WA ag agency asks thousands of property owners for help in fight against invasive bug

Property owners in Yakima, Benton and Franklin counties are being asked to cooperate with state efforts to eradicate invasive Japanese beetles by allowing Washington’s Department of Agriculture to treat their yards with an insecticide.

About 17,600 property owners in the area, located in central and eastern Washington, will begin to receive letters from the department with information about the project and consent forms to have their properties treated. These treatments are free of cost to anyone within the targeted area.

The beetles pose a threat to plants and crops as they can eat more than 300 species, chewing large, irregular holes in leaves. Roses, grapes and hops are among the crops that the insects feed on. Larvae are found in soil and eat the roots of grass causing it to brown and die. The bugs can easily spread in yard waste, purchased plants, infested sod or gardening soil.

Japanese beetles don’t bite or spread disease to humans.

Three of the beetles were detected in Grandview, Wash., in 2020. The following year, more than 24,000 were trapped in the area. Beetle numbers climbed in 2024, with the Washington State Department of Agriculture Pest Program collecting more than 26,700, up from 19,655 in 2023.

The department’s multi-year eradication plan includes mass trapping, insecticide treatment, and establishing a quarantine that restricts the movement of yard waste, plants and soil in areas with the beetle.

For property owners who cooperate with the upcoming treatment program, a contracted and licensed pesticide applicator will apply an insecticide called Acelepryn to their yards in the spring and summer. This product kills both the larva and adult Japanese beetles when they eat or come into contact with it.

This insecticide poses no risk to mammals, birds, or fish and raises a very low concern for human health as the active ingredient has not been found to cause allergic reactions, according to the Washington State Department of Health.

No symptoms or illness have been reported following applications of Acelepryn or Acelepryn G, a granular version of the pesticide, in Washington or Oregon, according to the health department.

“We need the community to come together and get their yards treated if we hope to stand a chance of eradicating this beetle,” said Sven Spichiger, pest program manager at the state Department of Agriculture.

“We’re looking for 100 percent participation,” he added. “If property owners don’t allow treatment, the beetle will establish here permanently, resulting in expensive quarantines and trade restrictions for our farmers and an endless battle with beetle infestations for homeowners.”

Jacquelyn is a Murrow News Fellow with the Washington State Standard. She has previously covered the state legislature in 2024 as an intern with The Seattle Times and has also interned in Samoa at the Samoa Observer and at The News Tribune and WA Latino News covering Latino issues in Washington state. She was one of five students nationwide chosen to be a part of ProPublica’s Class of 2023 Emerging Reporters and most recently graduated from the University of Washington in August 2024.