The caterpillars feed on a variety of forage crops, but seem to prefer lush, green, well-fertilized bermudagrass. Other forage grasses which are hosts for fall armyworm are bahiagrass, pearl millet, sorghum-sudan hybrids, tall fescue, and various winter annuals including ryegrass, rye, wheat, and oats. More than 60 plants have been reported as hosts of the fall armyworm, including corn, alfalfa, cotton, soybeans, and most vegetable crops. As the name indicates, fall armyworms are most numerous in late summer or early fall. Usually, reports of fall armyworm damage begin to come in during late July or early August.
First reports are usually from southern Alabama.
There are three or more generations of fall armyworm each year. Fall armyworms are susceptible to cold, and are unable to survive even the mildest winters in Alabama. Each year, fall armyworm moths, carried by air currents, make their way from Central and South America. The size and timing of the initial moth flights are two factors that influence the outbreak potential of this pest. Occasionally, severe outbreaks occur as early as mid-April.