ARTHROPODA. 245 



depositing them on food in crawling over it. Mankind 

 will undoubtedly wage a war of extermination on both 

 flies and mosquitoes during the next generation. 



FIG. 91. Stages in the development of the botfly (Gastrophilus equi). See also 

 Fig. 33. After Brehm. a, adult insect; b, egg attached to a hair; c, d, and e, stages in 

 the development of the larva. 



Questions on the Figure. Review the habits of this fly. What 

 are the special adaptations structures and instincts that fit it for 

 its mode of life? 



262. The Coleoptera (Beetles). This is probably the 

 largest group of the insects. There are said to be 100,000 

 known species. The beetles are easily recognized by the 

 fact that the front pair of wings are hardened and serve 

 as covers for the real wings. The mouth parts are well 



