Watch Cornfields For Armyworm Attack

By: Iowa State University

If you have cornfields in Iowa this spring, start scouting emerged corn for armyworm in late May. Larvae may be present and chewing on young corn plants, says Adam Sisson, an Iowa State University Extension pest management specialist. Insecticide treatment may need to be sprayed if armyworms reach threshold levels in the field and are doing damage. Continue scouting for this pest through June.

Significant catches of armyworm moths occurred in traps across Iowa in April, suggesting an armyworm invasion is possible in some counties in Iowa this spring.

True armyworm is a migratory pest that arrives in Iowa from Southern states and lays eggs on living tissue of plants. Adult females are attracted to fields with green plants, particularly weedy grasses or living cover crops. These plants serve as initial feeding sites for armyworm larvae that hatch from the eggs.