Japanese beetles may be spreading across state

The Japanese beetles are out in full force again. Some populations appear to be spreading. The metallic green-and-copper-colored Japanese beetles have once again begun wreaking havoc on maple and birch trees, some vegetables, and their personal favorite, roses.

UW Extension Agriculture Agent Steve Huntzicker is based in La Crosse. He says it is clear that the bugs are moving from southern Wisconsin to the north. “The La Crosse area, we’re probably seeing it here for the third, fourth, maybe fifth year where we started to see bigger populations of the Japanese beetle,” he says. “And I think you’re starting to see them even as you go farther north towards Eau Claire and even farther north, those populations are starting to pick up.”

Huntzicker says the dry conditions make it less favorable for the Japanese beetle to lay eggs, which he hopes will cut down on numbers.

Jeff Epping is the Director of Horticulture at Madison’s Olbrich Botancial Gardens. He says they’ve dealt with the Japanese beetle for about five years, especially in the rose garden. Epping says they don’t use insecticides to control the beetle because it could affect beneficial bugs, like pollinators. So, volunteers remove them by hand. “Put on a pair of gloves, squish them,” he says. “Grab them, throw them in a 5-gallon bucket of soapy water, which does them in. So we do that. It adds a little impact, I think it’s more of a feel good thing than a huge control, but it helps.”

Epping says they also use a bacteria to kill the Japanese beetle grubs that feed in the soil.