Japanese beetle found near Pasco; more could be hiding

PASCO — A Japanese beetle was confirmed in Pasco in July, according to a statement from the Washington State Department of Agriculture.

A Franklin County Horticultural Pest and Disease Board trapper found the beetle and state officials responded to the catch, verified the beetle, and set up a delimiting trapping grid around the find, according to the statement.

“This is an excellent example of just how important agency collaboration is,” Camilo Acosta, WSDA Japanese beetle eradication project coordinator, wrote in the statement.

The trap produced a single beetle. WSDA teams began immediately setting up additional traps and checking nearby nurseries for additional detections.

“A single beetle is less cause for concern because one beetle can’t reproduce,” Acosta wrote. “But we need to be sure there are not more. Last year, a single beetle was found in Richland, but extensive trapping in the area did not detect additional beetles.”

State officials urge anyone in Yakima, Benton or Franklin counties to look for and report these beetles, the statement said. Growers can consult crop protection specialists and community members can consult WSDA’s website for guidance from Washington State University Extension on protecting their gardens from this invasive pest. WSDA mapping specialists created a real-time detection map that growers can use to determine how close they are to known Japanese beetle detections.

Japanese beetle adults are metallic green and brown and have little tufts of white hair on their sides. They emerge — usually from lawns or in other soil — and feed on more than 300 types of plants. From fall to spring the grubs overwinter in the soil and slowly develop into mature adults ready to emerge again the next year in the summer as temperatures warm.

To rid the area of the pest, community members can help by trapping, reporting and killing the insects on their properties, the statement said. Residents who live in an area where the beetles have been detected can limit the spread by not moving plants, yard waste or soil from their property to prevent spreading the beetles.

“We also urge you to leave your plants, or treat them with an appropriate insecticide, before moving from the area,” Acosta wrote.

Adult beetles can hitchhike on vehicles and on items stored outdoors, according to the WSDA. When adult beetles are flying, those who live in or visit the quarantine area should take a second to ensure they are not giving a free ride to beetles when they leave the area. This can be as simple as checking the back of a pick-up truck to ensure that no beetles are taking advantage of a free ride.

In 2020, WSDA first discovered just three Japanese beetles in the Grandview area, according to the statement. In 2021, the department trapped more than 24,000 beetles, and in 2022, trappers caught just under 24,000. So far this year, teams have caught about 6,600 beetles. Japanese beetles are highly invasive pests of more than 300 plants, including roses, grapes and hops. Adult beetles damage plants by skeletonizing the foliage. Adults also feed on buds, flowers and fruit on the plants and are frequently intercepted with air cargo from the Eastern U.S.

If Japanese beetle becomes established in the area, it could have significant impacts on gardens and yards, parks and farms as well as farmers’ ability to move agricultural products out of the area, the statement said.