ORCHARD INSECTS OF THE PACIFIC NORTHWEST 



13 



The young scales settle on the undersides of the leaves, where the male 

 insects mature. The partly grown females, which are oval, flattened, 

 and greenish or yellowish, migrate to the twigs in the fall and hiber- 

 nate there. They complete their growth in the spring, when they are 

 brown, quite convex, and about one eighth inch in diameter. The egg 

 sac is formed gradually, as the eggs are laid, and the females die when 

 oviposition is completed. There is only one generation in a year. 



Applications of oil 

 emulsion or lime-sul- 

 phur solution during 

 the dormant season, as 

 recommended for the 

 San Jose scale, control 

 this insect very well. 

 In July, after the 

 young have settled on 

 the leaves, they may 

 be killed with nicotine 

 sulphate (40 percent 

 nicotine) in the pro- 

 portion of three 

 fourths of a pint to 1 00 

 gallons of water, to 

 which is added 2 or 3 

 pounds of soap dis- 

 solved in water, or 1 

 pound of casein 

 spreader. This spray 

 may often be com- 

 bined with an applica- 

 tion for the codling 

 moth. 



FRUIT TREE LEAF 

 ROLLER 



The fruit tree leaf 

 roller (Cacoecia argy- 

 rospila Walker) feeds 

 primarily on the fruit 

 and foliage of the 

 apple, but also on 

 those of most of the 

 other deciduous fruit 

 trees. The small cat- 

 erpillars, hatching 

 when the buds begin to open, feed on the unfolding leaves, webbing 

 them together and forming a protection for themselves (fig. 13). This 

 webbing often covers the blossom buds, causing considerable injury by 

 preventing normal blooming. As the caterpillars become larger, they 

 roll up one or more large leaves and include some of the fruit in the 

 webbing, making a sort of nest. They feed within this, eating large, 

 irregular holes in the fruit (fig 14) and foliage. In extreme cases they 

 practically defoliate the trees and cause a total crop loss. In regions 

 where much spraying is done for the codling moth and the San Jose 

 scale the fruit tree leaf roller has not been an important pest, but 



Figure 12. 



-Cottony maple scale on maple twig. Twice natural 

 size. 



