Introduced in the early part of the twentieth century from Japan, Japanese beetles are herbivores that eat the leaves, buds, and fruit of several hundred broadleaf plants as well as flowering ornamental trees. The females lay their eggs on the ground after which the larvae develop and pupate. The larvae eat plant roots including those of turfgrasses and can cause extensive damage to trees, shrubs, and lawns. Adult beetles emerge in late June and July in swarms and will rapidly defoliate flowering trees and shrubs within days.
Symptoms: The Adult beetles feed on leaves and buds. They will eat all the soft tissue between the veins. The resulting lacy remains will wither and fall off. For this reason, they are called skeletonizers.
More information: Ohio State University Extension and EAB Information Network