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> Invasive Threats >Brown Spruce Longhorned Beetle
Brown Spruce Longhorned BeetleTetropium fuscum
Hosts - Spruce (main host), fir, pine and larch. In North America, only spruce has been found infested to date. Stressed (e.g. drought, root disease), dying, recently felled, or healthy trees can be attacked. Middle aged and mature spruce trees are preferred.
Larvae feed on the inner bark and sapwood along the entire stem. However, the lower portions of the bole are the most heavily infested. Larvae bore into the inner bark and excavate a network of irregular, 6 mm wide galleries, which become filled with tightly packed, fine-grained frass and short wood fibers. Much of the tree's inner bark can be destroyed by these wide, irregular and meandering larval galleries. Adults exit through oval or circular exit holes that are 4 mm to 6 mm in diameter, which may or may not be plugged with coarse sawdust. Beetles are 0.8 - 1.8 cm in length. Adults are not likely to be detected, and are very difficult to distinguish from native Tetropium. Trees may be reinfested over subsequent years. Infested tree crowns exhibit progressive yellowing, browning and loss of needles. Once the tree has died, the remaining foliage changes to reddish-brown. USDA APHIS Federal Order restricting movement of spruce logs and firewood from Canada: http://www.aphis.usda.gov/newsroom/hot_issues/firewood/downloads/FederalOrderCanadaFirewood.pdf For more information: http://cfs.nrcan.gc.ca/pages/55 (Canadian Forest Service)
Photos: Canadian Forest Service, bugwood.org Based on information from Canadian Forest Service and Canadian Food Inspection Agency
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