Efficacy of Two Predatory Coccinellid Specie Feeding on Different Desities of Bemisia Tabaci (Homoptera : Aleyrodidae) Nymphs in The Laboratory

Abstract

Abstract Aseries of experiments were conducted laborators of biollogical control in the postgraduate laboratory at the Al-Mussaib Technical College, AL-Furat Al-Awsat Technical University-Iraq in 2020, The larval and adult phase of Hippodamia variegate and Coccinella Septempunctata.L were reard on different densities of Bemisia tabaci nymphs to reveae theis predation and the effect on this longevity too: The average number of predation whitefly nymphs per day from each age larvae and adults of the thirteen-spoted ladybird H. variegate and the seven- spoted ladybird C. Septempunctata. L was in direct proportion to the increase in the density of the whitefly nymphs supplied for it daily, The highest average of thirteen point ladybird larvae was (48.60) at density (64) nymphs/whitefly at the first larval phase. While the lowest rate of first-stage larvae was (6.40) at density (2) nymphs/whitefly for the same larval phase, while the highest average of fourth-stage larvae was (131.20) at density (64) nymphs/whitefly. While the lowest average of the fourth larvae phase was (39.20) at density (8) nymphs/whitefly, As for the seven- spoted ladybird, the highest average of first-phase larvae reached (53.80) at density (64) nymphs/whitefly, while the lowest average of first-phase larvae reached (5.40) at density (2) nymphs/whitefly for the same larval phase. While the highest average of fourth phase larvae was (160.40) at density (64) nymph/whitefly, while the lowest average of fourth phase larvae was (46.00) at density (4) nymph/whitefly. The number of whitefly nymphs preyed by the thirteen- spoted ladybird H. variegate is less than the number of whitefly nymphs preyed by the seven- spoted ladybird C. Septempunctata. L. The daily average of predation for male predation ladybirds understudy for whitefly nymphs is less than the daily average for females with significant differences.