HOW TO KNOW THE IMMATURE INSECTS 



40b. Tubercle iii of abdomen with 1 seta. 



Fig. 470 (Utethesia) Family ARCTIIDAE 





Fia 470. Fall webworm, Hy- 

 phontria cunea (Drury). 

 (U.S.D.A.) 



The caterpillars of this family are cov- 

 ered with dense tufted hairs often reddish- 

 brown and black. When disturbed they 

 often curl into a compact mass and are 

 called woolly bears or hedge hog cater- 

 pillars. The cocoon are made of silk and 

 the no-longer-needed body hairs. They 

 feed upon a wide variety of plants. The 

 fall webworm, Hyphantria cunea (Drury) 

 lives gregariously in webs. 



41a. Less than 4 pairs of abdominal prolegs; sometimes anal prolegs 

 reduced. Fig. 471 Family GEOMETRIDAE 



About 2,000 species have been de- 

 scribed. The caterpillars are called 

 loopers, measuring worms, or span- 

 worms because of their methods of lo- 

 comotion. They feed chiefly on living 

 plants but a few are able to subsist 

 upon dry vegetable matter. 



Fig. 471. PolMcrita vernato 

 Peck. 



41b. 4 pairs of abdominal prolegs or more. 



42 



42a. Crochets on prolegs uniordinol. 

 Fig. 472 



42b. Crochets on prolegs biordinal or 

 triordinal. Fig. 473 52 



Fig. 472. Uni- 

 ordinol crochets. 



Fig. 473. o, Biordinal crochets; b, 

 triordinal crochets. 



43a. Warts rudimentary or absent, or obscured by secondary hairs. . . 44 



43b. At least wart vi (subventral) many haired and distinct; r^econd- 

 ary hairs sparse or absent above prolegs 49 



166 



