WALLA WALLA, Wash. (AP) — The state has discovered a new infestation of Douglas-fir tussock moths in the Blue Mountains of Washington and Oregon.
Light defoliation was mapped across 9,000 acres of the Umatilla National Forest, with most of that in Washington. Most of the defoliation occurred in the Wenaha-Tucannon Wilderness Area, but it may spread and increase in severity this year.
Officials say another tussock moth outbreak that affected 1,600 acres in eastern Spokane County in 2011 will likely end this year.
The defoliation can reduce growth, cause top-kill, and may make some trees vulnerable to attack by bark beetles.
