INSECTS INJURIOUS TO STONE FRUITS 653 



The Peach-tree Bark-beetle * 



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

 and habits to the fruit-tree bark-beetle (consult p. 545), 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 dis- 

 trict 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, arc 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 or four years of 

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

 egg borrows beneath the bark and the larva) soon finish its 

 destruction. There are two generations a year, the summer brood 

 appearing in the last half of August and the other hibernating 

 over winter. 



Control. The same methods are advised as for the fruit-tree 

 bark-beetle, which see (p. 546). 



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

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



