14 



CIRCULAR 2 7 0, U. S. DEPARTMENT OF AGRICULTURE 



riety, and is very seldom seen on apple trees. It is primarily a 

 pest of maple trees (fig. 12), as its name indicates, and also lives 

 on grape, boxelder, blackberry, and a variety of other plants. It 

 is a native of Europe, and came to the United States over 100 years ago. 

 The insect is easily recognized by the cottony egg sac which the 

 female produces in the early summer, and which often remains for 

 some time. About 3,000 eggs are laid in this sac, and these hatch 

 dining June and July. The young scales settle on the undersides of the 



leaves, where the male insects 

 mature. The partly grown fe- 

 males, which are oval, flattened, 

 and greenish or yellowish, mi- 

 grate to the twigs in the fall and 

 hibernate there. They complete 

 their growth in the spring, when 

 they are brown, quite convex, 

 and about one-eighth inch in di- 

 ameter. The egg sac is formed 

 gradually, as the eggs are laid, 

 and the females die when ovi- 

 position is complete. There is 

 only 1 generation in a year. 



Applications of oil emulsion or 

 lime-sulfur 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 sulfate (40 percent 

 nicotine) in the proportion of 

 three-fourths of a pint to 100 

 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 combined with an 

 application for the codling moth. 



Fruit Tree Leaf Roller 



The fruit tree leaf roller (Ca- 

 coecia argyrospila (Walk.)) feeds 

 primarily on the fruit and foliage 

 of tne apple, but also on those of most of the other deciduous fruit 

 trees. The small caterpillars, 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 



Figure 13. — Leaf roller injury to 

 apple foliage. 



