We’ve been seeing a smattering of Japanese beetle adults in our traps for the last few weeks in West Lafayette, but it appears their numbers are starting to increase as we head toward the end of June. Expect to see emergence come into full swing over the next two weeks in this part of the state.
This imported pest is common east of the Mississippi river and in the Mississippi river valley. Adults feed on more than 400 plant species including many common ornamental plants. The soil-dwelling larvae (grubs) damage a variety of plant roots including those of ornamental trees, shrubs, and turfgrasses.
For more information about the biology and management of this insect, visit the following Purdue Extension Entomology links.
Japanese Beetles in the Urban Landscape http://extension.entm.purdue.edu/publications/E-75.pdf
Turfgrass Insect Management
Doug Richmond, Associate Professor and Turfgrass Entomology Extension Specialist