Chapter V: Part 5

In her childhood, or caterpillar state, her head is elliptical in shape, of a light pearly color, the rest of the body being a clear bluish-green. A faint yellow band stretches along each side, just below the line of her breathing-organs, from the first to the tenth segment, while the back, between the several body-rings, is crossed by narrow transverse bars, similar in coloration. Each segment, after the fashion of her kith and kin, is adorned with small pearly warts, tinged with purple, some five or six in number, each tipped with a few simple hairs. Three brown spots, bordered above with yellow, ornament the end of the tail. An interesting variety, whose general color is a dull reddish-brown, is sometimes met with, but the lateral and transverse stripes of yellow have disappeared, and the pearl-colored warts with edges of purple have assumed a richer hue and blaze like a coronet of rubies. When at rest, with the rings all bunched and body shortened, the infantile Luna is as thick as a man’s thumb, measuring but two inches in linear direction; but when she sets out upon her travels, feeling the dignity of her station in life, she stretches to her full length of three inches.

When have been completed her allotted days of feeding upon the leaves of the hickory, oak, walnut or sweet gum, and she is seriously contemplating the preparing of a shroud and casket in which to await her resurrection-morn, she casts about for leaves, which, when they are found, she securely draws together, and within the hollow space there is soon spun a very close and strong oval cocoon of silk, one and three-fourths inches in length, of chestnut-brown color, thin, and covered with warts and excrescences, but seldom showing the imprints of leaves. Cocoons of Luna so nearly resemble those of polyphemus, that many an experienced collector is greatly chagrined, after getting together a large supply of what he deems Luna cocoons, to find dusky, one-eyed polyphemi to issue from the silken tombs rather than a goodly throng, in delicate bridal attire, of proud empresses of the night. Polyphemus cocoons are, however, somewhat smaller than Lunas, white or dirty-white in color, rounded at each end, and sometimes angular, because of the leaves being unevenly moulded into their surfaces, and generally covered with a whitish meal-like powder.

Larva on Branch Below, and Cocoon on Twig Just Above.]

In June the Lunas awake from their death-like slumber, burst asunder their silken cerements, having at first made loose the compact threads by a fluid-ejection, and come out into the world in all the freshness and glory of a new and untried existence. Their wings, which expand from four and three-fourths to five and one-half inches, are of a delicate light-green color, the hinder ones being prolonged into a tail of an inch and a half or more in length. Along the anterior margin of the fore-wings is a broad purple-brown stripe, extending also across the back, and sending downwards a little branch to a glittering eye-like spot near the middle of the wing. These eyes, of which there is one on each wing, are transparent in the centre, and encircled by white, yellow, blue and black rings. The hinder borders are more or less edged with purple-brown. All the nervures are very distinct, and pale-brown in color. Near the body the wings are thickly invested with long white hairs. The under sides, excepting that an indistinct line runs along the margin of both wings, are like to the upper. As for the body, the thorax is white, occasionally yellowish or greenish, and coursed by the purple-brown stripe that traverses the entire length of the upper edge of the wings; and the abdomen, similarly colored, and clothed with white, wool-like hairs. The head is small and white, and furnished with broad, flat and strongly pectinated antennæ, which are very much wider in the male. The legs are purple-brown, and poorly adapted for walking, but this defect is largely compensated for in the wide stretch of wings, that fit their possessor for powerful and long-sustained flight.

Such is Luna in her various transformations. Notwithstanding her great size and almost matchless loveliness, her habits are not proportionally noteworthy. The gift of superior beauty, in the insect as in the mammalian world, does not often carry with it a high order of intelligence. It is true the young Luna knows pretty well the secret of dissembling. How quickly she perceives the approach of an enemy! And she knows how to deal with him, but her little trick of simulating death, or an immobile twig, does not always succeed with the wily spider, or artful ichneumon. That she is a tolerably good connoisseur of the character of foods, there can be no question. You cannot deceive her. Take from her the foods her ancestors have used for centuries untold, and substitute others she knows nothing about, and she is at once cognizant of the change. However hungry she may be, and in her early growing years she is ever a voracious feeder, she will starve rather than eat what the unwritten law of her race has strictly interdicted. I have known cases where death has ensued, or the caterpillar has pupated earlier than usual, when alien food has been given it to eat. But in the beginning of life, just after the first skin-moulting has been effected, ere the little creature has attained its seventh day of age, no trouble is experienced in changing the food, almost anything edible in the plant-line being eaten, though some things with a more decided relish than others. In the matter of cocoon-weaving, where the necessary leaves for a basis cannot be obtained, as occurs in captivity, the inconvenience is overcome, but not without difficulty. Leaves, you must know, are in Luna’s way of thinking, as essential to cocoon-building as wooden or iron beams and girders to man’s own constructing. Without a framework of some sort, what a sorry attempt would we make at home-building, but Luna does succeed, after a good deal of wise planning and no little worry, in producing a house which is well worthy her effort.

