INSECTS IXJrRIorS TO THE HOP-PLANT. 277 



suddenly in large numbers and rapidly eating the foliage 

 over a large area. 



They are not known to have any other food-plant than 

 the ho]) and hence are only found where that plant occurs, 

 though specimens have been taken from almost all sections 

 of the United States, southern Canada, and British 

 Columbia. 



Life-history. — It seems probable that the moths hiber- 

 nate over winter, as they emerge in the fall, and lay eggs 

 for the first brood early in the following ^i^j. The eggs 

 are of a pale-green color, and are deposited upon the under 

 surfaces of the leaves, sometimes several upon a single leaf. 

 The larv^ emerging from them become mature late in 

 June and early in July. When full-grown the larvge are 

 slightly less than one inch long, and *^of a green color, 

 marked with two longitudinal white lines down the back, 

 a dark-green line in the middle between and an indistinct 

 whitish line on each side of the body. The head is green, 

 spotted with black piliferous dots, and similar dots occur 

 on each segment, arranged in two transverse rows."* 



Before pupating the larva sjDins a thin silken cocoon, 

 either among the leaves, under the bark of the poles, or 

 at or slightly under the surface of the ground, various 

 observers having noted them in all of these positions. 

 The pupal stage occupies about ten days, and the moths 

 emerge from the cocoons early in July. Another brood 

 follows with a similar life-history, the moths emerging 

 late in August and in September and probably hibernating 

 over winter. 



* "Hop-insects," L. O. Howard, Bull. No. 7, n. s., Div. Ent., 

 U. S. Dept. Agr. 



