Phytoseiid predators as potential biological control agents for Bemisia tabaci.

Mites of the family Phytoseiidae are known to be predators of whiteflies in several agroecosystems, especially of Bemisia tabaci Gennadius, a pest with high resistance to chemical insecticides that occurs in greenhouses in temperate regions. We collected predatory mites that were found to co-occur with whiteflies in the Middle East for control of B. tabaci: Tvphlodromus athiasae (Porath and Swirski), Neoseiulus barkeri Hughes, Tvphlodromips swirskii (Athias-Henriot), Euseius scutalis (Athias-Henriot), Phytoseius finitimus Ribaga. As a first step in the evaluation of these species as biological control agents, we measured their life-history traits when feeding on whiteflies. The intrinsic rates of increase (rm) of the predatory mite species ranged between 0.131 and 0.215 per day and E. scutalis had the highest rm estimated. Comparisons with the rm of B. tabaci indicate that some of the species should be capable of suppressing local populations of whitefly. The ability of predators to use alternative food was also tested, since it facilitates the setup of mass cultures and it can promote their persistence in the crop, even if the prey is scarce. All predatory mite species tested were able to survive and reproduce on a diet of broad bean pollen.