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.
Armyworms usually feed only at night.
To sample for armyworms, examine 20 consecutive plants in each of at least 5 random locations in the field. Note the number of plants with the characteristic damage and the size of the larvae. In conventional tillage, infestations usually begin around the field margins adjacent to small grains or grassy strips. These areas should be scouted first. If armyworms are present, then determine how far the infestation extends into the field.