During late July or early August, in most years, reports begin to come in, beginning from more southerly areas, of fall armyworms on turf. Occasionally, severe outbreaks occur, like the one in 1977, that began with reports of fall armyworms in crops as early as mid-April. That year fall armyworms went from bad to worse, and most crops, including turfgrasses, were severely damaged before populations slowly diminished from August to late October. The front wings are mottled and have white or light gray spots near the tips. The back wings are white with a narrow, smoky brown edge.
Moths become active at twilight and feed on nectar.
They have an average lifespan of 2 to 3 weeks. The female moths lay eggs at night in masses of up to several hundred on light-covered surfaces. The eggs are light gray and covered with grayish fuzz from the female's body. These masses darken with age, and the eggs hatch within 2 to 4 days. All the eggs within a mass hatch about the same time.