128 
THE SCOLYTID BEETLES. 
cases the insects have first killed the timber, and the fire has then 
followed (see fig. 81), leaving the charred trunks and logs as apparent 
proof that the fire alone was responsible. 
In August, 1905, Supervisor A. W. Jensen, of the Manti National 
Forest, Utah, reported much destructive work by a beetle which 
proved to be this species. He stated that in some sections 20 per 
cent was then attacked or killed, including both the Engelmann 
spruce and the blue spruce. 
In August, 1906, Mr. Harry Gibler reported that all of the matured 
Engelmann spruce of the White River National Forest, in Colorado, 
was more or less affected by a beetle which the writer identified as 
this species. In response to a request for more detailed informa- 
FiG. 79. — Engelmann spruce evidently killed by Engelmann spruce beetle about 1853-6; pitch-marked 
galleries common on trunk. Pike National Forest, at elevation of about 10,000 feet. (Original.) 
tion, Mr. Gibler, in a letter dated November 13, 1906, wrote as 
follows : 
There is no portion of the reserve on which they are especially active, but are more 
or less over the entire area. In some places as much as 90 per cent of the mature 
timber is already dead and in some localities as little as 2 per cent seems to be affected, 
and in this connection I would state that so far the oldest trees, and that which is 
classed as strictly mature timber, have been affected. 
In the Twentieth Annual Report of the United States Geological 
Survey, p. 137, Mr. G. B. Sudworth states: 
There is a considerable quantity of dead standing spruce mingled with the green 
timber. It extends in an interrupted irregular narrow belt from the region of Deep 
Lake and Carbonate westward to the headwaters of East Elk Creek. The dead tim- 
