36 



THE HOP APHIS IN THE PACIFIC REGION. 



The cost of stripping the vines preliminary to spraying will be from 

 $1.80 to $2 per acre. 



The cost of spraying for the hop aphis, although apparently great, 

 is nothing compared to the losses which result from neglect to spray 

 for this insect. 



Thorough spraying is, then, a good business policy and should be 

 carefully done by all commercial hop growers. 



CULTURAL METHODS. 



CLEAN CULTURE. 



Suckers growing between the rows and vines growing over fences 

 and near-by trees usually have much dense foliage, due to the growth 



Fig. 8.— Short-pole hopyard, showing dense foliage around base of vines, which harbors the hop aphis. 



(Original.) 



of several plants upon a limited area, and form an ideal breeding place 

 for the aphides. Such plants may form a constant source of infesta- 

 tion and should be promptly removed. 



STRIPPING THE VINES. 



One of the most important cultural methods now in use is stripping 

 the vines to a point about 4 feet above the ground (fig. 8). This 

 removes the suckers and dense foliage, which protect and foster the 

 aphides, from around the base of the vines. Experiments show that 



