582 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



applied from the time the buds commence to swell until the 

 first blossoms, has also been widely and successfully used. 

 The wash should be applied as late as possible before blossoming. 

 Recently Mr. E. P. Taylor has shown * that in western Colorado 

 the larvae are very readily killed by arsenate of lead, 3 to 5 pounds 

 per barrel, applied just as the buds are beginning to open. The 

 arsenate of lead must contain no soluble arsenic, or it may burn the 

 foliage. This treatment is given at the same season as the lime- 

 sulfur wash and is much easier to prepare and apply. 



The Peach-tree Bark-beetle f 



The peach-tree bark-beetle is very similar in both appearance 

 and habits to the fruit-tree bark-beetle, and may be readily 

 confused with it. It is a native insect which attacks only peach, 

 cherry and wild cherry, and so far has been injurious only in 

 western New York, northern Ohio, and the Niagara district 

 of Ontario, though it occurs from New Hampshire to North 

 Carolina and west to Michigan. 



"When the beetles are present in large numbers their injury 

 to the tree is quickly brought to the attention of the orchardist 

 by the large amount of sap exuding from the trees through the 

 many small borings made both in the trunk and limbs of the 

 tree. . . . The adults or beetles produce the primary injury to 

 healthy trees, the work of the larvae being secondary. The healthy 

 trees, by repeated attacks of the adults, are reduced to a condition 

 favorable to the formation of egg-burrows. When the beetles 

 are ready to hibernate in the fall they fly to the healthy trees and 

 form their hibernation cells. These latter are injurious to the 

 trees, for through each cell there will be a tiny flow of sap during 

 the following season." When the beetles emerge in the spring 

 they bore into the bark of healthy trees and later leave them to 

 form egg burrows in sickly trees. From these numerous burrows 

 the sap issues in large quantities and in many cases forms large 

 gummy masses around the trees. After three 6r four years of 

 such injury the tree is so weakened that the beetles form their 

 egg burrows beneath the bark and the larvae soon finish its 



* E. P. Taylor, Bulletin 119, Colo. Agr. Exp. Sta., p. 8. 

 t Phlceotribus liminaris Harris. Family Scolytidce. See H. F. Wilson, 

 Bulletin 68, Part IX, Bureau of Entomology, U. S. Dept. Agr. 



