See Fall Armyworm. Winter is usually spent in the pupal stage. Moths emerge within 5 to 8 days. The life cycle requires 30 to 40 days, depending on temperature, and several generations can occur annually. Beet armyworm moths are known to migrate northward each year.
Caterpillars have chewing mouthparts.
Adults have siphoning mouths. They may spin a light web over the foliage. Older, larger caterpillars feed alone and consume leaf tissue that can result in complete defoliation of host plants. In cotton fields, they also feed on developing squares and bolls. Alfalfa, citrus, corn, grasses, legumes, onion, ornamental plants, pea, pepper, potato, soybeans, sugar beets, sunflower, tomato, vegetables and weeds such as plantain and pigweed also serve as hosts for this species.