Cutworms and webworms may totally cut the plants off at the ground level. Such cutting may occur in corn up to the 6th leaf stage. Webworms cutting will be restricted to small plants due to their smaller size. Webworm injury is often mistaken for cutworm injury unless webbing is found at the plant base. If a plant exhibits an entry hole above ground, the problem is generally associated with a stalk borer.
Cutworms often tunnel into a stalk, but from the ground level.
In the case of stalk borer injury, the striped leaves can usually be found when the stalk is split open and examined closely. In some areas the adults may originate for overwintering pupae, but most of the spring adult activity results from migrants carried from the south via weather fronts. Egg laying coincides with the planting of corn and is often associated with the availability of weeds in a field. Larvae of the black cutworm pass through 7 instars of which the 5th through 7th are most easily detected. The mature larvae pupate in the soil and a second and sometimes third generation occur by fall.