Population Dynamics and Management of Fall Armyworm Spodoptera frugiperda J E Smith

Abstract

newline The thesis embodies the experimental research conducted over two years (2021 and 2022) at the Entomology Farm, SKUAST-Jammu, focusing on the Population Dynamics and Management of Fall Armyworm, Spodoptera frugiperda (J.E. Smith) . The study encompassed fortnightly surveys across three distinct areas in Jammu district viz., Nagrota, Marh and R.S. Pura Block, to assess the host range and status of S. frugiperda and its natural enemies. The findings revealed widespread fall armyworm infestation, particularly in maize, with minor infestations observed in chilli, cabbage and sugarcane. In the maize ecosystem, ten natural enemies, comprising predators and parasitoids of fall armyworm, were identified. Population dynamics analysis indicated the emergence of adult fall armyworm starting from the 18th standard meteorological week (SMW), with first peak trap catches occurring in the 24th SMW during both years, followed by a second peak in 28th and 27th SMW during 2021 and 2022, respectively after which the population declined till 31st SMW. Similarly, the larval population of fall armyworm commenced from 20th SMW which attained the first peak population in 25th and 26th SMW in 2021 and 2022, subsequently the 2nd peak was observed in 28th and 29th SMW during 2021 and 2022, respectively. Thereafter, the larval population witnessed a gradual decline and observed the minimum population during 31st SMW. Comparative studies between protected and unprotected plots demonstrated higher fall armyworm larval densities in unprotected areas, leading to increased leaf and ear damage and lower yields than the protected plots, and the calculated avoidable yield losses was 33.85 per cent. Among the different management modules evaluated, chemical intensive management exhibited the lowest mean fall armyworm larval counts (0.17 and 0.18 per plant during 2021 and 2022, respectively), followed by IPM, IIMR recommendation, and bio-intensive modules while the control plots showing the highest infestation levels (2.01 and 2.13 per