It is an important time to be scouting your corn for Black Cutworm. The Southern 1/3 of Iowa is in prime cutting time right now with the Central area starting to be a problem and the Northern 1/3 of Iowa just starting. The worst problems are occurring in corn which doesn’t carry the SmartStax, Herculex or Viptera genes. The corn planted in early to mid April is showing the most vulnerability, especially if there were weedy areas when egg laying occurred.
The best solution, if significant cutting is observed, is to spray with an effective foliar insecticide that your chemical supplier will suggest. Cutting can progress rapidly, so a rapid spray response is needed. Next year I suggest planting corn with good Broad Lepidoptera resistance genes, such as Viptera. Feel free to call your seed sales representative or Bob Miller 319-325-6158 of Miller Hybrids for assistance.
The two pictures below are of plants showing signs of early death along with a cut plant. In wetter areas Pythium root rot is also killing some small plants, however the shoots on a cut plant will tend to be white and healthy vs the brown and slimy shoot.