188 NORTH AMERICAN INSECTS. 



while the}' conceal themselves during the da}', and 

 their depredations only are visible. But if by night 

 we examine our cabbage, cauliflowers and turnips 

 with a lantern, we sha*ll often find them covered with 

 a host of these noxious individuals. 



Many of the caterpillars live like hermits, a solitary 

 life, and pay no attention to their brothers and sisters, 

 whilst on the contrary, many species are real socialists, 

 and build in common their comfortable silk dwellings, 

 with which, if not prevented by man, they sometimes 

 cover entire trees. Here they live, and feed together 

 at regular hours, as for instance, the tent Caterpillar 

 (Clisiocampo americana, Harris,) on apple, pear, or 

 cherry trees, and by such confraternities the trees of 

 an entire orchard are ruined, unless the destructive 



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intruders are destroyed in April or the beginning of 

 May. 



Single parts of Caterpillars. 



Head. — The head of a caterpillar is horny, of a glo- 

 bular or oblong form : it contains a mouth with an up- 

 per and under lip, between which are sharp horny jaws, 

 with which they cut transversly the leaves, beginning 

 at the margin. They cut with their jaws as easily and 

 in the same manner as we do with scissors. 



Although we cannot distinguish in them any organ 



