As of last week, Japanese beetles are flying around Raleigh, eating everything in sight. If a pesticide application in the landscape is necessary, active ingredients like carbaryl (Sevin), bifenthrin, dinotefuran and imidacloprid are effective BUT will also have a negative impact on pollinators. Because adult beetles tend to aggregate (cluster) on plants, removal by hand of adults may provide enough protection for flowering plants in home lawns.
If you are making a preventive application for Japanese beetle larvae (white grubs), now would be a good time for an application, prior to egg hatch. If you are making an application near flowering ornamentals, please refer to the Pollinator BMPs in Turfgrass document before spraying. For more info on Japanese beetles, including specific chemical recommendations for white grub applications, visit Turffiles. For more info on Japanese beetle adults in the landscape, visit the Entomology Insect Notes.