Spring treatment proposed to protect Washington trees from gypsy moth

The Washington State Department of Agriculture (WSDA) is proposing to treat two areas in Western Washington in the spring of 2018 to eradicate introductions of gypsy moth, a non-native, invasive pest that decimates trees. The proposal calls for treating a total of about 1,300 acres in Kitsap and Pierce counties.

WSDA’s treatment proposal consists of aerial applications of a naturally occurring soil bacteria called Bacillus thuringiensis var. kurstaki, or Btk. It is an insecticide approved for use in organic agriculture that for decades has had a proven safety record around people, plants, pets, fish, birds and bees. Treatments would target gypsy moth caterpillars emerging in April or May as they begin to feed on Washington’s trees and shrubs.

The proposal comes after the department’s annual summer trapping program captured 117 male gypsy moths – the most caught in more than 20 years. The agency’s proposal was developed in consultation with national gypsy moth experts that included the U.S. Department of Agriculture and the University of Washington.

Next steps for WSDA include preparing environmental reviews, consulting with local, state and federal agencies, and public outreach, including informational postcards for local residents and businesses.

The 2018 gypsy moth eradication proposal is a fraction of the size of WSDA’s last gypsy moth eradication project, which took place in 2016 and appears to have been successful. At that time, the department treated over 10,000 acres, also with Btk. In the past two trapping seasons since that eradication project was conducted, no gypsy moths have been trapped in the treated areas.

“For over 40 years our gypsy moth program has been protecting Washington’s neighborhoods, parks and forests from this destructive pest,” WSDA Pest Program Manager Jim Marra said. “We have a very effective detection and treatment program. I’m confident that our proposal will prevent gypsy moth from gaining a foothold in our state and protect our environment from this invasive threat.”

European gypsy moths are now permanently established in 20 states, destroying millions of acres of trees annually and causing a host of problems for residents.  This year alone, one-third of the entire state of Massachusetts was defoliated by gypsy moth caterpillars.

WSDA will post regular updates on the project at agr.wa.gov/gypsymoth including specific information on treatment areas and public comment opportunities. Anyone wishing to stay informed can also sign up on the website to receive e-mail updates.

Comments