This drawing shows the life cycle of one of the worst of all white grubs, the larvae of Japanese beetles. Japanese beetles are a double threat because as adults the winged beetles fly around the garden, feeding on flowers and foliage of many plants, especially roses and related species such as cherries. To control the adult beetles in summer (when they feed on foliage and flowers) use Bayer Advanced™ Dual Action Rose & Flower Insect Killer Concentrate according to label directions.