Demography of predatory mite Amblyseius swirskii (Acari: Phytoseiidae) on Tetranychus urticae (Acari: Tetranychidae) under laboratory condition

developmental time, reproduction, survival and sex ratio of predatory mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were evaluated when feeding on Tetranychus urticae Koch eggs in laboratory conditions at three constant temperatures (25± 1, 30±1 and 35±1°C), 70±10% R.H. and 16L: 8D h on strawberry leaf discs. Total developmental time of the predatory mite was obtained 41.16±0.97, 35.98±0.49 and 33.39±0.49 days at 25, 30 and 35 °C, respectively,. Developmental time of different stages decreased as temperature increased from 25 to 350C. The intrinsic rate of increase (r) was 0.14±0.01, 0.21±0.01 and 0.23±0.01 day-1, at 25±1°C, 30±1°C and 35±1 °C, respectively. There was significant difference among the intrinsic rates of increase at three temperatures. The net reproduction rate (R0) was 21.22±2.66, 17.34±2.20 and 16.31±2.19 offspring, at the mentioned temperatures. There was significant difference between the net reproduction rate at 25 °C and two other temperatures. Our results provide information about demography of A. swirskii feeding on T. urticae at three constant temperatures. These results showed that population growth of A. swirskii at
35 °C is better than other temperatures (25 and 30°C). These results can be used to compare population growth of predatory mite, A. swirskii, with other different temperatures or on other diets, for better use of this predatory mite, in biological control.