Population dynamics of mustard aphid, Lipaphis erysimi (Kalt) in relation to biotic factors

A field experiment was conducted during Rabi 2019-2020 at Research Farm of Agricultural Research Sub Station Nagaur (Agriculture University, Jodhpur) to know the pest incidence in mustard variety ’BIO 902’. The incidence of aphid 3.65 aphids per plant started in the first week of January (1^st SMW) continued thereafter for a long period and reached to maximum 128.80 aphids per plant in the third week of February (7^th SMW). The incidence of ladybird beetles appeared in the second week of January and reached its peak 9.95 coccinellids/plant in the third week of February (7^th SMW). The correlation coefficient of L. erysimi with ladybird beetle population had a positive significant correlation (r= 0.979).