INSECT PESTS AND THEIR CONTROL 985 



being destroyed in order to starve out the bug. Destroy trash where it 

 might hibernate. 



Bur. Ent. Cir. 103. 



The Hop Aphis (Phorodon hamuli, Schr.). — This plant louse is found 

 on the plum in spring, but flies to the hop plant in early summer, where 

 it turns the leaves yellow, causing them to fall. 



Wingless Progeny of Winged Hop Aphids from Alternate Host. 1 



Treatment. — When aphids appear spray thoroughly with 40 per cent 

 nicotine solution diluted 1 part to 800 parts water. 



Bur. Ent. Bull. 111. 



The Hop Plant Borer (Hydroecia immanis, Get.). — The hop plant is 

 attacked in three places by this borer during the period of development of 

 the insect. Early in the season it bores into the tender tips, causing them 

 to droop; after a short time it falls to the ground and bores into the stem 

 at the crown. Later it bores out of the stem and goes below the ground, 

 feeding just above the old roots, where it nearly severs the plant. 



Treatment. — In the spring search for the affected tips and crush the 

 insects in the stem. 



Bur. Ent Bull. 7, p. 40. 



iBur. Ent. Bull. 111. 



