Effect of Weather Parameters on Population Fluctuation of Sucking Pests and Their Predators on Okra Crop

A field trial was conducted during the kharif, 2016 at Vegetable Research Centre, Pantnagar to study the correlation of the sucking pest population viz. leafhopper (Amrasca bigutullabigu tulla Ishida), whitefly (Bemisiatabaci Gennadius) and aphids (Aphis gossypii Glover) and their predators mainly Coccinella spp. and spiders with the prevailing weather conditions. The peak densities of insect pests and their predators were attained in September-October. A simple correlation coefficient was worked out between the sucking pests and their predators with the weather parameters. A negative significant correlation (r= -0.711*) of leafhopper population was observed with wind velocity, while positive non-significant correlation (r= 0.051) was observed with the sunshine hours. The aphid population was non-significantly correlated with weather parameters. Whitefly population was negatively and significantly correlated with wind velocity (r = -.718**). Among the predators there was a non-significant correlation of Coccinella with weather parameters while spider population was negatively and significantly correlated with wind velocity (r = -0.582*).