Biological attributes and feeding potential of three dominant predators of Lipaphis erysimi (Kaltenbach)

Basic biological attributes and feeding potential of three major predators viz., the seven spotted lady bird beetle Coccinella septempunctata Linnaeus and two syrphids Episyrphus viridaureus (Wiedemann) and Betasyrphus isaaci (Bhatia), of mustard aphid, Lipaphis erysimi were studied under laboratory conditions. The predators were multiplied on mustard aphids reared on mustard plants. C. septempunctata, E. viridaureus and B. isaaci completed their life cycle in 68.5± 6.5 days, 47±2 and 41±2, respectively. Coccinella septumpunctata completed the larval growth with four larval instars, while both the syrphids terminated the larval growth with three instars. Final instars of all the three predators were found to have highest predatory potential than the younger instars. C. septumpunctata was found to be the most dominant predator of mustard aphid with average lifetime consumption of 4312±537.74 aphids, followed by E. viridaureus (416.67±6.76 aphids) and B. isaaci (338±7.89 aphids). All the three predators have the potential to reduce the mustard aphids; however, C. septumpunctata has a maximum predatory potential with a longer life, which makes this species as an excellent bioagent of L. erysimi and further research on their utilization on a large scale should be undertaken.