OLYMPIA – The Washington State Department of Agriculture (WSDA) Pest Program has announced plans to eradicate spongy moth and Japanese beetle populations in several counties during spring 2026.
This initiative follows analysis of 2025 trapping data indicating reproducing populations in the proposed treatment areas, Washington State Department of Agriculture said in a release.
For Japanese beetle eradication, the WSDA is expanding treatment areas in Yakima, Benton, Franklin and King counties. Treatments will include spring lawn applications using Acelepryn, a reduced-risk insecticide. The program may also conduct summer foliar treatments in high-catch areas, if funding allows.
In King and Pierce counties, the WSDA plans to target spongy moth caterpillars. Two sites, one west of Lake Youngs in King County and another in the Lakewood area of Pierce County, will be treated. The WSDA intends to use Bacillus thuringiensis kurstaki (Btk), a bacteria used in organic farming, to treat 874 acres. This method is safe for humans, pets, birds, bees and fish.
WSDA said it will conduct public outreach, complete environmental reviews, secure funding and work with stakeholders before finalizing treatment areas.
