THE GENUS DENDROCTONUS. 141 



distribution is confined to the region of -the mountains of West Vir- 

 ginia and northward to northern New York. 



This species comes nearer to the European spruce beetle than it 

 does to any of the other species, and therefore will probably have 

 similar seasonal history and habits. 



BIBLIOGRAPHY. 



Hopkins, 1899a, p. 447; Hopkins, 1909, pp. 142-143. 



No. 21. THE EUROPEAN SPRUCE BEETLE. 



(Dendroctonus micans Kug. Figs. 92-94.) 



The European spruce beetle is a large, stout, reddish-brown, cylin- 

 drical barkbeetle, 7 to 8 mm. in length, with broad, convex head; 

 short prothorax, with sides of pronotum distinctly narrowed and 

 constricted toward head; elytra somewhat shining, with moder- 

 ately coarse rugosities between rows of rather distinct punctures, 

 and the declivity smooth and more shiny in the males than in the 

 females. (See fig. 92.) According to European writers, it attacks 

 the living bark, usually at the base of injured, dying, and living 

 trees and stumps of felled spruce, pine, fir, and larch, from central 

 to northern Europe and in Denmark, Russia, and eastern Siberia. 



HABITS AND SEASONAL HISTORY. 



It is said that the broods pass the winter in the mines in the bark 

 as parent adults, young adults, and all stages of larvae. The young 

 adults emerge in June and excavate long, irregular egg galleries 

 (fig. 93), usually in the bark at the base of stumps and trees, some- 

 times extending into the roots, but sometimes at various points on 

 the trunk, even to and among the branches. The female deposits 

 from one hundred to one hundred and fifty eggs in groups of from 

 thirty to fifty, and the larvae proceed in a body to excavate broad 

 brood chambers (fig. 93), very much in the same manner as with the 

 black and red turpentine beetles. 



The broods hatching from eggs deposited in May and June by the 

 overwintered adults develop into pupae and adults by September, or 

 later, but remain in the brood galleries until the next spring. The 

 broods developing from overwintered young larvae transform to 

 pupae and adults in June and July, emerge and deposit eggs in July 

 and August, or later, and pass the winter in different stages, as young 

 to matured larvae. 



