BlLLETIX 228] 



PEAR THRIP9 AND PEACH TREE BORER. 



373 



damage by boring long distances, often completely girdling the trees. 

 Gum flows as a result of this injury and is a fairly reliable indication 

 of the presence of the large "worms." Unfortunately there is nothing 

 to show the presence of the small "worms." 



The full-grown larvce are about one inch long and the diameter of a 

 slate pencil. They have white bodies and dark brown heads. When 

 ready to pupate, they seek places from which the moths can easily 

 issue and construct about themselves cocoons from the chewed-up wood 

 and bark. The cocoons are light brown capsule-shaped bodies, slightly 

 larger than the "worms." They may be found under the bark, in tlie 

 bark, or in the ground an inch or more from the tree. 



The usual method of combating the peach borer is to dig out the 

 "worms" during the winter season, but often the knife causes more 

 damage than the borers, especially if the digging must be done con- 



FiG. 6. — The asphaltum treatment for the peach tree borer. 



«ecutive years or by careless workmen. In the fall the soil is removed 

 from the base of the tree to a depth of six or eight inches and the borers 

 dug. In the spring they are dug again and the soil replaced. The 

 second digging is necessary because in the fall manj^ of the "worms" are 

 too small to be found. 



Many preparations are being used on the trunks of trees ; some to 

 keep the moths from depositing eggs, some to prevent the "worms" 

 from entering, some to kill the "worms" after they have entered. None 

 of these have been wholly satisfactory. Experiments along these lines 

 by the writer led to the use of hard asphaltum, grades "C" and "D." 

 with good results. This was applied early in the spring to badly infested 

 trees from which the borers had not been dug. It was found that a 

 thick heavy coating prevented both the issuance and the entrance of 

 about 95 per cent to 98 per cent of the insects, the degree of efficiency 

 •depending upon the thoroughness of the application. Asphaltum does 



