Impact of abiotic and biotic factors on population dynamics of Helicoverpa armigera Hubner (Noctuidae: Lepidoptera) in chickpea

Abstract

To determine the impact of abiotic factors and parasitization by Campoletis chlorideae on population dynamics of Helicoverpa armigera, investigations were undertaken in chickpea during winter 2010-11 and 2011-12. Weekly observations were recorded regarding abiotic factors in relation to larval intensity, larval parasitization, and rate of larval multiplication in field or lab conditions. It was concluded that during February month, the larval population had the highest peaks as 8.93 & 7.93 larvae m-1 row along with the highest multiplication rate as 0.44 & 0.33 larvae/day. The natural parasitization was the maximum during December month as 51.67 & 56.67%. Simple correlation coefficient (r) of temperature (maximum and minimum), wind speed, and evaporation rate had reflected positive values when relative humidity (morning and evening), rainfall and larval parasitization played a negative role on the pest population.