116 MISC. PUBLICATION 273, U. S. DEPT. OF AGRICULTURE 



in such numbers as to become aggressive in their attacks on heakhy 

 living trees. However, such outbreaks are usuallv of short duration 

 and seldom last more than one season. The most frequent damage 



Figure 5G. — The typical galleries of the Oregon pine engraver score the sapwood. 



is in the killing of young replacement trees from 2 to 8 inches in 

 diameter and the top-killing of older trees. 



The adults are reddish brown to nearly black, about one-sixth of 

 an inch in length, and with four small teeth along the margins on 

 each side of the elytral declivity. A typical sample of their work 



