Kentucky Corn IPM True Armyworm Description Larvae of the true armyworm are greenish brown with a narrow, mid-dorsal stripe and two orange stripes along each side. The yellowish head of the larva is honeycombed with dark lines. Armyworm larvae are about 1.5 inches long when full grown. Pupation occurs in the soil.
Adult moths are nocturnal with a small, white dot in the center of each wing.
Damage Armyworm larvae feed at night and damage corn by stripping the leaves and feeding in the whorl which may destroy the bud. Armyworms generally appear in Kentucky corn in early season, Mid-May through June. Infestations usually develop in small grains or other grass cover crops and in corn, infestations may develop throughout no-till corn following grains or grass crops. The larvae are most often found in luxuriant or lodged vegetation in low wet areas, and cool, wet springs will favor armyworm development. Other hosts of armyworms include wheat, bluegrass, oats, rye,and some forages.