They’re back: Popillia japonica!

First of the season

It must be mid-June in central Maryland. I was weeding Wednesday afternoon morning and there, sunning itself on a Shasta daisy bloom, was Popillia japonica—the Japanese beetle.

This is the month adults emerge from the ground, look for some tender fast food, and then head off to a single’s bar to find a mate.

Food, did you say? Yes, Japanese beetles dine on 200, 300, or 400 different plants—depending on the source you consult.

For veggie and fruit gardeners, common beetle foods are the leaves of green beans, brambles (especially blackberries), and stone fruits such as peach, cherry, and plum. Flower gardeners often find them dining on their roses and zinnias.

What to do?

Solutions abound. Hand pick them or flick them into soapy water is a traditional favorite. Floating row covers may keep them away from your favorite plants. Registered insecticides will do the trick—and you will follow directions, won’t you?

And then there are the yellow traps that lure the beetles with sex pheromone. But do you really want to entice all the Japanese beetles in your neighborhood to come to your garden? But you could buy a trap and give it as a gift to a neighbor. No, no—you wouldn’t do such a nasty thing, would you?

The list of remedies is a long one. You may not have heard of some of the newer approaches—such as imported parasitic wasps that prey on the beetles. If you want to be the expert on your block about Japanese beetles, I suggest you read “Managing the Japanese Beetle: A Homeowner’ Handbook,” by the Animal and plant Health Inspection Service of the U.S. Department of Agriculture (Program Aid 1599). To access the booklet, CLICK HERE.