SEASONAL INCIDENCE OF MAJOR INSECT PESTS ON SUMMER SESAME IN RELATION TO ABIOTIC FACTORS

Abstract

A field experiment was conducted during summer, 2019 and 2020 to study the seasonal incidence of major insect pests and their correlation with weather parameters. The pooled results revealed that, the initial incidence of leaf webber and capsule borer, A. catalaunalis population and gall fly, A. sesami flower infestation was observed on 6th SMW and 10th SMW, respectively. The peak incidence of A. catalaunalis and A. sesami infestation noticed during on 13th SMW (0.82 larvae/plant) and 11th SMW (5.75
% flower infestation), respectively. After that population of A. catalaunalis was declined gradually and reached to zero per plant on 16th SMW. Regarding, the correlation with weather parameters, A. catalaunalis population shows a positive and non significant correlation with maximum temperature (0.020), minimum temperature (0.164) and nonsignificant negative correlation with morning relative humidity (-0.408), evening relative humidity (-0.089), sunshine hours (-0.167) and rain fall (-0.113). Flower infestation by A. sesami shows a positive and nonsignificant correlation with rainfall (0.106). The maximum temperature (-0.051), minimum temperature (-0.010), evening relative humidity (-0.148) and sunshine hours (-0.023) showed nonsignificant negative correlation and morning relative humidity (-0.745**) shows significant negative correlation. Multiple linear regression analysis revealed that, all weather parameters collectively influenced the A. catalaunalis population to the extent of 58.60 per cent and A. sesami infestation to the extent of 75.02 per cent on sesame.