Apis mellifica. A, queen; B, drone; C, worker. (Natural

size.)
Fig. 727. — Hind leg of worker honey-bee, Apis 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-

Fig. 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, w^ax-plates, and other special structures of the
vi^orkers. 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;

Fig. 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 hfe-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

523

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

Fig. 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, (.\fter 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
larvai 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 larvae. After a couple of days of feeding with this
substance, the larv£e are fed, in addition to bee-jelly, pollen and honey taken
by the nurses from the cells stored with these food-substances. After three
days of this mixed feeding, the larvae 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-flies, Gall-flies, 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 spermatozoids
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 larvae which are fed and cared for in the same
way as the worker larvae, 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 no 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

^26 Saw-flies, Gall-flies, Ichneumons,

workers and larvae and pupaj 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 di\dsion 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 ahke, each possessing all the special structural
specializations, as pollen-basket, wax-plates, wax-shears, trowel-hke jaws,
etc., which have been developed for the special performance of particular
industries. In some other communal insects a differentiation or pohTnor-
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 speciaHzation
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

527

sometimes chewed and mixed with some saHva, 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

Fig. 731,

Fig. 732.

Fig. 731. — Ventral aspect of abdomen of worker honey-bee, showing wax-plates. (Three

times natural size.)
Fig. 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 gUbly 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

Fig. 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,

torn 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 (plantae) (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
each hind tibia. A forager loaded with pollen re-
turns to the hive, and, seeking an empty cell near
the brood-cells, stands over and with his hind legs
partly in it and thrusts off the two masses, with the
aid of the middle legs (the spurs of the middle tibiae
being apparently often used as pries). This pollen
is tamped down in the cell by inside workers and
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 ceUs without further treatment. It is sucked
and lapped up by the compUcated 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

Fig. 734. — First tarsal
segment of hind legs,
front and back view,
of honey - bee. i,
drone; 2, worker; and
3, queen, a, distal tip
of tibia; b, first tarsal
segment; c, proximal
end of second tarsal
segment. (After

Sharp; much en-
larged.)

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-sHts, making four hps. 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
oesophagus 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-
currents pass constantly over the open nectar-con-
taining cells; moreover, by the very vigor of this
activity on the part of the bees the temperature of
their bodies is raised ; by radiation of heat from the
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 suppHed 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 Cahfornia 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

Fig. 735 . — Alimentary
canal of worker honey-
bee showing (hs)
honey-sac lying di-
rectly behind {(e)
oesophagus. (Much
enlarged.)

530 Saw-flies, Gall-flies, Ichneumons,

many larvae 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 filHng 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 propohs 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 propoKs-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 antennae 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

531

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 larvae 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-Hce (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

Fig. 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

s?>^

Saw-flies, 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

Fig. 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 533

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 which is 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). Or a 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 hfted
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, propoHs,
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 w^sps and bees, the two other great groups of Hymenoptera
that contain communal-hving 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 Hahctus and other mining-bees) exist to con-
nect the ants with the solitary or independent life common to the great

to^ 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 famihar. They hve 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 dwelhngs. 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 shght 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 Httle 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 (maxillae and lips); antennae slender,
cyhndrical, 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 yig. 738.— A California black ant, species un-
wingless condition. In addition determined, showing winged forms and wing-

^, . 1 • !• . 1 T ^1 less worker. (After Jordan and Kellogg;

to the wmged mdividuals there ^^^e 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.

Fig. 739. Fig. 740.

Fig. 739. — Soldier (a) and worker (c) of Pheidole lamia; b, head of soldier in profile.

(After Wheeler; much enlarged.)
Fig. 740. — Male (a) and ergatoid female (i) of Tomognathus suhlcBvis. (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-

53^

Saw-flies, 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 Poneridae, 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

Fig. 741. — The little h\sLck ani, Mo7tomorium miniitum. a, female; fc, female with wings;
c, 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
Camponotidae, 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 estabhsh 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 Fig. 742. — Soldier and worker of Phei-
iVii i 1 • f • f dole commutata. (After Wheeler; en-

httle nest, laying a few eggs, carmg for i^rged.)

the hatching larvae 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 hke 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, Camponotiis pennsylvanicus , and in Europe Myrmica
ruginodis, Camponotus ligniperdiis, and Lasius alienns have been noted
to follow the same procedure. An interesting fact in these cases is that
the food given the larv£e 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-flies, 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 pupae 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 aiU 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 larvae, 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 accomphshed
by moving the larvas or pupae 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 pupae, 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-
Hce, 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 ahght 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 Hve 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-Uved 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

540 Saw-flies, Gall-flies, Ichneumons,

such a division of the group can be fairly made. These three famiUes 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, i).

Camponotid^.

Abdomen constricted between the second and third segments (Fig. 743, 2) . Ponerid^.
Basal peduncle of the abdomen composed of two segments (Fig. 743, 3) . .Myrmicid.e.

Of these families that of the Poneridae 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
a 0 , ^ ^j^g communal life) of all the ants. In the following

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 Poneridae only about 25 species are so far
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
and life-history before the recent studies of Profes-
sor Wheeler on three species occurring in Texas,

Fig. 743. Diagrams of namely, Odontomachus hcBtnatodes, Pachycondyla

lateral aspect of abdo- harpax, and Leptogenys elongata. The nests, made

men of representatives j . 1 ■ ■^- ^ j.

of the three families of under stones or logs, are primitive structures, com-

ants: i, Camponotida;; posed of a few simple and irregular burrows or gal-

2 Ponerid^; 3, Mynni- j j ^^^^ ^f ^^^^^ ^^^ ^^ ^^^ surface of the

cidas. a, thorax; 0, first ' ®

abdominal segment; c, soil immediately beneath the stone or log, while

second abdominal seg- others extend obliquely or vertically downwards
ment; a, third abdom- . . . , _^, . , 1

inal segment. for from 8 to 10 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. hmnatodes 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 larvae 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 larvae. The
feeding of the Ponerine larvae is also very irregular and capricious both as

Wasps, Bees, and Ants

541

Fig. 744. — A Ponerine ant, Leptogenys
elongata. (After Wheeler; enlarged.)

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
larvae 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 Myrmicidae and Campo-
notida?, where, as we shall see, the
character and amount of the food
given the larva? is carefully controlled
by the workers.

The family Myrmicidae 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-
acteristic species.

Nine species of harvesters (Pogonomyrmex) (Fig.
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

Fig. 745. — An agricultural-
ant worker, Pogonomyr-
mex imberbicolus. (After
Wheeler; much 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

Fig. 746. — Mound-nest of the western agricultural 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

Fig. 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. coeciim, E. schmitti,
E. opacitherce, 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 larvae and pupas, which are
used for food by the Ecitons.
Not all the booty is devoured
at once ; some of it may be stored
in the Eciton nest (which is
usually but a temporary habita-
tion) and gradually used through
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 larvae and pupae 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

Fig. 748. — Shed-nest of Cremastogaster lineolata,
18 inches long by 12 inches in circumference,
taken several feet from the ground in a bur-
row in Hyde County, North Carolina; this ant
usually nests under sticks and logs. (After
Atkinson.)

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 yV i'^^^ ^^ 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, larvae, and pupae.
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 larvae and pupae 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 httle 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 antennas 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,
chmbed 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 beheves that the Leptothorax get food only in this
way; they feed their queen and larvze 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 pupae
of another species is wide-spread among ants.

The third family, Camponotidae, a large one,
includes a majority of the famiHar 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
httle brown ant "whose nests abound along the
borders of roads, in pastures, and in meadows,"
are all familiar Camponotid species. The last-
named one is known in the middle states as the
corn-louse ant because of its interesting associa-
tion with the wide-spread corn-root \o\ise, Aphis
maidi-radicis. In the Mississippi valley this
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 hce. 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

Fig. 749. — Galleries and cham-
bers in wood of the Eastern
large black carpenter-ant,
Camponotus pennsylvanicus.
(After McCook.)

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

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 imparls (Fig. 750), is common in Cahfornia.

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 sangiiinea, represented by five subspecies, and Polyergns
rujescens, the shining slave-maker, represented by two subspecies. The
third slave-making species, Tomognathus americanus, is a rare Myrmicid.
The slaves of F. sangiiinea are other smaller species of the same genus, espe-
cially F. snbsericea, F. nitidiventris, and F. siiboenescens, while the slaves of
Polyergus are the same species of Formica and the additional one, particu-
larly common as a slave form, F. schaufussi. Communities of the slave-
making species are occasionally found in w^hich 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
larvae and pupae; 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 auxihary 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 schaujiissi (Proc. Phil. Acad. Sci., 18S0, p. 376
et seq.).

The observation and study of ants' ways must be partly done in the
field, but, thanks to the obhging 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 i\ inches
thick, 20 inches long, and at least 16 inches wide.

"To make the nest, proceed as follows: Cut a triangular piece about
I 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 f 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 i 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, larvae, and pupae 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 th? 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 b ing 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 pupae 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 of 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 hght 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

Fig. 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 reveahd 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»

Fig 752. — Plan of a Janet nest, o, opening covered by opaque cover, c; wc, 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

55^

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 particularly with the life-history of the individuals of the
colony. Miss Fielde uses still another kind of nest, also like Janet's with

"^"'^ ^

r"vi ' T'''-"

|^^V^^iiSs<.^vWs\\V\\^S^SK^NN^^^^

o.rt

c

I/.

Fig. 753. — A Janet nest in vertical section, w.c, wet chamber; i, 2, 3, brood-chambers;
o., circular openings for brood-chambers made in c, a transparent cover; o.c, glass
cover in three removable pieces; d.p., opaque cover; b.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

as
method of founding a new colony:
isolate a queen in a small artifi-
cial formicary, well provided
with food, and see if she can and
will begin one; isolate a small
group of workers with some eggs
or young larvae, but without a
queen, and see if they can and do
produce a queen and estabhsh pio. 754. — Plan of the Fielde ant-nest, 10
themselves as a permanent com- inches by 6 inches, a, entrance and exit to
munity. The characteristic habits
of feeding the young should be
determined for various species; the presence of or possibility of producing
ergatoid (wingless, worker-hke) 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

food-rooms (i); 2, nursery; 3, sponge-room;
b, screens; m, passage.

55^

Saw-iiies, 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
(Aphididte) 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-hfe, 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
or even encouraged by the hosts. A few of these
arthropods which inhabit ants' nests are true para-
sites or predaceous enemies, such as have to be
endured by almost all other insect kinds, but the
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 m 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; {h) 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-
mal food, as bits of freshly
killed insects, etc., collected by
the hosts, as well as the larvae

Fig. 755. — Ecitoxenia brevi-
pes, a rove-beetle (Staphy-
linidae), which lives in the
nests of the robber-ant,
Eciton schmittii, in Texas.
Note absence of wings and

Fig. 756.

Fig. 757.

Fig. 756. — Termitogaster texana, a rove-beetle
(Staphylinidse), which lives in the nests of the
termite, Eutermes cinereiis, in Texas. (After
, J J Brues; natural length ij mm.)
and pupae, and even the dead yig. TS7-—^nigmatis blattoides, a Phorid fly, which
bodies of the ants themselves; lives in the nests of the ant, Formica jiisca, in
, ,x ^1 .• 1 T •! r 1 Denmark. (After Meinert; thirteen times natural

{a) 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

Fig. 758. — Ant-giiests; at left, Psyllomyia testacea, female; next at right, Ecitomyia
whecleri, female; at extreme right, male of last-named species. These two insects
are species of flies of the family Phorida;, the females of which have become
extremely degenerate because of their myrmecophilous life. (After Wheeler;
much enlarged.)

which the families Staphylinidaj (rove-beetles), Pselaphidae, Paussidae, Clavi-
geridae, Histeridas, Silphidse, Thorictidae, Lathridictidae, and Scydmaenidae
make up all but 100 species, these latter representing 22
other famihes; 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 larvae, 20
are Thysanura, 18 Diptera, 7 Orthoptera, i a Pseudo-
Neuropteron, 34 are mites, 26 are spiders, and 9 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

mochfications, usually degenerative, are displayed also by ^^5.; 7.S9-— Larva of a

.1 . • , , T., . ; .,. .^. Phond fly attached

numerous other ant guests, particularly Phond flies (Figs. to the larva of the

757' 758), in adaptation to this extraordinary fife,

secrete a sweet substance which is greedily eaten by

the ants. The hosts in return care for, clean, and feed

by regurgitation the curious little beetles.

The "wonderful" and "marvelous" character of the behavior of the

ant, Pachycondyla
harpax. (After
Wheeler; much en-
larged.)

^^4 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 natura'.-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 stimuH, 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 incUned 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 law of heredity just as httle 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. iii) 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
quaHty 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 communit}' 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 :rharp
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
qu£en 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 environ-
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-flies, 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 in 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 Formicida;, as shown
in the following conspectus:

"i. The European L. muscoriim often lives in plesiobiosis [double nest]
with Formica nija.

"2. 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
miniitiim, var. minimum.

"4. The single colony of the Mexican L. petiolatus which I h ve seen
was living in parabiosis [interlacing nest] with species of Cryptocerus and
Cremastogaster.

"5. L. tiibenim, var. unifasciatus , lives with the European Formicoxenus
ravouxi, the relations between the species being, perhaps, the same as those
which obtain between Formica rufa and Formicoxenus nitididiis.

"6. L. muscorum, L. acervorum, and L. tuberum live as slaves or auxili-
aries with the European Tomognathus sublceids.

"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]."

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:

"i. The genus has a very wide geographical distribution, a prerequisite
to the estabUshment of such numerous and varied relations with other ants.

"2. 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 coespitiim). Forel has
shown that L. iubero-affinis will rear pupse of L. mylanderi and even of
Tetramorium coespUiim and live on good terms with the imagines when they
hatch.

"5. There is no very sharp differentiation in habits between the queens
and workers of Leptothorax. This, too, should facihtate symbiosis. The
queens, as I have shown in the case of L. emersoni, may retain the excavating
instinct and the instincts which relate to the care of the larvae.

"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. emersoni) and slaves {L. acer-

560 Saw-flies, Gall-flies, Ichneumons,

voriim) not only in the same genus but among closely allied forms. This
fact also suggests that the instincts oj the same species may he 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 larvae
and pupae of other ant species for food. From a raid on a neighboring com-
munity and the immediate devouring of as many larvje and pupse 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 ne.xt 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 pupae 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 for its own young. Speciali-
zation is leading Polyergus to its end 1

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
I which take nectar. The hundreds of bee kinds are the

» most familiar and conspicuous of the pollen-eaters, but

many little 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 hospitahty. And several particular
things about this pa\TTient 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 Httle
leaf-mining caterpillars wind their devious tunnels safely in the soft tissues
of even the thinnest of leaves; while in more speciahzed manner the extraor-
dinary galls developed on the oaks and roses and other plants serve as safe
houses for the soft-bodied Cynipid larvse enclosed by them. The making
of homes Uke 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

Insects and Flowers

563

v.i 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
but a gainer, and in as great measure
as the insect itself. Only plants with
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 pubhshing accounts
of the interesting modifications of
flowers due to their interrelation with
insects, and for discovering that the
insects were instrumental in poUinating
the flowers. (Das entdeckte Geheim-
niss der Natur im Bau und in der
Befruchtung der Blumen, von Chris-
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-poflination. It was reserved for Darwin
(On the Fertihzation of Orchids by Insects, London, 1862), on a basis not

Fig. 760 — Snapdragon being visited by
honey-bees. (From nature.)

5^4

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 speciahzation of this interrelation, and to explain the causal
factors in determining the marvelous phenomena attending its development.
These causal factors are (i) 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 He in the ovaries at the

Fig. 761. — Diagram of section of pistil and ovary of a flower, 'showing the descent of
the pollen-tube and its entrance into the ovule, p.g., pollen-grain; p.t., pollen-
tube; e.s., embryo-sac; ex., egg-cell; s.n., sperm-nucleus. Left-hand figure (i)
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 llower. 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.), hes in the fact that
the seeds produced when the ovules of one plant are fertilized by the sperm-
cells (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): (i) modifications such as to attract insects and insure
cross-pollination as the result of their visits (and to much less extent to attract
other animals, 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-poUination 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-fertihza-
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
(monoecious) or on separate individuals (dioecious); (h) 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 poUen ripens and is dis-
charged (proterogynous) ; (r) the having the stamens and pistils (in the

^66 Insects and P'lowers

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 speciahzation
referred to as those which have arisen in connection with the advantage
of cross-pollination, namely, the modification of the floral structures, we
shaU find these modifications to consist of (a) the secretion of nectar to
attract the insects, (b) 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,
(r) 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 sufl&ce for the plant's own uses,
i.e., 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 speciaHzed 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 poUinating 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 caiyx. 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 Araceas,
some Trilliums, and others have a carrion-Hke 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 brush 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, hke those
on the stamens of spiderwort or at the bases of the stamens of Cobcea scan-
dens, or may be denied access even to the flower itself by sticky glandular
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 (Iris versicolor) near Lake
Forest, 111., 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

Fig. 762. Blue flag, Iris sp., being robbed of nectar by skipper-butterfly; at left diagram

* shovving 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 Syrphidse). 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, 111. In twenty-six observing days 275
insect species visited the flowers of Pastinaca sativa, of which i 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 Asdepias verticillata, 52 were Hymenoptera,
42 Diptera, 16 Lepidoptera, and 3 Coleoptera; of 52 species visiting Rham-
nics 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 i 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
51 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 (b) 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 maxillae 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 speciahzation of the mouth structure in connection
with the nectar-feeding habit reaches its widest application and the extreme
of its speciahzation. 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 maxillae 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 Ukely 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 poUinated
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 Umbelliferae and the numerous Compositas. 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 CarHnville, 111.;:
238 visiting Ciciita macidata, and 191 visiting Slum cicutcejoliiim; 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 100 at Aster panicnlatiis 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 veriicillata
(Carlinville, 111.) in fifteen days, representatives of 58 of these actually got
poflinia (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
vway, but, as Darwin has shown, the foreign pollen would probably possess

Fig. 763. — Hawk -moth posed before a jimson-weed, Datura stramonium.
Stevens; one-half natural size.)

(After

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, Leguminosas, Scrophu-
lariaceae, 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
visitors are compelled to visit
the nectary in one particular
manner, a manner devised to
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

Fig. 764. — Salvia-flower. A, showing position
of pistil and stamens; B, anthers of stamens
in normal position; C, anthers of stamens
tipped down; D, bee entering flower; £, flower,
natural condition. (After Lubbock; natural
size.)

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
corniiti, 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

Fig. 765. — Honey-bee at
Asclepias - flowers, with
legs still fast in a stigmatic
chamber of the flower last
visited. (After Stevens;
natural size.)

"Each pollen-sac contains a compact mass of pollen-grains which never
become separated from one another, and so constitute what is termed a
pollinium. 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
when a bee, for instance, visits it, a good foothold
is not obtained until the bee shps its foot into the
recess between the anthers, termed the stigmatic
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
above and pulls out a second pair of pollen-
masses. Thus the bee goes from flower to flower
and from plant to plant, repeatedly pulling pollen-
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

Fig. 766. — Cabbage-butter-
fly caught by legs in
corpuscula of two Ascle-
pias - flowers. (After
Stevens; natural size.)

