STUDIES OF LIFE TABLE ON FALL ARMYWORM (SPODOPTERA FRUGIPERDA J.E. SMITH)

Studies on life table of Spodoptera frugiperda were carried out for two years (2019-20 and 2020-21) at Main Agricultural Research Station (MARS) and in Department of Agricultural Entomology, UAS, Dharwad.From the two years of studies, it was confirmed that the pest passed through five generations between June to February under field conditions.The third generation which began at the beginning of September was most destructive to the crops by the beginning of November month.However, in the field, overlapping generations have been observed.After February month, the pest was not traceable in the field until May, although the host crop was available.A very high negative correlation was observed among total life cycle and average temperature.However, the relative humidity was negatively correlated with total life cycle during both the years.Totally, 3 parasitoids have been recorded on Spodoptera frugiperda in the present investigation.In general, the major mortality influencing factors observed were larval cannibalism and the entomopathogenic fungus, Metarhizium rileyi.Among the parasitoids, Campoletis chloridae was the dominant species on larval stage.The other species included Exorista xanthaspis and Cotesia ruficrus on larva and none of the parasitoids were recorded on pupa.The fall armyworm completed five generations between June to February with overlapping generations under field conditions.The mortality rate was higher in the egg stage and larval mortality in LP-2 stage in both the years and the generation survivability declined rapidly from I generation to V generation.The key factors influencing the overall mortality (K) included cannibalism followed by Metarhizium rileyi and Campoletis chloridae.