180 Bulletin 176. 



may be to protect the borers from the gummy mass, thus giving 

 them a more comfortable home during the winter. In exceptional 

 cases we have seen nearly full-grown borers in winter curled up in a 

 hibernaculum on the outside of the bark, just at the head of their 

 burrow, which had become filled with the gummy mass. But usually 

 in New York the larger borers hibernate in their burrows beneath 

 the bark and the smaller ones, those less than half-grown, pass the 

 winter in hibernaculums on the outside of the bark in the gummy 

 mass ; there are exceptions, however, in both cases, as just noted in the 

 case of the larger borers, and some of the small ones apparently hiber- 

 nate on the bark or in the gummy mass without any hibernaculum. 

 This peculiar method of hibernation of the smaller borers is of con- 

 siderable importance economically, as several northern peach-growers 

 have discovered that they can quickly remove most of the borers a 

 safe distance from the trees during a warm spell in winter by simply 

 hoeing away the exuded gum from around the base of the trees. 



The peach-tree borer apparently eats nothing during the winter, 

 at least in the Northern States. 



Habits of the horers in the spring. — In the latter part of April, 

 1895, we found that some of the borers had already awakened from 

 their long winter's nap, and had broken the winter's fast by begin- 

 ning to feed on the bark. Yet some of them had not awakened or 

 begun feeding by May first, but still lay curled up in their hiber- 

 naculums. Climatic conditions in the spring will doubtless vary 

 these dates somewhat, but usually the borers cease hibernation and 

 begin feeding earlier than this in the spring, possibly feeding nearly 

 all winter in the extreme South. 



As the borers usually hibernate, either in hibernaculums at the 

 upper ends of their burrows, made the preceding summer and fall, 

 or in their burrows, they oftentimes simply begin work in the spring 

 where they left off to go into hibernation. The smaller borers often 

 feed over an irregular area in the outer bark, but soon burrow into 

 the inner bark and gradually excavate a burrow from one-half to an 

 inch or more wide and two or more inches long, just under the 

 outer bark in the inner bark and sapwood.* At w 5, in figure 46 is 



* Smith (1898) states that the borers "travel little and simply keep a clear 

 chamber about them, mostly cut out of the bark, and in this they lie, subsisting 



