Mature beetle grubs become active in the spring. They feed on turfgrass roots and can damage lawns. In the summer, adult beetles begin to emerge and feed on garden plants, trees, shrubs, and other foliage. Beetles also mate in the summer and lay eggs. In late summer, the eggs hatch and young grubs feed on grass roots throughout the fall season. As the weather becomes colder, mature grubs go deeper in the soil and become inactive. They will become active again in the spring.

Japanese beetles are a pest to hundreds of different species of plants, doing damage to both turf and foliage. Grubs live in the soil and feed on the roots of grass and other plants. When adult Japanese beetles begin to emerge, they feed on the leaves and flowers of trees and shrubs, causing considerable damage. It's important to know the lifecycle of Japanese beetles, as the wrong product at the wrong time can be a waste of money and effort.