Black cutworm caterpillars are blackish, thick-bodied, and up to 1 inch long. The adult moth has brown wings with a 1-1/2 inch wingspan.
Black cutworm attacks the transplants and seedlings of tomato, corn, bean, and other vegetables during the night and hides in the soil during the day. Young larvae climb the plant to eat the leaves, whereas older caterpillars eat through the stem of young plants about 1/2 inch above ground and then eat the plant. These older larvae curl their bodies around the stem to feed; thus older plants with thicker stems are less susceptible to attack.