Moths mate soon after emergence and feed on nectar for 7 to 10 days. Females then deposit up to 2000 eggs in small clusters or rows on the leaf sheaths of grasses. About 6 to 10 days later, larvae emerge. After feeding for 3 or 4 weeks, they drop to the ground and pupate in earthen cells 5 to 7.5 cm deep within the soil. Moths emerge about 2 to 4 weeks later.
True armyworms complete five or more generations per year in North Carolina.
When practical, cultural methods, such as disking large areas, can help reduce future armyworm populations by exposing the pupae to natural enemies and host weather. However, since armyworm moths are strong fliers, most areas will be subject to constant reinfestation. Because armyworms feed exposed, are active during their larval stages, and are susceptible to several insecticides, they are easily controlled when buildup occurs. Controls are warranted when defoliation by armyworms averages 20 percent. For specific control information, consult the current North Carolina Agricultural Chemicals Manual .