While the gaudy moth or butterfly, when contrasted in wisdom and sense with the dingy-colored bee, may suffer in comparison, yet she is by no means the dull, stupid creature she is pictured to be. She lives, it is a fact, as has often been said, for the increase of her race, but the interest she shows for the young she may never see, in laying her eggs upon the plant that is to serve them as food and home, puts her upon a rather high plane of intelligent existence. Luna’s life, in the perfect state, is usually quite brief. It is one of the happiest of honeymoons. Love conquers and destroys all other passions of her being, while her gormandizing offspring are never troubled by the ardent flame which consumes even the thought of sipping the nectar of the flowers that rival in beauty the wings of the mother, who is the perfect representation and embodiment of elegance and grace. While the early insect lives and eats, the adult form, upon whom Dame Nature has expended so much wealth of color and such symmetry of shape, which make her a “thing of beauty and a joy forever,” lives and dies, for in her seeming haste and forgetfulness the great mother of us all has made her without the essential means of tasting food, a delight and an enjoyment which the lords of creation are so wont to esteem the purpose and aim of all human existence.

BASKET-CARRIERS.

You who have been to the country, in the summer, and who have kept your eyes alive to the surroundings, have doubtless seen the Basket-worm feeding upon the leaves of the quince, apple, peach, linden, and other deciduous trees, as well as upon such evergreen as the arbor-vitæ, Norway spruce, and red cedar. In Germany these worms are popularly designated _Sack-träger_, or Sack-bearer, while the mature insect is spoken of as the House-builder Moth. Scientifically speaking, the latter is called _Thyridopteryx ephemeræformis_, a name which is nearly twice the length of the caterpillar it represents.

During the winter the curious weather-beaten bags of these worms may be observed hanging from the tree-branches, apparently without a trace of the odd-looking creatures that hung them there the autumn before. If a number of these bags are gathered and cut open at this time, many of them will be discovered to be empty, but the greater portion will be found partly full of yellow eggs. Those which do not contain eggs are male bags, and the empty chrysalis of the male will be found protruding from the lower extremity. Upon close examination these eggs will be observed to be obovate in form, soft and opaque, about one-twentieth of an inch in length, and surrounded by more or less fawn-colored silky down. If left to themselves, they hatch sometime in May, or early in June.

The young which come from these eggs are of a brown color, very active in their movements, and begin at once to make for themselves coverings of silk, to which they fasten bits of the leaves of the tree on which they are feeding, forming small cones that are closely adherent to the leaf-surfaces. As the larvæ grow, they augment the size of their enclosures or bags from the bottom, until they become so large and heavy that they hang instead of remaining upright, as they did at first.

By the end of July the caterpillars become fully grown. They are now exceedingly restless, and may be seen wandering from branch to branch by means of their true legs which are projected from the mouths of their baskets, to which they keep firm hold, or suspended from a branch of a tree by a long silken thread of their own manufacture. When very abundant, as they were in certain localities during the season just ended, they become a great nuisance, as one can hardly walk beneath the trees without being inconvenienced by a dozen or more dangling into his face.

Removed from the case at this stage of existence and closely examined, that portion of the body which has been covered by the bag will be seen to be soft, and of a dull brownish color, inclining to red at the sides, while the three anterior segments, which are exposed when the insect is feeding or travelling, will be found to be horny and mottled with black and white. The pro-legs on the middle and hinder segments, which are soft and fleshy, will show themselves fringed with numerous hooks, by which the larva is enabled to cling to the silken lining of its bag and drag it along wherever it goes. The external surface of the bag is rough and irregular, often presenting a beautiful ruffle-like appearance, which is due to the projecting portions of the stems and leaves which are woven into it. During their growing-period these caterpillars are slow travellers, seldom leaving the tree on which they were hatched. When about to change into chrysalids, they fasten their bags securely to the twigs on which they happen to be, and then undergo their change, the male chrysalis being very much smaller than the female, hardly one-third its size.

When we examine the cases of the Basket-worm, hardly any two will be seen to be alike in their ornamentation. So completely is the outside covered, when made upon the arbor-vitæ, which seems to be a favorite food-plant of the species, that the silken envelope is concealed from view. The bits of twigs and leaves are probably protective, and yet one would think that the extremely tough case which covers the caterpillar would be quite sufficient to protect it against all assaults of foes and stress of weather. Nevertheless, this leafy coat of mail, which sometimes wholly covers the sac, must certainly add very much to the protective value of the covering. The caterpillar has a soft, hairless body, and is thus more exposed than many of its neighbors, and nature, it would seem, has favored it far above all of its fellows.

How the worm manages to trim its coat in this manner must seem, to the uninitiated in such matters, wholly inexplicable. To enable the reader to understand the manner of operation, it will be necessary first to explain its mode of feeding. The larva has perfect control of its own movements, notwithstanding the fact that it carries its house upon its back. It can thus thrust its body out of the sac-mouth until nearly the whole of it is exposed, and twist and bend itself in every direction. Specimens have been met with that had dropped from the trees hanging by a thread and squirming, bending and snapping their bodies in the most grotesque ways, while the case spun around like an old-fashioned distaff. Now, when the caterpillar wants to feed it stretches its head and neck out of the case and moves them about until a satisfactory place has been secured, which it clasps with its true legs, three pairs of hard, conical organs armed with sharp claws, and pulls up its body and commences to spin. The spinning-organs are near the mouth, and after several movements of the head, as though smearing the liquid viscid silk upon the leaf, the head is drawn back, drawing out with it a short thread. A similar movement is then made against one side of the mouth of the sac, the process being repeated several times until a stout stay-line is spun by which the larva hangs securely. Now the creature is ready to feed. The behavior, however, varies a great deal. In feeding upon the white pine it secures itself to one leaf by its stay-line, while it reaches to an adjoining leaf which it bites off, and sitting erect, as it were, in its house, comfortably chews off the end which is continually shored upward by the first and second pairs of true legs that stand out free and untrammelled above the sac.

