An outbreak of Japanese beetles, whose wide-ranging diet includes fruit, hops, grass and asparagus, has been detected in Central Washington.
The state Department of Agriculture on Tuesday found 145 of the invasive bugs in eight traps in Grandview, Yakima County, the state’s top producer of farm goods.
It was the first day the department checked traps hung in the spring. The department will put up additional traps to document the spread, but more importantly to kill beetles, spokeswoman Karla Salp said June 30.
The beetles are above ground for about two months in the summer. The department probably won’t apply pesticides this year because it must do an environmental assessment first, she said.
“We’re doing everything we can this year without an actual eradication,” Salp said.
“The most important thing now is to keep as many as possible from reproducing,” she said. “Every female we trap this year is potentially 130 fewer we have to deal with next year.”
Japanese beetles are highly destructive pests that are difficult and expensive to control, according to the USDA.
The beetles infest the eastern half of the U.S. They have largely have been kept out of the West, though Oregon has been battling an outbreak for several years by spreading a granular larvicide on lawns and flower beds in Portland and its suburbs.
The Utah Department of Agriculture and Food this spring sprayed 300 acres scattered over three counties after trapping 89 Japanese beetles, the Standard-Examiner newspaper in Ogden reported.
Each year, Washington traps for Japanese beetles, but has never found many. A Grandview woman, however, reported finding dozens on her roses last year.
Her report tipped off the department and led to more intensive trapping in the area this year. “Thank goodness for that woman’s report,” Salp said.
The insects are underground in the larval stage for about 10 months a year and can spread in potting soil. Live beetles have been known to stow away on aircraft or hitch rides in vehicles. Interstate 82 passes through Grandview.
The beetles have metallic green bodies, bronze wings and white spots on the side. Traps scented to lure Japanese beetles are commercially available.
The agriculture department is asking people to report Japanese beetles online at agr.wa.gov/beetles.