PESTS OF THE TTOP CROP. 



131 



the leaves of whole fields The rather slender, green 

 caterpillars make their appearance in the latter part 

 of May, feed upon the substance of the leaves until 

 full-grown, and then form thin, imperfect^ silken 

 cocoons within a folded leaf or in a crevice or shel- 

 tered spot, transforming to chrysalids and issuing as 

 moths three weeks later. There are two annual gen- 

 erations, the second brood of caterpillars being found 



FIG. 64. HOP VINE SNOUT-MOTH 



a, Egg; t, larva; J, pupa; /, nu 

 and liair li 



moth, 

 iiies. 



All fiilarged; Jiatural size Indicated by dots 

 (Author's illustration.) 



Upon the vines in August. The insect hibernates in 

 the moth stage. 



HOP MERCHANTS ( Poli/fj07iia interrofjationis, Godart, 

 and Pubjgonia comma, Ilarr.) 



These are common, widespread, and, in the adult 

 stage, handsome butterflies, occurring in most parts of 

 the eastern United States, and in the caterpillar stage 

 feeding not only upon the hop, but also upon the elm 

 and several other closely allied plants. They have 

 derived their name of "hop merchants" through 

 the goM and silver markings upon the chrysa- 

 lids, which occasionally, probably through para- 

 sitism, become sufTused and give a general gold- 



