The Peach-Tree Borer. 



213 



The tobacco was applied about a month too early in 1894, wliich 

 may explain much of the difference in the results for that year 

 from the two following years. Note that the percentage of 

 untreated trees which were infested during the last two years is 

 from four to live times larger than the percentage of infested 

 treated trees. This indicates that tobacco kept out from two-thirds 

 to iiv^e-sixths of the borers during 1895 and 1896, which is decidedly 

 a good showing for the method. In fact, but very few other appli- 

 cations gave us as good results. Tobacco stems can usually be 

 obtained very cheaply from cigar manufacturers, and when thus 

 available the evidence indicates that they can be depended upon to 

 greatly aid the peach-grower in his light against this insect. 



We are not sure just how the tobacco stems act on the insect. 

 It is doubtful if they act as a mechanical barrier, and we are also 

 loath to believe that their odor is offensive to the insect. Perhaps 

 the liquid leached out of the stems by rains may kill the young 

 borers. 



The mounding method. — This consists in simply hilling uj) 

 the soil around the base of the tree. It was one of the lirst 

 methods devised and has been extensively practiced by peach-grow- 

 ers for a hundred years. Perhaps no other method has been so 



