NEWBERG, Ore. — The emerald ash borer has been confirmed in Newberg for the first time, state forestry officials announced Tuesday, marking the latest spread of a destructive invasive pest through the northern Willamette Valley.
The Oregon Department of Agriculture’s Max Ragozzino investigated a report submitted to the Oregon Invasive Species Hotline and found two ash trees in a parking lot on the outskirts of the city were heavily infested with emerald ash borer, or EAB. Six additional trees at the same location appear to be in the early stages of infestation, according to an Oregon Department of Forestry press release issued June 23.
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The detection is the first confirmed EAB find in Newberg, though the pest has been present in Yamhill County for two years. The first Yamhill County detection occurred on the county’s northern border with Washington County.
Newberg falls within the existing EAB quarantine zone established by the Oregon Department of Agriculture, which covers Clackamas, Marion, Multnomah, Washington, and Yamhill counties. Under the quarantine order, ash, olive, and white fringetree material must remain within those counties, as must firewood from any hardwood species.
EAB Support Specialist Matt Mills of the Oregon Department of Forestry said the Newberg find, along with simultaneous detections in Tualatin and Silverton, was not a surprise.
“We have long known that EAB would spread from infested sites to nearby areas, so these new detections are not unexpected,” Mills said in the release. “Experience from other states shows that four to five years or so after first being detected EAB spreads from pockets of infested ash trees and becomes much more widespread over an entire county or metropolitan area.”
The Newberg report was one of three confirmed detections announced this month, all submitted by private individuals who recognized infestation signs and used the Oregon Invasive Species Hotline to report them. Kat Bethea, also an EAB Support Specialist with ODF, said the volume of public reporting reflects years of outreach across northwest Oregon.
“We are thankful that people are paying attention to the health of ash trees around them and letting us know when signs point to a possible EAB infestation,” Bethea said.
Bethea said ODF has notified officials in the affected communities and surrounding areas to monitor ash trees for signs of the pest.
What Property Owners Should Do
Officials are urging Newberg-area residents who have ash trees on their property to act now rather than wait for visible signs of decline.
“This is a good time to identify any ash trees on your property,” Bethea said. “Decide which ones if any you want to keep and contact a licensed pesticide applicator to begin protective treatment with a systemically injected insecticide.”
Mills said homeowners planning to remove ash trees that are already in poor condition should wait until mid-October, after the adult EAB beetle’s flight season has ended.
“Pre-emptive removal of such trees will allow them to replant with trees that aren’t vulnerable,” he said. “This will start restoring tree canopy and also spreads out the cost of removals. Simply waiting for EAB to start killing trees in your town can become overwhelming in a short period of time and costly.”
Mills added that dead or dying ash trees quickly become hazardous, raising both the risk and expense of eventual removal.
He also cautioned against transporting firewood out of the quarantine zone. Moving firewood more than 10 to 15 miles from an infested tree can carry the pest into areas not yet affected, Mills said.
EAB was first detected in the United States in Michigan in 2002 and has since killed more than 100 million ash trees nationally. The pest arrived on the West Coast in June 2022, when it was confirmed in Forest Grove. Newsberg first reported on the threat to the Yamhill County area in 2023, noting a false positive detection in Newberg at the time.
Residents who suspect an infestation can report it at oregoninvasiveshotline.org. Additional identification and management resources are available at OregonEAB.com.