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-
niiti. 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 Araceae and Aristolochiacese.
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
and release the insects, which are now well
showered with pollen falling on them from the
anthers above. Visiting another Arum-flower,
they hardly fail to rub off some of this pollen
on the mature stigmas. Sometimes more than
a hundred smaU 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 speciah-

FlG. 767. — Flower of Aristolo-
chia clematitis in longitudinal
section: A, before fertiliza-
tion by little fly; B, after fer-
tilization, p, pollen -masses;
s, stigma; b, bristly hairs;
wb, without bristly hairs.
(After H. Miiller.)

tn(i Insects and Flowers

zation in orchids, namely, the development of sensitive parts in the flow^er,
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; famihar
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 poUen 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 (F. filamentosa) 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, ah 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

S71

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 sti'gmas.
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.

"If 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
to another flower. There it places itself
on the pistil between two of the stamens
(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 is a [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 until it 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.

Fig. 768. — Pronuba-moth depositing
eggs in ovary of Yucca. (After
Stevens; natural size.)

sji

Insects and Flowers

Fig. 769. — Pronuba-moth rubbing
pollen down the stigmatic tube of
Yucca. (After flash-light photo-
graph by Stevens; natural size.)

"The full meaning of this wonderful series of operations will not be
understood until subsequent developments have been followed. Since the
process of poUination 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 larvae, which find
their food in the developing seeds. But the
seeds are so numerous that the larvae 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.

"It appears that the mature moth takes
no food, unless it secures some of the
nectar of the Yucca blossoms in which it
is 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 larvae 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 poUinators; 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

^8o 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 vahd (at least in any
such all-sufficient degree as commonly held), despite its logical character
(in the Hght 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 ta
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 role, "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 aUied species may show; that flowers concealed by fohage 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 Uving

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, (i)
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 role 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
speciaHzation. 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-poUi-
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 inducements
more substantial to offer. These inducements are the pollen and, to the
great majority of flower-visiting insects, the nectar.

It is of distinct interest to note that no plants with colored flower-parts
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.
Winged insects are known from Devonian rocks, and much more numer-
ously from Carboniferous strata; but all these early Paleozoic insects belong
to the lower more generalized kinds, which to-day take httle 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
by the variety or intensity of their colors
and the arrangement of these colors in simple
or intricate S3Tnmetry of pattern. Even the
small and, at casual glance, obscure and
monochrome insects reveal on careful ex-
amination 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 aesthetic 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. i), or in Phyllium, the green-leaf Phasmid (PI. 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 larvae 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 brovm mottled color-pattern is simply con-
tinuous with that of the soil. The green larva; of the Pierid butterflies

PLATE XIII.
PROTECTIVE RESEMBLANCE.

1. Kallima scj.

2. Phyllium scj.

3. 4, 5. Larvae of Lyciena sq. on California buckeye, /Esculus californicus.

PLATE XIII

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 th's 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 ol
superposed lamellae, 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 tlieir 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 larvae,
are due to various substances, as derived plant pigments and others,
in the haemolymph (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 lamellje over a darker layer, or the fine
roughening of the surface by means of striae, 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.

Chemical
colors

f Black
Cuticular I Dark brown
colors I Brown

{_ Straw yellows

Located

primary
cuticula

Permanent. Insoluble in water,

alcohol, ether, oils, weak acids,

or alkalies
Soluble in strong concentrated

mineral acids with dissolution of

the cuticula

Hypodermal
colors

Chrome

yellows
Red

Vermilion
Scarlet
Blue

Located in

hypodermal

cells as

granules

•J I

Green

Yellow

White

Located in
or between
the hypo-
dermal
cells

Sub-
hypodermal
colors

Green

Yellow

White

Located in
the body-
cavity in
hsemolymph
or fat-body

Derived
pigments

Derived
pigments

Permanent. Insoluble
in water, oils, alcohol,
weak acids, or alkalies

Soluble in ether or other
fatty solvents

Not permanent.
Fade at death or
on exposure

Soluble in water, al-
cohol, etc.

Are chlorophyll or
xyanthophyll de-
rivatives largely

Not permanent. Fade
at death or on e.x-
posure

Soluble in usual or-
ganic solvents

' Reflection
colors

Physical
colors

White

) Caused by air included within scales, etc._ The most
j common, and perhaps the only true physical, color

Refraction I MetalUc I Opalescent
colors I colors I colors

Caused by combining white and
some metaUic refraction color,
usually with pigment present.
Frequently caused by thin irregu-
lar lamellae over pigment, giving
effect of Newton's rings

Diffraction j Iridescent I gee next class
colors I colors )

Chemico-
physical
colors

Reflection Colored surfaces
pigmental > with polished ap-
colors (a) pcarance

Blacks
Browns
Yellows
Reds

Caused by a polished lamellar
surface over layer of pig-
ment.

Refraction i Almost all
pigmental -| metallic
colors {b) ( colors

Cause— polished refractive lamella overlying a
layer of pigment

Diffraction ( Alniost all | Cause— surface structures, pits, ridges on refrac-
pigmental -l iridescent V ^j^^ lamella overiving a layer of pigment
colors (c) ( colors )

Combination
colors

Various iridescent metalUc and
opalescent metallic colors, etc.,
in which colors of groups a, b,
and c combine to produce color
effects

This class of color is con-
fined largely to Lepi-
doptera and almost ex-
clusively to scaled in-
sects or areas bearing
scales

Color and Pattern and their Uses

5^9

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-

FiG. 770. — Single scale from moths and butterflies, a, from Tolype velleda; h, from Casl-
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 .07 mm. {^^-^ inch) to .8 mm. {-^^ inch) if we Fig. 771.— Scale of
exclude the long hair-like forms common near the base epta us meg as i-

o am, snowing pn-

of each wing, and also the slender elongate ones mary and secondary

which project from the wing-margins. In width the stnation. (Greatly

^ •' a !D magnmed.)

scales vary from hair-like to a breadth of .4 mm. (^^^ inch).

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 striae. These striae vary in distance apart, on different scales, from
.0007 mm., as in the scales of the great blue Morpho butterflies, to .004 mm.,
as in the sulphur-yellow butterfly, Catopsila eubide.

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

„ , „ , , , , r toward the base of the wing in

I'IG. 772. — A small, partly denuded part 01 , °

the wing of a butterfly, Lyceita sp., showing subparallel rows runnmg 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 ^ . ^ ^ . . ,

inserted. (Photomicrograph by George O. anterior to posterior margin, and
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 tier

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 less than

the length of the scales, so that there

is an overlapping of the tip of the

scales of one row over the bases of the

scales in the next row in front. By this

double overlapping there is formed a complete shingled covering of scales

over each surface (upper and under) of each wing.

Fig. 773. — Bits of denuded wing of a
butterfly, Grapta sp., to show rows
of insertion-pits on upper and lower
sides, with three scales in position.
(Greatly magnified.)

Color and Pattern and their Uses 591

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.

Fig. 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 .043 mm. (on the
under surface the pits are .05 mm. apart); so that in a space 25 mm. by
25 mm. (i 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

1 1 1 i T. J • i.' r xi • Fig. 77=;. — Base of scales: a,

largely lost, by desiccation of the wmg mem- ^f ^^;^^,,,^.^ arizonesis; h, of

brane, and the pedicels are more easily brushed Morpho sp. (Greatly mag-
from the wing than when the insect is alive. mfaed.)

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 what 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 striae 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 stride, which traverse the scale
from base to outer margin and are very sharp, and sepa-
rated from one another by equal distances. The stride
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 Anosio-
plexippus from 33 to 46 striae, averaging .002 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 .0015 mm. to .002 mm. apart;
on opaque (pigment-bearing) scales from the same spec-

FiG. 776. Scale imen the striae were from .0007 to .00072 mm. apart,

of Lycomorpha or at the rate of about 35,000 to the inch.

constans, show- ^. . , • t -i \ ^ j a c

ins cross-stricc. ^^ ^^'^ examme a long series 01 scales brushed on from

(Greatly mag- different parts of a wing of moth or butterfly, we can
always note a series of gradating forms running from slender

The significance of this,

nified.)

hair-like form to typical short, broad, flat scale,
when we come to inquire about the origin
of scales, is plain. Scales are unusual struc-
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 a
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 -pio
uniform shingling manner previously described.
But even on the wings of a butterfly all the
gradations from hair to scale can be found by
going from base out to discal area of the wing.
These gradation series vary in character in dif-
ferent families, as shown in Figs. 778, 779, 780, and 781

777. Androconia from
wings of male butterflies, a,
from wing of Nymphalid
butterfly; h, from wing of
Pierid butterfly; c, from
wing of I-yca>nid butterfly.
(All greatly magnified.)

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

YiG, 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

Fig. 779. — Scales from a single fore wing of Gloveria arizonesis, showing gradations from
scale-hair to speciahzed 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).

Fig. 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

the origin of the indi-
vidual 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 myriad little scales
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
chiefly 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

Fig. 781. — Scales from a single hind wing of the
goat-moth, Prionoxystus robincE, showing gra-
dations from scale-hair to specialized scale.
(Greatly magnified.)

Fig. 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. 5.C., scale-
cells; /i^"/)., hypodermal cells; /.leucocytes; 5, devel-
oping scales. (After Mayer; greatly magnified.)

Color and Pattern and their Uses

595

chemical (pigmental) 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

Fig. 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 (b) striation. Each scale is composed of a pair of thin subtrans-
parent laminae (lamellae), 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 lamellae 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
mxa or bit of old weathered glass or film of soap-bubble produces color
(Newton's rings). In addition the striae-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 .0006 mm. apart:
in butterfly scales the striae are from .002 to .0007 mm. apart.

59^ 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-

FiG. 784. — Diagrammatic series showing development of color-pattern in pupal wings
of the monarch butterfly, Anosia plexippiis. (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, zl«05m
plexippHS, 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, b, illustrates the next stage, where the
black has begun to appear in the region beyond the cell. The nervures

Fig. 78:;. — 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 plexippuSy
as in CaUosamia 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. 785.

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,

Fig. 786. — Diagrammatic series showing development of color-pattern in pupae and young
adults of the giant wood-boring beetle, Orthosoma brunnea. The first three figures in
the upper line, counting from the left, are pupae of successive ages, the rest of the
figures adults of successive ages. (After Tower; natural size.)

Orthosoma hrimnea, 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 with 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 v/ith most insects all the indi-
viduals 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 individuals ranging through gray, brown,
reddish, plumbeous, and bluish, and such accompanying variablity in mark-

6oo 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 experiments of Tr!men, Miiller, and Poulton with the
pupating larvae of swallow-tailed 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 larvse, 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. Larvae 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 larvae (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 larvae 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 whxh 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 larvas of Lycana sp.,
abundant on the flower-heads of the just-blossoming (May) California
buckeye, .'Esculus calijornicus. The buds of the buckeye are green, or green

Fig. 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 Lycaenid larvae
lie longitudinally along the buds and their short stems, and are either green

6o2 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 (PI. XIII, Figs. 3, 4, and 5). The
correspondence in shade of color is strikingly exact: the utter invisibility,
or rather indistinguishability, of the larvae is something that needs to be
experienced as my artist, my students, and I have experienced it in the last
few vv^eeks, to be fairly realized. We have watched the larvae 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 Kalhma (PI. XIII, Fig. i,
also text Fig. 787) and of Phyllium (PI. XIII, Fig. 2, also text Fig. 788),
referred to in an early paragraph in this chapter, illustrate extreme and

often-referred-lo 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

I 7 brown line continuously across both wings,

1 ''^ j the lateral leaf-veins corresponding on one

\ ' side to the actual course of the wing-veins,

V ^ ^' 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

Fig. 788. — The green-leaf insect, -^i .1 u j • 1 r • j

Fhylluim^^. This insect is brigh; With the broad green wmg-covers, leaf -vemed

green with scattered yellowish and spotted with yellow like a fungus-
cltii^gMT'sC"" ''"''*<=d or insect-punctured leaf compose a
make the insect almost indistin- false picture of great effectiveness. Are
guishable when at rest among ^^^ ^j^ggg ^g^ails of deceit almost past
green leaves. ^

belief?

The slender grass-green larvae of many moths and butterflies are much
like green grass-leaves; their shmness 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

60

these larvae 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)

Fig. 789.

Fig. 790.

Fig. 789. — An inch-worm, larva of geometrid moth, in protective position. (After Jor-
dan and Kellogg; natural size.)
Fig. 790. — The walking-stick, or twig-insect, Diapheromera jemorata. (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

6o4 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 jemoraia (Fig. 790),
a Phasmid wide-spread over the whole of our country. The absence of
vdngs, 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 larvae 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 fideHty 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 famihar 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. — If 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

Fig. 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 terrifying
appearance. The large green caterpillars of the sphinx-moths have a curious
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.

6o6

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,

Fig. 792. — Larva of the pen-marked sphinx-moth, Sphinx chersis, showing threatening
attitude. (After Comstock.)

Chccrocampa 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

Color and Pattern and their Uses 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,
Pseudocreohotra 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

Fig. 793. — Larva of the puss-moth, Centra 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 Lycaenid
butterflies, and others. Marshall busied himself for a long time wiih 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

6o8 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
Lycaenidae to a head with antennae 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 antennae, 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 (Syrphidae, Asilidae, Bombyliidie), 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, Conopidas,
and some of the clear-winged moths, Sesiidas (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, i, 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
archippiis 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-

FlG. 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 Danaida^ and Heliconidae, are distasteful
to birds, and are mimicked by many species of other butterfly families, espe-
cially the Pieridae, and by the swallowtails, PapiUonidae. Many plates
illustrating such cases have been published by Poulton and Marshall, Haase,

6io

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-

FiG. 795._The monarch butterfly, Anosia plexippus (above), distasteful to birds, and
the viceroy, Basilarchia archippiis (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 6 1 i

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

6l2

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
speciaUzation 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

Fig. 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 Hzard.
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 v^^hatever 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

Fig. 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.

6 14 Color and Pattern and their Uses

Brooklyn Inst. Arts and Sci., Vol. I, No. 2, 1902); a paper by Tower on
"Color and Color-patterns of Coleoptera" (Decenn. Pubs. Univ. of Chicago,
Vol. X, 1903); a paper by Kellogg on "The Taxonomic Value of the Scales
of the Lepidoptera " (Kansas Univ. Quar., Vol. Ill, No. i, 1894); the papers
by Poulton and Marshall referred to on page 605, and that by Shelf ord
referred to on page 610.

CHAPTER XVIII
INSECTS AND DISEASE

IHROUGHOUT 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 Jose
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.

W^e 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

6i6 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,
one 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
larvae 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
indgnificant 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 Haema-
tozoa, have been found in reptiles, birds, bats, cattle, and monkeys. The
haematozoon 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 Haema-
mcebae, 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 Hasmamoebae of the
human body exist in three varieties, each apparently responsible for one

6i8

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, Itahan,
English, and American (Celli, Grassi, Mannaberg, Bignami, Danielewsky^
Carter, Osier, Labbe, 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 Haemamoebae in the human body as follows: The youngest para-
sites, or amoebulae, 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 haemoglobin of the corpuscle, due to the metabolism of the

Fig. 798. — Diagrammatic figure of stages in the development of the malaria-producing
Hsemamoeba (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 oi the Haemamoeba, the
amoebulag 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 Haemamoeba 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 6 1 9

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 metabohsm and multiplication of the Haemamoebs 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 Ha^mamoebae, 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 Haemamoebae of malaria; their questioning was made more insistent by
the discovery that some of the amoebulae 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 amoebulae
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 Haemamoebae 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 amoebulae 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 Haemamoebae 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.

"It 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 ivithin the stomach-cavity oj some suctorial
insect, and constitutes the first step in the life-history of the parasite outside
the vertebrate host.

"It 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 tick. 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 amoebula?
in the blood-corpuscles of the host become sporocytes, which produce asexual
spores (nomospores) ; while other amcebulas 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.

"I 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 Hcemomenas prcBcox, were examined cell by
cell — not even their excrement being neglected. Although they were known
to have swallowed Haemamoebidae, no living parasites like these could be
detected in their tissues — the ingested Haemamoebidae 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 — I 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 larvae 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 hoat-sha ped
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 jew
grannies of the characteristic coal-black melanin of malarial Jever — 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 of the parasite oj remittent jever
growing in the tissues oj 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 Hasmamcebidae
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. . . .

"Early 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 Hgemamoebidae of
birds. Birds have at least two species of Haemamoebidaj. 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 prec sely simi-
lar to those seen in the Anopheles were found to appear in gnats of the species
called Culex jatigans Wiedemann, when these had been fed on sparrows and
larks containing Hcemamceba 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 Hmnamoeba danilewskii .

" It 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
hsemocytozoa 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 jatigans fed on birds containing il. relicta 178, or 72
per cent., contained 'pigmented cells.' But, out of 41 Cuhx jatigans
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 H. relicta, were placed in separate cages within
three separate mosquito-curtains. A number of Culex Jatigans, all bred
simultaneously from larvae 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 in each gnat. The ten gnats fed on the sparrow with numerous parasites
contained 1009 'pigmented cells,' or an average of 100 cells in each gnat.
These thirty specimens were sent to Manson in England, who made a similar
count of the cells.

" I may mention one more out of several experiments of the same kind.
A stock of Culex jatigans, 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.

' ' It 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^

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
jatigans on b^rds with H. relicla 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 s x 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 hlastophore
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 i2-6fi 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 Haemamoebidae the simple term 'fiUform 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.

"It 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 in 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.

' ' It 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.

"I 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 Hsemamoebidae 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 EngHsh 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, "(i) 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 i6th, the date
of the report."

These two experiments alone would be conclusive. Since 1900, 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 role
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
1900 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 Stegoniyia
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 filariae or thread-
worms.

These organisms are of much higher organization than the minute unicel-
lular Haemamoebse that cause malaria; they belong to the group of round-
worms, the Nematoda, and in fully developed condition some species of
filariae 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 hancrojti, 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
filariae (sometimes called F. sangtiinis-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 repulsive 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-producing
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 filariae 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 filariae 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 this 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 reservoirs, ponds, or puddles of water to lay
their 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 filariae 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 filariae are transmitted by
the bite or puncture of the mosquito, and has actually observed the migration

634 Insects and Disease

of the filariae 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 filariae in Australia is Culex fatigans, var. skusii. Anopheles
rossii is also known to carry the filariae. 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
filariae that cause elephantiasis, it is the most formidable single species among
all the insect scourges of mankind.

In this brief account of the role 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.

APPENDIX
COLLECTING AND REARING INSECTS

The 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 — 12 to 14 inches in diam-
eter at the mouth and about 24 inches deep,
tapering to a rounded bottom about 4 to 6 inches
in diameter. The handle should be light and
about 3^ feet long. The wire ring supporting
the net should be strong — No. 3 galvanized iron

Fig. 799. Fig. 800.

Fig. 799. — Collecting-net. (After Packard.)

Fig. 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-

635

636 Collecting and Rearing Insects

mouthed bottle from three to six inches high (a quinine or quassia bottle is
good) and covering this with wet plaster of Paris. WTien 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 bottle
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. Larvae (caterpillars, grubs, etc.)
and pupae (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.

Collecting and Rearing Insects

637

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. i (Carlsbaeder No. 2).
Pin each insect straight down through the thorax (Fig. 801) (except beetles,
which pin through the right wing-cover near the middle of the body (Fig.
802)). On each 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

Fig. 801. Fig. 802. Fig. 803.

Fig. 801. — Insect properly pinned up. (Aftei Jenkins and Kellogg.)
Fig. 802. — Mode of pinning beetle. (After Packard.)
Fig. 803. — Pinning a bug. (After Packard.)

"locality and date" labels printed in diamond or agate type on paper not
too stifif 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: ^*funi9o'^' 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 Dermestidse, 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

638

Collecting and Rearing Insects

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. St>4 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

Fig. 804. Fig. 805.

