PESTS OF THE HOP CROP. 



127 



the upland usually have less mold ilian p^rowcrs with 

 yards alcjii^- lake shores 



In Oregon, the daniai;e was j^reater in 1890, two 

 years after the introduetiun of the inseet, than it has 

 been sinee, with the possible exception of 1897. In 

 1891 there was less injury than in 1890; 1897 was a 

 year of considerable damage, the extent varying from 

 2 per cent, of the crop in one yard to 95 per cent, in 

 another. The average loss, the state entomologist 



FIG. 63. HOP GRUB 



a, Segment of larva; l, larva; c, pupa; </, adult. All natural size except a. 

 (Author's illustration.) 



(Prof. Cordley) states, was about 33 1-3 per cent. It 

 was fully 50 per cent, in the neighborhood of Corvallis. 

 In Washington the damage has been more or less 

 constant since 1890. I am informed by Prof. Piper, 

 state entomologist, that some of the best hop growers 

 in the state of Washington grow A i hops with but one 

 spraying, using whale-oil soap and quassia chips, while 

 others spray two or three times. In the Yakima val- 

 ley, he states, the summer heat is so great that the 

 louse succumbs to it. although it may be abundant 

 early in the season, and it has not been necessary to 

 spray in that region, which, by the way, is irrigated, 



