Invasion! Japanese Beetles Have Agriculture Officials Concerned

Agriculture officials in Oregon say that a record number of Japanese beetles have been found this summer in Washington County within the city of Portland.

The species - which is invasive - has previously made its way to the area through air cargo carriers. It likes to feast on a wide variety of plant materials including trees, shrubs, flowers, fruits, and vegetables.

Officials says they have found 265 in traps as well as numerous live beetles damaging roses and other plants. They say the evidence suggests that a breeding population has been established in the area,

"What we know right now is that this infestation is localized yet producing enough adult beetles that we can find them feeding on roses and other plants in this area," says Clint Burfitt, manager of ODA’s Insect Pest Prevention and Management Program.

"Without community action, this pest will spread and cause an increased use of pesticides by homeowners and producers of agricultural crops such as cannabis, hops, nursery plants, and wine grapes."

Officials say that it appears the infestation has been present more than one year but was only detected this summer. Additional traps have been placed in the area of Northwest Saltzman and Northwest Thompson roads.

There are no plans yet to kill the beetles. Officials plan to keep trapping them in the hopes of pinpointing the location of the breeding population.

"We encourage residents to cooperate with field technicians who are maintaining traps and to be aware that this infestation can be spread by the movement of plants, roots, and soil that originate from this area," says Burfitt.

Photo courtesy Oregon Department of Agriculture.