Fig. 804.— Setting-board with butterflies properly spread. (After Comstock.)
Fig. 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 larvas, 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

Collecting and Rearing Insects 639

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 NitiduliE, Silphidffi, and other insects of similar habits, are certain to be
enticed and captured.'

"Planks and chippings of wood may be hkewise 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 larvae, especially the Longicorn beetles;
and weevils can be found in the spring, in all stages.
Numerous carnivorous coleopterous and dipterous
larvae dwell within them, and other larvae which eat
the dust made by the borers. The inside of pithy Fig. 806.— Water - net.
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.

640 Collecting and Rearing Insects

"Ponds and streams shelter a vast throng of insects, and should be dUigently
dredged with the water-net, and stones and pebbles should be overturned
for aquatic beetles, Hemiptera, and Dipterous larvae."

Much collecting may be done at night. Many nocturnal moths and
beetles are attracted by bright Hghts: the city's lamp-posts or your own
briUiant bicycle-lamp of acetylene gas may be reUed 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 roUed-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 Hkely 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 kiUing-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 larvae bring in
some chips and dust of the home log; with underground larvas bring in
some soil. Simply because you find such larvae in a certain place is sufficient
proof that their surroundings are of the right sort for them.

Collecting and Rearing Insects

641

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

Fig. 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 somethmg
like ours, in which consciousness and memory and choice play so important

a part.

Particularly available and interesting kinds of insects to rear m home
cages and aquaria are the larvae (caterpillars) of moths and butterflies, various
leaf-eating, wood-boring, and ground-burrowing beetle larvae, honey-bees

642

Collecting and Rearing Insects

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 larvae 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.

Fig.
Fig.

Fig. 808.
808. — Lamp-chimney and floor of breeding-cage.
809. — Bell-jar live-cage.

Fig. 809.
(After Jenkins and Kellogg.)

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 pupae can be kept we make much use of common wire-screened

Collecting and Rearing Insects

643

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

Fig. 810. — 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. 8ii). 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 larvae that live underground
cages with soil in must be provided.
The principal difficulty of rearing such
insects is to keep the right degree of
moisture in the soil. If too damp, fungi

grow and envelop the insects; if too dry, the larvae 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 position

Fig. 811.— Soap-box breeding - cage.
(After Comstock.)

644 Collecting and Rearing Insects

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-
mediately 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 larvai 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 pupae, in cocoons or in underground cells, o\-er
winter, for many insects, especially in the eastern and northern states, pass
the winter in the pupal stage. " Hibernating pupae 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 pupae 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 pupae 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. 54S
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 17X13X1^^ inches thick, grooved all
around about i 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 X9 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

Collecting and Rearing Insects

645

outside. (Bicycle-tape is good.) Place an oblong strip of glass 8^X1 inch
across the inside of each corner. Fill the space, thus formed, with cement.

Fig. 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:

White sand i part.

Plaster of Paris i "

Litharge i "

Powdered resin ^ "

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.

646 Collecting and Rearing Insects

Tradescantia (wandering-jew or inch-plant) is also useful. Avoid the
use of algae (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 mvist 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 everyday 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 algae, which are bound to accumulate.
For removing small particles from the bottom, a ^-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, Hft the finger, and the
water will rush up the tube, carrying out the object. Replace the finger on
the upper end and Hft 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-

Collecting and Rearing Insects 647

scavenger beetles; back-swimmers; water-boatmen; dragon-fly and May-fly
nymphs; mosquito larvae, etc.

Other animals may of course be kept in the aquarimn. 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 larvae feed at first on vegetable
matter, later on bits of meat, tiny earthworms, mosquito larvae, 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, ^^^ 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. Etymologies are given for the
order, suborder, superfamily, and family names. In etymologies of 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 -idee (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 Muscidse, 341
Acanthaclisis, 232
Acanthia Jiirundinis, 206
Acanthiidas, A c a n t h a
(aKavOa, acantha, thom) ,
195. 205
Achemon sphinx -moth,

larva of, *43i
Achorntcs nivicola, *64
AcliunDii brevipcnne, 142
Acoloithns falsarius, 387
Acridiidse, A c r i d i u m
{aKpi6iov,acridium, dim. of
a/cp/f, locust), 126, 133;
auditory organ of, *I34,
135-, impaled by shrike,
*I34; life-history of,
136; key to subfamilies
of, 136; migratory spe-
cies of, 133 ; sounds of,

Acridiinse, 136.

Acronycta americana, 404;

impressa, *405 ; occiden-

talis, *404 ; occidentalis,

larvae of, *404
Adalia bipunctata. 287
Adephaga {uSriv, aden,

enough ; (payelv, phagen,

eat), 251
Admiral, red, 454
^cilius sulcatus, stages in

development of nervous

system of, *25
Mschna constricta, head

of, *93

yEschnidse, ^schna (prob.
alaxpog, aischrus, ugly),
91,92

Agamic, 173

Agaristidae, Agarista
(etym. uncertain), 407

Agenius, 499

Aglais milberti, 456

Agonoderus pallipes, 255

Agrilus, 266 ; ruficollis,
267

Agrionidae, Agrion ( aypiog,
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, *I9

Aleyrodes iridescens, *I92 ;
nierlini, enlarged details
of pupa, *I93 ; pupa-case
of, *I93; pruinosa, *I92;
tcntacu latus, *ig2

Aleyrodidae, Aleurodes
(aXevp(j67jg, aleurodes,
floury), 166, 190

Alimentary canal. 13

Alimentary canal of cock-
roach, *I4; of dobson-
fly, *i6; of harlequin-
fly, *I5 ; of locust, *I4;
of thrips, *I5

Allantus basillaris, *4,64

Allorhina nitida, 276

Alternation of generations

of gall-flies, 469
Alulet, 327

Alypia 8-maculata, *4o8
Amber-wing dragon-fly,

*95
Amblychilia cylindri-

formis, 253
Amblycera ( afi3}.vq, am-

blys, blunt ; Kepag, ceras,

horn), key to genera of,

118
Amblycorpha oblongifolia,

*i5i ; rotundifolia, 151
Ambrosia-beetle, 299
Ambush-bugs, 195
American blight, 179
American locust, *I39,

141 _
American tortoise-shell,

455
Ammophila, nest-building

of, *494; nest-burrow of,

*494 ; nesting-ground of,

*492; nesting habits of,

492 ; putting inchworm

into nest-burrow, *493
Amnion, 38
Ampelophaga myron, 434,

435 ; zrr.ytVo/or, 435
Amphibolips coccinea;,

471 ; spongiiica. 471
Aniphiccrns bicaudatus, 271
Amphientomum, 112
Amphigerontia, 113
Amphion nessus, *438
Anal veins (see venation)
A n a b r u s purpurascens,

*i56, 157

650

Index

Ancea andria, 455
Anaphothrips striatus, 221
Anarsia lineatclla, 2>7A
Anasa tristis, *2i3
Anatis 15-punctata, 287
Anatomy, internal, 13; of
larva of giant crane-fly,
*2i ; of monarch butter-
fly, *I3 ; of silkworm, 430
Anax jttnitis, head of, *93 ;
stages in development of,
*83
Ancistrona, 119; gig as,

*i2i, 122
Ancyloxypha numitor, 443
Andrena, 517; nest of,

*5i6
Andrenidse, Andrena
{avSprjvT), andrene, bee),

Andriciis calif amicus, 472 ;

gall of, *473
Androconia from wings of

butterflies, *592, 445
Angerona crocotaria, 398,

*399
Angle-wings, 452
Angoumois grain-moth,

375

Angular-winged katydid,
*i5i

Anisolahis annulipcs, 162

Anisomorpha, 133

Anisoptera {aviaog, anisus,
unequal ; Trrepoi', ptcrurn,
wing), 89; key to fami-
lies of, 91

Anisopteryx pomctaria,

397

Anisota ruhicunda, 427;
senatoria, *428, 429;
stigma, 428 ; virginiensis,
428

Anobium, 113, 271

Anoniiopsyllus nudatus,
356

Anopheles, 305, 307; ma-
culipcnnis, *3o8; sp.,
eggs of, *3o6

Anosia plcxippus, *45i ;
arrangement of pharynx,
cesophagus, etc., in head
of, *36i ; complete meta-
morphosis of, *44 ; cross-
section of sucking pro-
boscis of, *36i ; devel-
opment of color-pattern
in pupal wings of, *596 ;

development of scales of
wing of, *59S ; external
parts of, *6; internal
anatomy of, *I3 ; larva
of, *6os ; mimicry of, by
viceroy butterfly, *6io;
part of maxillary pro-
boscis of, showing ar-
rangement of muscles,
*36i ; part of wing of,
showing scales, *36o ;
venation of, *ii; vena-
tion of wings of, *37i

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, *2y ; of beetles, *2So

Ant-guests, *553

Anthidium, 514

Anthomyiinse, 341. 345

Anthonomus grandis, 296;
quadrigibhtis, 296 ; sig-
natus, 296

Anthophora, 515; pilipes,
mouth-parts of, *5i2 ;
stanfordiana, 516

Anthophoridas, Anthophora
(^av6o(p6pog, anthophorus,
flower bearing), 515 .

Anthrax, 334 ; fiilviana,
venation of wing of,

""32,2,

Anthrenus museorum, 263 ;
scrophularice, *26s, 264;
varius, 263

Ant-lions, 55, 30

Ants, 56, _ 463, 533 ; and
rose-aphids, *I74; 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

Apanrcsis virgo, 413

Aphidiidas, Aphis ( cKbEiSeT?,
aphides, lavish), 166,
171

Aphids, 171 ; as ants' cat-
tle, 175 ; honey-dew of,

175, 180; killed by Hy-

menopterous parasites,

*I73 ; wax of, 175
Aphis-lion, 228, 229, 230
Aphis mali, 174
Aphodius Hmctarius, 274;

oblongus, 275 ; tcrmi-

nalis, 275
Aphoruridae, Aphrophora

{u(l>po(p6po(; , aphrophorus,

foam-bearing), 63
Aphrophora 4-notata, 171 ;

signoreti, 171
Apidae, Apis {apis, bee),

Apina, (see Apidae), 463
Apis Horca, comb of, *520;
mellHica, 520, 521 ; inclli-
Hca, hind leg of, *52i ;
mellifica, stages in devel-
opment of nervous sys-
tem of, *24 ; mclliiica,
varieties of, *S2i
Apoidea (see Apidse), 511
Apple aphids, 174, 179
Apple bucculatrix-moths,
376 ; pupal cocoons of,

*375. *37^
Apple tent-caterpillars,

*359
Apple-tree borer, *266,

*285
Aphodius, 274
Aptera (a, a, without;

nTepov,pterum, wing). 52,

58 ; ovarial tubes of, *59 ;

respiratory system of,

*59
Aquarium, battery-jar,

*645 ; for dragon-fly

nymphs, *88 ; how to

make and maintain,

644
Aquatic muscid, *348, *350
Arachnida, 3
Arachnis picta, 413
Aradidoe, Aradus {apa<)oq,

aradus, rumbling), 195,

207, 208
Aradus cinnamomeiis, 208.

*209

Aramigcs fiillcri, 295
Arctiidse, Arctia (arktos,

bear), 370, 411
Areoles, 232
Argia putrida, 84
Argynnis cybele, 456
Arista (antcnnal bristle)

Index

651

Aristolochia clematitis,

flower of, *575
Aristolochia, specialization

of, for insect pollination,

575
Army-worms, 325, *403,

404 ; ichieumon parasite

of, *482
A rp 1 1 ia su Iphurca, * 1 44 ;

tcncbrosa, *I44
Arthasia gallcata, *i6g
Arthropoda, classes of, 2 ;

defined, 2
Arums, specialization of,

for insect pollination,

575
Ascalaphinse, 232 ; key to

genera of, 233
Asclepias, catching cab-
bage-butterfly, *574 ; cor-
tinti, specialization of,
for insect pollination,
573 ; incarnata, visited by
insects, 571 ; vcrticillata,
visited by insects, 569,
571 ; visited by honey-
bee, *574
Ash-tree borer, *392
Asilidge, Asilus {asiliis, a
gad-fly, a horse-fly), 330
Asparagus-beetle, 278
Aspidiotiphagus citrinus,

*479

Aspidiotns aurantii, 188,
*i89, *i9o; Hens. 188;
pcniiciosus, *i8i, *i82,
*i84

Assassin-bugs, 195, 203;
incomplete metamorpho-
sis of, *43

Astata, 499; unicolor, nest-
burrow of, *500

Aster paniculatus, visited
by insects, 571

Ateuclms sacer, 274

Aflious scapularis, 268

Atlanticus dorsalis, 156;
pacJiynicnis, *I55

Atropidje, AtroposCArpOTrof,
a t r n p u s , one of the
Fates), 112; key to gen-
era of, 113

Atro^os divinatoria, 113;
sp., *II2

Attagcnus piceiis, *263,
264

Auditory organ in antenna
of mosqtiito, *29 ; of

Acridiidae, *i34, 135; of
locust, *28 ; of Locus-
tidae, 150

Australian lady-bird bee-
tle, 186, *i87

Autoiiicris io, 424, ^425 ;
larva of, 426; pamina,
424; zelleri, 424; zephy-
ria, 424

Bacillus, 132

Back-swimmers, 194, 198

Bacunculus, 133

Bag-worm, 369, *388 ;
moth, 386, *387; moth,
venation of wing of,
*389

Balancers, 302

Balanintis caryatrypes ,
*295, 296; nasicus, 296;
qiicrcus, 296 ; restus, 296

Baltimore butterfly, 456

Banded footman, 410 ; pur-
ple, 452

Bark-lice, 11 1

Barren-ground locust, *I46

Basilarchia archippus, 452 ;
artheiuis, 452 ; astyanax,
452 ; astyanax, venation
of, *440 ; Horidensis, 452 ;
lorqiiini, 452

Basilona iinpcrialis, 426

Battery- jar aquarium, *645

Bat-tick, 351, *352

Beak of mosquito, *302

Bean-weevil, 277, *28i

Bedbugs, 195, 205, *2o6 ;
hunter, masked, 203

Bee-flies, 222, 232,

Bee-fly, *334 ; mouth-parts
of, *334

Beehive, observation, *53i,
*532

Bee-lice. 351

Bee-louse, *3S2, 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,
*5i6; potter, 514; short-
tongued, 511 ; social,
517; solitary, 513

Beetles, 55, 246; antennae
of, *250 ; development
of, 250 ; eyes and tarsi
of, *25o; mode of pin-

ning, "^627", tracheal sys-
tem of, *i8

Bell-jar formicary, *55o;
live-cage, *642

Bclostouia amcricana, *2oo

Belostomatidse, Belostoma
{piXog, bcltis, dart ; aro/Mi,
stoma, mouth), 194, 200

Bembccia marginata, 391

Bembecidae, Bembex(/-^f/^/i/^,
bembix, buzzing insect),
500

Beiiibex spinoloe, 500

Bcnactis griscus, 200

Berytidse, Berytus (Bery-
tus, a seaport town of
Phoenicia), 195, 214

Bibio albipcnnis, *326; ve-
nation of wing of, '^'326

Bibio fcmorata, 326 ; fra-
ternns, 326 ; tristis, 326

Bibiocephala comstocki,
heads of male and fe-
male of, *3i6; larva of,
*3i5; pupa of, *3i5; ve-
nation of wing of, *3I7;
doanci, head of larva of,
showing formation of
adult head-parts, *3i8 ;
doanci, mouth-parts of,
*9, *3i6; doanci, mouth-
parts of larva of, *3i7;
clegantiiliis, female, *3i6

Bibionidae, Bibio {bibis,
an insect, from bibo,
drink), 304, 325

Bilateral symmetry (halves
of body similar)

Bill-bugs, 294

Bird-lice, 55, 113; biting,
III ; remedies for, 114

Bird-ticks, 351

Biston ypsilon, *3,g8

Bittacus, 236 ; ap terns, 238 ;
strigosus, *237

Black beetle, *I28

Black-bordered orange,
446

Black-flies, 313

Black-fly, *3i2; female,
mouth-parts of, *3i3;
head of larva of, show-
ing developing mouth-
parts of, *3i4: mouth-
parts of larva of, *3i3;
venation of wing of,

*3I2

Black scale, 187

652

Index

Black swallowtail, 450
Blastoderm, ^38
Blastophaga grossorum,

*487
Blattidae, Blatta (blatta,

insect that shuns light),

126
Blepharocera capitata,

cross-section of eyes of,

*3I7
Blepharoceridse, Blepharo-
cerus (probably jil-f^apov,
blepharus, eye ; Ktpaq,
ceras, divided), 304,

314-
Blissus leucopterus, 211,

*2I2

Blister-beetle, 288
Blood, 17
Blow-flies, 343
Blow-fly, *344 ; complete

metamorphosis of, *45 ;

compound eye of, *3S ;

larva, pupa, and adult

of, *302
Bluebottles, 343
Blue-striped looper, ^398
Body-louse, *2i6
Body-wall, section of, *4
Bolcototherus bifurcus,

289 ; larva of, *289
Boll-worm, cotton, 404
Bombidge, Bombus (fi6fi(iog,

b 0 m b II s , a buzzing
• noise), 518
Bombus, 518; aMnis, 519;

calif ornicus, 519; sd-

wardsii, 519; ferviotus,

519; sp., nest of, *5i9;

sp., worker and queen,

*5i8; tcrricola, 519
Bombycidse, B o m b y x

(bomby.v, silk), 369
Bombyliidse, Bombyllius

(fSofJtivhuc, bombylius,

humble-bee), 332, 2,33
Bombylius, 2>32) \ major,

*334 ; sp., mouth-parts

of, *334
Bombyx mori, 429; larvae

of. 428 ; venation of, *420
Book-lice, 55 ; iii
Book-louse, *ii2
Book-worm, 271
Borcus brumalis, 236; cali-

f ornicus, 236 ; nivoriun-

dus, 236 ; unicolor, 236
Bot-flies, 232, 337

Bot-fly, larva of, *337; of
horse, *338

Box-elder bug, *2i3

Brachycera {Ppaxvq, bra-
cliys, short; i^epag, ceras,
horn), 303, 327; division
into groups, 327 ; keys
to families of, 327, 332

Brachynemurus, 232

Braconidse, Bracon (Fa-
bricius, etym. uncertain),

463

Brain of locust, *22

Braula cceca, 353 ; sp., *352

Braulidse, Braula {jipavla,
braula, louse), 351, 353

Breathing of aquatic in-
sects, 20

Breeding-cage, *64i ; lamp-
chimney, *642 ; s o a p -
box, *643

Breeding-cages how to
make, 642

Broad-winged katydid,
*I50, *i5i

Brood-comb of honey-bee,
with young stages, *46

Bruchidse, Bruchus
{ppovxog, bruchus, a lo-
cust without wings),
277, 281

Bruchus obtectus, *28i ;
pisi, *28i

Brush-footed butterflies,
450

Bucculatrix pomifoliclla,
*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

Buprestidae, Buprestis
{povg, bos, ox; 'Kpijdeiv,
prethen, swell), 265, 266

Buprestis, 267

Burrower-bugs, 195, 215

Burying-beetle, *26i

Bumblebee, at clover-blos-
som, *5i8; guest, 519;
nest of, *5I9

Bumblebee-like robber-fly,
*33i

Bumblebees, 517

Butterflies, 358, 439; key

to families of, 441 ;
scales of, their structure
and arrangement, 589
Butterfly, part of wing of,
*590

