Source: Iowa State University
Western bean cutworm (WBC) moths have been reported in several Iowa counties. The first moth was captured in Adams County, located in the southeast part of the state, on June 16. Iowa State University trap data can be viewed by county. The presence of adult moths in traps indicates only that scouting efforts should begin in an area.
Adult emergence can also be predicted by combining a degree day (DD) model developed in Nebraska with actual trap captures. The DD model is based on the accumulation of DDs (base 50 F) from May 1. Corn field scouting should begin when 1,319 DDs (base 50 F) have accrued, as this is when 25 percent of adult moths have emerged.