Functional Response and Prey Preference of Neoseiulus bicaudus (Mesostigmata: Phytoseiidae) to Three Important Pests in Xinjiang, China.

Knowledge about the prey preference of polyphagous predators is important for determining their ability to suppress pest insects. Tetranychus truncatus (Tetranychidae), Tetranychus turkestani (Tetranychidae), and Thrips tabaci (Thripidae) often coexist in crops. Neoseiulus bicaudus (Wainstein) is a native predatory mite that was recently observed in the Xinjiang Uygur Autonomous Region of northwest China. The objective of this study was to assess the potential of N. bicaudus as a bio-control agent against the three pest species mentioned above. The results showed that N. bicaudus protonymphs, deutonymphs, and adults can be effective biological control agents for the three pest species. Neoseiulus bicaudus at all three developmental stages exhibited a Holling's Type II (convex) functional response to the prey. Neoseiulus bicaudus exhibited no preference between T. truncatus adults and T. turkestani adults, irrespective of the prey ratio. In comparison, N. bicaudus clearly preferred first-instar T. tabaci larvae to T. turkestani adults. The results of this study suggest that N. bicaudus could help control T. truncatus, T. turkestani, and T. tabaci. Among these pests, N. bicaudus may be most effective for first-instar T. tabaci.