12 



THE BLACK HILLS BEETLE. 



of gallery can be confused, namely, the mountain pine beetle, which 

 has not as yet been found in the same region. If it should occur, 

 however, the galleries may be distinguished by the smaller size, more 



Fig. 2.— Work of the Black Hills beetle (Dendroctonus ponderosse. Hopk.). Primary galleries and 

 larval mines in inner surface of living bark: a, entrance and basal chamber; b, ventilating holes in 

 roof of gallery; c, termination. The larval mines radiate from the primary galleries. About one- 

 half natural size. (Author's illustration.) 



crooked and slightly winding course, and by the fact that they are 

 more commonly met with in the silver pine, limber pine, and lodge- 

 pole pine. Whenever the Black Hills species is found in spruce the 



