pest

Everyday Gardeners

They’re baaaack!

Roses are one of the favorite foods of Japanese beetles. When one starts to feed, it releases a pheromone that attracts more beetles. Early control is essential to prevent a full-force invasion.

Japanese beetles are back in central Iowa, several weeks ahead of schedule. This morning while photographing in the garden, I noticed (and killed!) half a dozen of the pests on a rose bush, one of their favorite plants. Among the 300 or so other plants that attract them are grapes, hollyhocks, hibiscus, crabapples, and lindens.

Adult beetles usually don’t emerge until late June, but as with everything else garden related this year, they’re well ahead of schedule. Normally the adults feed for several weeks before laying eggs in the ground. We can hope that their early emergence also will result in their early departure! But this means it’s time to start my daily morning rounds of the garden with a bucket of soapy water. I find that’s the simplest and most effective way of controlling them. I hold the bucket under the flower/plant on which they’re feeding, give the bloom a little tap, and the beetles drop into the sudsy solution to their demise.

Avoid the temptation to purchase a Japanese beetle pheromone trap to control the pests. These devices do indeed lure and trap hundreds of the critters, but they also attract many more that never make it into the trap. Instead, the extra beetles feed on the plants in your garden, causing even more damage than had you done nothing.

Japanese beetle trap.