Effect of Varying Temperature on the Survival and Fecundity of Coccinella septempunctata (Coleoptera: Coccinellidae) Fed on Lipaphis erysimi (Hemiptera: Aphididae)

摘要

The observations on the survival and fecundity of Coccinella septempunctata at varying temperatures viz., 18±1, 24±1°C and 28±1°C coupled with 65±5% RH and 12 h L: 12 h D photoperiod under laboratory condition was made for two successive generations. The highest potential fecundity and net reproductive rate of C. septempunctata were obtained at 24±1°C (165.67 eggs/female and 41.09 females/female/generation, respectively) and the lowest at 28±1°C (146.63 eggs/female and 29.70 females/female/generation, respectively). Finite, intrinsic and annual rate of increase were however, found maximum at 28±1°C (1.0876, 0.0840 females/female/day and 2.04x1013/annum, respectively) and minimum at 18±1°C (1.0794, 0.0764 females/female/day and 1.281x1012/annum, respectively). The mean length of generation and doubling time was found minimum at 28±1°C (40.77, 8.26 days, respectively) and maximum at 18±1°C (48.27 and 9.08 days, respectively).