Young in House, Winged Male, Young Suspended and Bag-like Female in Longitudinally-Split Cocoon.]

But more frequently the worm feeds without separating the leaf from the point of suspension. By making itself fast to the under part of the leaf it is thus enabled to reach the edge, which it gnaws round and round until it has completed its destruction.

So securely does the caterpillar hold on to its house, that one would suppose that its body was lashed to the inside. But no, its body is unhampered, for it can turn itself easily around in its case, and go out at either end, although the head is generally directed upward. It clings to the inside with the hooks upon its hinder feet, and so tenaciously, too, that the writer has never been able to pull one out, being checked by the fear of tearing the creature in two. And now to the mode of attaching the leaf-cuttings to the case. This is always done at or near the mouth of the sac. The Ephemeraform larva is a growing creature, unlike the moth itself, which emerges a perfect insect of full growth. It commences life as a small worm, eats small quantities, and, as may be observed, down towards the foot of the case sews on very small tags. But after it has fastened on these pieces to the mouth, it grows itself, and so also does the case, which it continually stretches and enlarges. Hence the mouth of the case is continually changing, moving upward as the worm feeds, so that the pieces sewed upon the cap of the case thus appear, in an adult caterpillar, precisely as they are seen scattered along the outside from top to bottom. And now, as to how the pieces are put into the case, I shall endeavor to explain. That the worm cuts purposely through the twig which it needs for the case, I feel certain. Of course the outer or detached part drops down. But, while eating, the worm frequently, quite constantly, indeed, spreads its viscid silk along the leaf and so keeps it attached on both sides to the upper rim of the sac, or to its own mouth-parts, and thus the tip of the twig or leaf, instead of falling to the ground when it is severed from the stem, simply drops alongside of the case, to which it is held by the slight filament that attaches it to the sac, or, as happens in many instances, remains attached to the caterpillar’s spinneret. In either case the leaf, twig or stem remains, and, after being drawn up, adjusted and tightened by the worm, adheres tightly. As the creature is forever moving its spinning-tubes around the top of the sac, these fastenings are being continually strengthened, and thus one piece after another is added, and so the basket grows.

While the case of the Basket-worm, and even that part of its body which it chooses to expose to view, are known to the casual observer, yet but few persons have ever seen the mature insect. The female moth is wingless, and never leaves the bag, but makes her way to its lower orifice, and there awaits the attendance of the male. She is not only without wings, but is devoid of legs also, being, in short, nothing more than a yellowish bag of eggs with a ring of soft, pale-brown, silky hair near the tail. The male, on the other hand, has transparent wings and a black body, and is very active on the wing during the warmer portions of the day. After pairing the female deposits her eggs, intermingled with fawn-colored down, within the empty pupa-case, and when this task is completed works her way out of the case, drops exhausted to the ground and dies.

Though a Southern rather than a Northern insect, yet it is found as far north as New Jersey and New York, and occasionally in Massachusetts. It is extremely local in character, abounding in one particular neighborhood and totally unknown a few miles away. Where they occur in abundance they often almost entirely defoliate the trees they attack, but this can be easily prevented by gathering the cases containing the eggs for the next brood during the winter and destroying them. Hand-picking the cases with the worms in them, where their ravages are confined to small trees and shrubbery, will also help to hold them in check. Nature has provided two species of ichneumon for their destruction. One of them, _Cryptus inquisitor_, is about two-fifths of an inch in length, and the other, _Hemiteles thyridopteryx_, is nearly one-third of an inch. Five or six of this latter species will sometimes occupy the body of a single caterpillar, and after destroying their victim spin for themselves tough, white, silken cocoons within the bag.

HONEY-PRODUCING CATERPILLARS.

Late in June, growing abundantly in the edges of woods throughout this region, may be seen the _Cimicifuga racemosa_ of botanists, popularly called Rattleweed, or Black Snakeroot. It sends up a stalk, sometimes branching, four or five feet, terminating in a spike or spikes, six to ten inches long, of round, greenish-white buds, which stand upon short stems, and are arranged in rows about the stalk, diminishing in size till they reach the pointed top. The lower buds, when they are about the size of an ordinary pea, open first, and the flowering proceeds by degrees up the spike, so that buds are to be met with throughout a period of from four to six weeks. The flowers emit an intensely sweet odor, which renders them attractive to butterflies and bees.

But should you examine these buds with care, you will find a number of small caterpillars, the larva of the beautiful Azure Butterfly, called _Lycæna pseudargiolus_, feeding thereon. During its younger stages it is white, and so near the color of these buds that it is well protected, and very difficult to find. Later on, it may be white or greenish, and often diversified with a few black or brown patches, irregularly diffused over the surface.

