My basil plants weren’t only wilting in the scorching summer sun this week, they were swaying violently as if they were literally shaking from their stems. They were moving, but not from the wind. The once-supple green leaves were covered in iridescent green and bronze bugs. Tons of bugs! Crawling all over each other and taking out their appetites on my poor basil!

The culprit: Japanese beetles. They’re taking a bite out of Iowa gardens and farmers’ fields.
According to Iowa State University (ISU) Extension (, the beetles feed on 300 different types of foliage and they are difficult to control. For gardeners with small plots, one of the best ways to combat the bug is to shake them off of the plants. ISU Horticulturalist Richard Jauron says the best time to physically remove Japanese beetles is early morning when the beetles are sluggish. Collect or shake beetles into a bucket of soapy water and discard the carnage. If that doesn’t work, using an insecticide is the next step.

For farmers with hundreds of acres of soybeans, the small insects represent an even bigger problem. Steve Swenka, a farmer in Tiffin, says the Japanese beetles are a result of the dry conditions.

“If we had plentiful rains, those insects would be knocked down from the plants and washed away. Plus, it would encourage new plant growth to replace the damage caused by the beetles,” says Swenka. “This season’s dry weather has compounded that problem.”

Dustin Sage farms near Dunkerton and says the beetles are showing up in his corn and soybean fields, too. He says farmers are carefully applying insecticide to their fields in an effort to curb the damage. Protecting the crops will keep the plants healthy.

ISU Extension says Japanese beetles are present for about six to eight weeks every summer. Adult beetles usually begin to emerge from the ground in mid-June and new adults continue to appear through July. Each beetle lives from 30 to 45 days.

Farmers and gardeners like me alike are definitely counting down those days.

Written by Heather Lilienthal
Heather is a communications specialist with the Iowa Farm Bureau.