Seasonal incidence of Sucking Insect pests on Bt cotton in relation to Weather parameters

The seasonal incidence of sucking insect pests on Bt cotton indicated that the major activity of aphids was observed from 41 sl standard week attaining peak during 46^th standard week. Among the sucking pests, leafhoppers was the dominant pest with high activity from 4] SI standard week to 48^th standard week with peak population level at 45^th standard week. The peak incidence of thrips was observed during 38^th standard week. The incidence of whitefly was low throughout the season with peak incidence in 46^th standard week. The incidence of aphids had significant negative association with minimum temperature. The correlation between thrips and morning relative humidity showed significant negative influence, whereas maximum and minimum temperatures were found positive and significant. Leafhoppers showed significant negative correlation with morning and evening relative humidities. Both maximum and minimum temperatures were found to exert significant negative correlation, whereas morning relative humidity showed significant positive correlation on the whitefly population. Regression studies showed that the influence of all the major weather parameters was high on aphids (69.6%), leafhoppers (64.1%), thrips (70.0%) and whiteflies (66.1%).