Influence of environmental factors on the population buildup of Helicoverpa armigera Hübner and Epilachna vigintioctopunctata (Febr.) on Aswagandha (Withania somnifera Linn.)

The most favorable period for population buildup of H. armigera Hübner and E. vigintioctopunctata on W. somnifera Linn. was from 12^th to 14^th standard week and 10^th to 12^th standard week, respectively during which highest population and activity were recorded. The larval population of H. armigera and beetle population of E. vigintioctopunctata, and plant infestation due to both pests were positively influenced with fluctuation of temperature and sun shine hours but negatively influenced with relative humidity, rainfall and number of rainy days.