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UNITED STATES 
DEPARTMENT OF AGRICULTURE 
MISCELLANEOUS PUBLICATION NO. 417 
Bashi nc con, D.C. March 1941 
BARK BEETLES OF THE GENUS 
HYLASTES ERICHSON’® IN 
NORTH AMERICA 
By M. W. BLACKMAN, senior entomologist, Division of Insect Identification, 
Bureau of Entomology and Plant Quarantine 
CONTENTS 
: Page | Page 
PrLrOGUCLIONS 2-2 ae = 5 Peek wee ace Sober |S 1G PE ylastesias pers wane seen ek eee 14 
Synonymy of Hylastes Erichson______________ 2| Hylastes canadensis, new species_____________- 15 
Description of the genus______________________ DN IER AES GOA UCONN a Se 16 
Key to the species of Hylastes Erichson in Fiylastes longus*wecontes=—_-- 222-22 2) et 16 
INorthwAnm eri cate sie 2 2 es eee SE 3) ely tastes nitidusiSWalnewes se wes ee 17 
Hylastes salebrosus Eichhoff_____________-______ 5 | Hylastes fulgidus, new species___-_-_____-_____- 18 
HAylastes scobinosus Eichhoff_____________-___- lal PELYlastescgnaciismuecontees= = sae knee 19 
1 UASEES) TULVET: S Wallen =) =e ee ee 8 | Hylastes longicollis Swaine___...-..---....-_-- 21 
Hylastes subopacus, new SPCCleSsesee wets eZ Diehalastesiexiliss@hapuisea= = aes ae eee 21 
Hylastes webbi, new species__________________- LOnpeylastesitenitsybachho tees =-- - sae ee 22 
Hylastes porculus IDO AGO oo a a Se eS 10 | Hylastes pusillus, new species___-------------- 23 
HAylastes nigrinus (Mannerheim)______________ 13 | Hylastes parvus, new species.___-__- __-__--__- 24 
EMU LAStesIyeiKOntS Malle: 22a sue se) Se 14' Hylastes minutus, Ne WASPeCles= — =e ae 25 
) 
INTRODUCTION 
The genus Hylastes Erichson occurs throughout the continent of 
North America from Alaska to Central America and from the 
Atlantic coast to the Pecific coast. This publication is concerned 
with the forms found north of Mexico. Coniferous forests in every 
region of the United States contain one or several species of Hylastes. 
Most of the species of this genus favor the pines as hosts, but some 
“spruces are also attacked, as well as Douglas fir and to a less extent 
ithe true firs. 
The species of Hylastcs are not so important economically as are 
the members of several other genera of bark beetles. They seldom 
“or never cause the death of healthy large conifers by their unaided 
efforts. They are, however, often found in the bark of dying pine or 
“spruce, where they may well be erroneously considered the cause of 
‘the tree’s death. In the forests these beetles are most hkely to be 
found in the bases and main roots of dying trees or in the stumps of 
‘cut trees. They also often attack the under surfaces of recently 
2 Order Coleoptera, family Scolytidae, 
270849—41 al 
