State Officials Ask Residents to Check Trees for Invasive Insects and Diseases
News Date: 
August 10, 2022

National Tree Check Month comes as Washington scientists study emerging threats to western Washington tree health

Officials from the Washington State Department of Natural Resources, Washington State Department of Agriculture, and the Washington Invasive Species Council are asking members of the public to check their trees, water features, and other outdoor fixtures this month for invasive pests as part of National Tree Check Month.
August is the ideal time for Washington residents to make a habit of checking for harmful bugs and diseases on their properties and in public spaces, because it is often when the visible impacts of those pests become most obvious.
“We have a forest health crisis in Washington, and we know that outbreaks of invasive insects and diseases are one of the leading threats to the long-term health of our forests,” said Commissioner of Public Lands Hilary Franz. “Our all lands, all hands approach to forest health means we need everyone pitching in to help protect our forested lands from invasive pests.”
Taking a few minutes out of one’s day to inspect a backyard or park can help local and state officials limit the tree mortality inflicted across Washington by invasive insects and new diseases.
Just this year, a Washington State University researcher found evidence of sooty bark disease while walking his dog through a Tacoma park. In June, a biologist made the first confirmed sighting of emerald ash borer in the Pacific Northwest while he waited to collect his children from a summer camp west of Portland. Last week, WSDA announced the detection of Atlas moth – the world’s largest moth and a tree defoliator – in Bellevue.
“If you already exercise outdoors, walk your dog, or take your kids out to play, try adding a quick check of nearby trees for potential pests,” said DNR Urban and Community Forestry Program Manager Ben Thompson. “With kids, you can even turn it into a game. Challenge them to see how many different insects they can find. Kids are great observers; insects also fascinate many children. The reporting app makes it easy to help them file a report.”
People who suspect they’ve found an invasive insect or disease should submit a report and detailed photographs to the WISC mobile app or web portal. Scientists review submissions and can help connect those with confirmed pests to resources that can help address the infestation.
Private owners of non-industrial forests in Washington may be eligible for financial assistance administered by DNR for fuels reduction and other forms of forest management.
“We’re asking everyone to take a few minutes to search trees in their yards, parks, or along their streets for potential problem insects,” said Justin Bush, Executive Coordinator of the Washington Invasive Species Council. “If you spot and report a new, tree-killing invasive species, your report could prevent widespread and long-lasting costs and impacts. It’s up to everyone to keep the Evergreen State evergreen.”
The public is urged to keep an especially keen eye out for the following five invasive pests:
  • Asian Longhorned Beetle
    • This wood-boring beetle attacks many hardwood trees, including maples, birches, and willows. The insect feeds inside trees during its larval stage, and then chews its way out as an adult. There has not been a confirmed sighting in Washington.
  • Asian Spongy Moth
    • Formerly known as the Asian gypsy moth, these insects lay dark brown egg masses on everything from tree trunks to lawn furniture. Many tree species play host to this insect, which can completely defoliate trees during its larvae stage. The Washington State Department of Agriculture conducts annual surveys for the spongy moth.
  • Emerald Ash Borer
    • This small, green, wood-boring beetle is one of the most destructive forest pests in the United States. It attacks and kills true ash trees with alarming efficiency. Adults emerge from infected trees by creating distinctive D-shaped exit holes. Oregon confirmed the first sighting of this prolific pest in the Pacific Northwest earlier this summer.
  • Sooty Bark Disease
    • A fungus named for the distinctive sooty fungal structures that grow where bark has flaked off infected trees, this disease also causes branch dieback and leaf wilting. Confirmed outbreaks have recently occurred from Bellingham to Olympia. Additional research on the spread of sooty bark disease in Washington is ongoing. Host trees include bigleaf maple, red maple, sycamore maple, and horse chestnut.
  • Spotted Lanternfly
    • When not flying, this insect sports black spots on pinkish wings. It feeds on sap from many tree species, including those that grow fruits such as apples, cherries, grapes and plums. It also feeds on hops. While not confirmed to be in Washington, it was intercepted in California on commercial goods from the eastern United States. Dead specimens have been found in Oregon.
Will Rubin
Washington Department of Natural Resources
Phone: 360-764-0854
Justin Bush
Washington Recreation and Conservation Office
Phone: 360-704-0973
Karla Salp
Washington State Department of Agriculture
Phone: 360-480-5397