a — ee . “a >a * . Py i” iviat nei ay = ma + EI 33 OTHER WORKS ON BUTTERFLIES BY THE-AUTHGR THE BUTTERFLIES OF THE EASTERN UNITED STATES AND CANADA, with special reference to New England. 3 vols., imp. 8vo. 1889. 44+1958 pp.; 96 plates and maps, plain and colored. Half-levant, gilt top, $75.00. Published by Houghton, Miffiin & Co., Boston, Mass. BUTTERFLIES: Their Structure, Changes, and Life-Histories, with special reference to American Forms. With an Appendix of Practical Instructions. 12mo. 1881. 10+ 322 pp.; 201 figures. Cloth, $1.50. Published by Henry Holt & Co., New York, N.Y. FOSSIL BUTTERFLIES. gto. 1875. too pp.; 3 plates. Paper, $2.00, Published by the American Association for the Advancement of Sctence, Salem, Mass. HISTORICAL SKETCH OF THE GENERIC NAMES PRO- POSED FOR BUTTERFLIES: A Contribution to Systematic Nomenclature. 8vo. 1875. 203 pp. Paper, $1.00. Sold by the Cambridge Entomological Club, Cambridge, Mass. THE LIFE OF A BUTTERFLY: A Chapter in Natural History for the General Reader. 16mo. 1893. 186 pp.; 4 plates. Cloth. Published by Henry Holt & Co., New York, N.Y. IN PREPARATION: A STUDENT’S MANUAL OF THE BUTTERFLIES OF NORTH AMERICA, NORTH OF MEXICO. BRIEF GUIDE TO THE COMMONER BUTTERFLIES OF THE NORTHERN UNITED STATES AND CANADA Being an Tntroduction to a Rnowledge of their Litc=bistories ee Z SAMUEL HUBBARD SCUDDER NEW YORK HENRY HOLT AND COMPANY 1893 Copyright, 1893, BY HENRY HOLT & CO. ROBERT DRUMMOND, ELECTROTYPER AND PRINTER, NEW YORE PREFACE. DuRING the preparation of a long-projected and still unpublished Manual of the Butterflies of North America, it occurred to me that when that was ready there-would still be needed something less technical; something which should introduce to the young student the names and somewhat of the relationships and lives of our commoner butterflies; and that if such a guide were restricted to the commoner butterflies of the region where it would be most used, viz., our Northern States east of the Great Plains— much the same territory as was originally and wisely covered by Gray’s Manual of Botany—the actual extent of the work would be so limited as to bring it within the reach of all, not alarm the beginner by its magnitude, and, because they are better known, permit a fuller account of their interesting life-histories. I have accordingly selected the butterflies—less than a hundred of them—which would almost surely be met with by any industrious collector in the course of a year’s or two years’ work in the more populous Northern States and in Canada, and have here treated them as if they were the only ones found there. I have omitted many species which are common enough in certain restricted localities (such, for instance, as our White Mountain butterfly) and included only those which are common over wide areas. As the earlier stages of these insects are just as varied, as interest- 111 lv PREFACE. ing, and as important as the perfect stage, descriptions are given of these under the guidance of the same principle, only such stages as would be more commonly met with being fully described, and the egg and earliest forms of caterpillar omitted as rarities and as also too difficult for the beginner’s study. If, then, a young student can find noth- ing in this work to correspond with his particular capture, then he may rest assured that it is not one of the more common kinds, and he will have to go to the larger and more technical works to discover what it 1s. At any rate, he is likely to be pleased: either he has found out what it is and can thereby learn something of what is already known about it; or he has found a rarity, a discovery not always distressing to the amateur. | To aid in these determinations, separate keys are appended for each of the three stages, caterpillar, chry- salis, and butterfly, by which any insect included in the work may be tracked. There is another advantage in this restriction of the work to the commoner butterflies, for these are better known in the various stages of their lives, and interest in them is thereby greatly enhanced. I should be loath indeed to treat of butterflies as if they were so many mere postage-stamps to be classified and arranged in a cabinet; and if, by adding to the mere descriptions of the different species in their various most obvious stages some of the curious facts concerning their periodicity, their habits of life, and their relations to the world around them, I may spread before the eyes of the young some of the attractions which lie at the open door of Nature and induce some to wander into the by-ways for more eager personal search, I shall have gained my end. Those wishing still further accounts of the different species here described, and particularly descriptions and figures of the egg and earlier stages of the caterpillar of PREFACE. Vv any one of them, are referred to my “ Butterflies of the Eastern United States and Canada,” and to Edwards’s “ Butterflies of North America,” in one or the other of which ample accounts will often be found. Species which are found in the region embraced in this work, but not regarded as sufficiently common therein to merit a place in it, are mentioned by name in their appropriate places in smaller type; they number just about as many as those of which descriptions are given, and full accounts of most of them will also be found in the works above mentioned. A short Introduction to the study of Butterflies in gen- eral, with special application to our own, is prefixed to the body of the work, and is followed by a brief section show- ing where the principal literature upon the subject is to be found. An explanation of some of the terms used is appended, and a figure added on p. 60 explanatory of the nomenclature of the wing. CAMBRIDGE, April 13, 1893. CONTENTS. PAGS Preface iii Introduction . Bn viet ihe eh eines Ne 1 What are Butterflies ? eee sits i The Structure of the Perfect nee or pike 2 The Appearance of the Egg. a What the Caterpillar is like . 6 The Character of the Chrysalis. Y A Few Words about the Eggs . 8 The Lives and Habits of Caterpillars 9 How the Chrysalis Hangs 12 The General History of Hattoxtlics 14 Variation in the Butterfly 15 Some Remarkable Differences eee ie oe 20 The Senses of Butterflies . 92 Mimicry and Protective Een ince 23 The Classification of Butterflies D5 Some Works on American Butterflies . 27 Keys to the various Groups 32 Key to the Groups, based on the Peniack Battenily 34 Key to the Groups, based on the Caterpillar Ad Key to the Groups, based on the Chrysalis. 53 Nomenclature of the Parts of the Wing 60 The Commoner Butterflies of the Northern United States aad Canada ‘ 63 Family Brush-footed Bitierttics 63 Subfamily Danaids . 63 Genus Anosia 63 Anosia piexippus 63 Subfamily Nymphs. . 