254 
NOTE ON HYLESINUS SERICEUS. 
By E. A. Schwarz. 
One of the roost abundant species of scolytid beetles in the Rocky 
Mountains, as well as throughout the Northwest, is Hylesinus sericeus 
Mann. It develops under bark of various species of pine and spruce 
trees, and has no doubt a considerable economic importance, although 
at the present day no attention whatever is paid to the insect enemies 
of our Western forest trees. The beetle is abundant in the magnificent 
forests of the Coast and Cascade ranges in Oregon, Washington, and 
FlG. 25.— Work of Hylesinus sericeus under bark of Picea engelmanni (Mars del.). 
British Columbia, but it would be foolish to speak of it as injurious in 
these regions, since whatever damage it may do sinks into utter insig- 
nificance when compared with the devastations caused by the lumber- 
man. In the Eocky Mountains of the United States, where the forests 
are already considerably thinned out, the injurious work of this and 
some other scolytids of the genus Tomicus becomes much more appar- 
ent, as I recently witnessed myself on a vacation trip through the 
Wahsatch Mountains in Utah. The beautiful pine forests that once 
covered the canyons and higher plateaus have long since disappeared 
