NOTES ON THE BIOLOGY OF THE ENGELMANN SPRUCE WEEVIL, PISSODES ENGELMANNI (CURCULIONIDAE: COLEOPTERA) AND ITS PARASITES AND PREDATORS

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Abstract
The Engelmann spruce weevil, Pissodes engelmanni Hopkins, is an indigenous pest of spruce regeneration in western Canada and the adjacent United States. It is univoltine, overwintering as an adult in the duff beneath the host trees. Eggs are deposited in feeding punctures in the terminal leader. Larvae feed downward in the phloem causing two or more years loss of height growth. Deformities incurred by three or more consecutive years of weevil attacks produce a tree of no commercial value. The incidence of weevilling is most numerous in open grown, even-aged, young stands. Of 14 insect parasites and one predator, Dolichomitus terebrans nubilipennis (Viereck), Eurytoma pissodis Girault and Lonchaea corticis Taylor are considered principal natural control agents.