The Japanese beetle can cause serious damage to nurseries, seedbeds, orchards, field crops, landscape plants, and garden plants. The adults typically skeletonize leaves, consume flowers, and devour fruits. The upper canopy is often defoliated first. Trees with extensive feeding damage turn brown and become partially defoliated. Japanese beetle grubs primarily feed on roots of turf and ornamentals, but will also feed on roots of garden and field crops such as corn, beans, tomatoes, and strawberries. Dense populations can kill large areas of turf grass and seriously injure or kill other plants.

The Japanese beetle is considered the single most important turfgrass pest in the U.S. Sites with large areas of turf such as parks, golf courses, cemeteries, and businesses are at risk. It can also be a problem in residential lawns, gardens, fruit trees,
ornamental trees, and shrubs. Oregon has extensive habitat suitable for Japanese beetle survival and reproduction. The Oregon Department of Agriculture has successfully eradicated several isolated Japanese beetle infestations in western Oregon. Newly infested states are subject to strict quarantines on agricultural and horticultural products to prevent further spread of the pest.