Seasonal Dynamics of Spodoptera frugiperda (J.E Smith) on Maize in the Terai Region of Uttarakhand

The study on seasonal dynamics of Spodoptera frugiperda on maize was carried out at GBPUAT, Pantnagar during kharif 2023 and 2024. Spodoptera frugiperda population started appearing on maize at 28th and 31st SMW in 2023 and 2024, respectively, and persisted until crop maturity. The larval population reached the peak level of 3.08 larvae/plant in 33rd SMW during 2023 and 2.82 larvae/plant in 36th SMW during 2024 which declined thereafter. The plant damage ranged from 6.67-75.00% in 2023 and 5.00-80.00% in 2024. Pearson correlation revealed a significant and positive association of larval population with minimum temperature (r= 0.614 and r= 0.597) and evening relative humidity (r= 0.357 and r= 0.333) in year 2023 and 2024, respectively, while sunshine hours and rainfall showed negative effects. Principal component analysis confirmed minimum temperature and humidity as the key determinants of pest dynamics. These findings highlighted the significance of weather in S. frugiperda outbreaks and provide valuable insights for forecasting and long-term management strategies in maize cultivation.