comparing demographic parameters of serangium montazerii (coleoptera: coccinellidae) on citrus whitefly, dialeurodes citri (hemiptera: aleyrodidae) fed on two host plants

demographic parameters of the ladybeetle, serangium montazerii fursch feeding on citrus whitefly, dialeurodes citri ashmead were determined on two host plants, page tangerine and thompson navel orange. this study was carried out under laboratory conditions (25 ± 1 °c and rh of 60 ± 5% and a photoperiod of 16: 8 h (l: d). total pre-adult periods of the lady beetle were 20.84 ± 0.302, 19.27 ± 0.251days on page tangerine and thompson navel orange, respectively. the survivorship from egg to adult were very close to each other on the two host plants. the oviposition periods were 29.64 ± 0.905 and 33.36 ± 0.599 days and the total number of eggs per female (fecundity) were 457.14 ± 11.099 and 528.57 ± 12.369 on page tangerine and thompson orange, respectively. peaks of reproductive value occurred at ages of 31 and 33 days when reared on thompson navel orange and page tangerine, respectively. the intrinsic rates of increase (r) on thompson orange and on page tangerine were 0.134 ± 0.063 and 0.126 ± 0.006d-1 with no significant differences. the mean generation time (t) on these host plants were 39.03 ± 0.5 and 40.57 ± 0.46 days, respectively. it can be concluded that s. montazerii feeding on d. citri in general showed a slightly better reproductive performance on thompson navel orange than on page tangerine.