ONE OF OUR COMMON INSECTS.
BY W. SAUNDERS, LONDON, ONT.
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(Continued from page 11, No. 1.)
FIG. 3.
When the little caterpillar of the Cecropia Moth has eaten its way out of the egg, and makes its first meal on the empty egg-shell, it presents itself to us as a little, slim, black creature, with shining black knobs on its body, from which arise hairs of the same color. Being blessed with an excellent appetite, its growth is very rapid; and soon its skin becomes uncomfortably tight, when it is ruptured, and after much labor the little thing wriggles itself out of it; which process is repeated several times before the caterpillar attains its full growth. After each of these changes, or moultings, as they are called, the larvæ appears in an altered as well as an enlarged garment, and finally, when full grown, it attains the size and assumes the appearance presented in Fig. 3, and a very handsome creature it is. Its body is of a pale green color, and is ornamented with large warts or tubercles; these are coral red on the third and fourth rings of the body, while all the others are yellow, excepting those on the second and terminal segments, and the smaller tubercles along the sides, which are blue.
FIG. 4.
FIG. 5.
During its rapid and enormous growth it consumes an immense amount of vegetable food, and especially as it approaches maturity is its voracious appetite apparent. Where one or two have been placed on a young apple tree, they will often strip it entirely bare before they have done with it, and greatly damage the tree, and sometimes endanger its life by preventing the proper ripening of the wood.
FIG. 6.
FIG. 7.
The natural ratio of increase of this insect being very great, nature has provided means to curtail it. Being a somewhat conspicuous object, the larvæ sometimes serve as a dainty meal for some of the larger insectivorous birds, but is much oftener attacked and destroyed by parasites of several distinct species, all of which, in the larvæ state, live within the body of the caterpillar, and rioting on its substance finally occasion its death. One of these is shown in Fig. 4, a fat, legless grub or maggot, which is the progeny of a handsome four-winged fly, of a yellowish brown color, known as the long-tailed ophion fly, (Ophion Macrurum,) Fig. 5. The female fly deposits her eggs on the skin of her victim, fastening them firmly there; these, when hatched, eat their way through the exterior, and at once begin to feed upon the fatty parts within.
A two winged fly, known as a Tachina fly, very similar if not identical with the species known as the red-tailed Tachina fly, Exorista Militaris, figure 6, is often found infesting the Cecropia Caterpillar. The larvæ of this fly are of a translucent yellow color, and when mature, eat their way out of their victim and change to the chrysalis state under the ground. There are also two smaller species of parasites, known as Chalcis flies, which are destructive to this insect; one of these, (Chalcis Maria,) is shown in Fig. 7, much enlarged, the cross lines at the side showing the natural size.
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