Tuesday, 16 November 2004
D0337

The Douglas-fir beetle in Minnesota: Locating an indigenous exotic in a northern forest

Kevin J. Dodds, kdodds@umn.edu1, Daniel W. Gilmore, dgilmore@umn.edu1, and Steven J. Seybold2. (1) University of Minnesota, Department of Forest Resources, 1861 Hwy 169 East, Grand Rapids, MN, (2) USDA Forest Service, 720 Olive Drive Suite D, Davis, CA

Threats posed by non-indigenous invasive insects to native ecosystems are well documented. However, little is known about the potential impact to native ecosystems by indigenous exotic insects (i.e., native species introduced into areas where they were not previously found). In northern Minnesota, repeated commercial shipping of barked whole western larch logs from Montana has provided a pathway for the intra-continental movement of forest insects. Dendroctonus pseudotsugae Hopkins has been trapped in pheromone-baited funnel traps in northern Minnesota over a 3-year period, and we hypothesize that this indigenous exotic insect has become established in Minnesota and originated from the western larch logs brought into this area. We conducted a large-scale host selection study, using D. pseudotsugae pheromone-baited Douglas-fir and tamarack logs, to determine whether D. pseudotsugae would colonize and develop in a new host (tamarack) in northern Minnesota. Forty-four percent of Douglas-fir and 36% of tamarack logs baited with D. pseudotsugae pheromones came under attack by bark beetles. Currently, we are awaiting brood development to determine if D. pseudotsugae is present in the baited logs. If either D. pseudotsugae or the native D. simplex LeConte are present in the Douglas-fir and tamarack logs, we will compare attack density, number of successful and unsuccessful galleries, brood production, and adult lipid levels of the beetle species in the host logs.


Species 1: Coleoptera Scolytidae Dendroctonus pseudotsugae (Douglas-fir beetle)
Species 2: Coleoptera Scolytidae Dendroctonus simplex (Eastern larch beetle)
Keywords: host selection, indigenous exotic

See more of Display Presentations, Section Cd.
See more of Poster

See more of The 2004 ESA Annual Meeting and Exhibition