Two to 10 days later the small larvae emerge, feed gregariously on the remains of the egg mass, then scatter in search of food. Unlike the nocturnal true armyworms, fall armyworms feed any time of the day or night, but are most active early in the morning or late in the evening. When abundant, these caterpillars eat all the food at hand and then crawl in great armies to adjoining fields. After feeding for 2 to 3 weeks, the larvae dig about 20 mm into the ground to pupate. Within 2 weeks, a new swarm of moths emerges and usually flies several miles before laying eggs.
Several generations occur each year in North Carolina.
Cold, wet springs seem to reduce the effectiveness of these parasites and allow large fall armyworm populations to develop. The fall armyworm is more difficult to control chemically than the true armyworm. For specific control information, consult the state agricultural extension service recommendations.