We’re talking Japanese beetles here with the laugh-of-the-day provided by a University of Arkansas Division of Agriculture description of the pests.

“Japanese beetles have the perfect life…all they do is eat and have sex,” writes retired horticulturist Gerald Klingaman. “They emerge sometime in late June and quickly begin emitting a substance called ‘congregation pheromone’ which signals all their buddy bugs to come over for an orgy.  When they find a plant to their liking, they appear en mass and skeletonize it.”

That’s the worry of the Washington State Department of Agriculture based on an infestation discovered in the agricultural community of Grandview in Yakima County, home to grapes, hops, corn, cherries, and a number of other crops favored by the metallic green and brown beetles.

On a day in late June when trappers began re-checking a location with a few dozen beetles found on a rose bush last year, they collected over 400 of the beetles. 

“There’s definitely been an uptick in reports of beetle sightings centered around the small agricultural town with hops and grapes the biggest commodities that would be impacted,” department spokeswoman Karla Salp told Farm Press.

Once they infest grapevines, they skeletonize the leaves, sometimes attacking the fruit as well.  Feeding on the grape vine leaves, they eat the foliage surface material between the veins, leaving only the veins in place, with destruction looking like the vines were skeletonized.  Although mature vigorous grape vines can tolerate a bit of defoliation, this insect can cause some serious damage to a grape crop.

“There’s obviously a lot of concern here, not only from a crop production standpoint, but if the pest were to become established, it would probably have to have some form of quarantine until we could get a handle on it,” Salp said.  “It’s definitely going to have some kind of local impact, so our focus will be to contain it in the smallest area possible.”

‘At this point we’re optimistic’

Oregon is fighting a similar localized battle with the beetle.

“It’s challenging, but at this point we’re optimistic because it’s been limited in scope with the main infestation localized and that’s good news,” she said. “We’re going to ask for public assistance as we’re working on getting 3,000 traps to the general public and encouraging them to trap wherever needed.

“This year we’re working to try and figure out just how widespread the infestation might be and next year we’ll go with targeted eradication plans, usually a granular insecticide in infested areas,” she said. “They spend about three quarters of the year buried in the ground as larvae, feeding on the roots of grass and other plant material, and a granular application is one of the easiest ways to try and stop them.”

We’ll give the humorist horticulturist from Arkansas the last word on battling the beetles.

“Trapping is more controversial because, just like bug zappers, it attracts more bugs to your yard.  If your yard is isolated, this might be effective control, but in a suburban setting your yard may end up looking like the site of a teenage party when parents are away for the weekend.”