Cabbage-bug, harlequin,
214, *2I5

Cabbage-butterfly, caught
by Asclepias, *S74; Eu-
ropean, 445 ; northern,
445 ; southern, 445

Cabbage maggot-fly, 345

C a c oe c i a cerasivorana,
*3%0', venation of, *38o

Caccccia parallcla, *38o ;
pcrvadana, 380 ; rosa-
ceana, 380; obsoletana,
larva of, *364; obsole-
tana, pupa and adults of,

*365

Csecilius, 113

Caddis-flies, 23, 55, 240;
keys to families of, 244

Caddis-worms, case-build-
ing of, 240 ; fishing-net
of, *243 ; halDits of, 241 ;
pupation of, 242 ; cases
of, *24i ; key to families
of, 244

Ccenonympha calif ornica,

457

Calandra granaria, 297;
oryccc, 297

Calandridae, Calandra (F.
calandre, weevil), 294,
297

Calephilis cccnius, /[^i^A,

California flower-beetle,
279, *28o ; parasitic fun-
gus of, *346 ; tachinid
parasite of, *346

California honey-ant, un-
derground nest of, *546

California oak-worm moth,
*4o6

California ringlet, 457

California shield-backed
grasshopper, *r55

Caligo sp., *6i2

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-

Index

653

thea, 422, *424; cocoons
of, *423 ; development of
color-pattern in pupal
wings of, *597
Calocalpe undulata, *299
Calopterygidae, Calopteryx
(KaAof, caliis, beautiful ;
nripv^, pteryx, flight),

89

Calopteryx, 89; maculata,
89, *90

Calosoma calidum, *254 ;
frigidum, *254 ; larva of,
*253 ; scrutator, 254

Calotermes, 102 ; casta-
neus, 104

Calyptrate Muscidae, key
to subfamilies of, 341

Camel-crickets, 155

Camniila pellucida, 133,
*I45

Campodca sp., *6i ; staphy-
liniis, 60

Campodeidse, Campodea
(KdfiKTi, campe, caterpil-
lar; eU^oc, cidiis, form),
60

Camponotidse, Camponotus
(KafiTTT), campc, curve;
vij-oc, notus, back), 540,

545
Camponotus pcnnsylvani-

cus, 545
Canker-moths, lime-tree,

*397

Canker-worms, *395, 397

Canthon, 274

Capitate, *250

Capnia, 7;i ; pygmaa, 74

Caprification, 488 ; figures
showing effect of non-
caprification and, *489

Capsidae, Capsus (prob.
KanTEiv, cap ten, gulp
down), 195, 207, 209

C a r a b i d se, Carabus

(Kdpafioc, carabus,
horned beetle), 252

Carneadcs scandens, 402

Carolina locust, *i4i, 143

Carpenter-bees, 513 ; nest-
tunnel of, *5i3

Carpenter-moths, 369, 385

Carpenter-wasps, nest-tun-
nels of, *502

Carpocapsa pomonella,
381 ; larva or worm of,
*382 ; pupse of, *383

Carpocapsa saltitans, 382,
*383

Carrion-beetle, *26i ; larva
of, *262 ; smelling-pits
on antenna of, *27

Cases, for insect collec-
tions, 637

Cassida bicolor, 281

Castes, 503

Cat- and dog-flea, 356

Catcrva catcnaria, 399

Catocala cpiorc, 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

Ccanothus americanus, vis-
isted by insects, 569

Cccidomyia destructor, 323

Cecidomyiidas, Cecidomy-
ia (nr/Kig, cecis, gallnut ;
fivla, niyia, fly), 304,
322

Cecropia-moth, 418, *4I9

Celery leaf-hopper, *I70

Cclithemus epomina, *g6

Cell of wing {space bound-
ed by veins)

Cephalic (hcadward)

Cephus, grain, European,
467

Cephus pygmceus, 467

Cerambycidse, Cerambyx
(Kepafil3v^, cerambyx,
beetle), 277, 282

Cerasa bubalus, i6g

Ceratocampidse (prob.
«fp«f, ccras, horn ; KafiTrij,
campc, a bend), 426

Ceratophyllus stylosus, 356

Ceratopogon sp., mouth-
parts of, *3ii

Cerceris dcserta, locality
study of, *S0i ; tuber cu-
lata, dragging weevil to
nest, *495

Cerci, 73

Cercopidse, Cercopis {kbpkoq,
cercus, tail ; ut/", ops, ap-
appearance), 166, 170

Ccrcyonis alope, 457 ; pc-
gala, 457

Cerococcus ehrhorni, *igi ;
quercus, *ig2

Ceruchus piceus, 273

Cerura, 394; sp., larva of,

*6o7
Ceutophilus lapidicolus,

*i55; maculatus, *IS4,

155
Chccrocampa tersa, 435
Chalcedon, 457
Chalcid fly, *479
Chalcididje, Chalcis (;iraA/c/f,

chalcis, copper), 463
Chalcidoidea (see Chal-

cididse), 477
Chalcophora liberta, 267;

virginiensis, 267
Chauliodes, 224 ; serricor-

nis, adult depositing,

*225

Chauliognathiis margina-

tus, 270; pennsylvanicus,

270
Checkered beetles, 265, 270
Cheese-skipper fly, ^348
Chelymorplia argus, 281
Cherry aphis, 174
Cherry-bug, 214
Cherry-fruit fly, larva of,

*349; puparia of, *350
Cherry-tree leaf -roller,

*38o
Chicken-flea, 355
Chickweed geometer, 144,

399

Chigoe, 355

Chilocorus bivulnerus, 287

Chinch-bug, 211, *2I2;
family, 195

Chionaspis pinifolicc, 188

Chironomidse, Chironomus
(xEipovofioc, chironomus,
one who moves hands in
gesticulation [symmetri-
cal spreading of feet
when at rest]), 304, 310

Chironomus, alimentary
canal of, *I5; dorsalis,
part of sympathetic ner-
vous system of, *24 ;
nervous system of, *22;
pupa of, *3ii ; sp., *3io;
larva of, *3ii

Chitin, 4

Chloealtis conspersa, *I40,
142

Chloroperla, yj,, 74

Chlorops similis, 350

Chorion, 37

Chortophaga viridifasciata,
144, *I45

654

Index

Chrysalid, 44

Chrysididse. Chrysis (.rP'^ff'f .
chrysiSj a vessel of
gold), 463, 498

Chrysohothris fcmorata,
*266

Clirysochus aurahis, 280;
cobaltinus, 280

Chrysomelidse, C h r y s o -
m e 1 a (jcpvaofirjTi.o'kovdLov.
chrysomclolonthium, lit-
tle golden beetle), 277,
286

Chrysopa sp.. *228

Chrysophamis tlioc, 444 ;
venation of, ^440

Chrysophila thoracia, ve-
nation of wing of, *330

Chrysopidae, Chrysopa
{xpvouxp, chrysops, gold-
en eyes), 224, 228

Chrysops sp., venation of
wing of, *328

Cicada, mouth-parts of,
*q; scpjtcndccim, mouth-
parts of, *9; scptcndc-
ciin, 166, *i67; tibicen,
167; seventeen-year, 166,
167

Cicida-killer, 500

Cicadids, Cicada (r/carfa),
166 ; sound-making or-
gan of, *i67

Cicadula exitiosa, 170 ; 4-
lincata, *I70

Cicindela hybrida, larva
of, *252

Cicindelidse, Cicindela
(candcia, light), 252

Ctcuta macnlata, visited
by insects, 571

Cigarette-beetle, 271

Circotettix vcrruculatus,
*i46

Circulatory system, 16; of
young dragon-fly, *I7

Cisthene uni fascia, 410

Citheronia rcgalis, 426,
*427; larva of, *366,
*427

Class, 2

Classification, 52

Clastoptera pini, 171 ; pro-
teus, 171

Clavate, *250

Clavicornia (clava, club;
cornu, horn), 251, 264;
key to families of, 258

Claytonia virginica, visited
by insects, 569

Clear-winged moths, 368,
388; sphinxes, 438

Cleridse, Clerus {n/S/pnc,
clcrus, 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

Clisiocampa amcricana,
415; larva of, *359; ve-
nation of, *4i8; disstria,
stages of, *4i7

Close-wings, 277

Clothes-moth, *373, 374 ;
case-bearing, 374

Clothilla, 113

Clouded locust, *I45, 146

Clouded-sulphur, 446

Cob(ra scandcns, visited by
insects, 567

Coccidse, Coccus ( k6kko^,
coccus, berry or kermes
insect), 166, 180

Coccinella abdominalis,
*286 ; californica, *286 ;
calif ornica, stages of,
*287; novcmnotata, 2^7;
oculata, *286 : sanguinca,
*286; trifasciata, *286

Coccinellidse, Coccinella
(dim. of coccinus, scar-
let garments), 282, 286

Coccotorns Scutellaria, 296

Cockroach, alimentary ca-
nal of, *I4; egg-case of,
*i27 ; tracheae in head of,
*I9; wood. *I28

Cockroaches, 53, 126

Cockscomb gall-louse, 180

Codlin-moth, 381 ; larva or
worm of, *382 ; pupae of,
*383

Cccnis dimidiata, *69

Coleoptera (ko^ieo^, co-
leus, sheath ; Trrepdv,
pterum, wing), 55, 246;
genuina, 251 ; key to sec-
tions and tribes of, 251

Collecting insects, direc-
tions for, 635

Collecting-net, *635

Collembola (koaao, colla,
glue ; kjijioHi embole, in-
sertion, i. e., closely
joined, well framed), 60,
62 ; key to families of,
63
Colletes, 513
Colobopterus, 233
Colopha ulmicola, 180
Colorado potato - beetle,

*278
Coloration, directive, 607
Color-pattern, develop-
ment of, in giant wood-
boring beetle, *598 ; de-
velopment of, in pupal
wings of monarch-but-
terfly, *596 ; 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, 596; of in-
sects, their causes and
uses, 583 ; physical, how
produced, 586 ; produced
by scales, 594; warning,
604 ; cuticular, 587
Colpocephalum, 119
Comma-butterfly, *453
Communal life of ants,
537 ; of the honey-bee,

Compsomyia macellaria,

344
Compton tortoise, 456
Cone-nose, blood-sucking,

203, *204
Coniopterygldae, C o n i o -

p t e r y X ( kuvic, conis,

dust ; TTTepv^, p t e r y X ,

wing), 224, 235
Conocephalus, 154; cn-

sigcr. *I53
Conopidae, Conops (kwpwV.

conops, gnat), 332, 336
Conops, ZZ7
Co no rh in us sanguinisugus,

203. *204

Conotraclielus nenuphar,

*2g6 ; cratcrgi, *297
Copris Carolina, 274

Index

6J5

Coptocyla aiirichalcca,
*28o ; clavata, 281

Coral-winged locust, *I42,
144

Corbiculum, 514, *52i

Cordate {heart shaped)

Cordulegaster, 92

Cordulegasteridifi, Cor-
dulegaster (prob.
liopilvXjj, cordylc, a club ;
yaarr/p, gastcr, belly),
92

Coreida:, Coreus {k^'piq,
coris, bedbug), 195, 207

Corcthra sp., *309; pupa
and larva of, *309

CorimclcEtia publicaria, 215

Corimelasnids, Corimelrena
( Kupig, coris, bedbug ;
ue^avla, mclaina, f. of
mclas, black), 195, 207,

215

Corisa sp., *I99

Coriscnm cuculipcnncllum,
moth and leaf rolled by
larva of, *378

Corisciis subcoleoptratus,
204

Corisidse, Corisa (x^pic,
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, in; oe-
sophageal sclerite o f ,
112; structure of, in,
112; table of families of,
112

Corydalis, 224

Corydalis cornuta, *226;
alimentary canal of, *i6;
development of mouth-
parts of, *227 ; habits of,
227 ; head of, showing
mouth-parts, *6

Corymbctcs hamatus, 268;
hicroglyphiciis, 268

Corythuca, sp., *2o8; ar-
ciiata, 208

Cos)iiopepla carnifex, 214

Cosmosoma auge, 41G

Cossid, venation of a, *385

Cossidse, Cossus {cossus,
a larva under bark of
trees), 369, 385

Cossus populi, 385
Costa {sec venation)
Costal, 460
Cotalpa lanigcra, 276
Cotton-stainer, 210
Cotton-worm, 404
Cow-ants, 498
Cow-killer, *497, 498
Coxa, *3, *6, *247
Crab-louse, *2i7; egg of,

*2I7

Crabro stirpicola, 502

Crabronidse, Crabro {cra-
bro, hornet), 502

Crambidae, C r a m b u s
{Kpafi,8og, crainbus, dry,
shriveled), 277

Crainbidia cephalica, 410;
pallida, 410

Cranberry leaf-roller,
*38o; spittle insect, 171;
worm-moth, *38i

Crane-flies, 304, 321

Crane-fly, giant, anatomy
of larva of, *2i ; degen-
erating muscle from pu-
pa of, *5o; development
of wing-buds of, *48 ;
salivary glands of, be-
fore and after degenera-
tion, *5i ; stages of,
*T,^2 ; venation of wing
of, *32I

Creinastogastcr lincolata,
544; shed-nest of, *543

Crcophihis villosiis, *26o

Crepidodera cucumeris,
281

Crickets, 53, 126, 157;
ant-loving, 161 ; burrow-
ing, 161 ; degenerate
forms, 162 ; sound-mak-
ing file of, *IS7 ; wing-
less striped, chirping of,
159

Crioceris asparagi, 278

Cross-pollination, 564; of
flowers by insects, how
developed, 581

Croton-bug, 128, *I28

Crustacea, 3

Ctcnoccphaliis canis, *354,
356

Ctenucha multifaria, 410 ;
ruberoscapus, 410 ; ve-
nosa, 411; virginica,
410; venation of, *4il

Cubitus {see venation)

Cuckoo-flies, 463, 498

Cucujidse, Cucujus (Bra-
zilian cuciijo, a bu-
prestid beetle), 258, 262

Cucujus Aavipes, 263

Cucumber-beetle, 279, *28o

Cucumber flea-beetle, 281

Culex, 305, 307

Culcx fatigans, scales on
wings of, *3io; head of,
*7 ; incidcns, eggs of,
306; life-history of-,
*305 ; mouth-parts of,
*30i

Culicidse, Culex {culex.
gnat), 304, 305

Curculionidse, Curculio
{curculio, weevil), 294,
295

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, 338;
larva of, *237

Cuticle, 4; chitinized, *S

Cutworm, *402 ; climbing,
402

Cyaniris pseudargiolus, 443

Cybister, 255, 257

Cydnidse, Cydnus {KV(h6(,
cydnus, famous), 195,
207, 216

Cyllcnc pictus, 284

Cvinatopliora pampinaria,
"*3?8

Cynipidse, Cynips ( Kviip,
cnips, name of several
insects), 463, 467; al-
ternation of generations
of. 469

Cynipoidse (see Cynipi-
d£e), 478

Cynips quercus-saltatrix,
_ *474 ; galls of, *473

Cyrtophylliis c oncavus ,
*i5o, *i5i

Dagger-moth, gray, *404;

larvas of, *404 ; r a s p -

berry, *40S
Damsel-bug, 195, 204, *205
Damsel-flies, 53, 75, *78

656

Index

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 soceata, *33i
Datana angusii, 394; min-

istra, 393
Datura stramonium, spe-
cialization of, for insect
pollination, 571
Daunus swallowtail, 449
Dead-leaf butterfly, *6oi
Death's-head sphinx-moth,

*438, *6i3
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,

339; noxialis, 339
Dermestes lardarius, *264
Dermestidse, Dermestes
( Sspua, derma, skin;
eaSietv, 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, *598 ; 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, *4o; of egg
of saw-fly, *39; of egg
of water scavenger-bee-
tle, *38 ; of honey-bee,
522 ; of malaria-produc-
ing Haemamoeba in hu-
man blood-corpuscle,
*6i8; 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

of giant crane-fly, *48;

of wings of locust, *42 I
Devil's darning-needle, 76
Dexia, 346 :

Dexiinse, 341, 346
Diabrotica 12-punctata,

279 ; longicornis, 279 ;

soror, 279, *28o; vittata,

279
Diapheromera femorata,

*i3i, 132, *6o3
Diaspis rosce, *I90
Diastrophus nebulosus,

473
Dicerca divaricata, 267
Dichelia siilfureana, ^380
Dicromorpha viridis, *I4I
Dictyopteryx, 73
Diedrocephala mollipes ,

170
Diestrammena marmorata,

Differential locust, *I37.

Digestive epithelium, cells
of, of crane-fly, *I7

Digger-wasps, 463

Dimorphic, 469

Dineutes emarginata, *257

Diopsidse, Diopsis (<^i, di,
two; o-tf-'ic: opsis, eyes),

347

Dioptidse ( p r o b . "if,
dis, twice ; oi/'if, opsis,
seen, referring to the
two generations per year
in some forms), 407

Diplosis pini-radiata, *324

Diptera (f^t, di, two;
nrepov, ptcrum, wing),
56, 301 ; genuina, 303 ;
life-history o f , 302 ;
mouth-parts of, 302

Dipterous larvae, 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

Dissostcira Carolina, *i4i,
143 ; brain of, *22 ; ner-
vous system of, *22 ;
pericardial membrane of,
*i8; respiratory system
of, *i8

Diverse-land geometer,
*399

Dixa-flies, 304

Dixa sp., *3i9; larva of,
*3i8; mouth-parts of,
*3i9; pupa of, *3i9; ve-
nation of wing of, *320

Dixidas, Dixa (prob. f^'sof,
dixus, double, or ^cl^ii,
dixis, a showing, dis-
play), 304, 319

Dobson-fly, *326; alimen-
tary canal of, *i6; head
of, showing mouth-parts,
*6

Dobsons, 55

Docophorus calif orniensis,
116; communis, 116,
*i20, 122; cursor, 116;
excisus, 116; icterodes,
116, *ii9; lari, 116; per-
tusus, 117; platystoy-
nius, 116

Dog- and cat-flea, *354

Dog-day locusts, 167

Dog-louse, sucking, *2i7

Dolichopodid, venation of
wing of, *336

Dolichopodidae, Dolicho-
pus (fSoAfjoTTotjf, doliclio-
pus, with long feet), 332,
335

Dolichopus lobatus, *335

Dorcus parallclus, 273

Dorsal (backward, oppo-
site of ventral)

Dorsal vessel, valves of,
*i8; of locust, *i7

Doryphora lo-lincata, *278

Dorypteryx, 113

Double-eyed sphinx, *435,
437

Dragon-flies, S3, 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, *i7;
giant, stages in develop-
ment of, *83 ; hero, 93 ;
nymph of, *76, *77 ; ve-
nation of wing of, *89;

Index

657

water-prince, *9S ; wind-
sprite, *96
Drosophila ampelophila,

349
Drosophilidse, Drosophila
((5/3(5(70f, drosus, dew;
<pi\oq, p hilu s , loving) ,

349
Dynastes grantii, 276 ; her-

cules, 276; tityrus, *I2,

*276, *277
Dysdercus suturcllus, 210
Dyspcptcris abortivaria,

*397, 398 ; venation of,

*396
Dyticus, *2S5, *256
Dytiscidae, D y t i s c u s

{^vTiKog, dyticus, fond of

diving), 252
Dyticidae, 252

Earwigs, 53, 162, *i62
Echocerus maxillosus, 289
Ecitomyia whcclcri, *S53
Eciton caecum, *543 ; opa-
citherce, 543; schmitti,

