The pupal stage varies from 7 to 37 days. In South Texas, the life cycle generally requires 24-30 days. Fall armyworms vary in color from pale green to almost black. The adult is an ash-gray moth. Its front wings are mottled and have irregular, white or light gray spots near the extreme tip.
Hind wings are white and have a narrow smokey-brown edge.
When expanded, the wings are about one and one-half inches across. Preventive treatments normally are not justified because attacks are sporadic. Early detection seems to work best and is achieved by frequent, thorough inspection of plants. Complete coverage of insects and foliage is needed for good control. A high pressure sprayer may be necessary for to reach the tops of trees or to penetrate dense webs.