48 



HABITS AND NATURAL HISTORY. 



The species is double brooded, hibernating in the butterfly condition 

 and laying its eggs late in May or early in June. On account of this 

 comparatively early oviposition, the caterpillars of the first brood are 

 rarely found upon the hop, and the eggs are therefore laid upon some 

 one of the other food plants of the insect, which mainly belong to the 

 family Urticarial, and comprise, for the most part, elm, hackberry, 

 nettle, and false nettle. From late flyers of the hibernated adults, 

 however, a few eggs may be laid upon the hop plant, but iu general 

 this first brood of caterpillars plays no part in hop culture. The eggs 

 laid upon the other food plants, however, hatch in from four to eleven 

 days, the larvae growing rapidly and passing from eleven to fourteen 

 days in the chrysalis, and finally emerging as butterflies in July. 



These fly until the 

 middle of August, 

 laying their eggs 

 late in July and all 

 through August. 

 In hop-growing re- 

 gions eggs of this 

 brood of butterflies 

 are laid mainly upon 

 the hop plant, and, 

 as before stated, in 

 certain seasons are 

 numerous enough to 

 badly rag the leaves, 

 and in this way to 

 appreciably reduce 

 the vitality of the 

 plant. A number 

 of successive years, 

 however, may occur 

 in which the larvre are comparatively scarce. The butterflies from this 

 generation of caterpillars begin to appear toward the end of August 

 and continue to emerge from chrysalids until the end of October, the 

 chrysalis state in this brood lasting sometimes as long as twenty-six 

 days. These butterflies hibernate. 



In the South there are said to be three broods, and according to Mr. 

 W. H. Edwards there may be four or five in Florida. The eggs, which 

 are shown at fig. 37, are usually on the under surface of the leaves, 

 although occasionally upon the upper, and sometimes upon the stem, 

 the tender terminal leaves being preferred. They are laid either singly 

 or in hanging columns of 2 to 8, 3 or 4 being most common. 

 The caterpillars may occasionally be more or less gregarious. While 



Fig. 37. — Polygoniaivterrogationis: a, egg chain ; b, larva; c, chrysalis; 

 d, adult— all natural size except a which is greatly enlarged (original) . 



