ALLIES OF THE RED-LEGGED GRASSHOPPER 19 



the anterior wings and rubbing the rasp of the right wing 

 against the scraper of the left. Fig. 8 shows one of the 

 species common in the eastern United States. 



The mole crickets (Gryllotal'pa, Fig. 9) are burrowing in- 

 sects, which show interesting adaptations to subterranean 



Position 

 of scraper 



Rasp 

 Fig. 8. Cricket 



-'Attachment 

 of wing 



A, female (natural size) ; B, under surface of right wing of male, showing struc- 

 tures for producing sound 



life. The fore legs are thickened and adapted to burrowing. 

 Roots are easily cut in two by means of a shear-like motion 

 of the joints of each front tarsus against the teeth of the 

 tibia of that leg. For this reason mole crickets, when numer- 

 ous, are sometimes 

 a serious pest. The 

 female mole cricket 

 watches over her eggs 

 and, when they are 

 hatched, feeds the 

 young till the first 



molt. Mole crickets are found both in America and Europe. 

 Cockroaches. The cockroaches are cosmopolitan forms, 

 some of which infest our houses, where they feed on both ani- 

 mal and vegetable matter. They are dark-colored, flattened 

 insects, which depend upon their legs for escape, although 



Fig. 9. Mole cricket. (Slightly enlarged) 