66 Tribe Crescent-Spots 66 Genus Euphydryas 66 Vii Vill CONTENTS. Euphydryas phaeton Genus Cinclidia Cinclidia harrisii Genus Charidryas . Charidryas nycteis . Genus Phyciodes Phyciodes tharos Tribe Fritillaries . Genus Brenthis . Brenthis bellona Brenthis myrina . Genus Argynnis Argynuis atlantis Argynnis aphrodite . Argynnis alcestis Argynnis cybele Genus Speyeria . Speyeria idalia Genus Euptoieta Euptoieta claudia Tribe Angle-Wings . Genus Junonia . Junonia coenia Genus Vanessa . Vanessa. cardui Vanessa huntera Vanessa atalanta Genus Aglais Aglais milberti Genus Euvanessa . Euvanessa antiopa . Genus Eugonia . Eugonia j-album Genus Polygonia . Polygonia progne Polygonia faunus Polygonia comma Polygonia SR et Tribe Sovereigns . Genus Basilarchia . Basilarchia arthemis PAGE 66 68 68 69 69 "1 ra "2 72 "2 "4 16 76 77 78 79 80 80 81 81 82 82 82 84 84 85 87 89 89 90 90 92 92 93 93 - 94 95 97 98 98 98 CONTENTS. x1 PAGE CROCS, Se ial ee LES Seemmeurionocades . . 2. . 1. es eee 6150 DEMEATOIIS 9... 2 ee ee se «10 Se aS wuumemereresphonies 260s. 2 ee ses Lal nna Ah cg a ee ummmierenes 2 ee ee ee oe AOS Family Skippers . . Mens ie A Mien Se cae enerilalle eg OW ke 5 Tribe Larger Biippery: rch. ae MRR ce ce Semen et oa) eee Behe OIPERECEIS Cf a ae oe he SER RLVIUS-5 2 sf ok FS. Oe 8 oe ENNIS 2s fg NNR a ee Gummmerapyliies =. 2 2. PeMnEnnEES se EINE B RIS cc gc) tN a ee ge ements > pg Os eet ee Bee eemamecmenvernis fk a se GE RE se rat Se a A RS 2 Menmememmctnsy sf eo 8 Ne em tS ee SS TLE ORD LLIS SE Sees ie ie ce ae a on ene mene | |» Cemreermemims 26. or Se oe ee SEE RE Me gk 8 2 nb eS Pe ee veces ae EReMTEVAEA © 2 2 PO Se as 's BD Meteemiler SKIPpers . 2. we ee te we ee 1 Prepare te a De 2 on 166 PPIRA THWINETLOT £5 eg ee es OE ol: 3D eee ee er atc ke ieee aera may ey | Penne eC EBL ION ofS o>. 82 Le OE ee ee eS SEMCnENNEEEES Foose et ee PB PP MPMCeIEMS 6207 oe 6S ee Sr SS peseeeeeerunomaster. . .- 226 Set. Oe 1 aeiicier leonardus~.-...°. . . . . . . 150 La US LLDLEES eG ree One ae ea ne 1 DTM EN hi Se er ee el mo ET PennNet. 7) PS POE DE REEVGEIC (Ot ee OS EEE DerMMInneMITES: SS MINE PINON ta ee Se ETS Explanation of some Terms .. . eek Ae erEN Oc oe ee Appendix: Instructions for Se oe ae ae Bag ree eae CONTENTS. PAGE Tribe Coppers «© 6s. ea + cn Fe oe ee i Genus Chrysophanus. .. « Via 0% 2455 eee Chrysophanus thoe. . .. « 96) # so" 10-2 a Genus Epidemia . {. ws 0) «4 eed ye ee Epidemia epixanthe << ssi Ue Genus Heodes.. 2.03 Sa lS Ee ee Heodes hypophiaeas 2.0L ste & 02 Do Genus Feniseca.. .—.. ... ss > = « 22s = Feniseca tarquinius. . . . «s+ 20.) eee Family Typical Butterflies’. ..-. 2... =) 98 Subfamily Pierids . 1... . «3 @ « =a Tribe Red-Horns . ... «. « « + ¢a) oe see Genus Callidryas .- . 0 6.) 2) lace a Callidryaseubule . ..... ss. % sacs) =e Genus Zerene . . . . + 63 4) eee Zerene caesonia . -. . 4.) = Maes eg Genus Eurymus- .. 2... 2) =. 40-8 02 ee Kurymus philodice. =... ... « ¢« 3.406 ee Kurymus.eurytheme .....0 . «) 504° a! 0) eee Genus Xanthidia .- .0 2. 3. «tee See Xanthidia nicippe ..- .. «.% )) «nis ve Genus Eurema 8 wt be) all a: geal eas Siena Hurema lisa 4.2 '. ss 2 ses ee Genus Nathalis’. - 2...) Suseuieel Ser ca re Nathalisitole... . =. = i. e5ie wcle See ee Tribe Orange-Tips” . .0 34d oa Ss a 2 Genus Anthocharis . . &.4. 3.6245, =e Anthocharis genutia -. . | i~.4: “us + shee ee Tribe Whites 2. 6b co as SS 3 ae ee Genus Pontia .o« .. 6%. 5k Aiba Se Pontia protédicé. -.. 0s. . Ss“ =e eee Gentis Pieris..)) . 0 2 308 60 4 a oe) = eee Pierts-oleracen ... #5. (2°), x) ee Pierisrapae 2» 5 Sb... ae ee Subfamily Swallow-Tails. . 2.4) «0s (sce) a. Gia Genus Laertias 00 59. 5 oS “es et ee Laertias philenor . .* 5's .« yc “A> sah Genus Iphiclides .. .-s.- \< ad ouipre a4 7 eee Iphicldes ajax << 2) %2> le Umea Tee ee Genus Jasoniades. <<. 3-40), % Oo aoa wie CONTENTS. Basilarchia astyanax Basilarchia archippus . Tribe Emperors Genus Anaea Anaea andria . Genus Chlorippe Chlorippe clyton. Chlorippe celtis . Subfamily Meadow Browns or cee, ; Genus Cissia . Cissia eurytus. Genus Satyrodes Satyrodes eurydice . Genus Enodia Enodia portlandia . Genus Cercyonis Cercyonis alope . Cercyonis nephele . Family Gossamer-winged Butterflies . Tribe Hair-Streaks Genus Strymon . Strymon titus Genus Incisalia . Incisalia niphon . Incisalia irus . Incisalia augustus . Genus Uranotes Uranotes melinus Genus Mitura Mitura damon Genus Thecla Thecla liparops . Thecla calanus Thecla edwardsii Thecla acadica Tribe Blues. Genus Everes Everes comyntas Genus Cyaniris . Cyaniris pseudarg aes ix | PAGE 101 102 104 104 104 105 105 106 107 107 107 108 108 109 109 110 110 111 113 113 113 113 114 114 115 116 117 ily 118 118 119 119 120 121 122 123 123 123 125 125 INTRODUCTION. 1. WHAT ARE BUTTERFLIES? OnE of the great groups or “orders” into which in- sects are divided is called Lepidoptera (derived from two Greek words meaning scaly-wings). This group differs from all other insects by having in the perfect stage a long, hollow, thread-like tongue, through which fluids may be sucked or rather pumped up, and which, when not in use, is coiled up like a watch-spring; and by having four rather broad wings covered with colored scales overlying one another in rows like shingles, slates, or tiles on a roof. These insects undergo striking changes in the course of their lives; for they are hatched from the egg as crawling worms having a globular head with biting jaws, and a body -supported not only by the three pairs of short horny legs found in the young of most insects, but by several, gener- ally five, pairs of stumpy, fleshy legs behind them; while the two joints of the body next following those with horny legs and some other joints near the hinder end never have any; from this they change into a pupa or chrysalis, a mummy-like object with the legs, wings, and other members swathed upon the breast and with no possible motion except in the wriggling of the joints of the abdomen 2 THE COMMONER BUTTERFLIES. or hinaer end of the body; from this temporary prison escapes in due time the winged creature of beauty which adds such a charm to the summer landscape. Butterflies differ from other Lepidoptera by haying clubbed or knobbed antenne in their perfect stage, and generally in their transformations, for most of them are hung up by silken cords attached to hooks on the tail, and sometimes also bya girth around. the waist; they are rarely enclosed in cocoons, or, if so, the chrysalis is in most cases also supported within; while moths (1e., all other Lepi- doptera) usually construct silken cocoons, often of very close texture, or make cells in the ground, in either of which cases the chrysalis lies loosely within or attached by the tail only. Butterflies usually fly by day, moths usually by night. Butterflies usually rest with their wings erect; moths usually with wings flatly expanded or sloping ime ward on either side like a tent. 2. THE STRUCTURE OF THE PERFECT INSECT OR IMAGO. The body of a butterfly is distinctly separated into three divisions: the head, to which the antennez and the coiled tongue are attached; the chest, trunk, or thorax, which supports the four wings and three pairs of legs; and the abdomen. The head is the smallest part, but contains a wotideieal lot of interesting organs. The sides are almost entirely oc- cupied by large faceted eyes; from the summit spring a pair of slender thread-like but apically clubbed antenne; while beneath, between the scaly and hairy upcurved three-jointed appendages, called labial palpi, the spiral tongue (maxillze) is coiled. The most interesting of these organs is this tongue. It coils up just like a watch-spring, but may be extended at full length, as when plunged into the depths of a flower INTRODUCTION. 