Japanese beetles can be controlled by handpicking or the use of insecticides. Contact your local Extension office for up-to-date pesticide recommendations. Always follow the direction on herbicide labels. Late summer, early fall, and midspring are choice times to broadcast granules of appropriate insecticides. Always follow label directions when applying insecticides. The larvae of these hungry beasts feed on roots of all your valuable plants, waiting for proper warmth to come aboveground and attack the leaves and stems. Control is most effective in the larval stage. Japanese beetles can feed on more than 300 kinds of plants. The adults feed mostly from mid-July through August. In midsummer, the female lays eggs in lawns and cultivated land, from which larvae (grubs) develop. The grubs feed primarily on the roots of grasses and other plants. The grubs go through the winter and complete their development the following spring. They emerge as beetles beginning about mid-June. The adults attack and injure flowers and foliage, and the grubs can seriously damage lawns and cultivated crops by feeding on the root systems. Contact your local Cooperative Extension office for more information on insecticides available for Japanese beetle control.

Browse related Faqs by tag: horticulture, plant-insect relations, japanese beetles