90 HEMIPTERA. 



4. Tettigojiite. The female having a sheath 

 or tube projecting from the tail. Antennae 

 setaceous. 



5. Locusta. Having the tail simple, without 

 bristles or tube, with the Antennae fili- 

 form. 



With the exception of those of the first sec- 

 tion, which prey on other insects, all the Grylli 

 are herbivorous. The Achetae feeding chiefly 

 on roots, and the Tettigoniae and Locustae, on 

 leaves. 



It is no longer a doubt that the sharp chirp- 

 ing made by the grasshopper and cricket is ef- 

 fected by friction. When the Gryllus is in- 

 clined to make a noise, it raises its elytra, or 

 wing-cases, till they form a sharp angle with 

 the body, and then rubs them forcibly together 

 with a rapid motion that produces the sound. 

 The insect makes this noise only when in per- 

 fect security. As you approach a grasshopper, 

 the sound diminishes, and ceases entirely when 

 you are too near. 



The most singular insect of this genus, and 