*543
Ecitoxenia breviples, *552
Ecpanthcria deAorata, 413;

miizina, 413
Ectobia germanica, 128,

*I28

Egg, development of, of
water scavenger-beetle,
*38 ; fertilization of, 14 ;
of fish-moth, develop-
ment of, *4o; of saw-
fly, development of, *39 ;
tubes, *248

Egg-case o f cockroach,
*I27; of Hydrophilus
triangularis, *259

Eggs, micropyle of, *37 ;
of Anopheles sp., *3o6;
of Culex incidens, 306;
of katydid, *I49

Elaphidion villosum, 285 ;
stages of, *284

Elatcr acerrimus, larva of,
*268 ; nigricollis, 268 ;
rubricollis, 268 ; san-
guinipcnnis, 268

Elateridse, Elater (f^arrip,
elater, driver), 266, 267

Eleodes, *288

Elephantiasis and mos-
quitoes, 633

Elm-leaf beetle, 278

Elipsocus, 113

Elytra, 249

Embia texana, *I09

Embiidse, Embia (e/ifito^,
embius, living, viva-
cious), 109

Embryo, 37

Einesa longipcs, 204, *205

Emesidae, Emesa (Emesa,
city of Syria), 195, 204

Empididse, Empis (efJ^Trtg,
empis, mosquito), 332,
334

Empis. 335

Empodium (appendage be-
tween two tarsal pul-
villi)

Enchenopa binotata, 168 ;
gracilis, *i6g

Encoptolophus sordidus,
*I4S, 146

Endropia armataria, *399

Ennonos subsignarius, 398

Ensign-flies, 463

Entomobryidse, Entomo-
brya (prob. evTo/nov, cn-
tomum, insect ; (ipvov,
bryuni, moss), 62,

Entomophilous flower, 566

Epargyreus tityrus, 442 ;
venatioii of, *440

Ephemerida, Ephemera
(e^T/fiepog, cphcmcrus,
for a day), 53, 54, 65

Ephestia kuehniella, *377,

379
Ephydra, 347
Ephydridse, Ephydra
(ecpvilpog, ephydrus, liv-
ing on the water), 348
Epiivschna hcros, 93
Epicauta c in e r e a , 293 ;
pcnnsylvanica, 293 ; vit-
tata, *2go, 293
Epicccrus imbricatus, 295
Epicordulia princeps, *95
Epidapus scabies, 325
Epimartyria, 371
Epimenis, grape-vine, 409
Erax cincrasccns, mouth-
parts of, *33i ; venation
of wing of, *33i
Erebia, 457
Erebus odora, 401
Erctmoptera broivni, *3ii
Ergates spiculatus, *282,

284
Eriocampa cerasi, 466

Eriocephala, 371
Eriocephalidae, E r i o c e -
phala (prob. i/piov, eri-
um, mound ; Kecpa/y,
cephale, head), 368
Eristalis sp., mouth-parts
of, *340 ; t e n a X , *339,
340
Erynnis sassacus, 443
Erythroncura comes, *i7o;
vitis, 170; vulnerata,
*I70
Eubyia cognataria, *398
Euclca delphinii, 384 ;

pccnulata, 384
Eucleidae, Euclea (euKXeia,

euclca, glory), 384
Eudamus proteus, 442
Eudemis botrana, 381
Eudryas grata, *409, 410
Eiigonia calif ornica, 456 ;

j-album, 456
Eumacaria brunneraria,

*398
Eumenes, 498 ; vase mud-
nest of, *499
Eumenidse, Eumenes ( f^v,
eu, good ; fievog, menus,
disposition), 498
Euphoria inda, 276, *2'jy
Euphydryas phaeton, 456
Euplectrus comstockii, 485
Euplexoptera ( ev, eu,
well ; ttIeko, plcco, fold-
ed ; TTTEpdv, p t e r u m ,
wing), 53, 162
Eurymetopus, 118
Eurymus eurytheme, 446 ;

philodice, 446
Eustigmc acrcca, 415
Euthrips tritici, 221
Euvanessa antiopa, 455
Evaniidse, Evania {evcivlo^,
euanius, taking trouble
easily), 463
Exoprosopa sp., ^334
Exoskeleton, 4 ; attach-
ment of muscles to, *4
Exuvia, 186; of stone-
fly nymph, *7i
Eye, of horsefly, *3i ; of
moth, *3i ; of Lasio-
canipa quercifolia, *22 ;
of Catocala nupta, *32 ;
of May-fly, *32; of
blow-fly, *3;i ; spots, PI.
X., I
Eyed grayling, 457

658

Index

Eyes, compound and sim-
ple, 30; of May-flies,
*69 ; of net -winged
midges, *3i6

Eye - spotted bud - moth,
*38i

Fall canker-worm, 397

False crane-flies, Z'^l

Family, 56

Feather-wings, 376

Femur, *3, *6

Fcniscca tarquinins, 444

Fermenting fruit-flies, 349

Fertilization of egg, 14 ;
of plants, 564

Fig-insect, *487

Figitidae (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

p-Iat-bug, 195. 208, *209

Fleas, 56

Flesh-fly, 343. *344

Flies, 56; life-history of,
302 ; mouth-parts o f ,
302 ; the two-winged,
301

Flower-bug, 195, *209; in-
sidious, 206

Flower-fly, 332, *339

Flower, pistil and ovary
of, showing pollen tube,
*564

Flowers and insects, 562;
colors of, developed for
attraction o f 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, 409

Footman-moths, 370, 409

Foot of house-fly, *34i

Forest-fly, *352

Forest-moths, eight-spot-
ted, *4o8

Forest tent-caterpillar
moth, *4i7

Fork-tailed katydid, *I52

Formica cxscctoidcs, 545 ;
nitidrivcntris, 547; san-
guinea, 547 ; schauftissi,
547 ; subocncsccns, 547 ;
subscricca, 547

Formicina (see For mi -
coidea), 463, 539; key to
families of, 540

Formicoidea, Formica
{fonnica, ant), 539

Frenat3e {f r c n u in , that
which holds things to-
gether), 368

Frenulum, *376

Fritillaries, 456

Frog-hoppers, 170

Froth production of frog-
hoppers, stages of, *i7i

Fruit-worms, parasite of,

*485.

Fulgoridae (Fulgora, god-
dess of lightning), 166,
168

Fungus attacking chinch-
bugs, 212

Fungus, parasitic, of Cali-
f o r n i a flower-beetle,
^346

Fungus - gnat, 304, 324,
*325 ; venation of wing
of, *325

Gadflies, 328

Galcrncclla luteola, stages
of, *278

Galgulidge, Galgulus (gal-
gtilus, a small bird), 194,
202

Galgulus oculata, *202

Gall, blackberry, 473 ; fi-
brous, of the California
live-oak, ^472; of the
California white oak,
*473; rose, 473

Gallcria mcllonclla, 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 ;
juinping, of the oak,
*473 ; made by a Cynipid
gall-fly, *469 ; on leaf,
*47i ; on leaf of Califor-
nia white oak, *470 ; on
twigs of California white
oak, *47i ; trumpet, on
leaves of California
white oak, *47o; variety
of, 470

Ganglia, 21

Gastropaclia amcricana,
416, *4i8

Gastrophilus e qui , 337,
*338 ; nasalis, 338

Gclechia cercalella, 375 ;
gallce-solidaginis, 350 ;
pinifoliclla, 376

Genus, 56

Geometer-moths, 396

Gcoinctra iridaria, 398

Geometrid moth, larva of,
*395, *396; larva of, in
protective position, *6o3

Geometrid, venation of a,
*396

Geometrina, Geometra {,yv,
ge, earth ; fierpov, me-
tnim, measure), 370,
396

Gcotrupes, 275

Geotrupes excrementi,
275 ; opaciis, 275 ; splen-
didns, 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 arizoncnsis, base
of scale of, *59i ; scales
from wing of, *593

Glow-worm, 269

Goatweed-butterfly, 455

Golden-eyed fly, *228

Gomphidse, G o m p h u s
{yofi<pog, gomphiis, a fast-
ening), 92

Goiuphus cxilis, 92

Goniodes, 118

Goniocotes, 118; holo-
gastcr, 119

Goniotauliiis dispectus,
243

Gopher crickets, 155

Gossamer-winged butter-
flies, 443
Gnophccla latipennis, 407
Grain-cephus, European,

467
Grain-weevil, 297
Granddaddy-long-Iegs, 321
Grape-berry moth, 381
Grape-phylloxera, 172,176;
various forms of, *I76,
177
Grape-vine amphion, *438 ;
flea-beetle, larva of,
*28o ; roots infested by
phylloxera, *I78 ;
sphinx-moth, *434 ; root-
borer, 391
Grapholitha scbastiance, 383
Grapta sp., part of wing
o f , 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, *6o2
Green-striped locust, 144,

*I45

Grouse-locusts, 136, 147

Gryllidce, Gryllus (grylhis,
cricket), 126, 157

Gryllafalpa borcalis, 161 ;
Columbia, 161

Gryllus abbrcviatus, *is8;
assimilis, 158 ; domesti-
cus, *I58; luctuosus,
158 ; pcnnsylvanicus,

*I57

Guest bumblebee, 519

Gypsy-moth, 405

Gyrinidje, Gyrinus ( yvplvoq,
gyrintis, a circle, a whirl-
pool), 252, 255

Gyrinus mariims, larva of,
"*257

Gyropidse, Gyropus (yvpog,
gyrus, crooked ; TTovg,
pus, foot). 118

Gyropus, 118, 121

Hsemamoeba, malaria-pro-
ducing, development of,
in human blood-corpus-
cle, *6i8

Index

Hccmatopinus acanthopus,
218; antcnnatus, 218;
asini, 218; curystcrnus,
217, *2i8; ovis, *2i9;
pcdalis, 218; pilifertis,
*2I7; sciuroptcri, 218;
spinulosus, 218; sutu-
ralis, 218; urius, *2i8;
vcntricosus, 218 ; vituli,
217

Hadanucus subterrancus,
156 .

Ha genius brcvistylus, 92

Hag-moth, 384

Hair-streaks, 444

Hair, tactile, innervation
of, *26

Halesidota argcntata, 414 ;
carya, *4i4 ; lobecula,
414; maculata, *4i4; sp.,
larvae of, *4ii; tcsse-
lata, *4i4 ; tessclata,
caterpillar of, *4i3 ; tes-
sclata, venation of, *4i6

Halcsns indistinctiis, *24l

Halictus, 517

Halobates, 198 ; wUllers-
dorfR, *I97

Halteres. 302

Haltica chalybca, larva of,
*28o

Handmaid-moths, 392

Haploa c I y m c 11 c , 414 ;
contigua, *AiS ', fulvi-
costa, *4i5 ; Iccontei,
414

Harlequin-fly, alimentary
canal of, *I5 ; part of
sympathetic nervous sys-
tem of, *24

Harpalus pennsylvanicus,
255

Harrisina amcricana, 387 ;
coracina, 387 ; mctallica,
387

Harvester, 444

Harvest-flies, 167

Hawk - moth, 369, 431 ;
posed before jimson-
weed, *572

Head, interior of, of Mon-
arch butterfly, showing
arrangement of pharynx,
oesophagus, etc., *36i ;
of dobson-fly, parts of,
*6 ; of locust, showing
anatomy, *I24; parts of.

659

Head-louse, *2i6
Hearing, sense of, 29
Heart, 16; of locust, *I7;

valves of, *i8
Heel-flies, 338
Hcliconia sp., scales from

wing of, *594
Heliothis armigcra, 404
Hellgrammite, 226
Hemaris brucci, 439 ; dif-

iinis, larva of, *438;

thysbe, 438
Hemerobiidae, Hemerobius

{iifiEpoftiog, hemerobius,

ephemeral), 224, 229
Hemerobius sp., *229, 230;

sp., larva of, *230
H enter oeanipa leucostigma,

degenerating muscle of,

*50
Hemilcuca clectra, 425;

maia, 425 ; nevadensis,

425
Hemiptera {viJ-i, h e m i ,
half ; TTTspnu, ptcrum,
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, *i64

Hen-flea, 356

Heodes hypophlaas, 444

Hepialidse, H e p i a 1 u s

(fjTTialog, h e p ial US , a

ghost moth), 368, 370,

372
Hepialus gracilis, venation

of wing of, *372 ; nwg-

lasliani, scale of, *589
Hespcria tessellata. 442
Hesperid, venation o f,

*440 _
Hesperidse, H e s p e r i a

(Hesperus, evening

star), 442
Hesperotettix pratcnsis,

*i40
Hessian fly, 323 ; parasite

of, *478
Hetserina, 89; amcricana,

*90
Hetcrocarnpa guttivitta,

*393 ; larva of, *394

66o

Index

Heterocera (erepoc, hete-
r u s , different ; Kepac,
ceras, horn), 364

Heteromera (Irepog, h e -
terus, different ; fiepog,
merus, part), 252; key
to families of, 288

Heteroptera (Irepog, hc-
tcrns, different; Tzrepov,
pterum, wing), 166, 194;
key to families of, 194

Hexapoda, 3

Hibernia tiliaria, *397 ;
larva of, *396

Hilara, 335

Hippiscus tigrinus, *I43;
tiiberculatus, 144 ; fe-
male of, *I42; young of,

*I42

Hippobosca equina, 351,

*352
Hippoboscidae, Hippobosca

(tTTTTo, hippo, horse ;

^<j(jk6?, b 0 s c u s , feed) ,

351
Hippodamia convergens,

*286
Histoblasts of Dipterous

larvae, *47
Histogenesis, 49
Histolysis, 49
Hives, observation, for

studying honey-bee, *53i,

*532
Hccmatobia serrata, 342,

*343
Hog-louse, *2i8
Holcaspis centricola, 471 ;

globulus, 472 ; in anis ,

Holorusia rubiginosa,
anatomy of larva of,
*2i ; degenerating mus-
cle from pupa of, *50 ;
development of wing-
buds of, *48; salivary
glands, before and after
degeneration, of larva
of, *5i ; salivary gland
of, *i6; stages of, *322

Hoinolomyia canicularis ,

345

Homoptera {ppdg, homus,
same ; ■n-repov, pterum,
wing), 165; key to fam-
ilies of, 166

Honey-ant, 545

Honey-bee, *52i ; alimen-

tary canal of, *S29 ;
brood-comb with young
stages, *46 ; comb, brood
cells, *523 ; building
comb, *527 ; developing
muscle in pupa of, *5i;
development of mouth-
parts, *46o; 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, *52i ; life-
history of, 521 ; mouth-
parts of, *459 ; section
of body of pupa of,
showing histolysis and
histogenesis, *49 ; sec-
tion of ocellus of, *3o;
stages in development of
nervous system of, *24 ;
sting of, 460, *46i ;
swarming of, 525 ; ven-
tral aspect of abdomen
of worker, *527 ; visit-
ing A s c 1 e p i a s, *574 ;
wax-making by, 526

Honey-dew of Aleyrodidse,
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, *5o8

Horn-fly, 342, *343

Horn-tails, 463, 466

Horse-fly, 327, *328; cor-
neal facets of compound
eye of, *3i ; 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, *34i, 342; foot
of, *34i ; larva of, *342 ;
mouth-parts of, *8, *30i ;
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 vitripennts, 210

Hydrobatidae, Hydrobates
(^v6up, hydor, water ;
(iaTTi^, bates, one that
treads), 195, 196

Hydro charis obtusatus, 260

Hydrophilidae, Hydrophi-
lus {v6(op, hydor, water;
(plXog, philus, loving),
256, 258

Hydrophilus, development
of egg of, *38; external
anatomy of, *247; inter-
nal anatomy of, *248;
triangularis, *259 ; trian-
gularis, egg-case of,
*259; triangularis, larva
of, *259

Hydropsychidas, Hydro-
psyche (v6up, hydor,
water ; ipvxTJ, psyche,
butterfly), 244, 245

Hydropsyche, 243 ; sca-
lar is, *242

Hydroptilidse, Hydroptila
(v6up, hydor, water ;
T^rilov^ptilum, feathers),
244, 245

Hygrotrechus, 196, *I97

Hylotoma berberidis, de-
velopment of egg of, *39

Hymenoptera {vf^vv, hy-
men, membrane ; tttepov,
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

Hypodcrma bovis, 338 ;
lineata, 338

Hypoprepia fuscosa, 409;
miniata, 409

Hydroporus, 255

Icerya purchasi, attacked
by Australian lady-bird
beetle, *i87 ; male and
female of, *i86

Index

66 I

Ichneumon-flies, 56
Ichneumonidse, Ichneumon
(ichneumon, ichneumon

fly), 463 , , ^

Ichneumonoidea (see Ich-
neumonidse), 477

Ichneumons, 463

Imaginal discs of Dipter-
ous larvae, *47

Imago (adult)

Imperial-moth, 426

Inchworm, in protective
position, *6o3

Inchworms, 395

Indian Cetonia, 276; meal-
moth, 378

Inocellia, 233

Inquilines, 475

Insect, properly pinned up,

*637
Insecta, 3

Insect-killing bottle, *635
Insects, simplest, 52
Instincts of ants, 554
lo Emperor, 424, *425 1

larva of, ^426
Iphidides ajax, 449; «»«''-

celliis, 449; telamonides,

449

Iris versicolor, visited by
insects, 568

Isabella tiger-moth, 412

Ischnocera (prob. 'lc!Xvoq>
ischnus, thin, thread-
like; Kepa^, ceras, horn),
key to genera of, 118

Ischnoptera pcnnsylvanica,

*I28

Isoptera (}<yoQ, isus, equal ;
■KTEpov, pterum, wing),

55. 99
Isopteryx, 73
Isosoma hordei, 487
Ithobalus a Cauda, 450;

polydamas, 450

Janus integer, *465
Japanese locust, *iS5
Japygidse (Japyx, mythical

progenitor of Japyges of

southern Italy), 60, 61
Japyx sp., *62; subter-

raneus, *6i
JassidcC, Jassus (lassus, a

town in ancient Caria),

166, 169
Jerusalem cricket, *is6,

157

Jigger-flea, 355
Jimson-weed, hawk-moth

posed before, *572
Jugatae (juguni, yoke),

368
Jugum, 368
Jumping plant-lice, 171
June-bugs, 273, *27S
Junonia cania, 455

Kallinia sp., *6oi
Katydid and eggs of, *I49
Key. 53

Killing-bottle, for collect-
ing insects, how to make,

635
Kissing-bug, 203

Labels, for collected in-
sects, 637'

Labellum, *8

Labeo longifarsis, *479

Labia minor, *i62

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, *i87

Laemobothrium, 119; loo-
misi, 122

Lcertias philenor, 450

Lagoa crisp ata, 383

Lake-flies, 65

Lamellate, *250

Lamellicornia (lamella,
thin plate; cornu, horn),
251, 272

Lamp-chimney breeding-
cage, *642

Lampyridae, L a m p y r i s
(Xdfnrovpii, lampuris, a
glow worm), 265, 269

Lance-tailed grasshopper,

*I54
Lantern-flies, 168
Laphria, 331
Lappet-moth, American,

*4i8
Lappet-moths, 416
Largus succinctus, *2io
Larridae, Larra (Fabricius,

— derivation unknown),

500

Larva, 44 ; coarctate, 291 ;
of a phorid fly attached
to the larva of the ant,

*553
Lasiderma serricorne, 271
Lasiocanipa quercifolia,

ommatidia of, *32
Lasiocampidae, Lasio-
canipa (Adfftof, lasius,
hairy ; Kd/intj, campe, a
caterpillar), 370, 415
Lasius brunneus, 175, 545
Lateral (to right or left)
Leaf-beetles, 277
Leaf-bug, four-lined, *209 ;

predaceous, *2o6
Leaf-bugs, 195
Leaf-chafers, 273, 275
Leaf-cutter bee, nest of,

*5i4
Leaf-hoppers, 169
Leaf-insects, 132
Leaf-miners, 375
Least skipper, 443
Leather-jackets, 321
Lebia grandis, 255
Lccanium olece, 187
Lecanium scales attacked

by Cordyceps clavulata,

*i88
Leg, section of, showing

muscles, *5
Legs of beetles, *250
Lcistotrophus cingulatus,

261
Lema trilineata, 278
Lcmonias virgulti, 444
Lens of ocellus of larva of

saw-fly, *30
Leopard-moth, 413
Lcpidocyrtus americanus,

*64

Lepidoptera (AeTrtf, lepis,
a scale ; i^repSv, pterum,
wing), 56, 358; life-his-
tory of, 360; mouth-
parts of, 359. *362;
scales of, their structure
and arrangement, 589

