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Japanese beetle eradication plan announced

Japanese beetles are tiny—slightly bigger than ladybugs—but the destruction they cause is huge. They are voracious and undiscriminating. They’ll eat your roses, your tomatoes and your marijuana plants. They’ll even eat hops and wine grapes. Their appetites are costly, both to homeowners and Oregon’s $33 million nursery and horticulture industries.

Japanese beetle detections in NW Portland 2016. 402 Japanese beetles were caught between 1988-2015; 2016 catches (343) are 92% of the total for the past 27 years combined!

The Oregon Department of Agriculture has known about them and has had traps around Portland International Airport since 1991. They aren’t good flyers, said Clinton Burfitt, manager of the state Insect Pest Prevention and Management Program. But they are good at hopping flights from the Mid-West and East Coast—their current population centers. Traps have yielded only a few at the airport until 2010. And that’s where they’ve stayed.

But they hitched a ride to Cedar Mill in 2016. Last summer 372 were trapped near NW Saltzman and Thompson Road areas. Traps were baited with the scent of roses, which the beetles find irresistible. Because the damage they cause is so great and so many were found so far from their usual location at the airport, the Oregon Department of Agriculture has plans to eradicate the beetles before they spread further.

The Japanese beetle life cycle.

Starting this spring when the beetles lay their eggs, workers from the department will use seed spreaders to sprinkle Acelepryn G granules in the soil of infested areas. Adult beetles love our lush lawns and lay their eggs there in July. Grubs stay in the soil till June when they become adults. The pesticide, which the Environmental Protection Agency labels “reduced risk,” is designed to kill the beetles at the grub or larva stage. It’s not hazardous to mammals, but is to aquatic invertebrates, so where there are creeks, such as in the Willow Creek area, biological controls are planned, he said.

“It’s better to kill them in the larva stage than when they’re adults,” Burfitt said, noting killing adults with pesticides also kills beneficial pollinators. In that vein, he also strongly cautioned against homeowners applying pesticides on their own or as a preventative measure. Homeowners outside the area won’t have to be treated. Residents who find beetles are encouraged to report them to his office.

2017 Potential treatment area in NW Portland: ~2,500 single family properties, 900 acres

The timeline for treatment is:

• Jan.—Notification cards to affected residents (about 2,500 homes)
  
• Feb.—Dept. of Agriculture open house to explain plan
  
• Mid-Apr. to mid-May—Spread Acelepryn G granules

Burfitt said the 900-acre treatment area will be regularly monitored for up to five years. In a presentation to members of area homeowners’ associations in November, he asked residents to help get the word out about the need to eradicate the pests and his department’s plan to do that. With their help, he was hopeful that the effort would work. In Cave Junction, beetles were found and dispensed with in 1989,  2011 and 2012. None have been found there since. 

The Cedar Mill News is working with Burfitt to keep residents apprised. More information can be found at japanesebeetlepdx.info.

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