The western bean cutworm (WBC) has typically been an occasional pest of corn in northwest Iowa and is more notably known to cause damage to crops in western Nebraska. Yet, beginning in 1999, the WBC caused economic damage to corn in isolated locations of northwest Iowa, primarily in northern Ida County. In 2002, western bean cutworm moths were found in most northwest Iowa counties (Table 1). Because of the western bean cutworm’s potential to cause large yield losses in corn and its presence in successive years, ISU extension researchers felt it was necessary to monitor its presence in northwest Iowa with the use of moth traps. The trap data were also a tool to help determine when scouting for WBC should begin.