Temporal Dynamics of Gram Pod Borer, Helicoverpa armigera and Beet Armyworm, Spodoptera exigua in Relation to Weather Factors in Delhi

Temporal dynamics of Helicoverpa armigera and Spodoptera exigua in relation to weather factors was studied using pheromone trap catches during 2017–18 and 2018–19 at ICAR- IARI, New Delhi. Results indicated the presence of both the pest adults throughout the year with fluctuations. Male moths catches were 714 and 855 for H. armigera during 2017–18 and 2018–19, respectively, the corresponding values for S. exigua were 658 and 324. More H. armigera male moths were captured during 9th–19th standard meteorological week (SMW) and 8th–23rd SMW with peaks during 15th and 17th SMW in 2017–18 and 2018–19, respectively. In case of S. exigua, highest adult activity was observed during 9–20th SMW with peak activity during 15th SMW in 2017–18, while in 2018–19, it occurred during 49th SMW. Correlation analysis revealed that male moth population of both the pests had significant positive relationship with maximum temperature and sunshine hours, while they had significant negative association with relative humidity.