The P each-Tree Borer. 207 



minutes into a solution of one pound of whale oil soap to the gallon 

 of water, the temperature of the solution being maintained at from 

 120° to 130° F. The trees were examined five days later and all 

 the borers found " as lively and vigorous as ever." 



Thus it would seem that very hot (scalding or boiling tempera- 

 ture) liquids may sometimes be successfully used in killing peach- 

 tree borers in the tree, but there is danger of injuring or killing the 

 tree, and the method is not so practicable as others on a large scale. 



Bisulphide of carbon. — This is a liquid which evaporates very 

 rapidly and the fumes of which are sure death to animal life. Cook 

 suggested its use against the peach-tree borer in 1880. No one 

 seemed to have tested the liquid, however, until we treated a few 

 trees in 1895. On April ITth, several small trees were selected 

 which were so badly infested that there was a complete ring of the 

 characteristic gum around the base of each. With a sharpened 

 stick four holes were made around one tree, beginning about four 

 inches from the trunk, and extending in a slanting direction toward 

 the roots for a distance of six to eight inches ; seven teaspoonf uls of 

 the liquid were poured into these four holes, and then the holes 

 were quickly stopped up. An hour later, we found three half- 

 grown live borers in the tree and several living angleworms in the 

 soil near the tree. The soil all around the tree smelled very strongly 

 of the fumes. Around another similar tree, we introduced six tea- 

 spoonfuls in the same manner, and three hours later found live live 

 borers in the tree. Around a third tree we injected with the 

 McGowen injector four tablespoonfuls of the bisulphide. The 

 injector was forced into the ground as near the tree as practicable, 

 and straight downward After twenty-four hours we found two 

 living borers in the tree and live angleworms in the soil. These 

 experiments satisfied us that this was not a practicable or effective 

 method for killing the insect. 



About two years ago the liquid was extensively used in the San 

 Jose region of California for the Pacific coast peach-tree borer. 

 One of our correspondents there wrote that " they could not get the 

 liquid fast enough." Thousands of trees were killed, and the craze 

 apparently soon subsided. It must be used with great care around 

 the roots of trees, as has been demonstrated on apple trees in Mis- 