When mature the larva is one-half of an inch in length, and, like all Lycænid larvæ, is onisciform, or shaped like the little pill-bug, so common under stones and logs. The head is very small, and is placed on the end of a long, green neck, which at the junction is of the thickness of the head, but gradually enlarges, and seems to be fixed at the hinder part of the second segment, the latter being hollowed out so as to form for it a sheath. In the final larval stages this segment is elevated, transversely compressed, and inclines forward, thereby shielding the head as the larva moves about. When quiescent the neck and head are wholly retracted, and as the former, when fully extended, is very much longer than the depth of the second segment, it must possess considerable elasticity.

The larva feeds on the heart of the bud, and to reach this cuts away the surface on one side till an opening is made sufficiently large to admit its head; and as it feeds the second segment is firmly pressed against the bud so as to permit the utmost elongation of the neck. Thus it is enabled to eat out the contents of the bud, and only desists when there remains but the empty shell. When so engaged the anterior segments are curved up and the others rest upon the stalk of the plant, but very small larvæ repose wholly in the bud. Not a single instance has been observed where an open flower has been attacked, but the destruction of buds is very extensive.

But now comes the most remarkable part of the larval history of Pseudargiolus. The whole upper part of the larva is covered with small, glassy, star-shaped processes, scarcely raised above the surrounding surface, from the centre of which spring short, filamentous bodies, bristling with feathery-looking tentacles, which the caterpillar has the power of protruding at will. It throws them out like the tentacles of Papilio or the horns of snails. More singular still is an opening upon the eleventh segment, placed transversely and surrounded by a raised cushion, about which the granulations that cover the body of the caterpillar are particularly dense. From the middle of this opening, which is shaped like a button-hole, issues, at the caterpillar’s will, a sort of transparent, hemispherical vesicle, from which is emitted a good-sized drop of fluid, which the animal is capable of reproducing when absorbed.

Larva Feeding on Bud of Black Snakeroot, and Guarded by Ants.]

Four species of ants may be seen attending, not the small larvæ, but those that have attained the nearly mature condition. They are invariably found on or near the larva. Their actions, as they run over the body, caressing with antennæ, evidently persuading the larva to emit a drop of the fluid, are alike curious and interesting. Most of this caressing is done about the anterior segments, and while the ants are thus occupied, or rather, while they are absent from the last segments, the tubes of the twelfth seem expanded to their full extent, and so remain, without retracting or throbbing, until the ants come hurrying along with great excitement and set foot or antenna directly on or close by the tubes, when they are instantly withdrawn. The ants pay no heed to the tubes. They seek for nothing from them, and expect nothing. But they turn at once to the eleventh, caress the back of that segment, and, putting their mouths to its opening, exhibit an eager desire and expectancy. Suddenly a dull green, fleshy, mammilloid organ protrudes, and from the summit of which comes a tiny drop of clear green fluid, which the ants, some two or three perhaps standing about it, lap greedily up. As the drop disappears, this organ sinks in at the apex, and is so withdrawn. The ants then run about, some in quest of other larvæ upon the same stem, some with no definite object, but presently return and pursue the caressings as before. The intervals between the appearance of the globule vary with the condition of the larva. Where exhaustion by long-continued solicitings occurs, some minutes elapse before renewal is effected, the tubes in the meantime remaining concealed. Fresh larvæ, however, require little or no urging, and globule follows globule, as many as six emissions in seventy-five seconds, without even a retracting of the organ. Often the presence of the ant, when the larva is aware of it, evokes, all unsought, the sugary fluid.

Ordinarily the tubes expand when the ants are absent from the last segments, and are certainly withdrawn when they come near. These tubes, from all appearances, serve as signals to the ants. When the latter discover them expanded, they know that a refection is ready, and rush to the opening in the eleventh segment where it is to be found. The tubes certainly serve no other purpose. No visible duct appears in the dome of the tube when largely magnified, and the ants seek nothing from it or the twelfth segment. They cannot be used to intimidate, or to frighten away enemies, for in the younger stages, when the larvæ have the most to dread, neither the tube nor the organ in the eleventh segment is available. The outward openings, and the orifice in the eleventh segment, exist in the youngest larval stages, but are functionless until the larva has nearly attained maturity. Ants seldom attempt to caress or solicit young larvæ, but pass them by with indifference, seemingly knowing that they cannot emit the secretion. When an ant approaches one of these immature larvæ, the larva manifests considerable annoyance, throwing up the hinder segments, as though the ant was an enemy which it was desirous to get rid of. If the tubes could now be thrust out, the ant would be attracted, rather than repelled.

But when the period arrives that the tubes are free, and the secretion is ready to be ejected, which is perhaps just after the third skin-moulting, and it cannot be earlier, the larva grows now quiet and submissive, inviting the attentions of the ants, and rewarding their antennal caresses.

Four species of parasites affect these larvæ. Two are dipterous. These, which are of the size of the common house-fly, deposit their eggs, during the second larval stage, on the back, and near the junction of the second and third segments. In process of time the grubs hatch and eat their way into the larva, to emerge when the latter has become fully grown, thus destroying its life. Another of these enemies is a minute hymenopterous insect, whose egg is placed in the very young larva, probably in the first stage of its life. The grub, in this case, eats its way out of the half-grown larva, spins a silken cocoon, from which in a few days issues the newly-matured parasite. The destruction of larvæ by these, and very likely by other similar parasites, is doubtless immense. But no parasite attacks, it does seem, the mature larva, for, if it did, the grub of the former would live within and destroy the chrysalis, and instead of a butterfly emerging therefrom would come forth the parasite. Multitudes of chrysalids of other species of butterflies are thus destroyed, but Pseudargiolus, at this stage, appears to enjoy a singular immunity from enemies.

