2020 Eradication Information

WSDA treated two areas in Snohomish County totally about 1,300 acres in May of 2020 to eradicate introductions of spongy moth, a non-native, invasive pest that can decimate the environment.  One site included the first-ever detection of the Hokkaido spongy moth in the United States – a type of Asian spongy moth that predominately feeds on larch trees in its native environment.

The treatment consisted of aerial applications of a soil bacteria called Bacillus thuringiensis var. kurstaki, or Btk, which is an insecticide approved for use in organic agriculture and in organic gardening.

Printable Maps

Click on a map below to download a printable draft map of the treatment sites. Please note: while these draft maps of the treament areas include areas over water, the treatments themselves were not conducted over water. 

The Washington State Department of Agriculture (WSDA), Plant Protection Division issued a determination of non-significance (DNS) under the State Environmental Policy Act (SEPA) Rules (Chapter 197-11 WAC) for the Spongy Moth Eradication Project in the Woodway and Boulevard Bluffs areas of Snohomish County, Washington State.  After review of completed environmental checklists and other information on file with the agency, WSDA has determined this proposal will not have a probable significant adverse impact on the environment. A copy of the DNS and site-specific environmental checklists are available below. 

Determination of Nonsignificance     Boulevard Bluffs 2020 SEPA Checklist       Woodway 2020 SEPA Checklist

The Washington State Department of Agriculture (WSDA) in cooperation with the United States Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS) prepared a site-specific environmental assessment (EA) for two proposed treatment sites to eradicate spongy moth in Snohomish County, Washington State. 

A Finding of No Significant Impact (FONSI) was issued for two proposed treatment sites to eradicate an infestation of the non-native spongy moth in Snohomish County, Washington State. The FONSI and Final EA are available here.