8 E Canadian Arctic Expedition, 191S-18 



This species is abundant throughout the spruce forests of Canada, from 

 the Pacific Coast eastward to Newfoundland. It is rare in pine, and rather 

 commonly found in larch. 



About forty specimens were received in the bark of a section from a dead 

 white spruce trunk collected by Mr. Johansen at Camp creek, below Sandstone 

 rapids, Coppermine river. Northwest Territories, February. 15, 1915. 



The tunnels of this species, associated with those of Pityophthorus, were 

 numerous on the exposed wood surface of dead standing trees and beneath 

 the patches of bark which remained, particularly on the upper portions of the 

 trunk; numbers of dead adults were taken in the tunnels beneath these patches 

 of bark. On the dead and dying parts of the living trees these Polygraphus 

 and Pityophthorus tunnels were also found, but they were not so numerous 

 here as on the old dead trees, and were not found at all in some of the dying 

 branches and trunks examined. It was evident that cerambycid larvae had 

 been more injurious than bark-beetles during the season previous to the exam- 

 ination. 



Genus Pityophthorus Eichh. 

 Eichhoff, Berl. Ent. Zeit., 8; 39, 45, 46, 1864. 



Pityophthorus nitidus Sw. 



Plate II, figures 3, 4, 5. 



Swaine, Dom. Ent. Br., Dept. Agric. Bull. 14, pt. 1, p. 26, 1917. 



Description of the Female. — The length, 2.1 mm.; 21 times as long 

 as the width; the elytral striae not impressed, the strial punctures small; lihe 

 declivity sulcate-retuse, not acuminate. 



The head has the front flattened, the flat area bounded by a semi-circular 

 line behind, very densely, minutely punctured and densely pubescent with 

 short yellow hairs; the median carina nearly obsolete except the cephalic end which 

 forms a rather prominent carinate tooth on the epistoma; the eyes rather finely 

 granulate, deeply narrowly emarginate; the antennal club very wide, short 

 oval almost subcircular, the sutures broadly arcuate the third most strongly, 

 the first two segments each distinctly shorter than either of the last two; rather 

 closely pubescent. 



The pronotum is as long as wide; very broadly rounded behind, strongly 

 arcuate on the sides behind; moderately constricted before the middle, broadly 

 rpunded on the front margin which is finely serrate, the asperities slightly 

 stronger at the middle; the summit shghtly in front of the middle with a wide 

 transverse impression across the disc immediately behind the summit; finely 

 subconcentrically asperate in front, rather coarsely, very densely, subgranulately 

 punctured behind, the punctures smaller towards the lateral margins; with a 

 small impunctuate spot on the middle of the side, and a smooth median space. 



The elytra are shghtly less than twice as long as the pronotum, 9:5, faintly 

 narrower than the pronotum; truncate at the base; the sides subparallel for 

 over two-thirds the length then narrowed and rather broadly rounded behind, 

 very faintly sulcate-retuse as viewed from above; the upper part of the declivity 

 distinctly sulcate-retuse; the sutural striae finely impressed; the remaining 

 striae only very faintly indicated, except near the lateral margins the last two 

 strongly impressed, especially behind; the strial punctures small, fairly close 

 and deep, in only moderately regular rows; the interspaces not convex, sparsely 

 uniseriately punctured in the interspaces of the disc, more closely punctured 

 about the base and lateral margins; the ninth interspace moderately convex 

 behind. The declivity is broadly sulcate above, the sulcus wide, not deep, 

 not widened behind, shining, the sides feebly retuse, with a row of minute 



