ARTHROPOD ASSOCIATES OF THE SPRUCE BEETLE DENDROCTONUS-RUFIPENNIS (KIRBY) (COL, SCOLYTIDAE) IN SPRUCE STANDS OF SOUTH-CENTRAL AND INTERIOR ALASKA

The impact of competitors, parasites and predators on spruce beetle De ndroctonus rufipennis (Kirby) broods was studied at an endemic populat ion site near Fairbanks, Alaska, as well as at an epidemic area near S ummit Lake and Cooper Landing, Alaska. Logs of white spruce, Picea gla uca (Bong.) Carr., at the endemic area and Lutz spruce, Picea lutzii L ittle, at the epidemic site, were infested by spruce beetles. As logs became infested, associated insects were identified and their impact o n the development of D. rufipennis broods evaluated. Competing Dryocoe tes affaber Mann. broods were the most important interspecific mortali ty factor of larval D. rufipennis. The impact of dipteran and coleopte ran predators and hymenopteran parasites on spruce beetle survival was of less importance than this interspecific competition.