Epidemiology of Spodoptera litura in groundnut fields

Abstract

A field study was conducted during Kharif 2023 and 2024 at the Main Oilseeds Research Station, Junagadh Agricultural University, to assess the epidemiology of Spodoptera litura in groundnut and its relationship with weather parameters. Weekly observations were recorded from crop emergence to harvest. To study the influence of various abiotic factors on pest incidence, a simple correlation and multiple linear regression analysis were worked out between the S. litura population and weather parameters. The results showed that S. litura infestation commenced three to four weeks after sowing, peaked between late August and mid-September and declined by the end of October in both years. Correlation analysis indicated that maximum temperature was significantly negatively correlated with S. litura population, while morning and evening relative humidity and rainfall had significant positive correlations. Multiple linear regression analysis revealed that weather factors accounted for 96.80% and 88.90% of the variation in S. litura population during 2023 and 2024, respectively.