The Moths and Butterflies 
387 
and wings, relieved by brilliant patches 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- 
risina americana, a common Eastern species, may often be found arranged 
Fig. 550.—The bag-worm moth, Thyridopteryx ephemera} or mis; eggs, larva, pupa 
bag containing larva, bag containing pupa, male moth. (After 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 full-grown 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 
wrings. It flies slowly and unevenly during the warmest, brightest hours 
of the day, frequenting flowers. H. coracina , found in Texas and Arizona, 
expands f inch and is all dull black with a bluish tinge on the abdomen; H. 
metallica, the largest Pyromorphid, found in Texas and Arizona, expands 
if inches and is lustrous bluish green with orange prothorax. Acoloithus 