3 in search of honey. It appears as if single and solid, but is really composed of two exactly similar lateral halves grooved along their inner surface, so that when placed together the opposing grooves form a fine tube; and to secure them in place, so that the tube shall not leak, the edges of the grooves are delicately notched so as to dove- tail into corresponding teeth on the edge of the opposing groove, by which they become closely interlocked. To enable the butterfly to pump into its body through this tube the honeyed sweets of flowers, the throat at the base of the tube expands into a sac with muscles radiating toward the walls of the head and others encircling it; when the first set of muscles contracts, the interior space of the sac is enlarged; when the encircling muscles con- tract, it is diminished. By the alternating action of these sets, a pumping process goes on aided by a little flap at the base of the tube which lets the fluids pass in but not out; so tha’ the squeezing of the full sac presses the fluids into the stomach; its enlargement creates a vacuum which causes the honey in the flower to ascend the tube past the valve into the sac. The antennz may be divided into a base consisting of two joints stouter than those beyond; a thread-like stalk, slender and equal, consisting of many joints; and the club, which is composed of the swollen tip, sometimes arising almost insensibly from the stalk, sometimes abruptly; and in the Skippers having usually a recurved hook at the tip; the club is usually at least twice as thick as the middle of the stalk, generally naked beneath and often flattened. The eyes are usually very convex, but vary in different groups in this respect as well as in the amount of space they cover; they are ordinarily naked, but sometimes deli- cately hairy, and in the Skippers are overhung by a curv- ing tuft of bristles. The number of facets in the eye is yery great, numbering thousands to each eye. 4 THE COMMONER BUTTERFLIES. The thorax is divisible into three parts, called from in front backward prothorax or fore-trunk, mesothorax or ; mid-trunk, and metathorax or after-trunk. The protho- rax, however, is scarcely more than a flattened plate in front, and is easily overlooked; the division between the other two masses is readily seen behind when the scales are rubbed off, and the mesothorax is seen to be much the largest part of the thorax. The fore wings are attached to the mesothorax, the hind pair to the metathorax, and both are composed of two films supported by a system of branching hollow rods and the surface-covered with scales. | : Of these rods there are ordinarily four or five to each wing, but when all are present there are six. The two middle ones of the six are the only ones that branch, and are called respectively the subcostal (the upper one) and the median; generally they meet or nearly meet near the middle of the wing and enclose what is called the discoi- dal cell, and the subordinate rods or nervules appear to diverge from its margin. The scales are hollow flattened sacs, covered with longi- tudina! strize on the upper surface and generally toothed or serrate at the tip, with a short bulbed stem by which they are fixed in the wing membrane; upon which they lie like shingles on a roof, and by their pigment and the re- fraction of light by their surface striz give to the wing all its color and delicate markings. Certain scales, however, are peculiar to the male sex and are curiously distributed in special patches or concealed positions so as scarcely to be visible even under the micro- scope until they have been uncovered. These are often fringed with tassels at the end, each thread of the tassel a eanal leading through the body of the scale to a gland at the base and so serving as scent-organs—the odors being some‘imes appreciable to human senses and then in all INTRODUCTION. 5 known cases agreeable perfumes like flowers, sandal-wood, and musk. The legs are six in number, one pair to each division of the thorax; they are always very slender and stick-like. The front pair, however, as we pass from the lower to the higher butterflies becomes more and more atrophied and useless, first in the males, then in the females, until in the highest family they are utterly useless, often not easy to detect, and render this group practically four-legged in- . Stead of six-legged. Their principal divisions are the femur (plural, femora) or thigh, the tibia or shank—these two parts generally of about equal length and indivisible; and the tarsus, the last composed of five always unequal joints, armed beneath with short spines and at tip with claws, a pad, and often with paronychia or whitlows, a sort of membranous imita- tive accompaniment of the claws, perhaps best seen in the Pierids. The abdomen is formed of nine essentially simple seg- ments. ‘The males may be distinguished from the females by the structure of the last segment, the females being pro- vided with a pair of minute flaps, one on each side, which protect and form part of the ovipositor, while the males have side clasps and an upper median hook for clasping the body of the female. The abdomen of the female when filled with eggs is very much larger and fuller than that of the male, and the sex can thus often be told at a glance. 3. THE APPEARANCE OF THE EGG. The eggs of butterflies are very various in sculpture, and though often very simple, are at other times exquisitely ornamented. ‘They are usually broad and flat at the base, and more or less rounded above. One class may be called, in general, barrel-shaped; but this would include minor 6 THE COMMONER BUTTERFLIES. divisions, such as thimble-, sugar-loaf-, flask-, or acorn- shaped, or even fusiform; others are globular, or hemi-. spherical, or tiarate. The surface may be more or less deeply pitted, or delicately reticulate, or broken up by ver- tical ribs connected by raised cross lines, or may be per- fectly smooth and uniform; but all have a collection of microscopic cells at the centre of the summit perforated by little pores, forming the micropyle, through which the egg is fertilized; and these microscopic parts are often of exceeding beauty. 