PHYLUM ARTHROPOD A 



355 



wheat, oats, corn, timothy, blue grass, and other plants. They mi- 

 grate from one field to another in large numbers, hence their name. 

 The tachina flies 

 parasitize many of 

 them and fungus 

 diseases attack 

 others, so that 

 they are partially 

 held in check by 

 their natural ene- 

 mies. The cotton- 

 worm eats the 

 leaves of the cot- 

 ton plant, 

 boll-worm is 



Fig. 289. — Order Lepidoptera. Codlin-moth, 

 Carpocapsa pomonella. a, adult, b, larva in an 

 The a PPle- c, pupa or chrysalis. (From Farmer's Bui. 

 283, U. S. Dep't Agric.) 



widely distributed and feeds not only upon the cotton boll but 

 also upon corn, tomatoes, tobacco, and other plants. 



The larvae of the Geometrid^e are called measuring worms 

 because of their looping method of locomotion. One of the 

 most important species is the spring canker-worm, Paleacrita 

 vernata (Fig. 288), the larva? of which eat the foliage of fruit 

 trees in various parts of the country. 



The codlin-moth, or apple-worm (Fig. 289), Carpocapsa 

 pomonella (Family Tortricid^e), is the foremost apple pest in 



this country. The annual 

 loss due to this moth is 

 estimated at $11,400,000 

 (Simpson). The eggs are 

 laid upon the young fruit, 

 and the larvae eat their 

 way into the core. 



The family Tineid^: 

 a large num- 



moth, Tinea pdlionclla. a adult, b, larva. ber of smaU moths 



C, larva in case. (From Riley, in Circ. 36, J 



Bur. Ent., u. s. Dep't Agric.) The clothes-moth, Tinea 



Fig. 290. — Order Lepidoptera. Clothes- contains a large 



