Douglas-fir beetles are found in Minnesota

During a larch beetle trapping study in cooperation with Dr. Steven Seybold (U of MN), we caught three Douglas-fir beetles (DFB) on a site about 10 miles north of Grand Rapids. Further investigation showed that a company in Cohasset transports western larch logs into Itasca County and that the logs still have bark on them. The company extracts a long chain polysaccharide from the wood that is used in dietary supplements and human health care products.

DFB is a serious bark beetle pest in western North America where it infests Douglas-fir and western larch. Its impact in Minnesota is unknown but a study by Furniss in 1976 suggests that it is able to attack our native tamarack.

The presence of DFB was reported to the MN Dept. of Agriculture. In 2002 DNR, University of MN, and the MDA set out four lines of bark beetle monitoring traps extending from the woodyard in Cohassett out 10 miles to the NE, NW, SE, and SW. As would be expected the highest number of beetles, 111 were caught in and around the woodyard. In addition small numbers of beetles were caught in traps out to 10 miles to the NW and SE and 6 to 8 miles to the SW and NE.

A number of pathogenic fungi, as well as other insects, not native to Minnesota have also been collected from the western larch logs in the woodyard.

Being the state regulatory agency, the MN Dept. of Agriculture has been meeting with the company to develop measures to reduce the introduction of additional DFB.

The importation of exotic pests from other continents has gotten lots of attention and news coverage the past few years. The transportation of insects and fungi, native to one part of North America, to ecosystems where they are not native has received much less attention. The risks of doing this have received little study and are not well understood.

The threat of DFB, to the larch resource of Minnesota is not known nor is the threat of the other insects and fungi that have been brought into Itasca County. We do not know if any of these other pests have spread beyond the woodyard. Additional surveys as well as ecological studies are being planned for 2003 and 2004 to answer some of the questions. This situation also raises the question of what other non-natives are being brought into Minnesota and by what other routes.