4. WHAT THE CATERPILLAR IS LIKE. Caterpillars of butterflies do not differ from those of moths by any single characteristic. Each family of Lepi- doptera has certain peculiarities, and one has to become more or less familiar with them to determine whether or not a given kind falls in this or that family. They are worm-like creatures, but with a distinct horny head, separable from the body. The head is very different from that of the future but- terfly, having biting jaws, no compound eyes, but in their place a semicirclet of simple ocelli, and antenne hardly visible without a glass; these last, indeed, are very like the palpi, a series of two to four rapidly-diminishing rounded joints ending in a bristle. The body is composed of thirteen (apparently twelve) segments of which the first three, corresponding to the joints of the future thorax, have each a pair of horny five- jointed legs ending with a single claw; while the third to sixth and last abdominal segments bear each a pair of two- jointed fleshy “prolegs,’ armed at tip with a single or double series of minute hooklets. Breathing pores or spiracles are found on the sides of the first thoracic and. the first eight abdominal segments. Besides this, the whole INTRODUCTION. 7 body is clothed, when adult, with short hairs or longer spines set on little pimples, or with fleshy filaments or tubercles of some sort, all arranged toa greater or less extent (excepting generally the short hairs) in longitudinal series, but these are often not precisely aligned on the tho- racic and abdominal segments. In their earliest stage, however, before their first moult and sometimes for a stage or two after it, the clothing of the caterpillar is very different from what it is at maturity, the appendages usually consisting at first of longer or shorter bristles, often tubular and conveying fluids to the enlarged summit, and arranged in longitudinal series differ- ent from those of the spines or filaments of the mature caterpillar. This earliest stage, therefore, needs special attention in the study of butterflies, although the creature is then exceedingly minute, and, therefore, not considered in the present work. Certain caterpillars (and this peculiarity usually runs through whole groups of allied forms), have certain glands opening externally which may secrete fluids or odors of various kinds; some of these are eversible like the Y-shaped appendages on the top of the segment behind the head of the Swallow-Tails and here termed “ osmateria”; or the lateral polypiform extrusions called “ caruncies” on both sides of one of the hinder segments of some of the Blues, _ both kinds of organs being thrown out only under provo- cation, 5. THE CHARACTER OF THE CHRYSALIS. In this state the creature is a sort of mummy, all the appendages, both of head and thorax, folded over upon the breast, packed closely and tightly glued, extending usually to the fourth abdominal segment. In a few of the lower butterflies, the tongue extends still further and is then 8 THE COMMONER BUTTERFLIES. more or less free. All of the appendages, however, are not seen, for the palpi and hind legs are entirely concealed beneath the other members, and the organs that appear are ranged in the following order from the middle line out- ward: tongue, fore legs, middle legs, antenne, fore wings, hind wings, of the latter of which very little is seen, they being mostly covered by the fore pair. The body is compact, but there are usually some marked prominences upon the surface, notably in certain places, such as the front of the head, which usually has a pair of projections, sometimes only one; the middle of the back of the mesothorax, often ridged or with a pointed projection; the extreme base of each of the wings, which are usually tuberculate or humped; and the middle line of the back of the abdomen or the sides of the same, which are often ridged. In the highest family, where the caterpillars are spined, there are often rows of conical tubercles on the chrysalis corresponding generally to the position of the larger spines of the caterpillar. This is all that need be said regarding the actual struc- ture of butterflies in their different stages to one beginning their study, for it is better to dwell rather upon their lives and protean changes, their histories and habits, 1f we wish to gain a true and favorable insight into their character- istics. 6. A Frew WoRDS ABOUT THE EGGS. The eggs of butterflies are always laid in full view, ex- cepting that in a few instances they are partially concealed by being thrust into crevices. Ordinarily they are laid on one or the other surface of the leaves of the food-plant of the caterpillar or on the stem of the same, and usually on or in contiguity to the tenderer growing leaves. As a INTRODUCTION. 9 general rule, the eggs are laid singly, in some instances on the extreme tip of a pointed leaf; but in not a few cases they are laid in clusters of from two or three to several hundreds. Sometimes these are rude bunches piled loosely or in layers one upon another; sometimes they are laid in more or less regular single or double rows; sometimes in a _ single column of three or four or even as many as ten eggs, one atop another; or they may girdle a twig like a fairy ring. The duration of the egg state is commonly from one to two weeks, but it variesin different species in the summer-time from five or even less days to about a month; there are, however, some butterflies which pass the winter in the egg state. In all such cases the eggs are laid upon the stem, never upon the leaf, and some spot is chosen, like the neighborhood of a leaf-scar, which affords a certain amount of protection during the winter. i THE LIVES AND HABITS OF CATERPILLARS. When eggs of butterflies are laid in clusters, the cater- pillars are almost invariably social to a greater or less de- gree, at least in early life, sometimes to maturity ; if they are laid singly and it is only by accident that several are laid near together, the caterpillars are solitary. In the majority of cases where the egg is laid singly, the first act of the escaping caterpillar is to devour it entirely or in greater part. Solitary caterpillars may live exposed on the upper or the under sides of leaves, or they may retire to the stem of the food-plant for greater security, or they may construct, each for itself, some kind of concealment, or live within fruits. When fully exposed, they usually remain quite motionless, stretched at full length when not feeding, and may select for their resting-place peculiar spots. The most curious is one adopted by some Brush-footed Butterflies (and 10 THH COMMONER BUTTERFLIES. the egg is then commonly laid at or near the extreme tip of the leaf) which devour the apical portion of the leaf, leav- ing the midrib untouched, and perch themselves upon this midrib after having attached to it by a few threads a small packet of bits of leaf and frass which is moved by every breath of wind,—probably to