Population Dynamics of Mustard Aphid Lipaphis Erysimi (Kaltenbach) and its Natural Enemies

A field experiment on the population dynamics of mustard aphid Lipaphis erysimi (Kaltenbach) and its natural enemies in Indian mustard Brassica juncea was conducted during 2016-17 and 2017-18. The peak infestation was observed in the 5^th week of January (213.68 aphids/10 cm terminal shoot) and 4^th week of January (168.80 aphids/10 cm terminal shoot) in the 2016-17 and 2017-18, respectively. The maximum temperature had significant negative effect (r= -0.64), while relative humidity exhibited a significant positive effect (r= 0.64); and minimum temperature and rainfall led to non-significant effect. The coccinellid predator Coccinella septempunctata L., revealed a significant positive correlation with aphid (r= 0.76 and 0.72), and a non-significant correlation was observed with weather parameters.