Why this species, and doubtless many others of its family, are thus favored, will soon be apparent. Ants may be seen wherever these larvæ may be found, ever ready to receive the honeyed secretion when it pleases the little creatures to eject it, but all the while exercising the closest vigilance lest some wary ichneumon may come along and deal a thrust of its ovipositor, which means misery and ultimate death to their helpless friends. So intent is the larva, with its head buried in the flower, upon its feeding, and so quietly and stealthily does the ichneumon approach its intended victim, that hardly a single individual would be left to tell the story of its existence were it not for the ants. The larvæ know their protectors, it would seem from their actions, and are able and willing to reward their services. The advantage is mutual, and the association friendly. No compelling by rough means on the one part is noticeable, and no reluctant yielding on the other. All demonstrations made by the ants are of the most gentle character. They caress, entreat, and as they drink in the sweet fluid, lifting their heads to prolong the swallowing, they manifest to the utmost their satisfaction and delight. It is amusing to see them lick away the last trace, caressing the back of the segment with their antennæ as they do so, as though they were coaxing for a little more.

In Pseudargiolus the tubes are white, cylindrical, nearly equal in size, rounded at summit, and studded with little tuberculations from which arise the tentacles. These last are tapering, armed with small spurs set in whorls, and stand out straight, making a white hemispherical dome over the cylinder, but none of them fall below the plane of the base of the dome, nor do they ever hang limp or lie across the dome, as is the case in a European species. When the tube comes up the rays rise in a close pencil, and take position as the dome expands; but, on the contrary, when the tube is withdrawn, the top of the dome sinks first, the rays coming together in pencil again.

Larva, Protected by Ants, Feeding on Flower-buds of Dogwood.]

_Lycæna pseudargiolus_ is subject to great variation, and occurs under many forms, most of which having been regarded as distinct species. In the early spring Violacea appears, and is characterized by dimorphism in the female, some of that sex being blue, others black. This form, which may be called the winter form, deposits its eggs in the clusters of flower-buds of the Dogwood, the young larvæ obtaining their first food by boring into the buds, but later on eating their way into the ovaries. The flies that come from these larvæ late in May are Pseudargiolus, which, as stated before, lays its eggs on _Cimicifuga racemosa_, most of the resulting butterflies over-wintering to produce Violacea. A small percentage of the May chrysalids give butterflies as late as September, which are smaller than the parent-form, and also differ therefrom in the more decided character of the marginal crescent discal spots on the under side of the wings. There does not seem to be any regular second summer brood, that is, there are but two regular annual broods, the Violacea of March and the Pseudargiolus of May, the individuals happening to emerge in July, August and September being irregular visitants, for which the name of Neglecta has been given. The females of the last form lay their eggs upon _Actinomeris squarrosa_, and the chrysalids, thence resulting, give Violacea the next spring.

Larvæ feeding on Dogwood vary much in color from those that feed on the Black Snakeroot, few being white in the last stages, but nearly all dull-crimson or green, or a mingling of the two. Nevertheless, a small percentage of the larvæ on _Cimicifuga racemosa_ are also green or crimson, though the most of them white. Ants do not seem to visit the larvæ on the Dogwood, and on being introduced to them in confinement treat them with indifference. On rare occasions tubes have been discovered in the eleventh segment, fully expanded, and accompanied by a pulsating movement, but no teasing or irritating availed to make them appear. Even severe pressure applied to the sides of the segment failed to force out any fluid. As with the fall food-plant, _Actinomeris squarrosa_, the Dogwood is neither sweet nor juicy, and it is possible that the larvæ feeding on these plants do not secrete the fluid.

Eggs of this polymorphic species are round, flat at base, the top flattened and depressed, and have a diameter of one-fiftieth of an inch. Their ground-color is a delicate green, the entire surface being covered with a white lace-work, the meshes of which being mostly lozenge-shaped, with a short rounded process at each angle. In from four to eight days the egg hatches into a larva, which is scarcely one-twenty-fifth of an inch long, and whose upper side is rounded, the under being flat. On each side of the dorsal line is a row of white clubbed hairs, with similar ones at the base and in front of the second joint, making a fringe around the body. The head is very small, obovoid, retractile and black; the legs retractile, and the color a greenish-white or brownish-yellow.

The first moult occurs in from three to five days, the larva having increased to twice its former length, while very little difference is manifest in the coloration. In from three to five days the caterpillar has again changed its skin, doubled its length, assumed more pronounced colors, which are diversified in some with mottlings upon back and sides, and developed along the back, from the third to the tenth joint, a low, broad, continuous, tuberculous ridge, cleft to the body at the junction of the segments, the anterior edge of each joint being depressed, the sides incurved. The third moult takes place in three or four days more, but there is very little change from the former period. Three or four days subsequent to this change occurs the fourth or final moult, and in five or six days from this the larva is ready to pass into the chrysalis state.

