Feeding potential of Coccinella transversalis F. on different morphs of mustard aphid, Lipaphis erysimi (Kaltenbach)

Feeding potential of the aphidophagous coccinellid beetle, Coccinella transversalis F., was studied under laboratory conditions at Assam Agricultural University, Jorhat. The first instar larvae of C. transversalis were less voracious than older instars. The voracity (no. of aphids consumed/24h) of C. transversalis increased in succeeding instars. The fourth instar larva of C. transversalis consumed 65.67 apterous adults of L. erysimi in 24h and the overall consumption during the entire fourth instar was 252.90 apterous adults. The theoretical effectiveness was worked out as 107.50, which was a product of multiplication of its seasonal average numbers in the field by its average daily consumption.