Population dynamics of mustard aphid, Lipaphis erysimi Kaltenbach (hemiptera; aphididae) on Brassica germplasm

Mustard aphid (Lipaphis erysimi Kaltenbach) is one of the devastating pests on rapeseed-mustard. An experiment was carried out to observe its population dynamics in relation to the abiotic factors. The appearance of aphid was observed from 52^nd standard week, which disappeared after 10^th standard week. The peak population was found from 5^th to 7^th standard week. It is revealed from the stepwise regression equation that except wind speed and morning relative humidity none of the weather factors alone had influence on the population build up. The combined influence of rainfall, temperature, relative humidity and wind speed increased with the R² value of 0.707, 0.626 and 0.412 during 2009–10, 2010–11 and 2011–12, respectively.