190 



Il^SECTS INJURIOUS TO STAPLE CROPS. 



to look ragged, and Avlien these become scarce the tender 

 twigs and bads are attacked. When excessively abundant, 

 like the Boll-worm, the larger larvae develop cannibalistic 



Fig. 106. — Pimpln conquisitor, one of the principal Parasites of the 

 Cotton-caterpillar, a, larvae, enlarged: h, head of same still 

 more enlarged; c, pupa; d, adult female enlarged; e, f, end of 

 abdomen of adult male, still more enlarged. (From Fourth 

 Kept. U. S. Entom. Comm.) 



Fig. 107.— Cotton Worm-moth, a, with wings expanded in flight; 

 h, wings closed, at rest— natural size. (After Kiley.) 



tendencies and often feed upon the weaker caterpillars. 

 It requires from one to three weeks for the larv^ to become 

 full-grown, during whi(jh time it is necessary for them to 

 shed their skins some five times. 



The caterpillar now crawls into a folded leaf, which 



