Fall Armyworm,Laphygma frugiperda (J. E. Smith)

PLANTS ATTACKED: Grass crops, such as corn, small grains, grain sorghum and native grasses, and some legumes, especially alfalfa and peanuts.

DESCRIPTION: Adult. The moth is about 3/4 inch long and approximately 11/2 inches across its outspread wings. The forewings of the male are grayish and have a mottled appearance, with an irregular white spot near the tip. The female's forewings usually are duller than those of the male. The hind wings of both sexes have a pinkish-white luster, bordered by a smoky-brown band.

Larva. Newly hatched larva has a jet black head and light body but turns darker when about 3 days old. A fully grown larva is about 1 1/3 inches and varies from light green to almost black. The front of the head is marked with an inverted Y that usually is prominent but this character does not always serve as a reliable means of identification. The larva has three yellowish-white lines down the back from the head to tail: on each side next to each outer dorsal line is a wider dark stripe below which is an equally wide, wavy, yellow stripe, splotched with red.

LIFE HISTORY: The moth lays eggs at night in clusters of 50 to several hundred, preferably on blades of grass and frequently on lawn grass. The eggs hatch in 2 to 4 days. The larva becomes full grown in 2 to 3 weeks at which time it burrows into the soil 1 to 2 inches and pupates, where it remains for about 8 to 10 days and emerges as an adult. The biology of this insect is similar in many respects to that of the cotton leafworm. It can, however, overwinter as an adult along the Gulf Coast of Texas and fly north in the spring. Cold weather is unfavorable to the production of many insect enemies of the worm and the abundance of moisture provides conditions for luxuriant plant growth, upon which the larvae thrive. Outbreaks of the fall armyworm usually follow wet seasons, especially during the summer and early fall. There may be five to ten generations annually.

DAMAGE: The tiny larva begins feeding immediately after hatching on the shell of the egg from which it hatched, but soon attacks plants near the surface of the soil. The larvae grow rapidly and within 2 or 3 days begin to devour the plants. They frequently do considerable damage to ears of corn, similar to that caused by corn earworms. These worms also feed as "budworms" in the whorls of grain sorghum and corn. The unfolding leaves from the whorls of such crops attacked are perforated with holes caused by the feeding of the fall armyworm. Like the armyworm, they move in armies to other fields after devouring plants in the area where they hatched.