1 84 BULLETIN 407 



finding a female with her ovipositor inserted in a branch of black birch 

 (Betula lenta L.). The same year J. N. Knull, of Harrisburg, reported 

 that he had bred the insect on hackberry (Celtis sp.). At State College, 

 Pennsylvania, the writer has observed this insect running over the trunks 

 of dead pitch pines (Pinus rigida Mill), and has seen the females inserting 

 their ovipositors into crevices in the bark. An examination of such 

 places, however, failed to show that any eggs had been deposited. The 

 writer has taken this insect in shagbark hickory, osage orange, and honey 

 locust. Attempts were made to rear it in elm, but the females would not 

 oviposit in it, even tho no other material was supplied. 



In brief, then, the hickory borer has been reported as breeding in the 

 following kinds of wood: shagbark hickory, black walnut, pecan, butternut, 

 mulberry, honey locust, osage orange, bitternut hickory, elm, wild 

 grape, and hackberry. 



ECONOMIC IMPORTANCE 



The hickory borer is capable of causing considerable damage. While 

 it is never present in very great numbers, and does not attack healthy 

 trees, its work on recently killed, standing trees and on felled timber, as 

 well as on unseasoned products from which the bark has not been removed, 

 makes it of considerable economic importance on account of the value 

 of the wood destroyed. 



It attacks recently killed, standing timber and felled material from 

 which the bark has not been removed. However, the writer has never 

 found it boring in such material after it had been dead for more than one 

 year, altho repeated attempts were made to have females oviposit in 

 such material. It enters not only the trunks of recently dead and felled 

 material but also the branches, even those as small as one and one-half 

 inches in diameter. In fact, it seems to prefer the smaller trees and 

 branches to the large trunks, for the galleries are always more numerous 

 in such material. In all cases the most severe injury is due to the pupal 

 cells which penetrate the larger trunks and branches to a depth of from 

 one to two inches, while in smaller branches they extend to the heart- 

 wood. 



Hickory is particularly injured by this borer, for the sapwood, which 

 until recently has been considered the only part of the tree suitable for 

 the manufacture of vehicles, agricultural implements, and various other 

 commodities, is so riddled by the larval galleries that the manufacturer's 

 profit is considerably reduced, resulting in a higher price for the finished 

 product. Years ago, when the hop industry consumed large numbers of 

 hickory poles, the wood for this purpose was often seriously damaged, 

 especially if it was left standing in the woods during the danger season. 