Lepinotus, 113

Lepisma saccharina, *58,
61, domestica, *62 ; sp..
*62 ; sp.. development of
egg of, *40

Lepismidae, Lepisma
(Mniafia, lepisma, scaly),
60; key to genera of, 61

Leptidae, Leptis (AeTrrov,

662

Index

leptus, thin, fine, deli-
cate), 327, 330, 3Z2
Leptoceridse, Leptocerus
(AfTTTof, leptus, thin,
fine, delicate ; Ktpag,
ceras, horn), 244
Leptocerus resurgens, *240
Leptocoris trivittatus, *2i3
Leptogcnvs elongata, 540,

*54i
Leptoglossus oppositus,

214; phylloptis, 214
Leptoterna dolobrata, 210
Leptothorax cmersoni, 544
Lesser migratory locust,

133, *r37, 141
Lestes sp., nymph of, *84;

uncata, *%7
Leucania unipuncta, 404 ;

larva of, on corn, *403
Leuctra, 74
Libellula basalis, 94 ; pul-

cliella, 93, *94 ; quadri-

inactilata, 94; scmifasci-

afa, *94. 95
Libellulidse, Libellula

(libcllitlns, a tiny book),

91. 93
Libuniia lenttilenta, para-
site of, *479
Lice, 216

Lightning-bugs, 269
Ligyrus rugiceps, 276
Lime-tree canker-moths,
*397 ; inch-worm, *S96
Limnephilidae, Limnophi-
lus Q-i/iivT], limnc, a pool ;
(f)i?iog, philus, loving) , 244
Limnobatcs Uncata, *i97,

198
Limnobatidee, Limnobates
(?ii/j.i^V, limnc, a pool ;
jiarriq, bates, one that
treads), 194
Liodcrma ligata, 214
Liotheidse Q^eloq, liu s ,
smooth; Qelv, then, run),
118
Lipeurus, 118; baculus,
*I20, 121; fcrox, 122;
foriicidatus, 117; for-
Hciilatiis, development
stages of, *ii5; vari-
abilis, 119
Lipoptena cervi, 352
Litliosia bicolor, 410
Lithosiidse, Lithosia (At5of,
lithus, a stone), 370, 409

Live-cage bell-jar, *642;
meat-safe, *643

Live-oak moth, 407 ; scale,
California, *i9i

Locust, alimentary canal
of, *I4; 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, *2S ;
head of, showing anat-
omy, *I24; heart or dor-
sal vessel of, *I7; ner-
vous system of, *22;
pericardial membrane of,
*i8; respiratory system
of. *i8

Lociista viridissima, nerve-
endings in tip of maxil-
lary palpus of, *26

Locustidse, Locusta (lo-
custa, locust), 126, 149;
wingless, 154

Locusts, 53, 126, 133 ; au-
ditory organs of, *I35 ;
impaled by shrike, *I34;
life-history of, 136; key
to subfamilies of, 136;
migratory species of,
133 ; sounds of, 134

Locust-tree carpenter-
moth, 385, *386

Long-horned locust, *I46

Long-legged flies, 332, 335

Long-tailed skipper, 442

Loopers, 395

Lopidca media, 210

Lorquins Admiral, 452

Louse, sheep-foot, 218

Lucanidse, Lucanus {lu-
cerc, shine), 272

Lucanus dania, 273 ;
claplius, *273; placidus,

273
Lucilia cccsar, 344 ; vena-
tion of wing of, *344
Luna-moth, 420, *422
Lycrena, 443; sp., part of

wing of, *590
Lycsenid, venation of,

*440
Lycfenidas, Lycsena

(?imaiva, lye ana, a she

wolf), 443
Lycomorpha cons tans.

scale of, *592; grotci,

410 ; miniata, 410 ; plio-
lus, 410
Lyctocoris iitchi, *2o6
Lyda, 466

Lyggeidse, Lyseus ( Avyalog,
lygaiis, shadowy), 195,
207, 211
LygcEus tureieus, *2ii
Lygus pratensis, *2og
Lymantriidae ( IvfiavTi/pioq,
lymanterius, destruc-
tive), 370, 404

Machilis, 62; polypoda,
nerve-endings in tip of
labial palpus of, *26; sp.,
*63

Macrodactylus subspino-
sus, *27S

Maia moth, 424

Malaria-carrying m o s -
quito, *3o8

Malaria, mosquitoes and,
617

Malaria-producing Htema-
mceba, development of,
in human blood-corpus-
cle, *6i8

Mallodon, 284

Mallophaga (jj^alMq, mat-
ins, hair, wool ; (payeiv,
phagcn, eat), 55, iii;
distribution of, 116, 117;
keys for classification,
118; life-history of, 114;
oesophageal sclerite of,
115; pharyngeal sclerite
of,*ii6; structure of, 115

Malpighian tubules, 14

Mandible (see in 0 u t h -
parts)

Mantidse, Mantis (/^avng,
mantis, a prophet), 126,
129 ; ancient beliefs con-
cerning, 130

Mantis religiosa, *i2g, 130,
131 ; egg-cases of, *i62,
*i65

Mantispa styriaca, 234

Mantispidae, Mantispa (ir-
regular, fiavTiQ, mantis,
an insect; utp, ops, face),
224, 234

Maple-scale, *i88

Maple-tree borer, stages
of, *284

Maracanda, 232

March-flies, 304, 325

Index

663

March-fly, *326
Margarodes formicarum,

190
Maritime locust, *I47
Marsh-treader, *I97, 198
Marsh-treaders, 194
Marumba modcsta, 437
Masaridee, M a s a r i s

(fxaado/xai, masaomce, 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
Maxillae (see m 0 ut h -

parts)
Meadow-browns, 457
Meadow grasshopper,

*I53, *I54
Mealy-winged flies, 166,

190, *I93 ; respiratory

system of, *i9
Meat-safe live-cage, *643
Mecoptera (/J-r^Kog, mectis,

length ; nrepdv, pterum,

wing), 223, 235; key to

genera of, 235
Media (see venation)
Mediterranean flour-moth,

*377, 379
Megachile, 514; anthra-

cina, nest of, *5i4
Megachilidae, Megachile

(fieyac, incgas, great ;

Xt'iT^og, chelus, lip), 514
Megalopyge c r is p at a ,

scales, from wing of,

*593 ; opercularis, 383
Megalopygidse ( p r o b .

fieyag, in e g a s , great ;

nvyi], pyge, rump), 369,

383
Megathyma yucca, 441
Megathymidse ( p r o b .

fieyag, m e g a s , great ;

6v/u6g, thymus, spirit),

441
Megilla maculata, *286;

vitigera, *286

Melanactes piccus, 268
Melanoplus atlanis, 133,
*I37, 141 ; bivittatus,
*I38, 141 ; differcntialis,
*I37, 141 ; femur-rubrum,
*I35, 140; development
of, *42 ; nervous system
of head of, *23 ; postem-
bryonic development of,
*i25; spretus, 133, 136
Melipona, 520
Melissodes, 515
Melittia ceto, 391
Melitcca cJialcedon, 457
Mcloe angusticollis, 293
Meloidse, M e I o e (Lin-
naeus,— etym. uncertain),
288, 289
Melophagus ovinus, 351,

*352

Membracidae, Membracis

{fiefijipa^, membrax, a

kind of cicada), 166, 168

Membrane of wing {outer

half of fore-wing, He-

tcroptcra, *I96)

Mcmythrus polistiformis,

391
Menopon pallidum, *ii9
Mcrisus destructor, *478
Merope, 236

Mcsochorus agilis, para-
sitizing Xylina sp., *486
Mesothemis simplicicollis,

97
Mesobregma cincta, *I47
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, *i25 ; of
Hemiptera, 164
Metapodius femoratus,

214
Meta-thorax, 7
Meteor us hyphantrice,
*485 ; parasitizing Xy-
lina lacticinerea, *487

Mexican jumping bean-
moth, 382, *383

Microccntrum laurifolium,
*I5I, 152; retinervis, 152

Micropterygidse, Microp-
teryx {fiiKpdg, micrus,
small ; Trrt-pvi, pteryx,
wing), 368, 370, 371

Micropteryx sp., venation
of wing of, *372

Microdon mutabilis, larva
of, *340

Micropyle, 15; of various
eggs, *37

Midaidae, Midas ( //Mac,
midas, a destructive in-
sect in leguminous
plants), 330

Midas-flies, 330

Midge, larva of, *3ii;
male, *3io; pupa of,
*3ii

Midges, 304, 310

Migratory locusts, 133

Milkweed-bug, 211

Milkweed-butterfly, a r -
rangement of pharynx,
oesophagus, etc., in head
of, *36i ; cross-section
of sucking proboscis of,
*36i ; part of maxillary
proboscis of, showing
arrangement of muscles,
*36i

Milyas cinctus, 204

Mimesidae, Mimesa
(/lifXTjatg, mimesis, imi-
tation), 502

Mimicry, 609 ; of monarch
butterfly b y viceroy,
*6io ; of wasps by moths,
*6o8

Mining-bees, 513 '

Mochlonyx cu liciformis,
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, *i6i

Monarch butterfly, *45i ;
complete metamorphosis
of, *44 ; development of
color-pattern in pupal
wings of, *S96 ; external
parts of, *6; internal

664

Index

anatomy of, *I3; larva
of, *6o5 ; mimicry of, by
viceroy butterfly, *6io ;
part of wing of, show-
ing scales, *36o; vena-
tion of wings of, *37i ;
venation of, *ll

Moniliform, 258

Monobia quadridens, 502

Monohammus, 285

Monomorium minutum,
*536; pharaonis, 541

Monostegia rosce, 466

Monterey-pine midge, *324

Morpho sp., base of scale
of, *59i

Mosquito, auditory organ
in antenna of, *2g; beak
of, *302 ; female, mouth-
parts of, *30i ; head and
mouth-parts of, *7 ; life-
history of, *30S ; mala-
ria-carrying, *3o8

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, *3i

Moth-fly, 319, *320; larva
and pupa of, *320 ;
mouth-parts of, *320

Moth-like flies, 304

Moths, 56, 358; and but-
terflies, single scale
from, *589; and wasps,
showing mimicry, *6o8;
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, *3i8; head
of larva of black-fly
showing developing,
*3i4; developing, of tus-
sock-moth, *363 ; devel-
opment of, of Corydalis
cornuta, *227; of bee-
fly. *334; of dance-fly,
*335 ; of Cicada, *g ; of

Dixa sp., *3I9; of dob-
son-fly, *6; of Eristalis
sp-, *340; of female
black-fly, *3I3; of fe-
male net-winged midge,
*3i6; of a female mos-
quito, *30i ; of a female
punkie, *3ii ; of Hemip-
tera, *i64; of honey-bee,
*7, *459; of honey-bee,
development, *46o ; of
horse-fly, *329; of house-
fly, *8, *30i ; of Hymen-
optera, 460; of larva of
black-fly, *3i3; of larva
of net-winged midge,
*3i7; of larva of wasp,
*46i ; of Lepidoptera,
*362 ; of a long-tongued
bee, *5i2; of mosquito,
*7; of moth-fly. *32o;
of mud-wasp, *46o; of
net-winged midge, *9 ;
of robber-fly, ^331 ; of a
short-tongued bee, *5ii;
of sphinx-moth, *io; of
thrips, *8, *22o; variety
of, 8; of wasp, devel-
opment of, *46o, *46i

Mud-nest, vase, of Eume-
nes sp., *499

Mule-killer, 76

Murgantia histrionicOj 214,

*2IS

Musca domestica, *34i,
342 ; larva of, *342 ;
mouth-parts of, *8, *30i ;
pupa in puparium of,
*342

Muscardine, 412

Muscid, aquatic, *348

Muscidae, Musca (t^vla,
myia, a fly), 332

Muscinae, 341, 342

Muscle, degenerating,
from pupa of giant
crane-fly, *S0 ; degen-
erating, of tussock-moth,
*50 ; developing, in pupa
of honey-bee, 51; struc-
ture of, *I3, *I4

Muscles, arrangement of,
in maxillary proboscis
of milkweed butterfly,
*36i ; attachment of, to
body-wall, *4; of leg,
*5; of wing, *5

Muscular system, 13

Mutillidx, Mutilla {mu-
tilo, to crop short), 497

Mycetophilidae, Myceto-
phila (j^yK7}(j, myces, a
fungus ; ^('Aof, 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, *i62

Myrmecophily, 552

Mrymeleon, 232 ; adult,
*23i ; sp., larva and
sand-pit of, *230

Myrmeleonidae, Myrme-
leon (fivpfiTjt myrmex,
ant; Muv, lean, lion),
224, 230; key to subfam-
ilies of, 231

Myrmica hrevinodes, 544

Myrmicidae, Myrmica
(fivpfiTj^, myrmex, ant),
540, 541

Mystacides, 243

Mytilaspis pomorum, 189

Myzus cerasi, 174

Nabidae, N a b i s {nabis,

camelopard), 195
Nobis fusca, *205
Nathalis iole, 446
Naucoridae, N a u c o r i s

(vavg, naus, ship ; nopig,

coris, a bug), 194, 199
Necrobia ruHpes, 270; vio-

lacea, 270
Necrophorus marginatus,

*26l

Nectar, 566

Nectar-drinking, adapta-
tion of insects for, 569

Negro-bug, flea-like, 215

Negro-bugs, 195

Nematocera (vfj/ia, nema,
thread ; fcepaf, ceras,
horn), 303; key to fam-
ilies of, 304

Nematus erichsonii, 466 ;
ventricosus, 466 ; larva
of, *465

Nemobius fasciatus, form

Index

665

vittatus, *I59; chirping
of, 159
Nemoura, 74
Ncophasia menapia, 445
Nepa, 201
Nepidae, 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, Vcspa sp.,
*505 ; Fielde, for ants,
*55i ; Janet, for ants,
*550, *55i ; of Califor-
nia honey-ant, 546; of
Camponotus pcnnsyl-
vanicus, *545 ; of bum-
blebee, *5i9; of leaf-cut-
ter bee, *SI4; of a mud-
dauber wasp, *499 ; of
Vcspa crahro, *504; of
western agricultural ant,
*542; of yellow-jacket,
Vcspa sp., cut open to
show combs within, *5o6

Nest-building of wasps,
508

Nest-burrow of Ammophi-
la, *494 ; of Astata imi-
color, *500 ; of Oxybclus
quadri-notatus, *49i ; of
short-tongued mining-
beetle. *5i6

Nesting-grounds of Am-
mophila, *492

Nests, for rearing ants,
548

Nest-tunnel of carpenter-
bee, *5i3

Nest-tunnels of two car-
penter-wasps, *502

Net, for collecting insects,
how to make, 635 ; wa-

ter, for collecting drag-
on-fly nymphs, *87
Net-winged midge, cross-
section of body of larva
of, *3i5 ; cross-section of
eyes of, *3i7; female,
*3i6 ; female, mouth-
parts of, *3i6; head of
larva of, showing forma-
tion of adult head-parts,
*3i8; heads of male and
female of, *3i6; larva of,
*3i5; mouth-parts of,
*9 ; mouth-parts of larva
of, *3i7; pupa of, *3i5;
venation of wing of,
*3i7

Net-winged midges, 304,
314

Neuroptera (vevpov, neu-
runi, nerve ; nTspov,
pterum, wing), 55, 223;
key to families of, 224

Ncsara pcnnsylvanica, 214

Nicoletia tcxcnsis, *6i

Nirmus, 118; fclix, *I2I,
122; lincolatiis, 116; pi-
Icus, 117; prcEstans, *ii4

Nitzschia, 119

Noctuidse, Noctua (noctua,
a night owl), 370, 399

Nomadidse, N o m a d a
{vofiag, nomas, nomad)
455

Nomctettix parvus, *I48

"No-see-ums," 310

Notodonta stragula, *392

Notodontid, venation of,
*392

Notodontidse, Notodonta
(vuToc, notiis, the back ;
660VC, odus, tooth), 369,
392

Notolophus leucostigma,
405 ; developing mouth-
parts of, *363; larva of,
*405

Notonecta, 199

Notonectidje, Notonecta
(lyroQ, notiis, the back ;
vTJKTTig, ncctcs, a swim-
mer), 194, 198

Notum (dorsal wall of a
body segment)

Number of insect species,
56

Nycteribiidge, Nycteribia
{vv KTepi(;, nycteris, a

bat; /3/of, bius, life),
351, 352

Nycteribia sp., 352

Nymph (young of insects
with incomplete meta-
morphosis), *42, *67

Nymphalid, venation of,
*440

Nymphalidae, Nymphalis
(vvijcpTi, ny m p h e , a
nymph), 450

Oak bucculatrix - moths,

376
Oak leaf-roller, 380
Oak-apples, 471. *472
Oak-scale, southern Cali-
fornia, *I92
Oak-worm moth, orange-
striped, *428
Oblique-banded leaf-roller.

380
Oblong leaf-winged katy-
did, *i5i
Obsolete-banded strawber-
ry leaf-roller, larva of,
*364 ; pupa and adults
of, *365
Ocellar lens of larva of

saw-fl3\ *30
Ocellus, *3, 31 ; section of,

of honey-bee, *30
Ocncria dispar, 405
O d o n a t a (6(^ovg, odus,
tooth, applicability un-
certain), 53, 75
Odontomachus hccmatodes,

340
Odontomyia, venation of

wing of, *329
Odynerus, 499
CEcanthus angustipennis,
160 ; f a s c iat II s, *I59,
*i6o; nivcus, *I59, 160
CEdcmasia concinna, 394 ;
eximia, *393 ; larva of,
*393
Qidipodinse, 136, 143
(lEneis, 457

Qistridas, Oistrus (oiarpoc,
ccstrus, a gadfly, a
sting), 332, 337
Oikcticus abbotti, 386
Oil-beetles, 289
Olfcrsia americana, 351
Ommatidium, *3i, *32, *33
Omus, 253
Oncomyia, 337

666

Index

Oncopeltus fasciatus, 211

Oncophorus, 118

Onion-fly, 345

Onion-thrips, 221

Onychophora, 3

Opiiion piirgatmn, *482

Opsiccctus personatus, 203

Orange-puppy, 450

Orange-scale, 188, *i89,
*igo

Orange-sulphur, 446

Orange-tips, 446

Orchelimum vulgare, *i53,
*I54

Orders, key to, 52

Orl-fly, smoky, immature
stages of, *225

Orncodcs hexadactyla, Zll

Orneodidje, Orneodes
(opreov, onieum, bird ;
el6og, eidos, form), 368

Orphnephilidae ( p r o b .
"op^vri, orphne, darkness ;
(piloQ, philus, loving), 327

Orphnephila testacca, 2^7

Orphiila pclidina, *i4i

Orthoptera (op66c, or thus,
straight ; ■n-repov, ptcrum,
wing), 5, 123; key to
families of, 126 ; sound-
making by, 123, 134, 150,
*i5i, 152, 155, *i57, 159

Orthosoma brimnca, 283 ;
development of color-
pattern in, *598

Orchids, specialization of,
for insect pollination,
575 _

Oscinidas, Oscinis (La-
treille, — etym. uncer-
tain), 350

Osmia, 514

OtiorhynchidcC, Otiorhyn-
chus (uTiov, otium, little
ear ; ^vyxoc, rygchus,
snout), 294, 29s

Otiorhynchus ovatus, 295

Ovarial tubes of Aptera,

*59.

