Assessment of Early-Season Phenology of the Fall Armyworm (Lepidoptera: Noctuidae) in Mississippi 1

Abstract
The relationship of temperature to the development of the immature stages of the fall armyworm, Spodoptera frugiperda (J. E. Smith), was studied in the laboratory and in the field. Information from these studies was used to develop a procedure for examining the early-season phenology of the fall armyworm by estimating the ages of field-collected larval cohorts. Application of this procedure to fall armyworm larvae collected in an extensive survey in Mississippi during the spring of 1979 provided evidence that the observed populations were initiated by immigrant adults.