author(s)
Lipsa Dash, A Konar and Ashima Mishra

abstract
An experiment was conducted during rabi 2014-15 at In-check farm, BCKV, Nadia, West Bengal to study the population dynamics of mustard aphid, Lipaphis erysimi (Kalt.) and efficacy of some insectides against it on mustard. The incidence of aphid was initiated during second week of December, 2014. Population of aphid increased gradually to reach its peak (89.2 aphids/ top 10cm twig) during fourth week of January when minimum and maximum temperature was 11.79°C and 27.03°C Respectively, minimum and maximum relative humidity was 52.8% and 79.71% respectively with 0 mm rainfall and 6.4 Sunshine hours and persisted throughout the crop period with low incidence. Dimethoate 30% EC @ 660ml/ha was found to be most effective in reducing population of aphids also gave the highest cost: benefit ratio.