THE GRASSHOPPER 



23 



sects, and hence are useful to agriculture. 

 To the Heteroptera also belongs the bed- 

 bug, a loathsome human parasite, most 

 of whose near relatives hve in flowers. 

 Thus out of the Heteroptera, a prevail- 

 ingly herbivorous group, there have 

 arisen, through the acquisition of new 

 habits, certain carnivorous forms,- and 

 finally certain parasitic ones. The ex- 

 treme case of degeneration in this series 

 is the family of lice, which have become 



1 )c 1 manent 



Fig. 19. — The assassin 

 bug, Rcduvius. Black. 

 Nat. size. Photo. f:)y 

 \¥. H. C. P. 



Fig. 20. — Cicada seplemdecem, the 

 se^-en teen-year locust. Reduced. 

 Photo, by V. H. L. 



])aa.sites, being unaltle to eat 

 anx'thing except the liciuid or 

 ^( miliquid food afforded by their 

 ' hosts." 



The Homoptera include insects 

 of very diverse size and form. 

 1 he largest are the cicadas, or 

 ' locusts" (Fig. 20), some of 

 w Inch have the remarkal)le habit 

 of 1 equiring thirteen or seventeen 

 ■sears for their development. 

 ( onsequently these cicadas ap- 

 ]K ar only at intervals of thirteen 

 oi seventeen years. The eggs 

 are laid in t-\vigs, the young drop 

 to the gTOund, bury themselves, 

 and live by sucking juices from 

 the roots of trees. Eventually 

 they come to the surface, leave 



