Though often found in agricultural crops, fall armyworms can be present in certain
turfgrass species and we’ve had a few reports of them recently.
Description: Young larvae are ½ to ¾ inches long. Mature larvae can reach 1½ inches
long. Fall armyworms can be identified by the inverted “Y” on top of the dark head. Adult
moths are ½ inch long. The two front wings are brown-grey. Males have more dark
markings than females.
Life Cycle: As a tropical insect, fall armyworms are not able to overwinter in Kansas limiting them to 2-4 generations each year. Moths migrate to their seasonal home and lay hundreds of eggs in clusters. Larvae hatch and begin feeding. Once established, new generations can occur every 23-25 days.
Damage: Larvae feed on grass blades. Heavy infestations will occasionally chew the blades to the crown. Though the damage may be unsightly it does not typically kill the grass. Regrowth of the turfgrass can be expedited with rain and/or irrigation. To read more about fall armyworm and control options access our publication from the Horticulture Resource Center: Fall Armyworm. Learn more from K-State Entomology: Fall Armyworm.
