The Moths and Butterflies 



387 



and wings, relieved by brilliant jiatches of red, yellow, and orange. They 

 are favorites with collectors and, though few in number, are not at all uncom- 

 mon. The larvae feed on the leaves of various plants, but grape and Vir- 

 ginia creeper seem to be specially liked. Vineyards indeed often suffer 

 from the presence in considerable numbers of smoky-moth caterpillars. 

 These caterpillars often show a striking gregarious instinct, massing side 

 by side in lines while feeding. The small black and yellow larvae of Har- 

 risiitd americana, a common Eastern species, may often be found arranged 



Fig. 550. — The bag-worm moth, Thyridopteryx ephemer<ejormis; eggs, larva, pupa 

 bag containing larva, bag containing pupa male moth, (.-\fter Felt; about natural 

 size except the eggs.) 



side by side in single line clear across a grape-leaf. Feeding, when young, 

 only on the soft tissues of the leaves, they skeletonize them; when older, 

 however, they eat everything but the larger veins. When fuU-growTi they 

 disperse, each finding a sheltered spot, where it makes a tough, oblong- 

 oval cocoon of parchment-like silk, in which it pupates. The moth of this 

 species expands one inch, is bluish or greenish black, with orange protho- 

 racic collar broad above and narrow below, and narrow subtranslucent 

 wings. It flies slowly and unevenly during the warmest, brightest hours 

 of the day, frequenting (lowers. H. coracina, found in Texas and .Arizona, 

 expands 5 inch and is all dull black with a bluish tinge on the abdomen; H. 

 metallica, the largest Pyromorphid, found in Texas and Arizona, expands 

 1 1 inches and is lustrous bluish green with orange prothorax. Acoloithus 



