The infestations of bean leaf beetles in northwestern Illinois in 2002 are still a vivid memory among many growers and ag professionals. There is growing concern about this insect pest and its ability to transmit bean pod mottle virus. As you have heard from us in the past, we still know very little about this insect/disease combination, but we hope to learn more. A team of scientists--Eli Levine and Joe Spencer (Illinois Natural History Survey), Scott Isard (Department of Geography), and Glen Hartman and Les Domier (USDA-ARS)--have conducted some very good research in Illinois, and efforts continue. I will share some of the results from their work in a future issue of the Bulletin.
A question on many people's minds right now is "How will the colder winter temperatures affect bean leaf beetle populations this spring?" As you know, bean leaf beetles overwinter above ground, protected from cold temperatures only by debris and snow cover. It's generally believed that mortality of bean leaf beetle increases when winters are cold. In fact, researchers at Iowa State University have provided some excellent information regarding the relationship between winter temperatures and survival of bean leaf beetles. For details, read the article "Bean leaf beetle and winter survival" published in the May 7, 2001, issue of Iowa State University's Integrated Crop Management newsletter. You can read it on the Web at http://www.ipm.iastate.edu/ipm/icm/2001/5-7-2001/blbsurvival.html.
Scott Isard, whom I mentioned previously, was poking around in some woods and crop fields on March 23, and his observations were worthy of note: ". . . the number of BLB overwintering in the woods in Champaign County are far greater than they have been in the past two springs. Yesterday [March 23] I collected about 100 BLB from a single piece of cloth that I use as an overwintering trap. They are everywhere in the woods and can be found easily underneath corn and soybean stubble in the fields. . . . I estimate that BLB are about an order of magnitude more numerous than they have been during the past two springs . . ." Scott's observations deserve attention, suggesting that bean leaf beetles may have survived our winter in Champaign County quite well. We'll learn more soon enough.--Kevin Steffey