Key mortality factors of fall army worm (Spodoptera frugiperda) (Lepidoptera: Noctuidae) on rabi sorghum

Abstract

This investigation on the Spodoptera frugiperda was conducted at the Post Graduate Experimental Field of Department of Agricultural Entomology, College of Agriculture, Campus Latur during 2020-21. The study showed that the mortality in early instar larvae of S. frugiperda attacking on rabi sorghum was 8.32 and 10.00 per cent owing to the parasitisation of Aleiodes sp. during first and second generation, respectively. While 14.28 per cent larvae in early instar stage also recorded parasitisation due to Coccygidium melleum during first generation. However, in the early stages of larval development, the mortality rates were 14.28, 8.32 and 9.08 per cent due to physical injury, the SfMNPV and Mermithidae nematodes, respectively, during the second generation. The highest mortality in S. frugiperda populations during the first and second generations occurred in the late instar larval and early instar larval stages, with mortality rates of k=0.138 and k=0.192, respectively. This investigation highlights the influence of both living organisms (biotic factors) and non-living factors (abiotic factors) in driving population fluctuations of S. frugiperda during the rabi season.