250 WEST VIRGINIA EXPERIMENT STATION. 



the Spruce. The spruce bark beetle is by far the most abund- 

 ant of any of the species of the family to which it belongs 

 throughout the spruce region in this State. It appears in enor- 

 mous numbers in all sections in which timber cutting opera- 

 tions are carried on. As previously stated, its occurrence in 

 such vast numbers, together with other evidence obtained in 

 1890, with reference to its habits, seemed to warrant the con- 

 clusion that it was the species of all others which was <o blame 

 for the great destruction of spruce timber in 1883 to 1885. 

 While we have no additional evidence that this was so, it is 

 evident from what has been determined of the habits of the 

 species, that with a combination of favorable conditions, it may 

 have been one of the prime causes, if not the prime cause, of 

 the trouble. Its habits of gradually entering the inner bark, 

 first by excavating the nuptial chamber in the outer layer of 

 the inner bark, and then entering obliquely to the inner layer 

 and extending the preliminary gallery across the bark fibers, 

 indicates clearly that it has acquired this peculiar habit of at- 

 tack through efforts to overcome the resistance met with in the 

 bark of living trees, and that should it attack such trees in suf- 

 ficient numbers, it would easily accomplish this end. The con- 

 stant and abundant supply of stumps and tops m the extensive 

 cuttings of spruce since 1885, however, offered every desirable 

 condition for it to breed to its utmost limit without the neces- 

 sity of resorting to living trees, and as long as active timber 

 operations are continued in the spruce, there is little danger of 

 an invasion from this beetle. Should, however, the destructive 

 pine bark beetle, or an insect with like habits again invade the 

 spruce, this spruce bark beetle would prove its most powerful 

 ally in the destruction of the timber. 



Methods of Combatting this Enemy and Preventing Loss from 

 Possible Future Depredations. As already stated, the present 

 extensive cutting of timber is an effectual preventative against an 

 invasion by this insect, but if in the future it should, from a 

 series of favorable conditions, attack the living timber, serious 

 loss can be prevented, and the trouble abated, if not checked, 