Ovaries and oviducts of
thrips, *36 ; of queen bee,
*S2i

Ovipositor, *3, 7 ; of a gall-
fly. *468

Owl-butterfly, *6i2

Owlet-moths, 370

Ox-louse, long-nosed, 217;
short-nosed, 217, *2i8

Oxybelus quadri-notatus,
nest-burrow of, *49i

Oxyptilus pcriscelidacty-
l^^, 377 > tcnuidactylus,
*377

Pachycondyla harpax, 540,
*553

Painted beauty, 454

Palcacrita vcrnata, 397

Pale-green locust, *I40

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

Paviera longula, 211

Panorpa, 236 ; rufescens,
^236

Panorpodes, 236

Paonias cxcoccatus, *435 ;
myops, *435

Papilio, 448

Papilio cresphontes, 449 ;
dauniis, 449 ; Euryme-
don, 449 ; glaucus, 449 ;
polyxenes, 450; venation
of, *440 , rutiilus, *447,
449 ; sp., chrysalid of,
*448; troilus, 450; tur-
mis, 449

Papilionid, venation of,
*440

Papilionidas, Papilio {pa-
pilio, a butterfly), 447

Papilionina (see Papilion-
idse)

Papiriidae (prob. naTrvpog,
papyrus, paper, reed),
63 ■

Papirius maculosus, *63

Parandra brunnea, 285

Parasa chloris, 384

P a r a s i t a (parasitus, a
parasite), 165, 216

Parasite, chalcid, *479 ;
ichneumon, of army-
worms, *482 ; ichneu-
mon, of the pigeon-tre-
mex, *484

Parasites, importation of,
486; Hymenopterous, of
a social wasp, *48o ;
numbers of, 480 ; of

aphids, *I73; of caterpil-
lars, *476, *477

Parasitic fungus of Cali-
fornia flower-beetle, *346

Parasitic Hymenoptera,
476

Parasitism, characteristics
of, 478; of caterpillar,
*476, *477

Paratcttix cucullatus, *I48

Parnassian butterfly, *43g

Parnassians, 447

Parnassius clodius, 447 ;
sviiiitheus, 447, *439

Parnidse, Parnus (Fabri-
cius, 1792, — etym. doubt-
ful), larva of, ^264

Parorgyia parallcla, 405

Parthenogenesis, 221;
among aphids, 173, 175

Passalus cornutus, 273

Pastinaca sativa, visited
by insects, 569, 571

Patagia, 408

Patterns of insects, advan-
tages of, 584

Peach-tree borer, 389 ; lar-
va of, *39i ; cocoons and
empty pupal skins of,
*39i ; moths of, *390 ;
eggs of, *390

Peacock butterfly, 455

Pear-tree flea-louse, 171 ;
slug, 466

Pea-weevil, 277, *28i

Pectinate, *25o

Pediculidae, P e d i c u 1 u s
(pediculus, a louse),
216

Pediculus capitus, *2i6 ;
inguinalis, *2i7 ; vesti-
menti, *2i6

Peduncle, loi, 534

Pcgomyia vidua, 345

Pelecinidse, P e 1 e c i n u s
{nE7,Eidvoq, pelccinus, a
pelican), 463, 484

Pelccinus polyturator ,

*485
Pelidnota punctata. 275
Pellucid locust, 133, *I45
Pclocaris femorata, 199
Pelopceus, 499
Pemphigus t ess el lata, 180
Pemphredonidae, Pemphre-

don {iTEfKppe^uv, peniphre-

don, a kind of wasp),

502

Index

667

Pentamera (ttevts, pcnte,

five; iJ-tpng, j/trrMj, part),

251, 252
Pentatomidse, Pentatoma

{nevTE, p e n t e , five ;

Ta/iEcv, tanien, cut), 195,

207, 214
Pentatoma junipcrina ,

*2I5

Pepper-and-salt currant-
moth, *398

Pcpsis formosa, *500, 501

Pericardial membrane of
locust, *i8

Pericoiiia calif ornica,*320;
larva and pupa of, *320

Pericopidae (^rfp/, peri,
around ; Konreiv, copten,
ciit), 370, 407

Periplaneta americana,
127 ; australasia, 128 ;
orientalis, 128, *I28

Peripsocus, 113

Perithcmis domitia, *95,
96

Perla, J3 ; sp., *72

Pernicious scale, females
and young on bark of
fruit-tree, *i82; male
and female (enlarged),
*i84; on bark of fruit-
tree, *i8i ; structure and
life-history of, 182

PctropJwra divcrsilineata,

*399
Phagocytes, 49
Phagocytosis, 49
Phaneiis carnifcx, *274
Phasmidje, P h a s m a

{(pacfia, phasma, an ap-
parition), 126, 132; key
to genera of, 132; pro-
tective resemblance of,
132
Pheidolc cominufafa, sol-
dier and worker of, *537 ;
lamia, soldier and work-
er of, *535
Phigalia strigataria, *398
Philopteridas, Philopterus
((ptAEiv, philen, love;
TTTepov, pferuntj a feath-
er), 118
Philosamia cynthia, 421
Phlcgcthontius sexta, 434 ;
Carolina, larva of, *432 ;
celeiis, larva of, *432 ;
quinqiiemaculata, 434

PhobctroH pithccium, 384
Pholisora catallus, 442
P h 0 I II, s achemon, *433,

434; larva of, *43i, *434;

pandorus, *433, 434
Phorbia brassiccc, 345 ; ce-

parum, 345
Phorothvips sp., *2r9
Photiniis angulatus, 269;

nwdcstus, larva of, *26g;

pyralis, 269; scintillans,

*269
Phryganca cincrea, *239
Phryganeidse, Phryganea

{_^pv}avm>, pliryganum,

a dry stick), 244, 245
Phryganidia calif ornica,

*4o6, 407
Phyllium, 132, *6o2
Phylloxera vastatrix, 176
Phyllum, 2
Phyniata zvolii, 205
Phymatidse, P h y m a t a

((pv/j,a, phyma, a tumor),

195
Physocephala, 237 ! affiyiis,

*336
Physonota unipunctata,

281
Physostomum, 119
Phytophaga (<Pvt6v, phy-

tum, plant ; <paynv, pha-

gen, eat), 252, 277
Pierid, venation of, *440
Pieridse, Pieris ( Trieplg,

picris, sing, of TriepiSeg,

the Muses), 444
Pigeon-tremex, *467 ; ich-
neumon-parasite of, *484
Pimpla conqiiisitor, *483 ;

inquisitor, 483 ; sp., an

ichneumon-fly, *48i
Pinacate bug, *288
Pine-leaf miner, 376;

white, 445
Pinning beetle, mode of,

*637 ; bug, *637 ; insects,

637
Piophila casei, *348
Pipe-vine swallowtail, 450
Pistil and ovary of flower,

showing pollen-tube,

*564
Plagionottis speciosus,

*283, 284
Planta, 522
Plant - bug, leaf - footed,

214 ; tarnished, *209

Plant-lice, 171
Plants, fertilization of, 564
Plathcniis lydia, *97; tri-
maculata, issuance o f
adult, *86
Platycercus quercus, 273
Platygaster herricki, larva
of, *48i ; instricator, lar-
va of, *48i
Platynota Havedana, *38i
Platypsylla eastoris, 265
Platypsyllidce, Platypsyl-
lus {nXarvg, p I a t y s ,
broad, flat ; tpv^'Aa, psyl-
la, flea), 265
Plecoptera (7rAeKr<5f, plec-
tus, plaited ; Trrepdv,
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, *2i5
Podura sp., young and

adult, *4i
Poduridae, Podura {Trovg,

pus, foot; ovpa, ura,

tail), 63, 64
Pccciloeapsiis lineatus, *2og
Pogonomyrmex barbatus

var. molifaciens, 541 ;

occidentaiis, mound-nest

of, *542
Polistes, 294, 503, 506, 507 ;

sp., nest and stages of,

*5o8; parasitized by

Xenos sp., *293
Pollen, basket, 514, *52i ;

gathering, adaptation of

insects for, 569
Pollination, 564
Polybia, 503; llavitarsis, 507
Polycrgus rufesccns. 547
Polygonia comma, *453 ;

interrogationis , 454;

chrysalid of, *455 ; larvae

of, *454 .
Polymorphism, 526
Polyphemus - moth, 420,

*42i ; larva of, *42i
Polyphylla crinita, *274
Polypsocus, 113
Polystwchotes punctatus,

*22g

668

Index

Pomace-flies, 349
Pompilidse, P o m p i 1 u s

{-cifiTTt/, pompe, escort),

499. 501
Poneridae, Ponera ( Trow/pdf,

poncrns, bad, useless),

540
Pontia bcckeri, 445 ; napi,

445 ; occidentalis, 445 ;

pro to dice, 445 ; venation

of, *440 ; rapce, 445 ; si-

syinbri, 445
Poplar carpenter-moth, 385
Potter-bees, 514
Potato-beetle, 278
Potter-wasps, 498
Pofoinanthus hrunneus,

section through head of

male, ^69
Praying-mantes, 126; an-
cient beliefs concerning,

130
Praying-mantis, *I29, 130,

131 ; egg-cases of, *i62,

*i63
Predaceous diving-beetle,

252 ; ground-beetle, 252
Prenolcpis imparis, 547 ;

underground nest of,

*546
Prionidse, Prionus (Trpiiov,

pyion, a saw), 283
Prionidus cristatiis, 204
Prionoxystus robinicc, 385,

386 ; scales from wing

of, *594; venation of,

*38
Prionus calif ornicus, *282 ;

imbricornis, 283 ; laticol-

lis, 283
Pristophora grossularice,

466
Proboscis, *7, 8, *io
Proctotrypidse, Procto-

trypes (Trpw/crof, proctus,

the anus ; rpvirav, trypan,

to bore), 463, 477
Proctotrypoidea (see

Proctotrypidse)
Prolimacodcs scapha, 384
Promethea -moth, 422,

*424 ; development of

color-pattern in pupal

wings of, *S97
Prominents, 369, 392
Pronotum, *3
Pronuba moth laying eggs

in ovary of Yucca, *577 ;

I rubbing pollen down
i stigmatic tube of Yucca,
i *578 .
I Pronuba yuccasella, as a

cross-pollinator of yuc-
cas, 576
Prop-legs, 360
Propolis, 530
Prosopis pubescens,

mouth-parts of, *5ii
Prosternum, 136
Protective resemblance,

599; of Phasmidas, 132;

of Trimerotropis, 147
Prothorax, 7
Pselaphidse, Pselaphus

{■>liTjAa(pdv, psclapJian,

feel or grope about),

265
Pscudohazis cglantcrina,

426 ; h e r a , 426 ; shas-

tansis, 426
Pseudoperla, jt,
Psilopiis ciliatus, venation

of wing of, *336
Psinidia fenestralis, *i46
Psithyridse, Psithyrus

(ipidvpd^, psithyrus,

whisperer, warbler),

520
Psithyrus, 519
Psocidae, Psocus (ip^x^^'^i

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-

veri, 386
Psychidje, Psyche {i'vxv,

psyche, a butterfly) ,

369, 386
Psychoda sp., mouth-parts

of, *320
Psychodidse, Psychoda

( fvxn, psyche, butter-
fly; eldoc, edus, form),

304, 319
Psychology of insects, 32
Psychoniorpha epimenis,

409
Psyllidse, Psylla {rpvTCka,

psylla, a flea), 166, 171
Psylloinyia testacea, *553
Pteronarcys, JS
Pterophorida;, Pteropho-

rus {T^-repdv, p t e ru m ,

feathers ; (pepeiv, pheren,

bear), 368, 376
Pteroptrix Havimedia, *47g
Pterostichus, 255 ; storiola,

*254
Ptinidas, Ptinus ((pOivu,

phthino, decay, destroy),

265, 271
Ptynx, 233
Pulcx avium, 353 ; irritans,

*354, 356
Pulicidae, Pulex (pulex,

a flea), 355, 356
Pulvilliform, 332
Pulvillus, 102
Pulvinaria innumerabilis ,

*i88
Punkie, female, mouth-
parts of, *3ii
Punkies, 310
Pupa, 45
Pupipara (pupus, a child ;

parcre, bring forth), 303,

351

Puss-moth, larva of, *6o7

Puss-moths, 392, 394

Pyralid moth, venation of
wing of, *376

Pyralidina, Pyralis (^''p,
/'.v;-, fire), 368, 374, 376

Pyralis farinalis, 378 ; ve-
nation of wing of, *376

PyromorpJia d i m idiata .
388; venation of, *389

Pyromorphid, venation of
a, *389

Pyromorphidas (prob. Tt'p,
pyr, fire ; i^opipy, morphe,
form), 369, 386

Pyrrharctia isabclla, 412

Pyrrhocoridae, Pyrrhocoris
(■rrvppdc, pyrrus, red-
dish : KopLg, coris, a bug),
195, 207, 210

Radius {see venation)
Ranatra fusca, *20i ; eggs

of, *20I
Raphidia sp., stages of,

*233

Raphidiidae, Raphidia
(^a<pk, rapJiis, a needle),
224

Raspberry geometer, 398;
plume-moth, *377 ; root-
borer, 391

Rat-fleas, 357

Index

669

Rat-tailed larva of a Syr-

phid, *340
Rearing insects, directions

for, 640
Redbugs, 195, *2io
Red-humped caterpillar-
moth, *393 ; larva of,

*393, 394
Red-legged locust, *I35,

140
Red-spotted purple, 452
Red-tailed tachina-fly, *347
Reduviidae, Reduvius (re-

duvia, a hangnail), 195,

203
Reflexes 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,
*i8 ; of mealy-winged
fly, *I9; of thrips, *i8

Rlia^iuiii lineatum, larva
of. *266

Rhagolctis cingidata, larva
of, *349 ; puparia of, *35o

Rliainnus lanccolata, vis-
ited by insects, 569

Rhamphomyia, 335 ; longi-
cauda, *334; sp., mouth-
parts of, *335 ; venation
of wing of, *335

Rhinoceros -beetle, *I2,
*276

Rhoditcs roscu, 473

Rhopalocera {^o-na'kov, rho-
pahiiii, a club; K^pac,
ccras, a horn), 364

Rlwpotota vacciniana, *38i

Rhyacophilidse. R h y a -
c o p h i 1 a ((ii'aky ryax, a
stream ; (pi^e'iv, p hil c n ,
love), 244, 245

Rhynchophora, 251, 294;
key to families of, 294

Rhyphidse, Rhyphus ( ^vp6g,
rhynts, curved), 327

Rhyphus, diagram of wing
of, *327

Rice-weevil, 297

Robber-flies, 330

Robber-fly, *33i ; bumble-
bee-like, *33i ; mouth-
parts of, *33i-; venation
of wing of, *33i

Rocky Mountain locust,
133. 136

Rose-beetle, *275

Rose-leaf hopper, 170

Rose-aphids and ants, *I74

Rose-scale, *i90

Rose- slug, 466

Rostrum, 251

Rosy dryocampa, 427

Rove-beetles, 260, *552

Royal walnut-moth, larva
of, *366

Russet-brown tortrix, *38i

Saddle - back caterpillar,

384

Salda sp., *202

Saldidse, Salda (from a
proper name), 195, 202,
224

Salivary gland, *I5 ; sec-
tions of, of giant crane-
fly, *i6; before and after
degeneration, of larva
of giant crane-fly, *5i

Salix cordata, visited by
insects, 569 ; h u m i I i s,
visited by insects, 569

Salvia-flower, *572

Salvia oMcinalis, speciali-
zation of, for insect pol-
lination, 573

Sajiiia ceanothi, 419; ce-
cropia, 418, *4i9; larva
of, *420 ; moth and co-
coon cut open to show
pupa of, *367 ; Columbia,
419; glovcri, 419

San Jose scale, *i8i, *i82,
*i84

Sand-cricket, *I56, 157

Sand-diggers, thread-
waisted, 493

Sanninoidca cxitiosa, 389;
larva of, *39i ; cocoons
and empty pupal skins
of, *39i ; moths of, *39o;
eggs of, *390; pacifica,
389

Sapcrda Candida, *28s

Sarcophaga sarracenicE,

343. *344
Sarcophaginse, 341, 343

Sarcopsylla penetrans, 355

Sarcopsyllidse, Sarcopsyl-
la ((^op^, sarx, flesh ;
ipvMa, 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 Hcpialus mcgla-
shani, *589

Scale of Lycomorpha con-
st ans, *592

Scale-insects, 180

Scales, arrangement of, on
wing of butterfly, *59i ;
base of, *59i ; develop-
ment of, on wing of
Anosia plcxippus, *595;
development of, on wing
of Euvancssa antiopa,
*594 : single, from moths
and butterflies, *589 ;
from wing of Glovcria
arizoncnsis, *593 ; from
wing of goat-moth,
*594; from wing of
H e li c o nia sp., *594 ;
from wing of Mega-
lopygc crispata, *593;
of moths and butterflies,
producing color, 594 ; of
moths and butterflies,
structure and arrange-
ment, 589; of springtail,
*64 ; on wing of mon-
arch butterfly, *36o ; on
. wings of Culcx fatigans,
*3io

Scallop - shell geometer,

*399
Scapteriscus didactylus,

*i6i
Scarabeid beetle, larva of,

*274 ; leaf-chafers, 275
Scarabseidse, Scarabseus

(scarabccus, a beetle),

272, 273
Scatophaga sp., *348
Scavenger-beetle, 272, 273

670

Index

Scepsis fulvicollis, 411

Sciara, 325

Schistoccrca americana,
*I39, 141 ; cinarginata,
*I40

Schizura, 395

Sclerite, *5

Scolytidje, S c o 1 y t u s
{aKo/.vTTTEiv, scolypten,
to strip [bark]), 294, 297

Scorpion-flies, 55, 223, 236

Screw-worm fly, 344

Scuddcria furcata, *I52;
pistillata, *I52

Scutelleridse, Scutellera
(scutuin, a small shield),
195, 207

Scutellum (dorsal trian-
gular piece at the base
of and between elytra or
fore zvings)

Scydmsenidse, Scydmsenus
(i7Kvd/Liaivo^, scydmccnns,
angry-looking, sad-col-
ored), 265

Seed-gall, jumping, 472

Segment, 5

Self-pollination, 564

Scnilia caniclis, *i6g

Sense of hearing, 29; of
sight, 30 ; of smell, 27 ;
of taste, 26; organs, 24;
tactile, 26

Senses, special, 24

Scpedon fascipcnnis, *350

Sericostomatidse, Sericos-
toma {(^vP'-'^og, sericus,
silken ; orSfia, stoma,
mouth), 244, 245

Sermyle, 133

Serosa, 38

Serphiis dilatus, 200; sp.,

*200

Serrate, *250

Serricornia (serra, a saw ;
cornii, horn), 251, 265;
key to families of, 265

Sesia pictipes, *392 ;
tipuliformis, 390

Sesiidse, Sesia ((^vc, 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

Shad-flies, 65

Sheep-louse, *2I9

Sheep-tick, 351, *3S2

Shield-backed bugs, 195,
214; grasshopper, *I55

Shore-bug, 195, *202

Short - beaked mosquito,
*309 ; pupa and larva of,
*309

Short-winged cricket, *I58

Short-winged locust, *I40,
*I4I, 142

Sialidse, Sialis (oialig, si-
alis a kind of bird),
key to genera of, 224;
key to larvae of, 224

Sialis, 224; infumata, ma-
ture stages of, *225

Sibinc stiniulea, 384

Sight, sense of, 30

Silkworm dissected, *43o;
mulberry, ^428, *429

Silkworm-moths, 369

S i I p h a americana, 261 ;
lapponica, 261 ; novebo-
racensis, *26i, 262

Silphidas, Silpha {ailtprj,
silphe, a beetle), 258, 261

S i I V an u s surinamensis,
stages of, ^262

Silver-spots, 456

Silver-spotted skipper, 442

Silviiis pollinosus, 329

Simplecta sp., venation of
wings of, *32i ,

Simuliidse, S i m u 1 i u m
{simulare, imitate), 304,
,313 .