distract the attention of its enemies from itself. Others construct shelters more or less complicated. Some merely spin transverse threads across the floor of a leaf, causing its sides to curl, and then recline, half hidden, in the shallow trough; others make it so complete that the edges meet and the leaf forms a cylinder; still others fasten the opposite edges by silk and by biting weaken the resistant ribs and also the main rib so that the leaf droops; others bite channels into the leaf at two distant points and turn the flap thus formed over upon the leaf, securing it in place by silken strands; while for winter use the partly grown caterpillar of the later brood of Basilarchia and some allied genera not only coils a leaf into a cylinder but lines it within and without with silk, leaves a ledge to crawl out upon, and secures the leaf to the twig by strong silken fastenings. In nearly all these cases the caterpillar seems to rest upon the upper surface of a leaf and curl the sides upward, very rarely the reverse. But there are others which fasten several leaves together, generally very slightly, to form a leafy bower, or in the case of grasses a tubular burrow; and in a few instances, asin Vanessa huntera, bits of the inflorescence of the plant are caught in the slight meshes of the net to make a more perfect concealment. Among our Larger Skippers many which live half their life in a nest formed of a single leaf finish it in a bower made of many. Social caterpillars often construct nests in company, which then often embrace in an irregular web the whole or nearly the whole of a branch of the food-plant. Usually INTRODUCTION. 11 the web is thin and hardly conceals the surface, but some- times it is almost like parchment, as in the Mexican Hucheira socialis. Winter is sometimes passed in one of these webs, and when constructed, as it sometimes is, on an annual, the shrinkage after the death of the stalk makes a compact mass of leaves, frass, web, and caterpillars, from which it would seem as if no caterpillar could escape in the spring. When social caterpillars construct no shelter, they usually feed side by side in rows,and move from place to place in files. A very large number of our caterpillars live through the winter, and this is often the only means by which a species survives the inclement season; most of them hiber- nate when about half grown; others, strange to say, just from the egg, without having eaten anything but the shell from which they came; still others hibernate full grown and full fed, changing to chrysalis just when vegetation starts in the spring. Some of these caterpillars, especially those partly or fully grown, construct nests for hiberna- tion; others use the same nest which has served their larval life, strengthening it against the greater needs of winter; others seek crannies of any kind. In some cases where the caterpillars of a second brood hibernate when half-grown, the caterpillars of the first brood at the hibernating age, but in midsummer, will fall into lethargy, from which some will arouse after say a fort- night’s quiescence, while others will prolong their pre- mature into actual hibernation, and in the following spring caterpillars of the same stage but of two successive broods will mingle together. It is apparent, then, that there is considerable variety in the duration of life of caterpillars. Instances are on record where the time from birth to chrysalis was only about ten days; ordinarily it is at least a month; with those that hibernate it may be in some cases nearly a year; 12 THE COMMONER BUTTERFLIES. while there are several instances known where caterpillars have lived over two winters and might therefore take from eighteen to twenty or more months for their larval ex- istence alone. 8. How THE CHRYSALIS HANGS. In making its preparation for its final moult, when the change to chrysalis is to take place, the caterpiliar proceeds in exactly the same manner as in preceding moults, except that it spins more silk and, in addition to the carpet on which it stands, adds other strands of a special nature, according to the method in which the chrysalis is to swing. The chrysalis is provided with special hooks at its posterior end with which to engage the silken pad prepared for it, excepting in the case of a few which change on the surface of the ground. One mode of suspension is to hang pends by the tail alone from a pad of silk. Generally free to swing with every jar or breeze, the more so as the pad is usually more or less loosely woven, there are some in which the hooks are distributed over a more or less elongated area, and, the caterpillars having constructed a more compact pad, the attachments are firmer and more extended, so that the chrysalis may be more or less rigid and even hang in a position by no means vertical but inclined strongly toward the horizontal. The movements of chrysalids of the pendent type are not confined to the looseness of attachment of the hooks or the nature of the web to which they cling, but in all there is more or less capability of motion by the sliding of the abdominal joints upon one another, and the chrysalis may thus effect voluntary motion, sometimes, when dis- turbed, of an extraordinarily active kind. Some chrysalids, moreover, inake slow periodic diurnal movements, helio- INTRODUCTION. 13 tropic or phaotropic, i.e. toward or away from the sun or light, sometimes lateral, sometimes forward and backward. Other chrysalids are attached not only by the tail but also by a girth, whether tight or loose, slung around the middle of the body in the dorsal depression or saddle which always exists between the thoracic and abdominal regions. If the girth be tight, the ventral surface of the chrysalis, which touches the surface of rest, is nearly or quite straight; if loose, it is often bent to a greater or a less degree oppo- Site the girth, or describes a curve with the same point as the middle of the arc. A modification of this mode of suspension is seen in some Skippers, which make cocoons in which both the median girth and sometimes to a less extent the tail attachments form Y-shaped strands, which are attached at their ex- tremities to the walls of the cocoon ; into the centre of one set the hooks of the tail are plunged, while the middle of the body is slung between the longer arms of the other and larger set of strands. There is but one family of butterflies in which all the members construct cocoons—the Skippers. Their cocoons are usually of a rather fragile nature and consist (usually) of leaves, blades of grass, or other vegetable material, gen- erally living, shaped into a more or less oval or cylindrical cell by silken attachments ; sometimes the interior is more or less perfectly lined with athin membrane of silk; within this, as just stated, the chrysalis hangs by means of Y- shaped shrouds, the form of the smaller one sometimes difficult to determine from the mingling of its threads with those forming the extremity of the cocoon. Chrysalids which give birth to butterflies the same sea- son vary in their duration from about three days to a month, but usually from ten days to a fortnight. But a consider- able number pass the winter in this shape, and may then endure from five to eleven months, and sometimes this lat- 14 THE COMMONER BUTTERFLIES. | ter variation may occur in a single species having several broods, in which an increasing proportion of each succes- sive brood of chrysalids of one season pass over the ensuing winter. Instances are on record in which chrysalids, nor- mally hibernating, have been known to pass over a second winter and then give birth to the butterfly. 