65 



tured proepisternal area, the narrower and more sparsely asperate discal 

 interspaces, the more sparsely and finely punctured declivital interspaces, 

 and the close and overlapped basal crenulations of the elytra. 



Host trees. — White Pine and Jack Pine. 



Distribution. — From northern Manitoba across northern Ontario, 

 and northern Quebec, and probably to the Atlantic. Recorded from 

 Michigan by Hopkins. 



Economic importance. — We have taken it only in trees dying from 

 other causes. The type of our description agrees with Kirby's type; 

 compared by R. N. Chrystal. 

 Dendroctonus monticolae Hopk.; Bur. Ent., U.S. Dept. Agric, Bull. 56, 

 p. 11, 1905. 



Length, 3-7 mm. to 6-7 mm.; colour usually black or dark brown; 

 the front convex, faintly impressed behind on the middle line; the jpronotum 

 as wide as the elytra, with the sides strongly constricted in front, the punc- 

 tuation close, small, not very evidently irregular in size (PL 7, fig. 7); 

 the elytra with the striae distinctly impressed, more feebly on the sides, 

 the strial punctures small, the interspaces slightly convex on the disc, 

 with moderately close granules of varying size; the declivital striae rather 

 strongly, narrowly impressed, with very small punctures, the 2nd and 

 3rd strongly sinuate; the pubescence of the elytra short and sparse, with a 

 few longer hairs extending nearly to the base, and numerous short subrecum- 

 bent hairs on the sides, (the long hairs usually more or less abraded). 



The egg-tunnels are vertical, elongate, straight to moderately winding, 

 with the egg-niches arranged not very regularly in small alternate groups; 

 the larval mines and pupal cells mostly exposed in the inner bark, grooving 

 both bark and wood (PI. 30). 



Host trees. — Western White Pine, Western Yellow Pine and Lodgepole 

 Pine in British Columbia. Also recorded from Pinus lambertiana and 

 Picea engelmanni in United States. 



Distribution. — Throughout the range of its host trees in southern 

 British Columbia west of the Rockies, and in Western United States. 



Economic importance. — This is the most destructive bark-beetle of 

 British Columbia forests; it has already destroyed an enormous amount 

 of timber in southern British Columbia. 



D. ponderosce Hopk. has not been recognized from British Columbia. 

 It is described as distinct from monticolce through " its average larger 

 size, somewhat stouter form, with the elytral striae more distinctly impressed, 

 and the punctures distinctly coarser."* It is destructive to pine forests 

 in the central and southern Rocky Mountain region. 

 Dentroctonus punctatus Lee; Trans. Am. Ent. Soc. II, 173, 1868; Hopkins, 

 The Genus Dendroctonus, 72, 142, the only valuable description. 



This species is recorded by Hopkins in Picea rubens, from New York to 

 west Virginia. It is probably very rare, and has never been recorded from 

 Canada.} The coarse punctures of the elytral striae, especiahy on the decliv- 

 ity, separate it from its allies, as indicated in the key. 

 Dendroctonus engelmanni Hopk.; U.S. Bur. Ent., The Genus Dendroctonus, 

 p. 130. 



This species was described from the Rocky Mountain region of the 

 United States, and Canadian records were given from "(Horn) " H.B." 

 (Northwest Territory, probably Mackenzie River region)"; "(H. & S) 

 Calgary, Alta.; Glacier, B.C." These were probably similar to our more 

 coarsely punctured specimens left in this paper under borealis. 



* Hopkins, the Genus Dendroctonus. 



fSince this was written a species has been collected on the Coppermine River near the Arctic Ocean 

 by Mr. Johannsen of the Canadian Arctic Expedition which is either punctattis Leo. or a closely allied 

 undescribed species. 



36198—5 



