The reflector
Several state agencies are asking people to take ten minutes this month to check the trees in their community for signs of invasive insects.
The Washington Invasive Species Council, the Washington State Department of Natural Resources’ Urban and Community Forestry Program, the Washington State Department of Agriculture and Washington State University Extension meet each August to solicit the public’s help in identifying invasive wood-boring insects and the damage they cause to trees, according to a news release from the Washington State Recreation and Conservation Office.
“Late summer is often the time when these invasive insects most frequently emerge from trees in their adult stage,” the press release states.
Invasive insects are found not only in trees, but also in lights and standing water, such as dog bowls and birdbaths. Pool filters can also act as traps for invasive insects.
“Researchers and scientists are monitoring invasive species nationwide, but we need the public’s help,” Stephanie Helms, executive coordinator of the Washington Invasive Species Council, said in the release. “Public awareness of emerging invasive pest problems can significantly reduce the risk of spread, as human travel plays a large role in the spread of unwanted insects.”
According to a government study, at least 70 new insect species have been discovered in Washington since 1990. Thirty-six percent of the new insects were first discovered by the public, which underscores the importance of an informed and educated population, the press release states.
“While you’re outside enjoying summer, take 10 minutes to check your yards and neighborhood trees,” Zeima Kassahun of the Washington Department of Natural Resources said in the news release. “If you see or suspect you see an invasive insect, report your findings, including a photo, to the Washington Invasives mobile app or the Washington Invasive Species Council website, which will forward the report to organizations that can help.”
The Washington Invasives mobile app can be downloaded at invasivespecies.wa.gov/report-a-sighting/.
“Attentive residents can help identify infestations when they are easily manageable,” Helms said. “It only takes 10 minutes to check your trees in August, and you could save the state hundreds of thousands, if not millions, in potential invasive species control costs. And your report could be the one that saves your neighborhood’s trees.”
Early signs of invasive insect damage to trees include sudden dieback or death of trees that are otherwise strong and healthy. The news release says residents who see signs of invasive insect damage should take a closer look and look for sawdust, exit holes or adult beetles.
Invasive insects are more worrying
• Invasive longhorn beetles: The larvae of this group of large beetles feed on the wood of a tree. As the beetles mature, they hatch through holes that further weaken the tree. These beetles are extremely destructive to deciduous trees. Although not known to have become naturalized in Washington today, it has been detected and quickly stopped several times in the past, potentially preventing millions of dollars in damage and countless trees. Invasive longhorn beetles can easily be confused with native lookalikes such as the banded alder borer and the spotted pine wood beetle, which are beneficial to Washington forests.
• Asian ash beetle: This small, wood-boring beetle attacks and kills ash trees. The larvae burrow under the tree’s bark and eat the sapwood. Once damaged, the sapwood can no longer transport water and nutrients, causing the tree to gradually die. Although the beetle is not yet known to occur in Washington, it was spotted outside of Portland, Oregon, in 2022 and most recently in Vancouver, British Columbia, in 2024.
• Spotted lanternfly: This stinging, sucking insect feeds on sap from a variety of trees, including apples, cherries, grapes, plums, walnuts and hops. Although the lanternfly has not yet been found in Washington, it has been intercepted in California hitchhiking on goods from the eastern United States, where it is native.
How to find invasive species
• Look for signs of invasive insects on trees, outdoor lights, outdoor appliances and standing water.
• Report sightings
• If a suspected invasive insect is found alive, take a photo and submit a report with details to the Washington Invasive Species Council, either through the mobile app or the website invasivespecies.wa.gov/.
Follow these steps
If a suspected invasive insect is found dead in lights, pools, etc., take the following actions:
• Collect the insect and place it on an object with a white background (e.g. a paper plate, a piece of paper or a paper towel).
• Photograph the insect from multiple angles (top, side, etc.) and make sure your photo is in focus.
• Place the insect in a ziplock bag or sealable container for safe storage. Entomologists may ask you to send the specimen to a laboratory for identification.
• Report the sighting using the Washington Invasive Species Council mobile app or website.
• Repeat the process as often as you discover a suspicious insect.
Those who are not interested in getting up close and personal with the insects can still participate in August’s tree inspection month by taking the following steps to prevent the spread of unwanted pests:
• Don’t transport firewood from far away locations. Buy firewood where you plan to burn it, or collect it locally if allowed. When you transport firewood, you may also be transporting invasive insects that hide in the wood.
• Don’t transport pests. If you’re traveling within the region or moving to a new area, check your bags, outdoor gear, and boxes to make sure they’re free of insects. Invasive insects, which can be at any life stage from egg to adult, can easily be carried in bags, gear, and boxes, as well as on items that have been stored outside or in your garage.
