Part 10

The grubs are hideous hunchbacks, but possessed of brains and stomach. They live in the same localities as their parents, the anxious mother, with wise precision, having carefully deposited her eggs where food would be readily attainable by her children. Have you a desire to examine a larva? There is a hole that has been made by one of these creatures. Place down into it a small straw or a bit of fine twig. The cranky little hermit, who is always wide-awake, resists most fiercely such unprovoked insolence, and instantly seeks, by the aid of his broad, expansive head, to eject the intruding object. Now is your time. When he shows himself, quickly seize him with your fingers. You will find him a perfect Daniel Quilp, with head enormous, flat, metallic in color and armed with long, curved jaws. His legs are six in number, and on the back, half-way between the legs and tail, are two curious, odd-looking tubercles, each terminating in a pair of recurved hooks. The head and first body-division are horny, the rest of the creature being soft and very sensitive.

While the larval Cicindela has all the desire for slaughter which his parents manifest, yet his delicate skin, long body and stubby legs not only prevent him from chasing prey, but also from attempting a struggle with an insect of any size; nevertheless this imperfectly armed creature manages to secure his food without exposing himself to any serious risk. With his short, thick spiny legs he loosens the earth, and with his flat head, which he uses as a shovel, and turning himself into a z-shaped figure, hoists up the clay and upsets it around the mouth of his intended dwelling. With head and legs, and with a perseverance that is truly surprising, he sinks in a very short time a shaft a foot in length and as large in diameter as an ordinary lead-pencil.

Especial pains are taken to see that the tunnel is sufficiently wide, so that the little creature can crawl in with ease. If he wishes to remain set fast, he sticks the back of his body against the sides and rests safely with the aid of his hooks. In this position he can poke his head out of the ground, thus closing the entrance of his burrow, while in patient waiting for some unsuspicious wayfarer to pass over. As soon, however, as the luckless insect touches the top of his head, he relinquishes his hold within the tunnel and descends with great precipitation to the bottom, and thus his victim falls into the hole, where it is seized by the powerful jaws and its juices absorbed in a quiet, leisurely manner. The loose earth around the opening of the tunnel gives way on the approach of an insect, and thus the success of the cunning Cicindela is doubly insured.

Sometimes in the construction of a burrow, after a certain depth has been reached, the young Cicindela meets with a difficulty which he had not expected. A flat stone is encountered, and thus further progress in a vertical direction is prevented. If the obstacle, on account of its size, cannot be gone round, and the shaft is not deep enough for his purpose, it is not unusual for him to desert it and attempt the tunnelling of a home in some more desirable spot. He does not undertake a very long journey, for he knows too well the risk which he runs by so doing, as he is in danger of being assaulted by secret foes in the rear, an attack which the peculiar conformation of his hinder body ill fits him to resist. On land he is timid and cowardly, and well might he be, but within the protecting walls of his underground castle, with a pair of powerful swords with which to defend himself, he is the impersonation of fearlessness and courage.

When fully grown the larva closes up the mouth of its abode, and in quiet and solitude undergoes its metamorphosis, lying dormant during the winter months. But when the breath of warm spring days has melted the icy coldness of the earth, and filled the air with vivifying influences, then comes it forth in all the pomp and splendor of its nature--a winged existence.

It has been seen what a beautiful adaptation of means to an end is shown by the young Cicindela. Even the adult, or mature form, with its long, slender legs, so admirably formed for silence and fleetness of movement, which are alike necessary to pursuit of prey and escape from enemies, displays the wisdom of Him who breathed into all animated nature, no matter how small or how humble, the essence of His being, and endowed one and all with qualities of mind and body which should respond to environing conditions and thus prepare them to survive in the struggle for existence.

QUEEN OF AMERICAN SILK-SPINNERS.

No insect affords a better proof of high art in nature, and of the transcendent beauty of the Creator’s thoughts, than the Luna moth, which is as preëminent above her fellows as her namesake, the fair empress of the sky, above the lesser lights that dominate the night. Her elegant robes of green, set off with trimmings of purple, and jewelled with diamonds, added to her queenly grace and personal charms, will always distinguish her from the _profanum vulgus_ of the articulata.

And now for a short biographical sketch of this remarkable beauty from the cradle to the grave, and beyond, after she has assumed her resurrection-attire, to the day when, her appointed work on earth being ended, she quietly lays her body down to mingle with its native clay.

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.

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.

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.