Officials confirm first detection of emerald ash borer in Walla Walla County

OLYMPIA – Just one month after confirming the first-ever detection of emerald ash borer in the state, the Washington State Department of Agriculture (WSDA) and the United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) have confirmed a first-in-county report of emerald ash borer (EAB) in Walla Walla County.
 
A College Place area arborist noticed and reported potential emerald ash borer damage. Upon receiving the report, WSDA responded to the location and discovered multiple larvae as well as D-shaped holes — typical of emerald ash borer infestations — in multiple ash trees. WSDA collected specimens and sent them to USDA, which confirmed the specimens as emerald ash borer on October 14.
 
About emerald ash borer
 
Emerald ash borer (Agrilus planipennis) is an invasive insect that has proven to be one of the most destructive forest pests in North America. Since its initial detection in the United States two decades ago in Michigan, emerald ash borer (EAB) has wiped out more than 100 million ash trees throughout the country.
 
All true ash species (Fraxinus), including Oregon ash, the Pacific Northwest’s only native ash, have proven vulnerable to EAB.
 
A Washington State Department of Natural Resources (DNR) analysis found that without taking action to manage an outbreak, a municipality should expect to lose 90-100% of its ash tree inventory within 10 – 12 years of an initial EAB infestation.
 
There are no reliable methods to stop the spread or contain an outbreak of EAB other than limiting the transportation of firewood, removing affected ash trees and replacing them with non-ash species that are not susceptible to EAB or other common pests. A firewood quarantine adopted by WSDA to prevent the introduction and spread of invasive insects and diseases took effect on August 18.
 
There has never been a successful effort to eradicate EAB. Land managers and homeowners should immediately cease planting new ash trees.
 
Collaborative planning efforts, monitoring for continued spread and community preparedness initiatives will be essential for mitigating and managing the spread of emerald ash borer in Washington state.
 
The DNR Urban and Community Forestry Program, WSDA, WISC and Washington State University Extension (WSU) have led a collaborative effort in recent years to publish the State of Washington Urban Forest Pest Readiness Playbook and the Washington State Emerald Ash Borer Resource and Management Guide.
 
Both documents include detailed recommended actions for local governments to draw from as they plan their own EAB responses. These and related resources may be found at treehealth.wsu.edu/eab.
 
Financial and technical assistance for municipal urban forestry activities will continue to be provided by the DNR Community Forestry Assistance Grant Program as long as funding remains available. Technical assistance from DNR is available to local governments, special use districts, tribes, schools and 501c3 non-profit organizations, and may be requested using a new online portal.
 
Washington residents are urged to be vigilant and report suspected sightings to WISC by using one of the following options:
 

• Online at invasivespeciaswa.gov
• The Washington Invasives app available for free on Google Play and the Apple App Store.
• Email screenshots, links, and as much additional information as possible about reports made on social media or other platforms such as iNaturalist or Nextdoor to invasivespeciesinfo@rco.wa.gov.
• Preserve physical specimens as you are able by placing the insect in a plastic bag and freezing it. You may also place it in a vial with ethanol or isopropyl alcohol. Please write your name, the date, and where the insect was sighted (GPS coordinates preferred) on the container.

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Karla Salp
WSDA Communications Consultant
pio@agr.wa.gov
 
Will Rubin
DNR Communications Manager
Cell: 360-764-0854
will.rubin@dnr.wa.gov
 
Jan Fore
WISC Executive Coordinator
360-704-0973
jan.fore@rco.wa.gov