Armyworms usually feed at night and damage corn by chewing leaves. They prefer to feed on the succulent leaves in the whorl first. Feeding is usually confined to leaf margins, but occasionally they may strip the entire plant leaving only the midrib of the leaves. During the day, armyworms are found in the soil or underneath ground cover. Ragged leaf feeding in the spring and early summer is evidence of armyworm feeding.
Corn can usually recover from light to moderate feeding by armyworm without significant yield loss.
However, severe damage, particularly if the growing bud is injured, can cause significant loss in yield. Monitoring Treatment recommendations are based on scouting. If the characteristic armyworm damage is observed while scouting, look on the ground for armyworms or their black pepper-like droppings littering the ground. Remember, during the day, armyworms hide in soil cracks or under clods and crop residues. Occasionally they may be found in the whorl of the plant during the day.