40 



GENERAL ZOOLOGY 



the eastern United States seem to show that, so far at least 

 as the birds are concerned, these repellent odors are not in 

 all cases entirely effective, since many species of plant 

 bugs are fed upon quite generally by various kinds of birds. 



a, 



Fig. 24. The chinch bug 



adult insect ; b, egg ; c-f, stages in development of the nymph ; wheat plant 

 with eggs on lowermost leaf and with nymphs on stems. (After Forbes) 



Chinch Bug. The chinch bug (Blis'sus leucop'terus, Fig. 24) 

 is one of the worst enemies of the grain growers of the Mis- 

 sissippi Valley. Agricultural authorities estimated that in 

 one year (1914) the chinch bug alone caused a loss of more 



