This species will feed on a very wide variety of plants but prefers plants in the grass family. Most turf and pasture grasses are subject to infestation.
Fall armyworms are potential turf and pasture pests in late summer and fall. Large numbers can consume all above-ground plant parts, and they are capable of killing or severely retarding the growth of grasses. This species may migrate in large numbers in search of new areas in which to feed. The moths are attracted to lights and may lay masses of eggs on nonhost plants, walls, clothes on lines, etc.
The fall armyworm does not overwinter in Oklahoma, and we are reinfested each year by moths that migrate northward from Texas or Mexico. They usually reach the state by late June. Each female lays about 1000 eggs in masses of 50 to several hundred. Larvae are present by early July. After feeding for 2 to 3 weeks, the larvae dig into the soil to pupate. A new generation of moths emerges about 2 weeks later. There are several overlapping generations extending into October or even November in some years.
Male moths have dark gray front wings mottled with darker and lighter splotches. There is a prominent pale, diagonal marking near the center of the front half of each wing and a prominent white spot at the extreme tip. The front wings of female moths are dull gray brown with only small, inconspicuous markings. The hind wings of both sexes are white with a slight purplish sheen. The wing spread is about 1 1/2 inches. The eggs are pale gray, laid in masses, and covered with grayish, fuzzy scales from the body of the female moth. Mature larvae may be green, brown, or almost black and are about 1 1/ 2 inches long. There are black and reddish brown stripes on each side of the body and four small, black spots on the dorsal side of each abdominal segment. The head capsule is mostly black and is marked with a pale, inverted "Y" on the front.
Please contact your local county extension office for current information.