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. 



No. 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 

 Nos. 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. 



(Dendroctonus 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 



