The larval stage lasts about 2 to 3 weeks and has five or six instars. Smaller larvae tend to occur in new, still-rolled foliage, whereas larger larvae tend to feed on open leaves. All stages tend to feed on flowers, tender new leaves and fruit. Late-stage larvae tunnel 5 to 15 cm into the soil and pupate. The pupal stage lasts about 2 to 3 weeks.
Adults then emerge from the soil.
Duration from egg to adult emergence is 6 to 8 weeks under field conditions. Corn earworm overwinters as a diapausing pupa in the soil and undergoes several generations each year. In the North, the pupa can survive only during mild winters. Adults are strong fliers and, in the spring, are spread northward from warmer overwintering areas. Infestations in greenhouses occur when the corn earworm moths fly through open doors, windows, and vents and then deposit eggs on the plants.