224 Peach-Growing 



versity Experiment Station concluded that the simple ex- 

 pedient of mounding up the soil about the base of the tree 

 was one of the most effective and satisfactory methods of 

 prevention. Trees so treated contained markedly fewer 

 borers than others not so treated. Why this should follow 

 is not apparent,.'since the eggs are laid more or less at random 

 on the trunk. 



After trying many washes, gas tar proved in Slinger- 

 land's experience the most effective of any in keeping out 

 the borers, and it caused no injury to the trees. However, 

 others have reported considerable injury under some con- 

 ditions, hence its use in any particular orchard or region 

 cannot be advised until after its effect on the trees has been 

 thoroughly determined by experiment. 



Any preventive measure to be effective must be applied 

 prior to the time when the moths begin to emerge in any 

 considerable numbers in the spring and be continued until 

 the period of egg-laying is ended, which is two to three 

 months later. However, there appears to be no method of 

 prevention which is sufficiently effective to eliminate the 

 necessity of digging out the borers. 



When they are at all troublesome, "worming" should 

 be done twice a year, — in the fall towards the close of the 

 season and again early in the spring. The second time is 

 for the purpose of finding any borers that may have been 

 overlooked in the fall. In this operation the soil is re- 

 moved from about the base of the tree to a depth of 6 or 8 

 inches. Then by carefully scraping the bark with a knife 

 or other suitable implement, the burrows can usually be 

 located without difficulty. To reach the borers, consider- 

 able cutting of the bark and sapwood may be necessary; 

 but if done carefully and the channels followed closely. 