9, THE GENERAL HISTORY OF BUTTERFLIES. Beginning life as an egg which usually hatches. within a few days after being laid, the young caterpillar finds its sole duty to be to eat and escape being eaten. It feeds voraciously, and outgrows its skin so often that it is obliged to moult four or five times before it is full grown. On each of these occasions it stops feeding for a while, spins a carpet of silk, and fastens its claws therein; when the time for change comes, the old skin splits along the middle of the back of the thoracic segments by violent muscular effort, the old head-case (from which the new head was first withdrawn) is shaken off and the creature crawls out of its old skin, which in many instances it there- upon devours. In the last change, to chrysalis, the head is not removed from the old skin, but itself splits in the middle and down one or both sides of the frontal triangle, and the chrysalis emerges. After hanging awhile, the chrysalis skin splits at much the same points and the but- terfly emerges to begin the cycle again with the laying of eggs. The cycle of changes through which a butterfly moves is in temperate climates commonly passed once each year,— or rather once each season, for it is winter that usually in- terferes with the activities by robbing the creature of its means of sustenance and paralyzing its action. Inasmuch as the pupal stage isin the higher insects the period of longest inactivity, one would presume beforehand that INTRODUCTION. 15 this period would coincide with winter ; and so it does in a large number of cases. Yet among butterflies the ex- ceptions to such arule are not only exceedingly common, but, as might be expected were there any departure, they are very varied and winter is passed, by one species or an- other, in every conceivable stage of existence, including every part of caterpillar life. Indeed, cases are not un- known, especially in high latitudes and altitudes, where more than one season is required to bring a butterfly to maturity. On the other hand, a large number of our butterflies, and this is especially true southward, complete the cycle of their changes twice or oftener in a season, and there are nota few having an extended latitudinal range which vary in this respect, having one or more broods in the northern part of their range, and an added brood or more in the southern. The end of the season generally surprising multiple-brooded butterflies in all stages of existence, an opportunity has easily arisen for every possible form of hibernation or lethargic life, which accounts for the variation discoverable in the lives of our butterflies, each form settling at last upon that series of changes which is best fitted for it. 10. VARIATION IN THE BUTTERFLY. Like most creatures, butterflies, when they are found over a wide territory, show great difference between indi- viduals found in the extremes of the range, so that it is sometimes difficult to tell, at least until collections are made over the intervening country, whether specimens from distant places should be regarded as distinct species or as geographical varieties. The most skilled may make mistakes for lack of proper material. But quite apart from this, butterflies appear to be ex- ceptionally sensitive to the environment and to offer an unusual amount of variation of a different sort; for di- 16 THE COMMONER BUTTERFLIES. morphism or polymorphism of various kinds, that is, the + existence of a given species under recognizably distinct forms (two or more, even sometimes to five or six) is by no means uncommon. | This distinction is often sexual; indeed there are relative- ly few species in which the outward aspect of the two sexes does not differ, in some cases to a remarkable degree. It is universal in the numerous species of Kurymus, for example, where in general the inner margin of the dark outer bor- dering of the wings is sharp and precise in the male, con- fused and irregular in the female. In very many cases, however, it is accompanied by a simple dimorphism, some- times affecting one sex only (and then usually the female), as In many species of Kurymus, where one form of female has the bright ground color of the male, the other a pallid ground color; at other times affecting both sexes, as in some species of Polygonia: in P. interrogationis, for ex- ample, there are four sets of individuals differmg in the general coloring of both surfaces of the wings and even in the form of the wings—differences all of which may occur in the progeny of a single individual and fed on the same plant. 7 But these differences are very often correlated with, generally confined to, differences of brood. One of the most striking and at the same time one of the simplest examples is in the double-brooded European species Araschnia prorsa, where the first brood is composed of individuals of one type with highly variegated markings (levana), the second of a very distinct type with more sharply-contrasted coloring (prorsa), which, until they were bred from each other, were universally, and reason- ably, regarded as distinct species. This is called seasonal dimorphism. Numerous striking examples occur in this country, not a few of which are excellently shown in Edwards’s Butter- >. we a INTRODUCTION. Ty flies of North America, such as many species of Polygonia (in P. intferrogationis they are largely seasonal, the latest brood being all of one type), Phyciodes tharos, the species of Pieris, and especially /phiclides ajax. The latter instance is the more remarkable, because the three forms (marcel- lus, telamonides, and ajax), though sequent in the order named, do not strictly represent distinct broods, since the earlier emerging individuals of the first brood are marcel- lus, the later-appearing individuals of the same brood are telamonides, while the subsequent broods, of which there are several, are ajax. Distinct climatal differences, whether temperature or moisture (or both), are unquestionably the prime cause of seasonal dimorphism, the former in temperate, the latter in tropical,regions. ‘The first has been practically proved by experiment, the latter by the correspondence of the