Destructive Japanese beetles found in two Idaho counties

BOISE – A destructive invasive insect has turned up in Ada and Kootenai counties, prompting warnings from the Idaho state Department of Agriculture.

The Japanese beetle, a half-inch-long, shiny metallic-green bug with copper-brown wing covers, destroys trees, rose bushes, stone fruits, gardens and field crops, and its larvae or grubs destroy turf by feeding on the roots of grass.

The department is asking anyone who finds one of the bugs in Idaho to place the dead specimen in a plastic bag and mail it to its Plant Industries Division, P.O. Box 790, Boise, ID 83701, along with contact information.

The state also has begun placing green and yellow traps in the two counties. The traps are nontoxic, and people who see them are asked to leave them be.

The beetle was introduced to the United States in 1916 in plants imported from Japan.

No infestation has been reported in Eastern Washington. The Washington Agriculture Department has monitored for Japanese beetles since the mid-1980s and puts out about 1,500 traps each year, said Mike Louisell, a public information officer for the department. They are put up in June and monitored regularly through September.

Most traps are near airports and other facilities that handle air cargo, including Spokane International Airport and Fairchild Air Force Base.

The traps detect a couple of Japanese beetles each year, including one Aug. 7 near the Spokane airport, Louisell said. But there is no local breeding population in Eastern Washington, and there’s no indication that the beetle caught this month is connected to any population in Kootenai County, he added.

Washington is following reports of Japanese beetles in Idaho, “but we’re not sounding any alarms,” he said.

Idaho agriculture officials said this is the first time the beetles have turned up in Idaho.