Simulium sp., *3i2; head
of larva of, showing de-
veloping mouth - parts,
*3i4; larva and pupse of,
*3I2; mouth-parts of,
*3i3 ; mouth - parts of
larva of, *3i3 ; venation
of wing of, *3i2

Sinoxylon basilare, 272

Siphonaptera (ol^uv, si-
phon, tube; awrepog, ap-
terus, wingless), 56, 353;
key to families of. 355

Siricicoidea (see Siri-
cidse), 464

Siricidae, Sirex (aeipr/v, si-
ren, a siren, wasp), 463,
466

Sisyra umbrata, stages of,

*229

Sitaris humeralis, life-his-
tory of, 291

Sitrodrepa panicea, 271

Siiim cicutcefoliutn, visited
by insects, 571

Skipper-butterflies, 442

Slave ants, 547

Slave-maker ants, 547 ;
shining, 547

Slaves, 547

Slug, pear-tree, 466; rose,
466

Smell, sense of, 27

Smelling-pits on antenna
of carrion-beetle, *27

Sinerinthus geniinatus,
*435, 437 ; larva of, *436

Smoky-moths, 369, 386

Smynthuridae, Sminthurus
{afiiv&og, s m i n t li u s,
mouse; ovpa, ura, tail),
63

Smynthurus aquations ,
*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, 294

Snow-flea, *64

Snow-white Eugonia, 398

Snowy tree-cricket, *I59,
160

Social wasp, Hymenoptera
parasites of, *48o

Soldier-beetle, 269

Soldier-bug, banded, 204

Soldier-flies, 327, 329

Solenopsis molesta, 544

Solidago canadensis, vis-
ited by insects, 571

Song of snowy tree-
cricket, 160

Sooty-wings, 442

Sound-making lay Orthop-
tera, 123, 134, 150, *ISI,
152, 155, *I57, 159; file
of cricket, *I57; organ
of the Cicadidae, *i67

Southern grain -plant-
louse, *I72

Span-worms, 395

Species, 56

Index

671

Spermatheca, 14

Spermatozoa {see Repro-
ductive organs)

Spcycria idalia, 456

Sphccrophthalma aureola,
498; califoriiica, 498; pa-
cifica, *498 ; similima,

*497

Spharagemon bolli, *I46;
coll arc, *I46

Sphccina ((T0r;^, sphex, a
wasp), 463

Sphcciiis spcciosiis, 500

Sphecoidea (sec Sphc-
cina), 464

Sphenophorus, 297

Sphex ichneumonea, 499;
occitanica, *492

S plungicampa hicolor, 429

Sphingidse, Sphinx ((y<ihi,
sphigx, sphinx), 369,

431

Sphinx, 437 ; chersis, larva
of, showing threatening
attitude, *6o6 ; gordiiis,
*436

Sphinx-moth, 431 ; front
of head of, showing
frontal sclerites and
mouth-parts o f , *362 ;
mouth-parts of, *io;
pen-marked, larva of,
showing threatening as-
pect. *6o6 ; sucking pro-
boscis of, *36o

Sphyraccphala brevicor-
nis, 347

Spice -bush swallowtail,
450

Spilosoma virginica, 412

Spiracles, 7, 19

Spittle-insects, 170; stages
of froth production, *I7I

Spondylidse, S p o n d y 1 i s
(aTT6v6v?iog, spondylus,
a vertebra, a joint), 277,
285

Sporotrichum globulife-
rum, 212; sp., *346

Spotted-winged locust,
*i4i

Spotted wingless grass-
hopper, *iS4

Spreading-boards, how to
make, 638

Spring azure, 443

Spring canker-worm, 397

Springtail, American, 64;

pond-surface, *58 ; scales

of, *64; spotted, *63
Sprinkled locust, *I40, 142
Spur, 232
Squash-bug, *2i3 ; family,

195
Squash-vine borer, 391
Stable-fly, *342
Stag-beetle, 272, *273
Staphylinidse, Staphylinus

((jra^vAiTOf, staphylinus,

a kind of insect), 258, 260
Staphylinus cinnamoptc-

rus. 261 ; maculosus, 261 ;

toincntosus, 261 ; viola-

ceus, 261
Stegomyia, 305, 307 ; fas-

ciata, 308
Stelidse, S t e 1 i s {oteIl^,

stelis, a parasitical

bee), 515
Stcnobothrus curtipcnnis,

*I40, 142
Stenopehiiatus sp., *I56,

Stcnopogon inquinatus,

Stcphania picta, *I97
Stephanidse, Stephanus

(aTEipavog, stephanus,

crown), 463
Sternum (ventral wall of

a body segment)
Sthcnopis argenteo-macu-

latus, 373
Stigma (opaque spot,

costal area of wing)
Stigmata, 19
Stilt-bugs, 195, 214
Sting of the honey-bee,

460, *46i
Stink-bugs, 195, 214. *2is
Stobera tricarinata, *i68
Stomoxys calcitrans, *342
Stone-crickets, 155
Stone-flies, 53, 65, 70; life-
history of, 71
Stone-fly, *72 ; exuvia of

nymph of, *7i ; young

(nymph) of, *7i
Stratiomyia, 330
Stratiomyidse, Stratiomyia

(arpaTtuTTjc, stratiotes,

a soldier; iivia, myia, a

fly)- 327, 329

Strawberry root - borer,
*374

Strepsiptera (aTpf:<pEiVj

strephen, twist ; nrepov,

pterum, wing), 293
Striped ground-cricket,

*I59
Stylopidse, Stylops ( arv^iog,

stylus, a pillar ; uip, ops,

eye, face), 293, 294
Stylops, 294

Subcosta (see Venation)
Sugar-beet midge, 345
Sugar-maple borer, *283
Sulphur - colored tortrix,

*38o
Suture, *5
Swalloiv-tailed butterAies,

446, *447 ; butterfly,

chrysalicl of, *448
Swarming of honey-bees,

525
Swifts, 368, 372
Sword-bearer, *iS3
Sympathetic nervous sys-
tem, 23 ; of larva of

harlequin-fly, *24
Syinphasis signata, *234
Synithnrus aquaticus, 64
Synchloe sara, 446; genu-

tai, 446
Synchlora glaucaria, 398
Synhalonia, 515
Syntomidae (prob. cvvrofiia,

syntomia, abridgment,

shortness), 410
Syritta pipicns, 340
Syrphid, rat-tailed larva

of, *340
Syrphidffi, Syrphus ( ffi'P^of,

syrphus, a gnat), 332,

339
Syrphus, 340 ; continuax,
venation of wing of,

*339

Syrphus-flies, 339

Syssphinx heiligbrodti, 429

Tabanidse, Tabanus (ta-
baniis, a horse-fly), 327,
328

Tabanus, 329 ; lineola, *328

Tachina-fly, 345, *346

Tachinid parasite of Cali-
fornia flower-beetle, *346

Tachininse, 341, 345

Tactile hair, innervation
of, *26 ; sense, 26

Tsenidia. *ig

Tasniopteryx, 7:^

Tapestry-moth, 374

672

Index

Tarantula-killer, *500, SOI

Tarsi, *6; of beetles, *250

Taste, sense of, 26

Tegmina, 134

Tegulse (cup-like scale
over base of forewing),
490

T e I e a polyphemus, 420,
*42i ; larva of, *42i

Telephorus bilineatiis, 270

Tcnebrio molitor, 289 ; ob-
scurus, 289

Tenebrionidse, Tenebrio
(tenebrce, darkness),
288

Tent - caterpillar, apple-
tree, 415 ; forest, 415

Tent-caterpillar moths,
370

Tenthredinidas, Tenthredo
(TEvOprjSuv, tcnthredon,
a kind of wasp), 463,
464

Tenthredinidoidea, (see
Tenthredinidae), 464

Tcrias nicippe, 446

Termes, 102 ; bcllicosus,
106 ; depredation b y ,
107 ; Aavipes, comple-
mentary queen, *I03;
habits of, 102, 103 ;
winged male, *I03;
worker, *I02 ; lucifugus,
104; redmani, *io6

Termites, 55, 99; artificial
distribution of, 108;
food of, loi, 109; forms
in a community, loi ;
key to genera of, 102 ;
of Africa, 106 ; origin of
castes of, 108 ; nests of,
*ioo ; sheds in Samoa,
*ioi ; structure of, loi

Termitogaster texana, a
rove-beetle, *552

Termitophiles, 108

Termitophily, 108

Termopsis, 102 ; angusti-
collis, 99, *I04; habits
of, 104, 105, 106

Terrifying appearances,
604

Tetanocera pictipes, *348

Tetracha, 253

Tetragoneuria epinosa, *96

Tetramera {rerpa, tetra,
four ; fiepoq, m e r us ,
part), 252, 277

Tetraopes tetraophthalmus,
284

Tettigidea lateralis, *I48,
149

Tettiginae, 136, 147

Tettix granulatus, *I48 ;
0 mat us, *i48

Thalessa lunator, *484

Tliecla halesus, 444

Therioplectes, 329; sp.,
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, *2i9; alimen-
tary canal of, *I5 ; head
and mouth-parts of, *8 ;
mouth-parts of, *220 ;
respiratory system of,
*i8 ; tabaci, 221

Thyreus abbotti, 437; lar-
va of, *437

Thyridoptcryx ephemcrce-
formis, 386, *387 ; vena-
tion of wing of, *389

Thysanoptera (dvaavog,
thysanus, a tassel ; TVTEp6v,
pterum, a wing), 55, 220

Thysanura (0v(javoc, thy-
sanus, tassel ; ovpa, ura,
tail), 60; key to families
of, 60

Tibia, *3, *6

Tide-rock fly, *3II

Tiger-beetles, 252

Tiger-moths, 370, 411

Tiger swallowtail, 449

Tinea biselliella, 374; pel-
lion ella , *2>73, 374 ;
tapetzella, 374

Tineidse (see Tineina),

374
Tineina {tinea, a gnawing

worm), 133, 368, 374
Tingitidai, Tingis (Fabri-
cius, 1803, — etym. un-
certain), 195, 207
Tiphia inornata, 497
Tipulidse, Tipula (tipula,
a water spider), 304, 321
Tmetocera ocellana, *38i
Toad-bug, 194, *202
Tobacco-worm moth, 434

Tolype velleda, 416
Tomato-worm moth, 434
Tomicus plastograplius,

galleries and stages of,

*299
Tomognathus americanus,

547 ; sublocvis, male and

ergatoid female, *535
Tortoise-beetle, *28o, 281
Tortricina, Tortrix (fem.

of tortor, tormentor),

368, 374, 379
Tortricid, venation of a,

*38o
Toxoptera gramineum, va-
rious stages of, *i72
Tracheae, 7, 10 ; in head of

cockroach, *I9; struc-
ture of, *20
Tracheal gi 11 s , 20 ; of

May-fly nymph, *20
Tracheal system of beetle,

*i8
Traniea lacerata, 95
Tree-bug, bound, 214 ;

green, 214; spined, *2i5
Tree-hoppers, 168
Tremex c'olumba, ^467
Tremex, pigeon, *467
Tricenodes ignita, *243
Trichodectes latus, *I20,

121 ; parumpilosus, *I20,

121 ; pilosus, 121 ; scala-

ris, *I20, 121 ; subro-

stratus, 121
Trichodectidse, T r i c h o -

dectes (9p'?, thrix, hair ;

SijKTTjc, dectes, bite), it8
Trichodes, 270 ; apianis,

270; ornatus, *269
Trichoptera ( 5p''s, thrix,

hair; Trrepov, pterum,

wing), 55, 223. 239; key

to families of, 244
Tridactylus apicalis, *i6i
Trigonalidse, Trigonalys

( rpiyuvoc, t r i g 0 n u s ,

three- cornered ; u?mc,

alas, disk), 463
Trimera (I'P"?, tris, three;

fiepoq, merus, a part),

252, 286
Trimerotropis maritima,

*I47
Trimerotropis, protective

resemblance of, 147
Trinoton, 119; luridum,

116, 120

Index

673

Triphleps insidiosus, 206

Tripoxylon alboptlosum,
502 ; frigidum, 502 ; ru-
brocinctum, 502

Triprocris, 388

Triungulin, 290

Trochanter, *247

TrocJiilium fraxini, *392

Tropizaspis sp., *I55, 156

Tropcca luna, 420, *422;
cocoons of, *423

Trox, 275

Trumpet-galls on leaves of
California white oak,
*470

Trypeta longipennis, *349 ;
ludens, 350; solidaginis,
350

Trypetidae, Trypeta
( Tphiravov, trypanum, a
borer), 350

Tryxalinse, 136, 142

Tumble-bugs, 273, 274

Turkey-gnats, 313

Turnus butterfly, 449

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, *6o3

Two-striped locust, *I38,
141

Typhlocyba rosa, 170

Udcopsylla robusta, *154
Uloma impressa, 289
Ulula hyaiina, *232
Underground nest of the
California honey - ant,

*S4
Underwings, a group of

red and yellow, *400
Utetheisa bella, 413

Valves of dorsal vessel or

heart, *i8
Vanessa atalanta, 454 ;

cardui, 454 ; caryos, 454 ;

huntera, 454
Vedalia cardinalis, 186,
- *i87, 287 _
Veins of wings, 10
Veliidae, Velia (perhaps

Velia, a Greek colony in

Southern Italy), 195,

Velvet-ants, 497

Venation, 10; of a cossid,
*38s ; of dragon-fly wing,
*89; of a Geometrid,
*396; of monarch but-
terfly, *ii; of social
wing, *ii3; of a Pyro-
morphid, *389; of a
Tortricid, *38o ; wing
o f Anthrax fulviana,
*2,i3\ of wing of bag-
worm moth, *389; of
wing of Bibio albipennis,
*326 ; of wing of black-
fly, *3i2; of wing of
Chrysophila thoracia,
*330 ; of wing of crane-
fly, *32i ; of wing of
dance-fly, *335 ; of wing
of Dixa sp., *32o; of
wing of a Dolichopodid,
*336 ; of wing of fungus-
gnat, *32S ; of wing of
Hepialus gracilis, *372 ;
of wing of horse-fly,
*328 ; of wing of Lucilia
ccesar, *344 ; of wing of
Microptcryx sp., *372;
of wing of monarch
butterfly, *37i ; of wing
of net-winged midge,
*3i7; of wing of Odon-
tomyia, *329 ; of wing of
Pyralid moth, *376 ; of
wing of robber-fly, *33i ;
of wing of Syrphus con-
tinuax, *339

Ventral (bellyward)

Ventral plate, 38

Vertex, 142

Vespa, 503, 506; crabro,
nest of, *S04 ; cuncata,
506 ; germanica, 506 ;
maciilata, 506; sp., *505

Vespidse, Vespa {vespa, a
wasp), key to genera of,
S03

Vespina (see Vespidae),
463

Vespoidea (see Vespidae),
464

Viceroy, 452 ; butterfly
mimicking monarch but-
terfly, *6io

Vine-hoppers, *I70

Vine-loving pomace-fly, 349

Violet-tip butterfly, 454,
*455 '

Vitelline membrane, 27
Volucella, 340

Walking-stick, *I3I, 132,
*6o3

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, *46o,
461 ; mouth-parts o f ,
*46o ; mouth-parts of
larva, *46i ; mud-dauber,
nest of, *499

Wasp-flies, T,:22, 336

Wasp-like fly, *336

Wasps, 56, 490; carpenter,
nest-tunnels of, *502;
classification of, 490;
mason, 498 ; mimicry of,
by moths, *6o8; nest-
building by, 508 ; potter,
498; social, 503; social,
key to genera of, 503 ;
solitary, 491 ; classified
by habits, 497 ; habits of,
492; stinging prey, 495;
structure of, 491 ; true,
463

Water-beetle, stages in
development of nervous
system of, *25

Water-boatmen, 194, 198,
*I99

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, 194, *20i ;
eggs of, *20i

Water-skater, ocean, *I97

Water-striders, 195, 196,
*I97; broad-bodied, *I97

Water-tiger, ^256

Wax-making o f honey-
bee, 526

Wax secreted by aphids,

175.
Webbing clothes-moth, 374
Web-worm, fall, 412
West-coast lady, 454

6/4

Index

Western cricket, *I56, 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,
*59i ; developing, of cab-
bage-butterfly, *ii; of
monarch butterfly, part
of, showing scales, *36o;
muscles of, *S

Wing-buds, development
of, of giant crane-fly,
*48

Wings, 9 ; of butterflies,
androconia from, *592 ;
of Heteropters, showing
venation, *i96; of locust,
development of, *42

Winthcmia, 4-pustuluta,
*347

Wood-boring beetle, giant,
development of color-
pattern in, *598

Wood-borers, metallic,
265

Wood leopard-moth, 385

Wood-nymph, *409, 410,
457; moths, 370, 407

Woolly apple-aphis, 179

Woolly-bear caterpillars,
*4ii

Workers, 459

Xenos, 294; sp., parasitiz-
ing Polistes, *29

Xestopsylla, 355 ; gallina-
cea, 356

Xiphidium, 154; attenu-
atiim, *i54

Xylina antcnnata, *402 ;
grotei, *402 ; lacticincra,
parasitized larvae of, *486

Xylocopas, 513

Yellow-fever, mosquitoes
and, 630

Yellow- jacket, communal
nest of the, ^505 ; nest
of, Vespa sp., cut open
to show combs within,
*5o6 ; queen, nest of,
*507

Yellow-jackets, *505, 506

Yellow-winged locust, *I44

Yolk, 37

Ypsolophus pomatellus,
*374; larva of, ^373

Yucca-borer, 441

Yucca aiamentosa, 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 iiuminea, *200
Zalysus spinosus, 214
Zebra swallowtail, 448
Zcrena ccesonia, 446 ; eiiry-

dice, 446
Zeusera pyrina, 385
Zodion, 337

Zygsenid, venation of, *4ii
Zygsenidse, Zygsena [Fabri-
cius, 177s] {^vyaLva, zy-
gasna, supposed to mean
the hammer - headed
shark), 370, 410
Zygoptera (prob. ^vyov,
zygum, yoke; ~Tzpnv,
pterum, wing), 89; key
to families of, 89

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