63 



in front and behind, the eyistomal process with the sides nearly parallel, its 

 front margin reaching but not passing the epistomal margin; the pronotum 

 constricted in front with the punctures distinctly irregular in size, small, 

 with a few coarse punctures intermixed, moderately close, small and more 

 regular in size behind; the elytra slightly wider than the pronotum, the 

 striae moderately impressed, the strial punctures small and deep, the inter- 

 strial granulations coarse and sparse; the declivity with the striae rather 

 deeply impressed, the strial punctures very small and deep, the interspaces 

 coarsely, sparsely, uniseriately asperate, and finely, very deeply punctured; 

 the hairs are sparse, erect and moderately long, extending nearly to the 

 base of the elytra, with the minute pubescence indistinct. The male has 

 the elytral striae more strongly impressed on the declivity, the declivity 

 brightly shining, not asperate except at the sides, smooth, but deeply, rather 

 closely punctured. 



The egg-tunnels are longitudinal, somewhat winding, variably branched 

 and anastomosing, grooving the inner bark and the wood surface; the eggs 

 are arranged in small groups, the larval mines and pupal cells in the inner 

 bark. 



Host tree. — Eastern Larch. 



Distribution. — This species is abundant in dying larch throughout the 

 larch areas of Eastern Canada from the Atlantic westwards across Manitoba, 

 northern Saskatchewan, and northern Alberta. A rather distinct variation 

 occurs about Lesser Slave Lake. It probably follows the eastern larch 

 throughout its range in North America. 



Economic importance. — This species prefers dying bark, but may 

 become a serious enemy to trees weakened by the sawfly or through other 

 causes. 



Dendroctonus valens Lee; Pac. R. R. Explor. Ins. V, 12, pt. 2, p. 59, 1860. 



Length, 5 mm. to 9 mm., usually 7 to 8; a large reddish species, some- 

 times piceous, or rarely black in old individuals; the epistomal process 

 broad, concave, the sides oblique, the median line of the vertex black; 

 the pronotum faintly narrower than the elytra, moderately constricted in 

 front, the punctuation rather large, strongly impressed, fairly regular in 

 size, and close, smaller and denser towards the caudal margin; the elytral 

 striae distinctly impressed, the discal interspaces convex, rather coarsely 

 granulate; the striae impressed on the declivity, with small rather indistinct 

 punctures, the pubescence sparse and short with a few long hairs on the 

 declivity and disc, frequently denuded (PI. 12, fig. 7). 



The egg-tunnels are usually at the base of living or dying trees, or 

 stumps; they are longitudinal, variably winding and branched, and may 

 reach more than a foot in length ; cut in the inner bark somewhat grooving 

 the wood; the eggs are placed in layers at intervals along the tunnel walls; 

 the larvae feed in congress, excavating chambers of varying size between 

 the bark and the wood surface (PI. 27, fig. 7). 



Host trees. — Abundant in Western Yellow Pine and other pines and 

 spruces of southern British Columbia, and in pines and spruces of Eastern 

 Canada. 



Distribution. — Throughout the pine and spruce forests of Eastern 

 Canada and in southern British Columbia, and southward throughout the 

 United States. We have no records from the northern parts of Saskatchewan, 

 Alberta, and British Columbia, nor from the Yukon. 



Economic importance. — An important assistant of monticolce and 

 brevicomis in outbreaks in British Columbia yellow pine. Frequently found 

 killing patches of bark at the base of living pines and spruces. 



