The predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is produced commercially for biological control of insects and mites on crop plants around the world. The aim of this study was to compare the effects of a diet of natural prey, Tetranychus turkestani Ugarov and Nikolskii (Acari: Tetranychidae), date palm pollen, or bee-collected pollen on A. swirskii development, reproduction, and life table parameters. Completely randomized, no-choice experiments were conducted in replicated experimental units, i.e., 3 x 3 cm plastic sheets inside Petri dishes. A life table analysis was also conducted. Results indicated that diet type did not affect A. swirskii preimaginal survival; it ranged from 97-100% on T. turkestani and both pollen diets. However, total development time was significantly shorter for A. swirskii females fed date palm pollen than T. turkestani or bee pollen. Adult females fed T. turkestani lived longer, had longer oviposition periods, and produced more eggs. The intrinsic rate of natural increase (0.396 d^-1) was higher for A. swirskii fed date palm pollen than T. turkestani or bee pollen. The finite rate of increase, net reproductive rate, and gross reproductive rate did not differ significantly between A. swirskii fed date palm pollen or T. turkestani. Mean generation time (7.56 d) and population doubling time (1.043 d) were shorter for A. swirskii fed date palm pollen than T. turkestani or bee pollen. This study suggests that the T. turkestani diet or date palm pollen diet is suitable for A. swirskii. Date palm pollen has great potential as a cost effective diet to mass produce A. swirskii in the absence of natural prey. Future research could determine whether long-term rearing on date palm pollen reduces the ability of A. swirskii to locate, capture, and consume T. turkestani or other Tetranychus species on crop plants.

The tetranychid Tetranychus turkestani Ugarov and Nikolskii is a serious pest of many important crops around the world. Management of T. turkestani by augmentative biological control using predators such as the phytoseiid Amblyseius swirskii (Athias-Henriot) is envisioned as an environmentally safe alternative to acaricides. Foundational knowledge on T. turkestani – A. swirskii interactions in the laboratory are necessary to predict the outcome of A. swirskii augmentative releases in the field. In this study, the functional and numerical responses of adult A. swirskii females feeding on immature stages of T. turkestani were determined in the laboratory. Prey densities were 2, 4, 8, 16, 32, 64, or 128 individuals per Petri dish arena. The functional response of A. swirskii to prey showed a Holling's type II response. The attack rate and handling time estimates from the random predator equation were 0.1148/h and 0.3146 h, respectively, indicating that A. swirskii consumed 76.28 individuals per day at the maximum level. The number of eggs laid by the predator, i.e., the numerical response, increased as host density increased up to a maximum of 33.10 eggs per female; then oviposition rate leveled-off. This study suggests that A. swirskii is a suitable candidate for augmentative biological control of T. turkestani but follow-up experiments in greenhouses or open fields are necessary.