16 MISC. PUBLICATION 417, U. S. DEPT. OF AGRICULTURE 
HYLASTES MACER Leconte 
Hylastes macer Leconte, 1868, Amer. Ent. Soc. Trans. 2: 175; Leconte, 1876, 
Amer. Phil. Soc. Proc. 15: 388; Schwarz, 1894, Insect Life 7: 255; Swaine, 
1918, Canada Dept. Agr. Ent. Branch Bul. 14 (2) : 78, 79. 
Female.—Piceous brown to black, 5.0 to 6.5 mm. long, about 3.16 times as 
long as wide. 
Frons moderately narrow between eyes, frontal rectangle about 1.13 times as 
long aS wide, piceous brown with epistomal margin black; epistoma moderately 
deeply and widely impressed at each side, divided by a fine, rather low median 
carina which ends above in an arcuate transverse impression; epiStomal mar- 
gin darker, thickened, and liplike, median lobe wide, very short, entire middle 
half impressed, free end rather shallowly emarginate; surface subopaque, 
finely, very densely granulate-punctate; vestiture coarser, longer, and more 
visible than usual, longer on epistoma. Eye nearly twice as long as wide, 
widest above; inner margin entire. Antenna with first segment of club almost 
exactly as long as other three combined. 
Pronotum distinctly narrower than elytra, about 1.27 times as long as wide; 
posterior outline rather weakly arcuate, posterior angles rather strongly 
rounded, sides on posterior half nearly straight and feebly divergent to widest 
point just anterior to middle, then more strongly, arcuately narrowed to meet 
the broadly rounded front margin; surface feebly shining or subopaque, rather 
deeply, moderately coarsely, and closely punctured on disk, much more finely 
so in front, weakly granulate and somewhat more finely punctured on sides; 
median line narrow, elevated, shining on posterior two-thirds. 
Elytra distinctly wider than pronotum, slightly more than twice as long as 
wide; sides subparallel and nearly straight on nearly three-fourths of their 
length, then gradually narrowed to apex, which is very broadly, often subtrun- 
eately rounded; surface subopaque; striae weakly impressed anteriorly on disk 
and sides, more strongly so posteriorly and on declivity, first and second more 
strongly so throughout; punctures rather coarse, moderately close, separated by 
slightly less than own diameters; interspaces wider than striae, ranging from 
feebly convex at base to strongly convex on declivity, surface finely reticulate, 
rather weakly rugose, finely punctured on disk, becoming distinctly rugose and 
uniseriately granulate on declivity; disk subglabrous, declivital interspaces with 
a middle row of short, fine hairs, and with rather narrow, appressed scales at 
each side; ninth interspace only moderately elevated. Last abdgminal sternite 
moderately narrow behind, strongly convex, slightly flattened posteriorly; punc- 
tures deep, moderately coarse, and close; hairs rather short, fine, appressed. 
Male.—Similar to female in proportions and sculpture; last abdominal ster- 
nite shorter and more broadly rounded behind than in female, with a broad, 
posterior, median impression, with the punctures there fine and dense, giving 
rise to fine, rather long, cinereous hairs. 
Remarks.—Both Leconte’s cotypes of macer are males, one from 
California and the second from Nebraska. The Nebraska specimen 
shows certain small differences and may possibly represent another 
closely allied species. Three other specimens in the Leconte collec- 
tion are females from California. 
The writer has studied numerous specimens of this species from 
California, Oregon, and Washington, as well as short series from 
Idaho, Montana, South Dakota, Nebraska, Colorado, New Mexico, 
and Arizona. They show only minor differences, which are not con- 
sidered sufficient for their separation. The hosts are Picea engel- 
mannii Engelm., Pinus ponderosa Laws., and P. lambertiana Doug]. 
HYLASTES LONGUS Leconte 
Hylastes longus Leconte, 1876, Amer. Phil. Soe. Proc. 15: 388, 389; Fall and 
Cockerell, 1907, Amer. Ent. Soc. Trans. 33: 218; Swaine, 1918, Canada Dept. 
Agr. Ent. Branch Bul. 14 (2): 78. 
Description of type.—Dark reddish brown, 4.68 mm. long, about 3.05 times as 
long as wide; similar to macer Lec., but smaller and not quite so slender. 
