Douglas Fir Tussock Moth Claims 13,000 Acres of Trees
An infestation by Douglas fir tussock moths has claimed 13,000 acres of forest in Idaho, killing trees and driving the Idaho Department of Land to hold salvage timber sales. Infestations are cyclical, occurring every 8-12 years, and lasting 2-4 years. Though trees can sometimes recover, with severe infestations such as this one, damage can lead to tree death. One of the Most Damaging Defoliators Though the Douglas fir tussock moths prefer the Douglas fir, they will sometimes move to other conifer species such as true firs or spruce. The pests feed on foliage, beginning at the crown and tips and working toward the interior of the tree. Foliage shrivels and browns, leaving trees with a skeleton-like appearance as foliage disappears. Dead Tree Dangers Once the firs have succumbed to the moths, they pose a considerable safety risk. The timber poses a fire hazard intensified by the piles of needles left below trees. The dead timber also increases the risk of bark beetle at...