واکنش تابعی کنه شکارگر Amblyseius swirskii (Phytoseiidae) روی مراحل مختلف رشدی کنه تارتن روی گیاه توت فرنگی

Management of Tetranychus urticae Koch (Acari: Tetranychidae) by augmentative biological control using predators such as the Amblyseius swirskii Athias-Henriot is envisioned as an environmentally safe alternative to acaricides. The predatory mite A. swirskii has been used to control different greenhouse pests including thrips, whiteflies and spider mites. We evaluated the functional response of A. swirskii fed on different densities (2, 4, 8, 16, 32, 64 and 128) of egg, larva and, deutonymph of T. urticae at 30 °C on strawberry under laboratory condition (70 ± 5% RH and a photoperiod of 16L: 8D h). The results obtained were analyzed in two steps. At the first step, a logistic regression was used to determine the type of functional response. According to the logistic regression, the predatory mite showed a type III functional response when fed on egg and shows a suitable reaction to different densities of eggs. Also, with the change of the developmental stage of the prey, this predator mite shows a different behavioral response and it showed type II to different densities of larva and deutonymph of T. urticae. Then, the Roger's models were used to estimate the parameters of attack rate (searching efficiency) (a) and handling time (Th). The handling time was 0.83, 0.30 and 1.03 h when the predatory mite fed on egg, larva and deutonymph, respectively. The searching efficiency was 0.59, 0.04 and 0.05 h-1 when the predatory mite fed on the above-mentioned stages of prey, respectively. The handling time increases as the prey grows from larva to deutonymph. The maximum attach rate (T/Th) was (34.42 prey/day) when larva was served as food. According to the present findings, this predatory mite can be more effective for managing early stages of T. urticae.