Controlling Japanese Beetles
You can’t miss them. These voracious pests eat and mate in broad daylight and feed on the leaves and flowers of over 300 different types of plants and the roots of turf grass.
You guessed it - Japanese beetles. Knocking the beetles off the plants into a bucket of soapy water is the most environmentally-friendly method of control. Try doing this in the morning when the beetles congregate on the plants.
Milky spore disease applied to the lawn kills the larvae of the Japanese beetles. It takes several years for the disease to build up and provide control. In the meantime, you can’t use other pesticides on the lawn. And, keep in mind the adults can fly up to 2 miles and move in from surrounding areas.
Some gardeners find it easier to embrace the damage, calling it “Japanese lace” and give up the fight. Healthy plants can tolerate the damage.
A bit more information: Organic insecticides such as Neem, pyrethrin, rotenone and spinosad will provide some control. Systemic insecticides such as Bayer Tree and Shrub Insecticide are applied to the soil at least 20 days before feeding is expected to begin. I don’t recommend traps as most experts agree that traps attract more beetles into your yard.