Page:Insects - Their Ways and Means of Living.djvu/321

 CATERPILI.AR AND THE MOTH

to live under trying circumstances she grants it some safeguard against destruction. The web-spinning habit is one which, as we shall see, these caterpillars will develop to a much greater extent later in their lives, for our little acquaintances are young tent caterpillars. They are round most often among woodland trees, on the chokecherry and the wild black cherry. But they commonly infest apple trees in the orchards, and for this reason {heir species has been named the apple-tree tent caterpillar, to distinguish it from

related forms.that do hOt com- monly inhabit cultivated fruit trees. The scientific name is ,lla/acosoma americana. The egg masses of the tent caterpillar moths are not hard to find at this season. They are generally placed near the t"lps of the twigs, which they appear to surround, and being of the same brownish color as the bark, they look like swollen parts of the twigs themselves /Plate 4 A, Fig. 244A). Most of them are five-eighths to seven-eighths of an inch in length and ahnost hall of this in width, but they vary in thickness with the diameter of

FIG. I43. Young tent cater- pillars on the egg mass from which they have just hatched. (I_- rimes natural size)

the twig. A closer inspection shows that the mass really clasps the twig, or incloses it like a thick jacket lapped clear around. In fcrm the masses are usually sym- metrical, tapering at each end, but some are of irregular shapes, and those that have been placed at a forking or against a bud have one end enlarged. The greater part of an egg mass consists of the cover- ing material, which is a brittle, fihny substance like dry mucilage. Some of it is often broken away, and some-

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INSECTS