BARK BEETLES OF THE GENUS HYLASTES 3 
Fore coxae narrowly separated; mesosternum not protuberant in front. . Fore 
legs with third tarsal segment slightly widened and emarginate, not bilobed. 
Venter of abdomen horizontal, first and fifth sterna longer than others, fifth 
shorter in males and often flattened or grooved, and with special pubescence. 
Synonymy.—The genus Hylastes was described by Erichson (1836) 
to include Bostrichus ater Payk. (1800) and several other species, 
among these a new species, H. porculus Er., from Pennsylvania. 
H. ater (Payk.) was the first species treated in the new genus, but 
Erichson did not cite it as the genotype. Westwood (1840) mentions 
ater as a typical species representing the genus Hy/astes, but he does 
not definitely refer to it as the genotype. Thomson (1859), however, 
definitely fixes B. ater as the genotype. 
The situation, however, is considerably complicated by doubts cast 
upon the validity of Bostrichus ater. ‘There is some question as to 
whether B. ater Payk. (1800) is identical with either Dermestes pin- 
perda L. (1758) or B. piniperda F. (1891), and as to whether the 
last two species are identical with each other but distinct from ater. 
Each of these three species has served as the basis for a different 
genus. Bostrichus ater Payk. has been designated as the type of 
Hylastes Er., Bostrichus piniperda F. as the type of Zomicus Latr. 
(1802), and Dermestes piniperda Li. as the type of Myelophilus 
Eichh. (Blastophagus Eichh.). Several European writers believe 
ater Payk, to be identical with piniperda F. but distinct from pinz- 
perda L. If this should be proved true, Zomicus Latr. would replace 
Hylastes Er. On the other hand, other authorities consider pind- 
perda Li. and piniperda F. as identical and believe ater Payk. to be 
distinct and a valid species. If this interpretation is accepted, 
Hylastes Er. stands with ater Payk. as the type. 
It would appear that the conclusions of both parties to this con- 
troversy are based on their opinions as to what the describer of 
each of the three species had before him, and not on facts which 
can now be definitely established. Since at present there seems to be 
no possibility of arriving at absolute proof in the matter, it seems 
wisest to continue the use of the generic name Hylastes Er., as this 
name is almost universally used by recent workers. 
KEY TO THE SPECIES OF HYLASTES ERICHSON 
IN NORTH AMERICA 
1. Beak with distinct median carina, frontal rectangle longer than wide; 
discal interspaces of elytra nearly devoid of hairs, except in ruber 
Sw. and longicollis Sw.; male with last sternite grooved, impressed, 
or flattened in median line, often with special pubescence___________- 2 
Beak devoid of median carina, frontal rectangle not longer than wide in 
female; elytral interspaces distinctly hairy; male with last sternite 
not impressed or grooved and without special pubescence; slender 
hatnvaspecies-ess:than’3.0)mm: long 2 22 tees es eee 17 
2. Body less than 3.0 times as long as wide; pronotum widest at or near 
middestexcep tein (SCOOMLOSILS)) Wich.) eee pay cet i a) es 3 
Body more than 3.0 times as long as wide; pronotum widest in front of 
elytra with deep striae and strongly convex, very coarsely rugose in- 
terspaces; ninth interspace less strongly elevated behind than eighth; 
reddish brown in COlOI za PS AI foul lle Asner Sahl I 8 1.) Ga . L eahehs a 
