ORCHARD INSECTS OP THE PACIFIC NORTHWEST 



59 



CONTROL 



Lead arsenate, 3 or 4 pounds to 100 gallons, should be used for 

 controlling the beetle on prunes. It is most effective if used just 

 before and just after blooming, and it may be added to the fungicides 

 used at that time for the control of brown rot. A third application, 

 when the husks have fallen, may be necessary if the infestation is 

 severe. 



CATERPILLARS 



The caterpillars of various moths often become injurious to prune 

 trees in western Oregon and Washington. These caterpillars are 

 most likely to be the tent caterpillars, fall webworms, or caterpillars 

 of tussock moths. A discussion of these insects will be found on 

 pages 38 to 40. 



PEACH TWIG BORER 



Prune trees are attacked by the peach twig borer in much the same 

 manner as peach trees. The brown worms bore into the tender new 

 growth, causing the 

 leaves to wilt, and 

 later thev feed in the 

 fruit. The life his- 

 tory and control of 

 this pest are given 

 on page 61. 



PEACH INSECTS 

 GREEN PEACH APHID 



A serious reduc- 

 tion of the peach crop 

 is sometimes caused 

 by large numbers of 

 green peach aphids 

 (Myzus persicae Sul- 

 zer) (fig. 70) in the 

 opening blossoms. 

 These sucking insects, by removing the juices from the newly formed 

 fruit, may cause it to drop. They also curl the leaves badly and 

 prevent them from developing normally. It is important, therefore, 

 that control measures be taken early, as little or no injury occurs 

 later on. The green peach aphid came from Europe and is common 

 in all of the peach-growing districts of the West. 



LIFE HISTORY 



The glossy black wintering eggs may be found on the twigs, in the 

 axils of the buds, and in the crevices of the bark. They hatch early 

 in the spring, and the pinkish young commence feeding at once on 

 the opening buds, pushing their way into the unfolding blossoms and 

 between the developing leaves. The second and third generations 

 are green, and the latter acquire wings and migrate to summer food 

 plants, which include many of the common vegetables and ornamental 

 plants, such as cabbage, cucumber, lettuce, potato, tomato, turnip, 

 carnation, chrysanthemum, snapdragon, and violet. In the fall 

 winged forms return to the peach and produce a wingless generation 

 that lays the overwintering eggs. 



Figure 70. — Green peach aphids on pear foliage. 



