Bark Beetles Eating WA Trees, Bug Levels at 10-Year Highs

The Department of Natural Resources has released its annual Forest Health Highlights report for 2022, after taking a year off due to the pandemic.

 Survey shows increased activity by bark beetles

According to DNR, surveyors and experts flew over and charted 22  million acres of wildlands and forests, charting conditions of trees and growth.

The 2021 report covered 19 million, crews did not fly in 2020 due to the pandemic.

Bark beetles are very active

According to DNR:

"The report details the 672,000 acres observed to have some level of tree mortality, defoliation, or foliar disease – a 14,000-acre increase from the last full-scale survey in 2019. Bark beetles accounted for 346,000 of the 604,000 acres with damage from mortality agents."

Bark beetles in general bore through a tree's bark, which is its defense, and not only eat the living wood underneath but also lay their larvae. This also interrupts the tree's natural feeding process.

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According to DNR, the most noticeable areas include:

"Areas that saw the highest concentrations of bark beetle-caused mortality included wide swaths of Yakima County, Kittitas County, and Okanogan County. Most of the increase of Douglas-fir beetle-caused mortality occurred in those three counties, as well as in the Blue Mountains southeast of Walla Walla.

 Much of the Puget Sound region, including King County, Pierce County, and Lewis County, saw higher concentrations of Douglas-fir beetle-caused mortality compared to the rest of western Washington."

According to experts, most of the time a healthy tree can fight off a lot of beetle activity, but during dry conditions such as drought, the tree is not strong enough to resist. Dry weather also contributes to more beetle activity.