Impact of weather parameters on Lipaphis erysimi (Kalt.) and predator, Episyrphus balteatus (DeGeer) on Brassica oleracea var. gongylodes

The impact of weather parameters on the population build up of Lipaphis erysimi and syrphid predator, Episyrphus balteatus on Brassica oleracea var. gongylodes were studied for two cropping seasons in the field. The numerical density of the predator were observed to increase in response to the aphid prey in the field. The correlation analysis studied show highly significant positive correlationship between the aphid prey and predator syrphid. Temperature, wind speed and sunshine correlated positively with the population of prey and predator whereas relative humidity and rainfall showed negative influence on both.