Arthropod associates of the spruce beetle <i>Dendroctonus rufipennis</i> (Kirby) (Col., Scolytidae) in spruce stands of south‐central and interior Alaska

Abstract

Abstract The impact of competitors, parasites and predators on spruce beetle Dendroctonus rufipennis (Kirby) broods was studied at an endemic population site near Fairbanks, Alaska, as well as at an epidemic area near Summit Lake and Cooper Landing, Alaska. Logs of white spruce, Picea glauca (Bong.) Carr., at the endemic area and Lutz spruce, Picea lutzii Little, at the epidemic site, were infested by spruce beetles. As logs became infested, associated insects were identified and their impact on the development of D. rufipennis broods evaluated. Competing Dryocoetes affaber Mann. broods were the most important interspecific mortality factor of larval D. rufipennis. The impact of dipteran and coleopteran predators and hymenopteran parasites on spruce beetle survival was of less importance than this interspecific competition.