phe- nomena to that of temperate climates and their synchro- nism with the dry and wet seasons. Many cases of dimorphism are compound. Instances of this have already been given; indeed, most cases of dimor- phism inyolve some distinct element, such as season or lati- tude, or temperature in some form. ‘Thus, Jasoniades glaucus, which exhibits dimorphism in the female, does so only in the south, for the dark form of the female (in which the conspicuous normal stripes of the male are ob- scured) occurs but rarely north of Pennsylvania, although there is a distinct tendency in both sexes to a broadening of the darker markings and the partial suppression of the yellow in high northern latitudes or their equivalent, as among the White Mountains of New Hampshire. A sim- ilar instance occurs in Hveres comyntas with the boundary limits of the dark female at about the same place. Nearly all the above instances of dimorphism where it is not of the simplest kind (whether seasonal or not) may be termed polymorphic, since more than two types of individ- 18 THE COMMONER BUTTERFLIES. uals appear in a single species; especially is this the case where a sort of double dimorphism occurs, like that of Iphiclides ajax or of Polygonia interrogationis mentioned above. Instances have also been cited where the geo- graphical element entered; but polymorphism is most con- spicuous and complicated where all the above elements are combined,—where dimorphism between the sexes, dimor- phism also between the members of one sex confined to distinct portions of the range of the species, and seasonal dimorphism more or less limited in its geographical range and in its correlation with the broods (as the species may be multiple-brooded or not), may be further complicated by geographical variations independent of and running through all the others. ‘Two cases may be cited as remark- able instances of complicated polymorphism if the facts shall prove well grounded. In the extreme north, Cyaniris pseudargiolus is single- brooded and appears in two forms, an earlier with heavier markings (lucia) and a later (violacea); the males of both are blue above; the females paler blue with broad dark | margins to the fore wings. In New England it is double- brooded, the sexes differing as before; the first brood is trimorphic and serial, the earliest individuals having heavy markings (lucia), the next intermediate markings (vio- lacea), the last light markings (neglecta), while the second brood is composed entirely of neglecta; in the northern part of the belt in which the first brood is trimorphic, the form neglecta is comparatively rare, and lucia the most abundant, while the reverse is the case in the southern part of the same belt (and lucia itself is so variable that one type of it has been separated as marginata). Farther south lucia disappears altogether and the first brood is di- morphic,—violacea and neglecta in theorder of their appear- ance; but now a new element is introduced, for the males I INTRODUCTION. 19 of violacea become dimorphic, one form resembling the males of the same found farther north, the other being uniformly dark above (violacea-nigra). In the southern part of its range, the latest individuals (neglecta) of the first brood are usually much larger than the members of the second brood, all of which are otherwise of the same type. This butterfly flies not only from Hudson Bay to Georgia, but also from the Atlantic to the Pacific, and in California we have a new form (piasus), hardly distinguish- able from neglecta, which appears to be double-brooded in the south but to show no difference between the broods. Farther north, however, near the British boundary, the conditions of New England are at least in part repeated, while in Arizona an ashen variety (cinerea) occurs. The different forms assumed by Hurymus eurytheme have caused their description as distinct species on four or five occasions. It, too, has an immense range. In Texas the cycle begins in November (the summer and not the winter interfering with its activities) with a yellow type (ariadne) succeeded by a yellow-orange type (keewaydin) and finally by an orange type (amphidusa), each a distinct brood, the last-named indeed double-brooded; with the in- crease of temperature, the size and the depth and brillancy of color increase; the form keewaydin has a sexually di- morphic female, one resembling the male in ground color, the other pallid (keewaydin-pallida), and the form amphi- dusa is similarly favored (amphidusa-alba), In the north- ern part of the range of the species, the earliest (May) form, a yellow one, differs so much from the earliest (November) type of the south as to be given a distinct name (eriphyle), and when keewaydin and amphidusa have had their turn, it again appears in the latter part of the season, and though the autumn form has not received a distinct name, it can be distinguished from the spring form, at least in oO THE COMMONER BUTTERFLIES. the male sex, the spring individuals being uniform chrome yellow above, while the October males are of a whitish yel- low and the hind wings are dusted with gray. 11. Some REMARKABLE DIFFERENCES BETWEEN THE SEXES. Many male butterflies may be readily distinguished by characteristic tufts, rows, or wisps of hairs or patches of special scales or membranous folds generally rendered in some way conspicuous, and which do not occur in the female. Of the first we have a good example in our species of Argynnis, which show a row of long semi-recum- bent hairs on the upper surface of the hind wings between the costal and subcostal nervures; of the second in the mealy-looking margins of the upper surface of the wings of Callidryas, the discal patch on the fore wings of many Hair-streaks, the apparently blackened and thickened veins of the fore wings of Argynnis, or the discal streak accom- panied by large tilted scales so common in the Smaller Skippers; of the last in the blackened pocket of the hind wings of Anosia, the plaited fold of the hind wings of Laertias, or the deftly none costal fold of the Larger Skippers. These very patches or folds usually conceal scales differ- ing to a greater or less extent from the surrounding scales and peculiar to the males, called scent-scales or androconia, i1.e., male-scales. They do not, however, always occur in these patches (where they are usually concealed from view to some degree), but may be simply scattered among the other scales and then, being almost invariably much smaller, almost completely concealed from view. While the ordinary scales of butterflies, common to both — sexes, show very little variety in their structure, being striate, more or less fan-shaped or shingle-shaped laminz INTRODUCTION. 