Washington state is proposing to treat a combined 2,313 acres in the Puget Sound region for the invasive spongy moth, which the State Department of Agriculture calls one of the worst invasive pests introduced into the U.S.

Treatment areas include 1,393 acres in the Steamboat Island Road area of Thurston County and 920 acres near Concrete in Skagit County.

The agency plans aerial applications of Bacilllus thuringiensis var. kurstaki – more commonly known as Btk -- which is approved for use in organic agriculture and has an excellent safety record for humans, pets and wildlife, officials said.

Treatments would begin in the spring when caterpillars begin to feed on the trees and shrubs. WSDA has used this product successfully for the last several decades.

Before the proposed treatment plan is finalized, WSDA will be conducting state and federal environmental reviews at both sites, which will include a public comment period as part of the process.

The department will also conduct extensive outreach to those who live in or near the area to ensure they are aware of the proposal. WSDA will be holding in-person and virtual open houses about the project as well as mailing information to residents in and near the proposed treatment areas.

The moth – formerly known as gypsy moth -- is established in over 20 eastern states, where in outbreak years it can defoliate millions of acres of trees and shrubs. If the moth were to establish in Washington, it could have significant impacts on neighborhood trees, parks and forests, as well as the native species that depend on trees and shrubs for food or habitat.

Although there are new introductions from other states or overseas most years, WSDA has successfully and safely protected the state’s natural resources from the moth for 50 years. Visit agr.wa.gov/moths for more information about WSDA’s work.

Source: Washington State Department of Agriculture