In soybean fields and elsewhere, adult bean leaf beetles are fairly common right now. I have spotted them as I walked across campus, and a few have flown through the open windows of my car. Reports from the field indicate that the beetles are relatively easy to find, at least in central Illinois, and that symptoms of injury are apparent. However, no one has reported significant amounts of defoliation yet.
Of special interest is the possibility that bean leaf beetles might transmit viruses to soybeans. Researchers at the University of Illinois, Iowa State University, and University of Wisconsin are investigating the relationships among bean leaf beetles, viruses, and soybean plants; and results of their efforts will be forthcoming this fall. Hopefully we'll be able to manage the problem effectively in the future.
Information about bean leaf beetles and the injury they cause in soybeans was offered in issue no. 18 (July 28, 2000) of the Bulletin. Let us know what you find.--Kevin Steffey