21 with finely-toothed apical margin, the androconia show an extraordinary variety of structure, but are rarely toothed at the tip. They may be shaped like an Indian club, a shepherd’s crook, a long needle ending with a whip-lash, a twisted ribbon, a battledore, an elongated fan, a row of beads, a spatula, a tapering ribbon with fringed tip, or may assume many other forms which could only be described at length; they are generally very slender and minute. Where they are fringed, it is highly probable that the separate threads of the fringe are so many canals conducting to glands at the base of the scale, for in many instances odors plainly perceptible have been traced to this source. These odors are in all cases of an agreeable nature and have generally been compared either to the fragrance of certain flowers or to the musky odors of quadrupeds; the last is a very common scent among insects and is known in such different creatures as the imago of the beetles Prionus and Osmoderma, the imago of the butterfly Argynnis, and the half-grown caterpillar of the moth Arctia parthenos. These androconia are very capricious in their occurrence both as to exact location and as to their presence or absence in allied forms. ‘They appear to be almost invariably pres- ent in all the species of any given genus or else absent from all, but allied genera in a single tribe often vary in this particular. They occur in all families and in most, per- haps all, tribes of butterflies. They are usually found upon the upper surface of the fore wings, very rarely, if ever, upon the under surface of any; they may be scattered indiscriminately over the wing, be collected into definite but vague areas traversing the in- terspaces, assemble along the principal nervures or at the extremity of the discal cell, or in a narrow discal streak or costal fold, or be confined to a little pocket on the broad ‘face of the hind wings, or lie in acclosed plait next the anal margin, or in various other positions, 22 THE COMMONER BUTTERFLIES. 12. THE SENSES OF BUTTERFLIES. The power and range of vision in butterflies (and in insects in general) have without doubt been popularly overestimated. Both direct experiments and study of the structure of the compound eye lead to the same conclusion: that while insects have a quick perception of moving objects © or of objects among which they are moving, they have no power of distinguishing precise form or delicate distinc- tions of color or patie their visual perception being confused or vague. The delicacy of the sense of smell in-insects, and espe- cially in Lepidoptera, makes full amend for defective vision. The quick advent of males among many tribes to secluded and concealed females, the possession of many odoriferous organs, the evidence that many others exist where the odors are imperceptible to human sense, all point to a delicate and keen perceptive power in this direction. It is alto- gether probable—and no other explanation has so great probability—that it is by the exercise of this sense that the parent butterfly discovers the proper food-plant for the deposition of her eggs. The organs for this sense are probably resident in the antenne. The fondness of butterflies for the honeyed sweets of flowers at once suggests a high development of the sense of taste; for that it is not purely a matter of hunger or the need of nourishment may be seen in the cases so often noted where butterflies fill their bodies until they can scarcely fly, which is far beyond any need of nourishment; or in the groups which continue for hours around a moist spot in a road imbibing the innutritive fluids. The organs for this sense are probably resident in the tongue-papille. There seem to be no reasons for believing that any high degree of power in hearing is to be found among butter- INTRODUCTION. 23 flies, as there are no organs known to serve as receptive elements, and the sounds made by butterflies are apparently due simply to the rustling of the wings. All motions that look as if possibly meant to convey sound (where none can be detected by the human ear), such as the quivering of the wings in sexual approximation, may be solely to waft emitted odors the more effectively. Little can be said or presumed regarding touch of animals whose external parts are all crustaceous; but it is plain that warmth and cold, which deal with the same nervous elements, have decided influences in every stage beyond the egg. The ordinary inactivity of caterpillars in the night can not be laid to the absence of hght, for their behavior in darkened apartments is much the same as out of doors; the movements of chrysalids tell the same story; and we know that a measurable amount of movement of the antenne occurs with changing temperature in hiber- nating, practically dormant, butterflies. 13. MimIcRY AND PROTECTIVE RESEMBLANCE. Most butterflies when at complete rest close their hind wings back to back and sink the fore wings as far as pos- sible into concealment behind them. ‘The area of these wings then exposed to view is in a very large proportion of butterflies so colored and mottled or marbled as to render the butterfly immensely less conspicuous in its resting- place than if settled with wings expanded or the front pair not mostly concealed; in very many cases so little con- spicuous as to be difficult to detect. Rarely are any other parts similarly colored. That this resemblance is protective there can be no doubt, especially in view of its common occurrence. There are, however, innumerable instances of special and striking provisions in this direetion, of which one of the 24. THE COMMONER BUTTERFLIES. most generally known is that of the oriental genus Kallima, the species of which are highly colored on the upper sur- face and conspicuous objects when in flight, but which are so colored and marked upon the under side that when alighted upon a twig, as they do with the fore wings thrown well forward and all wings closed, the pattern and color of the under surface are such as to make a perfect resem- blance to a leaf whose midrib, a colored stripe crossing both wings and terminating at the apex of the fore pair, takes its rise from a tail-like extension of the hind wings which just reaches the twig from which the mock leaf thus springs, the tail of the wing corresponding to the pedicel of the leaf ! These phenomena, however, reach their culmination in the examples of mimicry of one butterfly by another, of which there are numerous examples of an extraordinary kind such as perhaps no other group of animals can pro- duce. iJ . . - . = . e s : i # 4 V 2 t ‘ - | ¥, ’ : ' d a ‘ i = , te 7 ‘ \ ; ‘ F ‘ . * 7 ; 2 ' . { Fs * . ' 4 ‘ : . ‘ i ' i ee . i ‘ . . . * . 2 . . . : n ‘ A ¥ i - a 7 . = ‘ ° - - s . . ’ . . ' of a i * 4 ‘ . i a Py 4 4 . ' ' % 7 P e . 7 - 3 ' * « . ‘ 4 ‘ 4 “a . : < 1 4 - 7 — 5 . - . - , ‘ 4 = ‘ J ‘ F . . ie 7 . - . ‘ . a , ’ < 7 a ‘ _ . <3 - . . ‘ ba a * . ‘ . ae ee evbe. . eas ay |e % ¢ . s ‘ . - ® i * te. F - a . : ‘. E * oe ; % . ‘ ~ as w Be ; - . 7 , “Se P “ Rip OO ns la es oem he ois ‘4 s ~ _ * om ee ae i) inal Bag, ~ oa HAE 894 592