The Peach-Tree Borer. 195 



hibernates during the winter, either in its burrow or in a thin 

 hibernacnhnn made over itself on the bork near the surface of the 

 soil. The winter is always spent as a larva or borer, a few of them 

 being nearly full-grown, but most of them being considerably less 

 than one-half grown. In the spring, usually about May 1st in New 

 York, they break their winter's fast and grow rapidly for a month 

 or more, most of them getting their full growth in June. They 

 then leave their burrows and spin about themselves a brown cocoon 

 (figure 48 and g in figure 47) at the base of the tree, usually at 

 the surface of the soil. A few days after its cocoon is made, the 

 borer changes to a pupa (figure 49) in which stage it remains for 

 about three weeks, usually in June in New York. From the pupa 

 the moth emerges, thus completing its life-cycle in a year, fully ten 

 months of which are usually spent as a borer in the tree, the 

 remainder or a little more than a month being spent in the egg, pupa 

 and adult stages. About the middle of July all stages of the insect 

 may be found in some orchards. The above brief sketch of the life 

 of the peach-tree borer will apply in general to most localities in the 

 United States north of Washington, D. C. In Canada the moths do 

 not begin to fly until about a month later, while in the South they 

 appear a month or more earlier, so that the dates in the above sketch 

 will not apply to these regions. 



Its Natural Enemies. 



As the peach-tree borer spends most of its life under the bark 

 beneath the surface of the soil, it is not readily accessible to enemies. 

 But it does not entirely escape, for several insects have discovered a 

 way to include this serious peach pest in everj^ course served to their 

 growing progeny. At least eight different enemies of the peach-tree 

 borer have been found, and all of them are parasitic Hymenoptera. 

 In 1872, the Ichneumon, Pliaeogenes ater Cresson, and a Braconid, 

 Bracon^ n. sp., were reared from the peach-tree borer in Missouri 

 (Insect Life, II, p. 349 and III, 152). In 1880 Comstock recorded 

 that " four species of parasites have been bred from the peach-tree 

 borer the past season — two chalcids and two small Ichneumonids, 

 the one belonging to the genus Ificrogaster and the other to the 

 genus BraconP Dr. L. O. Howard writes us that the Braconid 



