Life History of Fall Army Worm Spodoptera frugiperda (J E Smith) on Castor, Under Laboratory Conditions

The fall army worm, Spodoptera frugiperda (J E Smith), an invasive polyphagous pest, poses a significant threat to global agriculture. This study investigated its life history and morphometrics when reared on castor (Ricinus communis L.) under laboratory conditions. Egg dimensions averaged 0.89± 0.54 mm (width) and 13.72± 2.64 mm (length). Larval head capsule and body measurements consistently increased through instars, with the sixth instar exhibiting the largest dimensions. Pre-pupal dimensions closely resembled those of the final larval instar. Sexual dimorphism was evident: male pupal length was slightly greater (17.09± 0.65 mm), while adult female wing expanse was larger (32.37± 1.34 mm) and male body height was greater (16.12± 0.57 mm). Notably, larval mortality was 0%, indicating the high suitability of R. communis as a host. The study further revealed a rapid life cycle, completing from egg to adult emergence within 30-34 days, coupled with high egg hatchability (95–100%) and substantial female fecundity (1,233 - 2,203 eggs/ female). A balanced sex ratio (1:1) was observed. These findings underscore the considerable potential of R. communis for efficient mass rearing of S. frugiperda, offering a reliable resource for research, pest management, and biological control initiatives.