Page:Popular Science Monthly Volume 50.djvu/518

500 also live over winter beneath chips or bunches of leaves near the roots of their food plant, or in webs of their own construction, which are woven on the stems close to the buds whose expanding leaves will furnish them their first meal in spring.

Many insects pass the winter in the quiescent or pupal stage; a state exceedingly well fitted for hibernating, requiring, as it does, no food, and giving plenty of time for the marvelous changes which are then undergone. Some of these pupæ are inclosed in dense silken cocoons, which are bound to the twigs of the plants upon which the larvae feed, and thus they swing securely in their silken hammock through all the storms of winter. Perhaps the most common of these is that of the brown Cecropian moth, the large oval cocoon of which is a conspicuous object in winter on the twigs of our common shade and fruit trees. Many other pupæ may be found beneath logs or on the under side of bark, and usually have the chrysalis surrounded by a thin covering of hairs, which are rather loosely arranged. A number pass the cold season in the earth with no protective covering whatever. Among these is a large brown chrysalis with a long tongue-case bent over so as to resemble the handle of a jug. Every farm boy has plowed or spaded it up in the spring, and it is but the pupa of a large moth, the larva of which is the great green worm with a "horn on its tail," so common on tomato plants in the late summer.

Each of the winter forms of insects above mentioned can withstand long and severe cold weather—in fact, may be frozen solid for weeks and retain life and vigor, both of which are shown when warm weather and food appear again. Indeed, it is not an unusually cold winter, but one of successive thawings and freezings, which is most destructive to insect life. A mild winter encourages the growth of mold which attacks the hibernating larvæ and pupæ as soon as, from excess of rain or humidity, they become sickly; and it also permits the continued activity of insectivorous mammals and birds. Thus, moles, shrews, and field mice, instead of burying themselves deeply in the ground, run about freely during an open winter, and destroy enormous numbers of pupæ; while such birds as the woodpeckers, titmice, and chickadees are constantly on the alert, and searching in every crevice and cranny of fence and bark of tree for the hibernating larvæ.

Of the creeping, wingless creatures which can ever be found beneath rocks, rails, chunks, and especially beneath those old decaying logs which are half buried in the rich vegetable mold, the myriapods, or "thousand-legs," deserve more than passing notice. They are typical examples of that great branch of the animal kingdom known as arthropods, which comprises all