Population dynamics of fall army worm Spodoptera frugiperda (J E Smith) on maize.
Population dynamics of the fall army worm (FAW) Spodoptera frugiperda on maize was carried out at the research field of Tamil Nadu Agricultural University, Coimbatore (kharif and rabi, 2018 and 2019). The results revealed that maximum FAW trap catches were obtained during 34th (7.6 moths/ trap) and 5th (7.8 moths/ trap) standard weeks (SW) of kharif and rabi seasons of 2018, respectively. During 2019, a more or less similar trend was observed with a maximum during 31st (7.2 moth/ trap) and 48th (8.2 moth/ trap) SW of kharif and rabi seasons, respectively. Correlation with weather factors indicated a significant negative correlation with evening relative humidity (RH) and significant positive correlation with morning RH during 2019-20. No significant effect of weather factors was observed during 2018-19 except for a significant positive correlation with evening RH and rainfall. The correlation between larval counts and pheromone trap catches were significantly positive with r-value of 0.55 and an R2 value of 0.907 during 2018-19.