THE LEPIDOPTERA 



273 



and the larva feeds for 3 or 4 weeks until about an inch and a half long. 

 It is now a nearly naked caterpillar (Fig. 280), somewhat variable in 

 color but generally rather 

 greenish, with a broad dark 

 stripe along its back with a 

 fine, broken, white line along 

 its middle, and a dark stripe 

 along each side. 



Before this size has been 

 attained all the food where 

 these insects are, may have 

 been consumed if the larvae 

 are abundant, and in this case 

 they march off in armies to 

 find new feeding grounds, 

 and it is these marching 

 armies which usually attract 

 attention in July or August. 

 When feeding has been com- 

 pleted they pupate in the 

 ground and the moths emerge 

 in September or October and 

 probably lay eggs which soon 

 hatch, the caterpillars thus 

 produced, feeding to some ex- 

 tent before winter. The 

 spring-feeding generation ap- 

 pears to be little noticed, the 

 destruction seen being by the 

 summer generation. 



When the caterpillars are 

 abundant numerous flies re- 

 sembling, but larger than 

 house-flies, and called *'ta- 

 china flies," are usually 

 noticed flying about the 

 army. These are, nearly al- 

 ways at least, parasites laying 

 their eggs on the caterpillars. 

 The maggots which hatch 

 from these eggs bore into the 

 caterpillars and feed upon and 

 finally kill them. There are also several other insect enemies of the 

 Army Worm. 



18 



Fig. 280. — Army Worm Caterpillars feeding on 

 corn. Natural size. (From Britton, Fourteenth 

 Rept. Ent. Conn. Agr. Exp. Sta. 1914.) 