In its mature form the larva is about one-half of an inch in length. The body is onisciform, flattened at base, furnished with retractile legs, and has the back elevated into a rounded ridge, which slopes backwards from the sixth segment. The sides are rather deeply hollowed, and in the middle of each segment, from the third to the eleventh, is a vertical, narrow depression. The last segments are flattened, the last of all terminating roundly, its sides being narrowed and slightly incurved, while the second segment is flattened, arched and bent nearly flat over the head. Standing on the body is a ridge, tubercular in nature, which in each segment from the third to the eleventh is distinct and cleft to the body. In color, specimens vary. Some examples are white, others decidedly greenish, but many have the posterior slope of the second segment black or dark brown, while a few have most of the back a dark brown, irregularly mottling a light ground, or with small brown patches diffused over the back, but mostly on the anterior segments. The entire surface is velvety. This appearance is caused by minute stellate glossy processes, scarcely raised above the surface, mostly six-rayed, and sending from the centre a concolored filamentous spine a little longer than the rays. These stars are arranged in nearly regular rows, and are light, except in the brown patches, where both star and spine are brown. This velvet-like condition of the skin only reveals its true composition under a magnifying glass.

On the eleventh segment, near the posterior edge of the back, is a transverse slit, in a sub-oval spot, from which proceeds a membranous process; and on the twelfth, on each side, is a mark like a stigma, but a little larger, from which proceeds a membranous tube, ending in a crown of feathery tentacles, these three special organs being exposed or concealed at the will of the larva. The head is small, obovoid, dark brown, and is placed at the end of a long, pale green, conical neck, which is rectractile, both neck and head being covered by the second segment.

Before changing to a chrysalis, the summer larvæ sometimes turn pink, and from pink to brown, or become brown without the pink stage, although others remain white or change to rusty brown. The body contracts to about three-tenths of an inch and takes on a rounded form.

The chrysalis is dark-brown or yellow-brown, but varying in color, the wing-cases being dark or green-tinted. Two sub-dorsal rows of blackish dots are found on the abdomen, and sometimes a dark dorsal line. In the few instances in which the butterfly emerges the same season the duration of this stage is from thirty to sixty days, but most chrysalids pass the winter and mature in the spring.

Larva Feeding on Central Florets of Actinomeris, and Guarded by Ants.]

Now for a description of the butterfly. In general terms, the upper side of the wings of the male is a deep azure-blue, with a delicate terminal black border. On the apical part of the fore-wings the fringes are black, but white and barred with black on the rest of these wings and on the hind-wings. In the female the fore-wings have a broad, blackish outer border, in some examples extending along the costa, while the hind-wings have a blackish costa and a row of dark spots along the outer margin. Usually the ground-color is a lighter blue in the females than in the males. A pale silvery gray, with a silky lustre, is the color of the under side of the wings, which is relieved by a row of spots along the outer margin, each preceded by a crescent, a curved row of elongate spots across the disk of the fore-wings, and several spots on the basal part of the hind-wings, all the markings being of a pale brown color. Violacea, the so-called winter form, has the dark parts and crescents on the under side of the wings quite prominent, but they do not, either in the outer border or in the basal portion, coalesce. Pseudargiolus, the largest of the series, there being but three forms in Pennsylvania, expands one and four-tenths inches. The upper surface of the male usually has a terminal border to the hind-wings of the same shade of blue as is visible on the fore-wings, the middle area of the hind-wings being a little paler than this border on the fore-wings. On the under side of the wings the spots are much smaller than on the preceding form. Neglecta, which resembles Pseudargiolus, and has the spots on the under surface small, is a smaller form, never expanding more than one and one-tenth inches. It is a summer form when there is more than one generation in a season, ranging from Canada, through New England to West Virginia and Georgia, and occurring also in Montana and Nevada. Violacea has a more extended limit, being found in Alaska, British America, Ontario, Quebec, New England to West Virginia, and Colorado, while Pseudargiolus ranges from Wisconsin south to Tennessee, and on the east from Pennsylvania to Georgia.

HIBERNATING BUTTERFLIES.

Early in March, and often while the snow yet lingers upon the landscape, may be seen flying in and out among the forest-trees, or lazily meandering along some deserted road through a thicket, the beautiful Antiopa. Her rich crimson dress, so dark that it almost seems black, with its buff-colored, sky-dotted border, serves to distinguish her from her no less interesting, but smaller, sisters of the Vanessa family of butterflies. But the Antiopas you then see are generally ragged and shabby, which is not to be wondered at, when it is considered that it is their last year’s dresses they wear, for late in the preceding August they had their being, and all through the autumn had been exposed to a hundred misfortunes or more while seeking their living.

But with the coming of frost and of cold comes the blighting of flowers. A feeling of torpor in consequence steals over their once bouyant spirits, and into some crevice in a barn or a wood-pile or stone-heap they creep, and there sleep the winter away, till the warmth of the sun from his southward-bound journey returning sets the brown buds a-swelling, when out of their hibernating retreats they leisurely crawl for a flying stroll through the awakening trees. Slow and deliberate their movements are, as though some grave and momentous event were dependent thereon.

