40 College. of Forestry 
the base of the trees. This species is capable of extensive 
depredations on the largest and best larch, but apparently 
prefers to infest injured, dying and felled trees,” 
The winter is passed principally in the adult stage, within 
the inner bark of trees and stumps in which the larve have 
spent the preceding summer. Activity begins with the first 
warm weather in the spring. There is apparently but one 
generation annually, although under certain circumstances 
there may be at least a partial second generation. The larvee 
of the first generation begin to transform to the adult stage 
at Crittenden during August, and by the first of September 
practically all the brood are callow adults. 
In our work this species was taken during three successive 
seasons but in each year was found only in one tree. In the 
springs of 1915 and 1916 the wintered-over brood was found 
under the bark of the lower part of the trunk associated with 
Polygraphus rufipennis. No pitch tubes were seen and while 
the egg galleries in many cases did contain some pitch, there 
was not evidence of a copious flow of the material. In mid- 
summer, 1917 (July 24), a large larch tree was observed 
which had numerous streams of pitch from one to seven 
inches long running down the bark. No pitch tubes were 
present but this material came from recently made burrows 
of D. simplex. On examining the inner bark, many dead 
bodies of the adults were found embedded in the pitch which 
completely filled many of the egg galleries. Other egg gal- 
leries had been kept free of pitch i the work of the adults. 
The larvee were nearly full grown but no pupze were observed. 
This tree was about one foot in diameter. <A strip of bark 
about ten inches wide and five feet long had been removed 
from one side. The tree was still quite green but had made 
practically no growth during the season. The streams of 
pitch were present upon the ‘bark from the base to a height 
of about fifteen feet. A few -—— but only a few — burrows 
of Polygraphus rufipennis were found on this tree but the 
attack of this insect seemed to have been unsuccessful on 
account of their inability to combat the excessive flow of 
resin. In Tree No. I also P. rufipennits was found associated 
