The Oregon Department of Forestry encourages landowners to act quickly to remove downed or damaged trees to prevent a native pest from damaging more trees.
After the heavy snow that came through Douglas County and much of Oregon two weeks ago, one of the department’s Forest Entomologist Christine Buhl began warning people that the conditions could lead to further damage from the pest.
“Normally this pest is scattered on the landscape wherever Douglas-fir grows,” Buhl said in a press release. “However, they tend to concentrate in tree stands where there has been a lot of storm damage. The beetles first attack downed Douglas-firs and then move to nearby standing Douglas-fir trees that are stressed, injured or less vigorous.”
The Douglas-fir beetle is a naturally occuring pest that is smaller than a fingernail but can bring down large Douglas fir trees once the population is large enough.
Department spokesman Jim Gersbach said the beetle could cause economic damage as a timber is a large industry in the area so damaged and downed trees should be removed before the beetle becomes active in April.
“It’s one that’s naturally occuring in the Pacific Northwest, but it’s population can increase,” Gersbach said. “Standing trees may be your future timber production. For people who are forest landowners who have healthy trees but lost trees from a stand, if those are big enough to be enticing to the beetle then they can spread to standing living trees and that can be costly to landowners.”
The department recommends removal as soon as possible or a naturally occurring beetle repellent, MCH (methylcyclohexenone), can be applied to downed logs or standing green trees to prevent Douglas-fir beetle attacks. Beetles approaching treated areas are fooled by the pheromone into sensing that beetles already occupy the site and will pass it by.
“This technique is useful in parks, camps or habitat conservation areas where salvage is not possible, but there is a desire to preserve the remaining standing trees,” Buhl said. “It’s also helpful in forestlands where downed wood can’t be removed before April for one reason or another. However, it will not make beetles that have already infested a tree leave. Once they are in, they’re in.”
More information can be found at the Oregon Department of Forestry’s Forest Health webpage.