OLYMPIA—A new guide to help Washington landowners and land managers detect and limit the spread of an invasive, wood-boring beetle that attacks and kills ash trees is now available thanks to the collaborative effort of state and federal agencies.
Native to eastern Asia, the emerald ash borer first appeared in the United States in 2002 in Michigan. Since then, it has killed millions of North American ash trees in the eastern and midwestern United States, with some locations suffering deaths of nearly all ash trees.
“While emerald ash borer has not been detected in Washington, its presence in neighboring Oregon and British Columbia means it could arrive soon, posing a serious threat to ash trees in Washington state,” said Dr. Joey Hulbert of the Washington State University Urban Forest Health Lab. “Taking action recommended in this guide now will prevent and help mitigate numerous issues when this destructive beetle arrives.”
The Pacific Northwest is home to one native ash species, the Oregon ash, but the beetle can impact other ash species that are popular as ornamental or street tree plantings, such as white ash and green ash. Washington could experience near-total mortality of ash trees within 10 years of infestation.
In wild environments, losing trees to emerald ash borer has changed forest structure, leaving gaps that can have lasting impacts to forest health. Loss of ash trees will affect wildlife dependent on them for food and habitat, including birds, beavers, deer and elk, and may increase stream temperatures, harming salmon and other animals that live there.
Without proactive management to mitigate the loss of ash trees in streets, parks and yards, cities likely will see more maintenance costs, liability concerns, and loss of shade.
The Washington State Emerald Ash Borer Resources & Management Guide is intended to help landowners, educators, resource managers, tree care professionals and the public take steps to reduce risk, strengthen readiness and plan a coordinated response for when the emerald ash borer arrives. The guide includes general information about the beetle, prevention steps and response and management strategies.
“We encourage reports on the Washington Invasives mobile app or website,” said Jan Fore, executive coordinator of the Washington Invasive Species Council. “But we also want everyone to know that the emerald ash borer can be difficult to identify, with many native lookalikes. The council has online resources to help improve accuracy in reporting.”
Multiple state, federal and local partners collaborated to develop the guide as part of the Washington State Emerald Ash Borer Interagency Working Group. Members include the Washington Department of Ecology, Washington Department of Fish and Wildlife, Washington Department of Natural Resources, Washington Invasive Species Council, Washington State Department of Agriculture Washington State Parks, Washington State University and U.S. Department of Agriculture.
“This guide is intended to help communities act early to form working groups, review policies, diversify their tree populations, monitor ash and set up detection and response systems,” said Zeima Kassahun, a specialist in the Washington Department of Natural Resources’ Urban and Community Forestry program. “Good preparation can cut costs, protect public safety and preserve trees in our cities.”
May 17-23 is National Emerald Ash Borer Awareness Week, aimed at raising awareness of the beetle that has killed millions of ash trees across the United States.
View the guide and visit the Washington Invasive Species Council website to learn more about emerald ash borer and native lookalikes.