Nature biographies; the lives of some every-day butterflies; moths; grasshoppers and flies . ating up nearly all their sub-stance. About two weeks after the eggs are laid, theparasitic larvae change to pupae, and soon afterwardagain change to adults. These caterpillars are also subject to the attack of cer-tain bacterial diseases which are often very destructive,especially during w^et seasons. And sometimes whensmall they are killed off in enormous numbers, by latefrosts. It has frequently been pointed out that one of thegreatest services which birds render to man is that of 54 A Devastator of
Nature biographies; the lives of some every-day butterflies; moths; grasshoppers and flies . ating up nearly all their sub-stance. About two weeks after the eggs are laid, theparasitic larvae change to pupae, and soon afterwardagain change to adults. These caterpillars are also subject to the attack of cer-tain bacterial diseases which are often very destructive,especially during w^et seasons. And sometimes whensmall they are killed off in enormous numbers, by latefrosts. It has frequently been pointed out that one of thegreatest services which birds render to man is that of 54 A Devastator of Forests. concentrating their attack upon outbreaks of injuriousinsects. In this respect they are hke a great standingarmy that, on short notice, can be mobiHzed upon anypoint where danger threatens. Although these foresttent caterpillars are protected from many birds by theirhairy coverings, they furnish a good illustration of thevalue of birds in such emergencies. Careful observa-tions upon this phase of the recent outbreak were madein Vermont bv Miss Caroline G. Soule, who kindly com-. Fig. 58. — Cast Skins of Poorest Tent Caterpillar. municated to me the results. A surprising number ofbirds were seen feeding upon the caterpillars, the listincluding robins, orioles, chipping sparrows, cat-birds,cuckoos, three species of vireos, cedar-birds, and nut-hatches. The latter were particularly useful, as theywould stand by a patch of larvae, lying close togetherbelow^ a tar band on a tree, and eat so voraciously, andwith such an entire abandonment of self-consciousness,that I could go close and put my hand on them beforethey would fly. This experience was repeated several 55 Nature Biographies. times. During the last season that the caterpillarswere abundant Miss Soule wrote: I am almost surethe caterpillar has drawn the birds here; for in foursummers I have never seen nearly so many as this year,though I have been observing birds for years. Toomuch cannot be said for the birds. T
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsects, bookyear1901
