132 
THE SCOLYTID BEETLES. 
National Forest, and in the Holy Cross National Forest, Colo., and 
at Encampment, Wyo., in 1907. Additional localities through cor- 
respondence and from collections are: Ephraim and Alta, Utah; 
Meeker, Silver Plume, Argentine, Glenwood Springs, and Leadville, 
Colo.; Capitan, Lincoln National Forest, and Las Vegas, N. Mex.; 
Calgary, Alberta Province, and Glacier, British Columbia. It is 
represented in the forest-insect collection of the Bureau of Entomology 
by more than 200 specimens. 
BIBLIOGRAPHY. 
Packard, 1877 (under Dendroctonus obesus), p. 803; Hopkins, 1906a (under D. 
piceaperda), pp. 4-5; Hopkins, 1907 (under "The Engelmann spruce beetle"), pp. 
161-162; Hopkins. 1909, pp. 130-133. 
Xo. 16. THE ALASKA SPRUCE 
BEETLE. 
(Dendroctonus borealis Hopk. Figs. 83, 84.) 
The Alaska spruce beetle resem- 
bles closely in general characters 
the eastern spruce beetle, but is 
smaller, and is distinguished by the 
coarser punctures of the pronotum 
being more regular in size. (See 
fig. 83.) 
This species is represented in 
the collections by but four speci- 
mens, two in the United States Na- 
tional Museum collection, labeled 
"Alaska/' and two in the forest- 
insect collection of the Bureau of 
Entomology, collected by Mr. W. 
H. Osgood from white spruce at 
Eagle, Alaska, in August, 1903. 
Nothing further is known about 
this species, but it will probably 
be found that its habits and life 
history are similar to those of 
Xos. 14 and' 15. . 
Fig. 83.— The Alaska spruce beetle (Dendroctonus 
borealis): Adult. Greatly enlarged. (Author's 
illustration.) 
BIBLIOGRAPHY. 
Hopkins, 1909, pp. 133-135. 
No. 17. THE SITKA SPRUCE BEETLE. 
(Dendroctoiius obesus Mann. Figs. 85, 86.) 
The Sitka spruce beetle is a large, stout, black, cylindrical bark- 
beetle 6 to 7 mm. in length, with broad convex head, the sides of 
pronotum narrowed and constricted toward the head, and surface 
