Western Balsam Bark Beetle

From: Furniss, R. L. and Carolin, V.M., 1977. Western forest insects. Misc. Publ. 1339. Washington, DC: U.S. Department of Agriculture, Forest Service: 383 p.

The western balsam bark beetle, Dryocoetes confuses Swaine (Bright 1963), is the most destructive species in the genus.  In combination with Ceratocystis dryocoetidis Kend. and Moln. and other woodstaining, pathogenic fungi, D. confuses kills Abies lasiocarpa extensively in British Columbia and in Western States southward to Arizona and New Mexico (Molner 1965).  Other Abies, Picea engelmannii, and Pinus contorta are occasional hosts.  The adults are 3.4 to 4.3 mm long.  They resemble D. autographus except that the declivity is flattened rather than evenly rounded, and the front of the head of the female is densely rather than sparsely hairy.  The egg galleries commonly but lightly etch the surface of the wood. Little is published regarding the biology of this species. A 1- to 2-year life cycle is indicated.

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