Dates range from May 11 in south central and southeastern Iowa to May 20 in northeastern Iowa. This map is probably the most complex map we have produced in the last 10 years, but it reflects our best estimates of first cutting based on the two moth flights. Scouting of seedling corn near the first cutting date is the only reliable method to determine whether a problem exists. Then, insecticides can be applied if needed. Begin walking the field a couple of days before cutting is predicted.
Problems are more likely to occur in fields with spring weed growth or in soybean stubble.
Look for cutworm injury on corn leaves. Dingy cutworms also feed on young corn leaves, but rarely cut corn. If leaf feeding is detected, try to find the cutworms to determine whether they are blacks or dingys. If you find only dingys, then you shouldn't have a cutting problem. If you find only leaf feeding and only black cutworms, then mark off 100 plants in a row with stakes or flags and scout these same plants for cutting over a period of several days at several locations across the field.