81 



D Larger and stouter species; the pronotum closely punctured with 

 large and small punctures intermixed; strial punctures small, 

 distinct, with sides approximately straight; interspaces rather 

 sparsely, moderately rugose; epistomal carina distinctly acute 

 (PL 18, fig. 2). pinifex Fitch. Page 81. 



DD Smaller species, the pronotum densely, rather regularly punc- 

 tured; strial punctures rather coarse and indistinct, interspaces 

 closely, coarsely rugose; epistomal carina usually a narrowly 

 convex ridge (PI. 18, fig. 3). rugipennis Mannh, Page 81. 

 CC Rather slender species; not inflated behind; the pronotum at most 

 only sHghtly sinuate on the sides in front; the mesosternum only 

 moderately protuberant ; the third tarsal segment only moderately 

 widened; the pronotum rather feebly margined at the base. 

 D The pronotal punctures small and fairly regular in size; the 

 elytral interspaces finely granulate on the basal half. N. 

 Mexico. knausi Sw. 



DD The pronotal punctures notably unequal in size; the elytral 

 interspaces rugose on the basal half. 

 E The pronotum with many minute and numerous medium- 

 sized punctures intermixed; the elytra deeply striate on 

 the disc and dechvity. porosus Lee. Page 82. 



EE The pronotum with many large and a few minute punctures 

 intermixed, the elytra rather feebly striate. 



lecontei Sw. Page 82. 



AA Bases of the elytra strongly arcuate, subacute and irregularly subserrate; 



the elytral interspaces alternately carinate, more strongly behind; the 



elytra and pronotum everywhere minutely scaly, frequently encrusted 



(PI. 18, fig. 4). subcostulatus Mannh. Page 82. 



Hylurgops pinifex Fitch; N.Y. Agric. Soc. Trans., 43, 1851 (Hylastes). 



Length, 4-5 mm.; width, 1-8 mm.; colour reddish brown to nearly 

 black; the pronotum a little narrower than the elytra, the sides strongly 

 arcuate behind, strongly narrowed and constricted in front of the middle; 

 the elytra slightly widened behind the middle, the striae deep, the inter- 

 spaces convex, granulate and asperate, more strongly on the dechvity; the 

 vestiture of minute hairs, scale-like on the dechvity, with a few long erect 

 hairs behind; the male has the dechvity more densely scaly, the arcuate 

 impression on the front deeper and wider, and the carina of the 2nd ventral 

 segment usually more strongly developed. This species is distinguished 

 from the closely aUied H. glahratus Zett. of Europe by the more sparsely 

 and more irregularly punctured pronotum, and the less strongly arcuate 

 bases of the elytra. 



Host trees. — Pines, Spruce, and Eastern Larch. 



Distribution. — Eastern Canada and Eastern United States; very widely 

 distributed. 



The tunnels are usually at the base of the trunk, often extending 

 below the surface of the ground; a secondary enemy. 



Hylurgops rugipennis Mannh.; Bull. Mosc, 297, 1843, (Hylurgus). 



Shghtly smaller and more slender than pinifex, with the pronotum 

 more decidedly narrower than the elytra and the asperities of the declivital 

 interspaces coarser. 



Host trees. — Sitka Spruce, Engelmann's Spruce, Western White Pine, 

 and probably all pines and spruces within its range. 

 36198—6 



