FOREST GROVE, Ore. — The emerald ash borer, an invasive wood-boring beetle that infests and kills North American ash trees, has been found in Oregon.

The discovery was the first known sighting on the West Coast, according to Oregon Department of Agriculture.

The beetle was found on June 30 by Dominic Maze, an invasive species biologist for the City of Portland.

Maze was in Forest Grove, Ore., waiting to pick his kids up from summer camp, when he noticed several unhealthy-looking ash trees. Upon closer examination, he recognized the distinctive D-shaped holes that adult emerald ash borers make as they exit an infested tree.

“When my kids arrived, I asked them to look for adult beetles,” said Maze. “My son promptly found one crawling on him. Knowing how many millions of ash trees across the country these beetles have killed, I felt like I was going to throw up.”

Maze was rightly worried.

The notorious emerald ash borer — native to Asia — has left widespread destruction in its path across the U.S., so its arrival on the West Coast concerns biologists. ODA calls the emerald ash borer the most destructive forest pest in North America.

According to a 2022 study in the academic journal Sustainability, since it was first found near Detroit, Mich., in 2002, the beetle has killed more than 8 billion native ash trees.

The beetles have infested much of Canada and the U.S., spreading out from the Midwest.

Native North American ash trees are not resistant to emerald ash borers, so nearly all infected trees will prematurely die if left untreated.

Ash trees are an important part of ecosystems nationwide, and when they die, there are ripple effects.

According to the University of Illinois Extension Service, the death of ash trees reduces property values for homeowners, creates losses in timber, reduces important wildlife habitat, increases heating and cooling costs and increases stormwater runoff.

Researchers estimate it would cost billions of dollars to replace lost ash trees in just the Midwest alone, where many trees have already died.

State officials say Maze played a crucial role in alerting the state to his discovery so that agencies can try to track and curb the beetle’s spread.

After finding the emerald ash borer in Forest Grove, Maze immediately called the Oregon Department of Forestry’s Forest Health Unit to report the sighting.

ODF forest entomologist Christine Buhl drove to the site and identified an adult emerald ash borer, known for its metallic, shiny green color. Her identification was later verified by two more invasive species specialists, Max Ragozzino of ODA and Wyatt Williams of ODF.

Within 48 hours of the discovery, officials cut down and chipped the infested trees.

Officials urge the public to learn what an emerald ash borer looks like and report sightings online at the Oregon Invasive Species Council hotline. More information can be found on ODA’s Emerald Ash Borer webpage.

“This will help the state know how far and how fast this destructive insect is spreading in Oregon,” said ODA.