Influence of weather factors on population dynamics of major sucking pests of Bt cotton

Abstract

A field experiment conducted over Kharif seasons of 2020 and 2021 at All India Coordinated Cotton Improvement Project, MPKV, Rahuri, examined the impact of weather factors on sucking pest populations in Bt cotton. The data reveal that aphids were predominant, ranging from 4.60 to 120.86/3 leaves in 2020 and 0.64 to 63.60/3 leaves in 2021. Jassids ranged from 2.04 to 11.46/3 leaves in 2020 and 0.52 to 5.76/3 leaves in 2021. Thrips ranged from 0.26 to 13.78/3 leaves in 2020 and 0.18 to 57.46/3 leaves in 2021. Whiteflies varied from 0.24 to 8.32/3 leaves in 2020 and 0.04 to 5.82/3 leaves in 2021 with peak activity recorded in the 42nd SMW of 2020 and the 46th SMW of 2021. Natural predators like lady bird beetles, green lace wings and predatory spiders were observed throughout the cropping season, showing peak activity in specific weeks.