ORCHARD INSECTS OF THE PACIFIC NORTHWEST 



35 



consists of irregular surface feeding or a series of small holes in the 

 skin (fig. 41). Sprays used for controlling the codling moth on apple 

 and pear usually prevent this insect from becoming a serious pest on 

 these fruits (p. 5). If additional control is 

 necessary, lead arsenate, 3 pounds to 100 

 gallons, may be added to the pink spray of 

 lime-sulfur solution which is often used for 

 scab or mildew, or the lead arsenate may be 

 used alone at this time. 



Flatheaded Borers 



Two species of flatheaded borers, the flat- 

 headed apple tree borer (Chrysobothris femo- 

 rata (Oliv.)) and the Pacific flatheaded borer 

 (C. mail Horn), occur in the orchards of the 

 Pacific Northwest, They are very similar, the 

 adult beetles (fig. 42) being flattened, and dark 

 greenish blue or dark bronze with coppery 

 spots. The larvae or borers are most often 

 injurious to young trees, particularly those weakened from sunburn or 

 other causes. They are waxy white, about an inch long when full- 

 grown, legless, and with the fore part of the body broad and flat (fig. 

 43). The beetles emerge in the spring and lay eggs on the tree trunks, 



Figure 41. — Holes in an 

 apple made by larvae 

 of the eye-spotted bud- 

 moth. 



Figure 42. — Flatheaded apple 

 tree borer (adult). X 3. 



Figure 43. 

 tree borer. 



-Flatheaded apple 

 Slightly enlarged. 



preferably in the sun. The young borers burrow into the bark and 

 require a year or more for complete development. Both species are 

 native American insects. 



Trees should be kept in a resistant, healthy condition, as the 

 young borers are unable to thrive in vigorous trees with strong-flowing 

 sap. If the trunks of young trees are protected with whitewash, 

 or if a board or stave is placed so that it will shade the trunk, danger 

 of injury will be reduced. 



