State officials confirmed the presence of the emerald ash borer Wednesday after two people passing through Vancouver spotted the insect on their windshield in early August

Aspen Ford
Washington State Standard

One of the most destructive invasive pests in the nation has arrived in southern Washington, posing a grave threat to ash trees.

State officials confirmed the presence of the emerald ash borer Wednesday after two people passing through Vancouver spotted the insect on their windshield in early August. They took photos, collected the specimen and turned it over to officials for identification.

“We anticipated it would only be a matter of time before emerald ash borer arrived in our state,” said Sven Spichiger, pest program manager at the Washington State Department of Agriculture. “This is yet another example of how alert, observant members of the public help us detect new, invasive pests.”

There has never been a successful eradication of the emerald ash borer, a metallic green beetle that feeds on wood, according to the state’s Department of Agriculture. The insect has wiped out more than 100 million ash trees in the United States since its initial detection twenty years ago.

All true ash species are vulnerable to an infestation.

Without efforts to manage an outbreak, municipalities can expect to lose 90% to 100% of their ash trees within 10 to 12 years of an initial infestation, according to a Department of Natural Resources analysis.

The only reliable method to contain an outbreak is by limiting firewood transportation and replacing infested trees with non-ash species, according to the Department of Agriculture. On Tuesday, the department started a firewood quarantine, which prohibits the transportation of untreated firewood in the state.

State officials have been preparing for the pest’s arrival for years. Washington state agencies have developed an Emerald Ash Borer Resource and Management Guide and an Urban Forest Pest Readiness Playbook to help residents and local governments detect and respond to infestations.

Forestry assistance for municipalities is available through the Department of Natural Resources as long as funding is available.

State officials are urging the public to keep an eye out for the pest and report suspected sightings to the Washington Invasive Species Council or via the Washington Invasives app.

“This is deeply unfortunate, but we knew the emerald ash borer would arrive here and we’ve been preparing for it,” said Dave Upthegrove, Commissioner of Public Lands. “Please use our shared resources to educate yourselves and heed the recommendations to slow the spread of this destructive pest.”

The beetle has been active on the West Coast since it was detected in Forest Grove, Oregon, west of Portland, in 2022. It was detected a year later in Vancouver, British Columbia.

This report was first published by the Washington State Standard.