INSECTS AFI-ECTIXC; I'AKK AND WOOULA.V U TKEES 363 



eiitirul)' to the inner l)ark, hut as it. increases in size the saijwootl may be 

 scored, and eventually iht! borer may 1,^0 to some depth in tiie wood, 

 particular])- on the apprfiach of winter. 



This ^rub wlien near maturity is very stront,'- and excavates larj^a-, 

 irregular galleries in almost any clirection in the wood, and has been fr(!- 

 quenll\- met with 1)\- the writ(;r at the: depth of 6 or 8 inches from the 

 surface. He lias seen small balsam trees, 6 inches in diameter, penetrated 

 to the center b\- the grub, which subsec^uently completed its transformations 

 and the beetle emerged on llu! opposite side. This borer works so vigor- 

 ously that it may be heard at night gnawing in the wood. 



The jieriod re(|uired for the completion of the life c\cle is unknown, 

 though mosi writers are of the oinnion that vmder or(linar\- circumstances 

 three years are necessary. 1 )r James Fletcher calls attention to the tindinc- 

 of larva of all sizes in a ])ine which had been killed bv rir-; the j)revious 

 spring and from this he is inclined to believe that under certain conditu)ns 

 the life cycle may be completed in a year. It is known that this time mav 

 be enormously extended, since beetles have been bred out from wood which 

 had been cut 10 to 15 or more )ears before. 



Distribution. This insect, which appears to have a general distribution 

 in pine, spruce and balsam regions, ranges from West Virginia into Canada 

 and, according to published accounts, it appears to be much more abundant 

 to the north. 



Protective measures. \'ery little, or nothing can be done to protect 

 standing trees from attack by this insect, other than the prompt cutting of 

 dying and dead timber. Dr James b'letcher has pointed out that logs may 

 be protected to a considerable extent by covering them with lir boughs so 

 as to shade them from the sun. Probably any other shade wouUl be nearly 

 as effective. The removal of the bark would also aid materiallv in pre\ent- 

 ing the borers from entering the logs. 



Bibliography 

 1857 Fitch, Asa. Ins, X. V. 4tli Rep't, p. 21-24 

 1890 Packard, A. S. U. S. Ent. Com. 5tli Rcp't, p. 686-95 



