BUTTERFLIES and gnats, bees, ants, flies, crickets, and many other insects, have inspired writers of poetry or prose; but up to the present time, as far as we know, no one has made the caterpillar his theme. Yet, closely examined, many of the caterpillars are well-nigh as gorgeous in their raiment as the most beautiful of butterflies. The caterpillar is free from the flippancy and vanity of the butterfly—who spends by far the greater portion of its life in play and flirtation; it has business to do, and does it conscientiously, and is indeed a character to be admired, save in the matter of the destruction of choice vegetables, for which, after all, its mother, who deposited the egg upon them, is, in fact, solely responsible. The caterpillar is infinite in its variety of hue, but chiefly affects black, ashen grey, and white, bright greens, yellows and browns with rich bands or blotches of white, yellow and scarlet, and indeed almost every variety of brilliant colour. Sometimes it is soft, smooth, and hairless; at others covered with a short, thick, silken coat like velvet; and occasionally bristling with long, stiff hair, a very porcupine among its fellows. Caterpillars from the time they are born give evidence of the possession of two predominant faculties, the one an all-devouring appetite; the other, the knowledge of constant danger and the efforts to escape the eye of their teeming foes. This they do in accordance with varied instincts inherited from progenitors.

Some will hide on the under side of a leaf, others will eat into its substance, and establish themselves a domicile between the outer and inner tissue, proceeding at once to enlarge their house and to satisfy their appetites. Others, on the approach of danger, will curl themselves up, and drop to the ground, trusting to fortune to fall between two clods of earth, but, in any case, shamming death until the danger has, as they believe, passed away. Another kind, a greyish-brown in colour, and rough and knobby of skin, will stand upright, imitating so exactly the appearance of a little bent twig, that the keenest eye would fail to detect the difference; while a great many caterpillars guard themselves against unpleasant surprises by establishing themselves from the first in a place of concealment, and there passing the greater portion of their lives. When, as not unfrequently happens, the chosen hiding-place is in the heart of a bud just beginning to form, the results are naturally the death of the flower, and extreme exasperation upon the part of its owner. There is nothing pugnacious about the caterpillar, all its means of defence being more or less passive in their character. A not inconsiderable section no sooner leave the egg than they set to work to form themselves a shelter by turning over the edge of the leaf, and fastening it with silken threads, so as to form at once a house and a hiding-place. Lastly, there are the caterpillars who live in communities, and establish a rampart against their foes by throwing round their dwelling-place a thick curtain of silken threads, through which their insect foes cannot break, while even birds seem to hold it in high respect.

The mission of the caterpillar may be considered as two-fold: he has to reach the chrysalis stage, from which he will emerge as a butterfly or moth, and then perpetuate his species; and he is an admirable machine for the conversion of vegetable matter into a form in which it can be digested and relished by birds. He stands to the feathered world, indeed, in exactly the same position that the ox and the sheep occupy in relation to man. Although partial to seeds and fruits, birds are not vegetarians in the broad sense of the term, and many would starve had they nothing but leaves, whether of the rose or the cabbage, to devour; the caterpillar then comes to the rescue, and forms the intermediary link. He possesses an appetite of extraordinary voracity, and in the course of his not very long life eats many hundred times his own weight of vegetables, and converts them into a rich and luscious food for the birds. It may be said that, in some respects at least, the instincts of caterpillars must be defective, or, knowing that their plumpness is their danger, they would eat less. This is no doubt true, but as it is true also of sheep and bullocks, it can hardly be made the subject of reproach to the caterpillar.

But, after all, vast as is the number of caterpillars who go to feed the birds, it cannot be said that birds are by any means their chief enemy. Their great foe and relentless exterminator is the ichneumon, against whom none of their cunning devices of concealment avail, for he can discover them unerringly in their inmost lurking-places. The ichneumon varies in size as greatly as does the caterpillar himself. Some of them are as long as wasps, although with a slender body, no thicker than a bodkin; some so tiny that they can scarce be seen with the naked eye; but all are alike in their habits. Watch one, large or small, as he settles upon a leaf. Straightway he begins to hunt up and down with quick eager motion, like a dog quartering a turnip field for partridges. Up and down, below and above, prying into every cranny, he hunts, hurrying from one leaf to another until he finds a caterpillar. He wastes no time with him, but thrusts the long ovipositor through the skin, and places an egg there snugly. He repeats this two, three, or half a dozen times, according to his own size, and that to which the caterpillar will grow. His young ones must be fed where they are hatched, and it would not do to lay more than the caterpillar can support. What the sensations of the caterpillar are when thus treated no one has so far attempted to explain. It gives a little wince each time the operation is performed, and then pursues its vocation as quietly as if nothing had happened. There can be little doubt that it is profoundly discouraged; it must feel that all its efforts to elude the foe have been wasted. It doubtless knows that it has received its death wound, that it will never soar in the air as a bright-winged butterfly, and that its chrysalis state will be its last. It speaks well, then, for the sense of duty of the caterpillar, that it goes as doggedly on as before, eating as largely and steadily as if nothing had occurred, and showing no sign of pain or disturbance at the birth of foes, who soon begin to gnaw away at its interior. It is to be hoped, indeed, that it suffers but slightly. The organs of the caterpillar are simple. It is little more than a tube, and it is probable that its sensibility is slight. Still it is inevitable that it must suffer more or less; but it goes on until, just as it is about to assume the chrysalis state, or shortly after it has done so, it dies, and the little ichneumons make their way through its skin, and, after a brief repose, fly away to recommence the deadly work of their parents. It is calculated that fully 80 per cent. of caterpillars are slain by ichneumons.

The caterpillar is distinguished for its imperturbable good temper; no one has yet witnessed a good stand-up fight between two of them. Even when browsing in hundreds upon a leaf, each caterpillar continues its work of eating, wholly regardless of the multitude feeding around it. Its fellows may press it on every side, or walk across its back, without its evincing the slightest sign of irritability, or even dissatisfaction. It may be said that, after all, this host are its brethren, and that the nearness of the family tie produces this feeling of universal benignity. But family ties are not always found to have this effect, even among human beings, and, moreover, the caterpillar’s good temper and forbearance extend to individuals of entirely different species and families. The largest caterpillar coming across a small one makes no attempt to bully or interfere with it, and the whole race appear to be imbued with a spirit of admirable courtesy and gentleness.

The caterpillar, in confinement, develops qualities of a quite distinct nature to those which it exhibits in the wild state. The silkworm caterpillar, for example, is intolerant of noise of any kind, and the most absolute silence is maintained in the feeding house. It is not that noise excites irritability or anger, but it fills it with such disgust that it falls ill and speedily dies. Gardeners would be gratified, perhaps, were the wild caterpillar equally susceptible; as, in that case, two or three discharges of a gun would extirpate the whole race throughout the extent of a garden. The caterpillar is clearly worthy of much greater attention and study than it has yet received; and as we are told to look to the ant and the bee as examples of patience and industry, so we may advantageously take a lesson of courtesy and good temper from the hitherto little regarded caterpillar.