Never have I watched such actions, so human-like have they seemed, than the conviction has gone home to my mind that they plainly evinced a thought and a purpose, which had their origin, if not in a brain, at least in one of the several ganglions which largely make up their wonderful and somewhat complicated nervous machinery.

No matter how low in intelligence she may rank, Antiopa has nevertheless, or all experience is at fault, some general ideas of the time and fitness of things. From her gloomy abode in the wood-pile she has emerged, while all the gay butterfly world, barring a few familiar exceptions, is asleep, for a tour of investigation. Her venture is seldom ill-timed, for the violets have preceded her, and from their delicately curved flagons proffer her food and refreshment.

Cool and unhealthful as the mornings are at first, it is not till the sun is nearly overhead that she leaves her retreat, for what of plant-life exists is then, under the full force of his beams, at its very best. Three or four hours a day, with few intervals of rest, she is actively on wing, regaling herself with exercise and food, thus storing little by little her body with some of the strength and vivacity which were hers when the famine of winter overtook her and forced her to retirement, so as the better to prepare for that work, the propagation of her kind, which is the principal, but not the only, aim of her existence. After four in the afternoon her presence is scarce, as she has sought her old, or some other, place of shelter and security.

But when the days have grown longer and warmer, and the trees are arrayed in their livery of green, she is in the fields bright and early, and often ere the dew has disappeared from the grass and the flowers. The most restless of beings she now is. Anon alighting upon a bush for a momentary rest, then off for a dozen or more rods, when the presence of some favorite blossom meets her quick sight and invites her to pause, which she does, but only for a second to quench her thirst. Where willows, or elms, or poplars abound, she is more frequently seen later on in May, but flying more slowly and sedately than ever before. The flowers pass unheeded. She seems in a dream, in a reverie. But all of a sudden she quickens her speed. You look for the cause. There, in the distance, another is seen, just like her in mien, some would-be suitor for her hand and affections. He enters his suit, he pleads his great love, and awaits her sweet pleasure. The answer is brief, and soon by their actions, as high up in the air they circle and circle, caressing each other with strokes of the antennæ, the story is told that his love has been requited. A brief honey-moon of two or three days and the love-scene is over, and the two settle down to the prosy realities of everyday life. The male goes back to his old-time pursuit of rifling the flowers of their honeyed treasures, whilst the female, upon whom devolves the duty of providing for the offspring whom she is never likely to see, looks scrutinizingly about for her favorite trees, the poplar, the elm, or the willow. In her selection of a tree a wonderfully keen discernment is shown, for she seldom, if ever, mistakes her plant-species.

Larva Feeding on Willow Leaf, and Chrysalis Suspended from Twig.]

When a choice has been made, no time is expended in fruitless endeavor. She proceeds at once to deposit her eggs. They are laid in a cluster round the twig, and near the petiole of a young leaf, upon which the newly-hatched larvæ are to feed. The eggs hatch inside of a week into small black spiny caterpillars which, in their early stages, are very social in their habits. Just before the final skin-moulting they separate, each caterpillar living alone, the necessity for food, which their very vigorous appetites now demand, being the impelling motive. In a state of maturity the larvæ are two inches in length. They are black, and minutely dotted with white, which gives them a greyish look. A row of brick-red spots are found down the back, and their body is armed with many black, rather long and slightly branching spines. The head is black, and roughened with small black tubercles.

Having completed their period of feeding, which they do in about four weeks, the caterpillars attach themselves by means of their tails to a fence-rail, a window-ledge, or some such place, and pass into the chrysalis state, which is accomplished in about four days. In this condition they present an odd-looking appearance. The head will be found to be deeply notched, or furnished with two ear-like prominences. The sides are very angular. In the middle of the thorax there is a thin projection, somewhat like a Roman nose in profile, while on the back are two rows of very sharp tubercles of a tawny color, which contrast very markedly in coloration with the dark-brown of the rest of the chrysalis. Fifteen days, when the weather is favorable, are sufficient for the development of the imago, or butterfly. As maturity approaches, the chrysalis-shell becomes quite soft, and the efforts of the imago to free itself from this covering are facilitated by the ejection of a blood-red fluid, which rots the case, while it acts, at the same time, as a lubricant to the emerging butterfly.

When these caterpillars are very abundant, as was the case in the vicinity of Germantown some twenty-five years ago, every fence-rail was hung with chrysalids, as many as a dozen being found upon a single rail. The caterpillars even climbed up the sides of the houses and suspended themselves from the window-ledges and the edges of the overhanging shingles. When the butterflies emerged, great blotches of the fluid bespattered the fences and houses as though the clouds had rained great drops of blood. The willows and poplars were alive with the caterpillars, and even the maples were overrun when there came a scarcity of the leaves of the natural food-plants. Green caterpillar-hunters were everywhere plentiful, and the writer could have taken hundreds of specimens, but these highly-useful beetles made a very sorry attempt in holding the enemy in check.

Two broods of the caterpillars are raised, one in June and the other in August, but the agencies by nature employed for their destruction so effectually accomplish their mission that hardly a season brings to my notice a dozen full-grown larvæ. _Vanessa antiopa_, as this species is called by the scientific student, or Mourning-Cloak by people and amateurs, is generally found through the whole of North America. In England, where it is popularly called the Camberwell Beauty, because specimens were first taken near Camberwell, it is the rarest of butterflies; while on the Continent, as in this country, it is a very plentiful insect.

