Survival and development of Spodoptera frugiperda (J E Smith) on public sector Bt cotton hybrids in India

The fall army worm, Spodoptera frugiperda (J E Smith) (Noctuidae; Lepidoptera) is a recently introduced polyphagous pest, poses a potential threat to cotton cultivation in India. Therefore, laboratory assays were conducted on different public sector Bt cotton hybrids to study the survival and development of the pest. The results confirmed significantly (p=0.05) higher mortality of early larval instars, than the later. The surviving larvae showed adverse effects on the growth and developmental parameters along with low growth and survival indices. S. frugiperda reared on leaves (60-80 days old crop) and squares (90-110 days old crop) showed low growth and survival indices values, compared to those reared on young bolls (120-140 days old crop) and mature bolls (150-170 days old crop). Among the different public sector Bt cotton hybrids, significantly superior results were exhibited by the PKV Hy-2 BG II when larvae fed on leaves and squares, and the NHH-44 BG II when fed on young and mature bolls.