Development and reproduction of the predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) on Tetranychus urticae Koch (Acari: Tetranychidae) and Bemisia tabaci Gennadius (Heteroptera: Aleyrodidae)

Abstract

ABSTRACTAmblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is an effective predator feeding on different insect and mite pests such as whiteflies, thrips and two-spotted spider mites. In this study, we documented the life table of A. swirskii on eggs of Tetranychus urticae and Bemisia tabaci under laboratory conditions (25 ± 1°C, 70 ± 5% RH and 16L: 8D). The results indicated that the developmental times of egg, larva, protonymph and deutonymph stages of A. swirskii were 1.36 ± 0.07, 1.23 ± 0.07, 1.43 ± 0.08 and 2.49 ± 0.14 days when fed on T. urticae and 0.95 ± 0.02, 0.96 ± 0.04, 1.25 ± 0.08 and 2.83 ± 0.1 days when fed on B. tabaci. The average of all immature stages on eggs of T. urticae and B. tabaci were 6.58 ± 0.12 and 6.01 ± 0.13 days, respectively. The average adult female longevities on the two different prey species were 25.58 ± 1.13 and 25.35 ± 0.81 days, respectively. The intrinsic rates of increase (r) and finite rates of increase (λ) on eggs of T. urticae and B. tabaci were 0.22 ± 0.01 and 0.12 ± 0.01 day−1 and 1.25 ± 0.02 and 1.13 ± 0.02 day−1, respectively. The net reproductive rates (R0) and mean generation times (T) on the two prey species were estimated as 12.14 ± 1.84 and 3.90 ± 0.63 offspring/individual and 11.08 ± 0.23 and 11.24 ± 0.2 days, respectively. These results indicate that A. swirskii can successfully survive and reproduce on T. urticae and B. tabaci and have the potential to be a more effective biological control agent of T. urticae than B. tabaci.