Corn Earworm (Helicoverpa zea) larvae are greenish with black heads and conspicuous black hairs on the body. Fully developed worms are about 1.5 inches long and range in color from pale green or pinkish to brown. The corn earworm may be present throughout the season but is most abundant during August and September. In beans, larvae feed on leaves, buds, flowers, and within pods, often damaging the beans.