GILDED BUTTERFLIES AND DUSTY MOTHS
The butterflies and moths, whose beauty attracts more collectors than any other group of insects, constitute the order Lepidoptera, the meaning of which term is "scaly winged," in reference to the fact that the hairs that clothe and ornament the wings are scalelike. Butterflies have club-shaped antennæ, and belong to the division Rhopalocera. Moths are Heterocera. Some of the moths, especially the males, have feathered antennæ, some threadlike, while a few tropical ones have "club" antennæ, so that this distinction is not perfect. The pupæ of butterflies are not protected by cocoons, as are those of most moths, and are usually called "chrysalides" (singular, "chrysalis"). Butterflies in general only fly during the daylight, when few moths are stirring, and usually hold their wings erect when at rest, while moths hold them flat or folded against the body.
The Lepidoptera undergo a complete larval metamorphosis, and the process is more familiar to general readers than in the case of other insects. From the eggs, which are often objects of great beauty when examined through a lens, are hatched wormlike creatures that grow rapidly by repeated moltings of the skin into full-sized "caterpillars"; those of certain moths develop in community nests, but ordinarily they live singly. All have three pairs of thoracic legs, and a variable number of temporary "prolegs" near the rear of the body. Caterpillars may be smooth, round, and colorless, or coated with a heavy fur, or bristling with knobs, tufts of hairs, and other appendages, and brightly ornamented with color; and many of these peculiarities appear to be wholly defensive in purpose. Some caterpillars give off, when alarmed, disgusting and acrid fluids, and the hairs of others irritate venomously the skin of anyone handling them, and probably account for the fact that few birds will touch certain species. All caterpillars feed voraciously—in fact, this is the only time in the life of many species when food is taken, the adult moths and butterflies as a rule being neither willing nor able to eat. At a certain time, having completed its final molt, the caterpillar arranges itself according to the custom of its race, and subsides into a pupa.
| CATERPILLAR OF THE MILKWEED BUTTERFLY |
| (Anosia plexippus.) (Smithsonian Institution.) |
A century ago men interested in butterflies spoke of themselves as aurelians, explaining that "aurelia" was a proper name for the butterfly pupa because of the golden ornaments it usually bore. Really, however, this characteristic, so marked in the gilt "buttons" of our common milkweed butterfly, pertained to only a single family—the Nymphalidæ. When the nymphalid caterpillar reaches the turning point, it withdraws the abdomen a little from the cracking skin, exudes a little sticky silk which it fastens to its support, then hooks the tip of its abdomen firmly into this silk; this done, hanging thus by its tail, the caterpillar finally shakes off its coat and, as a chrysalis (a Greek word of the same general sense as the Latin aurelia) the pupa hangs, head down and inert, until the following spring.
The butterflies of greatest size and most splendid coloring belong to the family Nymphalidæ, whose hundreds of species are scattered all over the warmer parts of the world. Here belong those gorgeous tropical ones, whose wings, sometimes with a spread of five inches, emulate the prismatic hues of the "eyes" in a peacock's tail, and which are so often seen mounted as lovely ornaments in curiosity shops; and here also is classified that strange "leaf butterfly" of Malaysia, whose wings when closed so perfectly imitate a leaf of the tree on which it alights that the sharpest eyes can hardly find it. Here, too, belong our brown-streaked "fritillaries," such as the vanessas, and darker ones like our mourning cloak, and many others well known to amateurs.
| FINAL MOLTING OF A NYMPHALID CATERPILLAR |
| (a) Before shedding skin. (b) In act of shedding skin. (c) Trying to catch hold of silk button. (Smithsonian Institution.) |
All of this family have their chrysalides hung by the tail; but in the remainder of the butterfly families they are held in an upright position by a loop of silk that passes around them like a girdle. Such are the "coppers," the "blues," the "hair streaks" and many other small, gayly colored species (Lycænidæ) common in summer, to which season they add so beautiful an interest. In another large family, the Papilionidæ, are found the great yellow and black "swallowtails," which are almost exclusively American, and several dark blue or purple-marked species, with "tails" to their wings, that attract the attention of the most careless as they lazily flit among the flowers. In this family, too, are the sulphur-yellow butterflies that dance over the roads and fields in little flocks; and, alas, the white ones whose caterpillars are so injurious to cabbages and similar vegetables. The last family (Hesperidæ) contains small, rather obscurely marked, butterflies that connect the Rhopalocera with the Heterocera, or moths.
| Photo, A. N. Mirzaoff |
| CATERPILLAR BEGINNING ITS COCOON |
In fact the distinction between the two divisions of Lepidoptera is one of convenience rather than of science, for it marks difference of habits rather than of structure. Instead of a naked pupa, that of the moth is inclosed in some sort of envelope called a "cocoon." This may be an earthen cell underground, or a woolly tuft fastened to some such support as the bark of a tree, or a leaf rolled and tied by silken threads into a tube, or a burrow in dead wood, or a paperlike case fastened to a twig; but in every case some special provision is made for the easy emergence of the imago when the time comes for its birth as a moth. The moths themselves do no harm. Their few weeks of life are devoted entirely to mating and putting their eggs in just those places where the larvæ they will never see can have the food proper for them and the best chance for life—a matter of marvelous instincts and adaptations. Few of them, except the hawk moths, eat at all. That is done in the caterpillar stage, when many sorts become destructive of the labor and hopes of the farmer and gardener and orchardist, or make havoc in stores of grain and meal, and in garments of wool and fur, carpets, and cabinets of natural history specimens.
| Photo, A. N. Mirzaoff |
| MOTH AND EGGS |
Most of the moths are small, inconspicuous, grayish or brownish creatures whose markings, very lovely when closely examined, so closely resemble in their mottlings the places where the moths rest during the day, that they are comparatively safe from the birds, monkeys and other enemies that seek to catch and eat them. Some, however, are of large size and brighter hue. Thus the silkworm moths of the Orient (and of our own land) may measure four or five inches across the outstretched wings, as does the cecropia and others that flit about evening lights; and a near relative among us is the exquisite, long-tailed, luna moth, which is pale green with chestnut edgings; many others in this group are almost as "richy bedight" as butterflies. It is these that make the large papery cocoons so easily seen in the fall in trees and bushes.
A remarkable family (Bombycidæ) is that of the hawk moths, which much resemble in shape and action humming birds. They are day flyers, but most active in the morning and evening twilights, and hover on whirring wings before a flower, while with their long, tubular tongues they suck its nectar, for these moths feed as well as do their fat, uprearing, bulldoglike caterpillars, to which they owe another common name for the family—that of sphinx moths. Their pupæ are lodged under, on, or near the ground in a loose cocoon, and are to be recognized by an appendage, curled around like a jug handle, in which lies the chrysalis' long tongue.