— by Dr. Jeff Whitworth and Dr. Holly Davis
The first adult Dectes stem borer was detected on 23 June, from north central Kansas (specifically, DK Co.). These beetles traditionally spend approximately 7-14 days congregating or aggregating around the borders of stubble fields near where they overwintered. Then, they disperse throughout soybean and sunflower fields and begin depositing eggs in plants of either crop. Several more have been collected since the 23rd.
Bean leaf beetle adults have been and will continue chewing characteristic round or oblong holes in soybean leaves. However, at least around north central Kansas, populations seem reduced from recent years.
So far, other than a few small grasshopper nymphs, there seem to be less defoliators than usual in either alfalfa or soybeans. However, there is still time left for significant populations to develop. A few garden webworms and yellowstriped armyworms were collected from a couple of fields and many of the soybeans are still very small, in the 3-5 trifoliate stage.
