Emerald Ash Borer

*Picture: Close-up of an adult female emerald ash borer feeding on an ash leaf; length ranges from 0.33 to 0.53 inches, that’s smaller than a penny. Credit: Leah Bauer, USDA Forest Service Northern Research Station, Bugwood.org

Emerald ash borer (EAB), an invasive beetle that infests ash trees, was discovered in Forest Grove, Oregon, on June 30, 2022. This is the first time EAB has been identified in Oregon, but the state has been preparing for its arrival for years.

EAB was first discovered in the United States in Michigan in 2002, likely arriving in wood packing materials from Asia. This metallic wood-boring beetle threatens all species of ash tree (Fraxinus genus) and is considered the most destructive forest pest ever seen in North America with the potential to create billions of dollars in damages nationwide. EAB has killed hundreds of millions of ash trees across the east coast and Midwest over the last 20 years. Here in Oregon, loss of our native ash tree, Oregon ash (Fraxinus latifolia), a very important riparian and wetland species west of the Cascades, is of grave concern, as well as the loss of widely planted non-native and cultivated ash trees in urban landscapes.

Unfortunately, there are no effective means of eradicating EAB, but here’s what you can do to help:

Be on the lookout for EAB. Learn to identify ash trees and EAB (there are many look-alikes), and report suspected sightings immediately.
 
Don’t actively plant ash trees, but take good care of the ash trees you have. This includes providing supplemental water during summer heatwaves, treating high-value ash trees with systemic insecticides, and removing dead and dying ash trees and replanting with another species suitable for the specific site conditions. A qualified and experienced plant health care specialist can prescribe and implement appropriate treatments.
 
Don’t move firewood and be sure to dispose of ash wood properly. 

Learn more about EAB by visiting these resources:

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