Western bean cutworm adults have begun emerging in Iowa this year, particularly in the southwest and southeast. Corn fields in the late whorl stage are most attractive to egg-laying females, with damage becoming evident in August and early September. University of Nebraska has developed a degree day model for 50 percent adult emergence. This year, 50 percent emergence of western bean cutworm moths in southern and central Iowa was approximately July 21. So now is the time to start scouting for egg masses before larvae enter developing corn ears.
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