Spotted cucumber beetles feeding on fall flowers

At the end of August, my husband asked me what the heck was flying all around the gourds that were planted in the garden. I was quite shocked at the population of spotted cucumber beetles! I have never seen that many in one spot.

They were not only eating the foliage of the gourds, but were feeding on the gourds themselves. They were also on the thistles that were growing in the garden (yes, I have a weed problem!).

After spraying the gourds with a product containing pyrethrins, I noticed that many of them left the area quickly only to settle on some of my nearby perennials. I kept an eye on them for a few days and then forgot about them.

Last week, while sitting on the back porch, I was extremely annoyed by the spotted cucumber beetles once again; this time they were hanging around my salvia, lantana and other annuals in my containers.

Again, the populations were so high that we were swatting them away almost like mosquitoes (which, by the way, are annoying right now as well). I didn’t spray these plants as the pollinators were still working them aggressively.

Take note! Every few years it seems that there are high populations of spotted cucumber beetles that have moved from vegetable gardens into the flower beds. They love to feed on the supple, tender sweet petals of dahlia, mum, petunia, portulaca, sunflower and many others.

What I found interesting was that they seemed to be working the salvia but not actually feeding on it.

The problem when they feed on some of our annual and perennial flowers is that they like to burrow down into the multiple-petaled plants (dahlias, portulaca), only to be discovered when the flowers bloom. The petals are riddled with holes and by that time it’s too late.

Start inspecting your flowers now for these pests and knock them into a bucket of soapy water or use recommended sprays. If you spray, make sure to follow the label to protect pollinators, however.

There are two primary species of cucumber beetles, the spotted and the striped. The spotted are a yellowish-green color and the striped is more yellow.

The spotted cucumber beetle has 12 black spots on its back and the striped has three black stripes down the length of the wings. Both striped and spotted cucumber beetles are a vector of plant diseases (cucumber bacterial wilt, mosaic viruses, and more) and can be a serious pest in cucurbits (those in the squash, cucumber family).

Spotted cucumber beetles are sometimes called “rindworm” because of the feeding damage to the surface of the fruit. The damaged almost all of my dipper, swan, and bird house gourds.

They also feed on roots and the base of stems while the striped cucumber beetle feeds mostly on stems and roots. The spotted tends to be more of a pest on cultivated flowers. Pamela Corle-Bennett is the state master gardener volunteer coordinator and horticulture educator for Ohio State University Extension. Contact her by email at bennett.27@osu.edu.