LEAF-CUTTER BEE.

Few hymenoptera of the family of bees are so little known as the Megachilidæ, or Leaf-cutters. They are stout, thick-bodied insects, with large, square heads, and armed with sharp, scissors-like jaws, which admirably fit them for the work they have to do in preparing materials for the building of their homes.

Our commonest species, _Megachile centuncularis_, is about the size of the hive-bee. In gardens and nurseries where shrubbery abounds, it is very prevalent, especially the female, which is readily distinguished by a thick mass of stout, dense hair on the under side of the tail, which serves as a carrier of pollen. The honey- and bumble-bees differ materially from them, for they have the hind tibiæ and basal joints of the tarsi very much broadened for that purpose.

Megachile is by no means a remarkable-looking insect. Judging from its very humble exterior, one can hardly believe it possessed of the wonderful intelligence, as shown in its wise provisions for its young, which it is found to display.

Ordinarily the female, who is entrusted with the discharge of this very essential business, places her nest in the solid earth underneath some species of shrub. A vertical hole, three inches in depth, is dug, and this is enlarged into a horizontal gallery, some five or six inches in length.

You should see the little creature in her never-tiring work of preparing material for her nest. In and out among the roses she goes, examining each leaf with the most critical care, and only desisting from her labor when a suitable one has been chosen. She scans it over and over, and at last from a position on its upper or nether surface proceeds to cut a piece just fitted for her work, which, heavy as it seems, is seized between the legs and jaws and carried on swiftly-agitated wings to her burrow.

Two Tunnels Being Filled With Leaf-Cells.]

Ten pieces or more, each differing in shape, are cut and borne away, which the ingenious insect tailor twists and folds, the one within the other, until is formed a funnel-like cone, whose end is narrower than its mouth. So perfectly joined are the parts, that even when dry they have been found to retain their form and integrity. A cake of honey and pollen, for the use of some yet unborn Leaf-cutter, is deposited within, and on this, in due time, is laid a single small egg. Nought now remains but to wall up the cell. A circle of leaf, of the size of the opening, is cut, and this is closely adjusted within the wall of rolled-up leaves. Sometimes as many as four pieces are thus utilized. A second cell, similarly built, is fitted to the first, and this is succeeded by eight or ten others. When all is completed, the eggs being laid and the cells all victualled, the hole of the shaft is closed with the earth that was thrown out, and so carefully, too, that not a trace of her doings remains to tell us the story.

Like other insects, Megachile is occasionally prone to change. Some laborers while digging, one early spring-day, some thirteen years ago, about a cluster of plants of _Spiræa corymbosa_, a species allied to the roses and cinquefoils, came unexpectedly upon a dozen or more cells of this insect, arranged horizontally in layers, some three or four inches below the ground’s surface. These cells were three-fourths of an inch in length, one-fourth in width, and formed of the leaves of Spiræa. Six circles, of three pieces each, constituted the cell, and these were so arranged that each succeeding circle was made to project but slightly beyond its predecessor. Six circular pieces, larger than seemed needful, closed up the opening of each cell. That there was a purpose here manifested was very apparent. This purpose, as it appeared to the writer, was the better accommodation by the hollow surface of the cell that was to follow, and the giving of greater firmness and security to the entire structure.

More curious, however, were some cells that were found the ensuing year, which, in looks, resembled very closely those of Pelopæus, a species of wasp, familiarly designated the Mud-dauber. These cells, in numbers of three, were adherent to the rafters of a hardly-used garret. In form, and in the peculiar combination of their pellets of clay, they were the exact counterpart of the Mud-dauber’s. But the curious funnel-like arrangement of leaves on the inside, so strikingly characteristic of the Megachilidæ, was evidence of the most positive kind that Pelopæus had nothing whatever to do with their putting together. It bespoke a piece of work that was entirely beyond the highest capability of her being to execute.

Each of the included leafy cells was one and one-eighth inches in length, and just barely exceeding one-fourth in width. Elliptical pieces of Spiræa, less in size than those previously described, but arranged in a similar manner, composed the several structures. Within each, a dead but perfectly-formed Megachile, encased in a cylindrical bag of silk, was found, so that there could be no possible doubt of the builder. That this inner fabric was the labor of some mother Megachile admits not of a scruple, for no other bee is known to construct a nest of like character. But what of the outer enveloping fabric of mud? It was clearly impossible for the skill of a Megachile, who, while certainly fitted for tunnelling the ground and for snipping circular and elliptical pieces of suited dimensions from leaves with all a tailor’s precision, would find herself wofully unadapted for the making of mortar and the building of nests, in imitations of tunnels, out of pellets of mud that had to be moulded into consistency and shape by the jaws of the builder. Pelopæus alone, of all hymenopters, possesses the ability and means of making such structures. Megachile, who is known to occasionally build under the boards of the roof of a piazza, might sometimes in her quest of a place appropriate the discarded cells of some pre-existent Pelopæus for nesting purposes, but she runs a very great risk in so doing, for the Mud-dauber does not always build a fresh home for her treasures, save when there is a lack of the last year’s structures. Old nests, when found, are put in speedy repair and made to do as invaluable a service.

BATTLE BETWEEN ANTS.