A pest that feeds on a number of plants, including roses, grapes and certain trees has been spreading slowly across Iowa. Iowa State University Extension Entomologist Donald Lewis says the good news is the beetle population has peaked for this summer.
Lewis says if you draw a triangle from Davenport to Boone back to Dubuque, that includes most of the counties that have Japanese beetle infestations. He says there have been reports farther southeast and southwest, and Council Bluffs and Mills and Woodbury County have reported infestations. Lewis says if you’re contemplating a trap to help control the green and copper colored beetles — save your money.
Lewis says research in other states have shown that the Japanese beetle traps attract more beetles than they catch, so the damage near the traps is worse than if the traps has not been there. Thirty-eight of Iowa’s 99 counties report infestations of Japanese beetles.
Lewis says the beetles, which can eat all the leaves off a plant, have been plaguing Iowans since 1994.
He says the beetle populations will slowly taper off until mid-August.