The Role of Atmospheric Transport in the Economic Fall Armyworm (Lepidoptera: Noctuidae) Infestations in the Southeastern United States in 1977

Abnormally cold air penetrated into the southeastern U.S. in January, 1977 for a duration of time sufficient to virtually eradicate the fall armyworm, Spodoptera frugiperda (J. E. Smith), populations as far south as Homestead, FL. However, anomalously warm, wet conditions developed in late winter to enhance the host crop environment for the reintroduction and subsequent development of fall armyworm populations that caused extreme agricultural losses in the southeastern U.S. in 1977. Atmospheric data for the southern U.S., Mexico, Central America, and the Caribbean Islands for the period October 1976-June 1977 revealed atmospheric anomalies which were significantly correlated with the population dynamics and dispersal of the 1977 fall armyworm populations. Retrogressive atmospheric trajectories targeted probable fall armyworm overwintering regions which impacted the southeastern U.S.