90 THE SCOLYTID BEETLES, 
collections and through correspondence , are Piedmont and Keystone, 
Wyo.; Pokegama, Ashland, and Washington National Forest (Port- 
land), Oregon; Columbia Falls, Lewis and Clarke National Forest, 
Saltese, Missoula, Medicine Bow National Forest, Lolo National 
Forest (Iron Mountain) , and Big Four, Mont. : Coeur d'Alene National 
Forest and Weiser National Forest, Idaho. It is represented in the 
forest-insect collection of the Bureau of Entomology by more than 
500 specimens, including all stages and work. 
BIBLIOGRAPHY. 
Hopkins, 18996 (under Dendroctonus n. sp.), pp. 15, 26; Hopkins, 19016, p. 67; 
Hopkins, 1902c, p. 21; Hopkins, 1903a, pp. 59-60; Hopkins, 1904 (under ''mountain 
pine Dendroctonus"), pp. 19, 42, 45; Hopkins, 1905, p. 1; Uebb,1906,p. 22; Hopkins, 
1909, pp. 105-109. 
Xo. 10. THE BLACK HILLS BEETLE. 
(Dendroctonus ponderosse Hopk. Figs. 51-59.) 
The Black Hills beetle is a stout, black, cylindrical barkbeetle, 
4 to 7 mm. in length, with head broad and without frontal groove, 
but with slight longitudinal impression above or behind the middle; 
the prothorax short, broad, and punctured, the sides narrowed and 
slightly constricted toward the head; the elytra with moderately 
coarse rugosities between the rows of punctures, which are usually 
distinct on the sides, and the declivity, which bears a few long hairs, 
slightly impressed each side of the middle line, the impressed striae 
narrow, and the interspaces broad and roughened with sparsely 
placed, coarse granules. (See fig. 51.) The adult beetles attack 
living and sometimes injured and felled, yellow pine, lodgepole pine, 
limber pine, Mexican white pine, white spruce, and Engelmann 
spruce from the Black Hills, South Dakota, to southern Arizona, 
and westward into Utah, and are very destructive. The parent 
beetles excavate long, nearly straight, longitudinal egg galleries 
(fig. 52) through the inner living bark and groove the surface 
of the wood on the main trunk (figs. 53, 54). The eggs are placed 
at quite regular intervals, or more often arranged in groups of four 
or five along the sides. The short, broad larval mines and trans- 
formation cells are exposed in the inner bark and mark the surface of 
the wood; the short, whitish, grublike larvae (fig. 51) transform to 
pupae (fig. 51), usually exposed in the inner bark, and the broods 
usually work independently of other species and occupy exclusively 
the greater part of the bark on the main trunks of the trees. The 
attack causes pitch tubes (figs. 55, 56) on the trunk of the infested 
trees in the summer and fall, and the leaves fade and turn yellow 
and red the following season during the period from May to August. 
