Life history of Phytoseiulus macropilis (Acari: Phytoseiidae) feeding on Mononychellus planki (Acari: Tetranychidae) on common bean leaves (Phaseoulus vulgaris L.)

Mononychellus planki (Tetranychidae) is a phytophagous mite present mainly on common bean, soybean and cottonweeds in Central and South America. Phytoseiulus macropilis (Phytoseiidae) is a predatory mite commonly associated with tetranychid populations in South and Southeast Brazil. This study tested the hypothesis that M. planki is an alternative prey enhancing the survival of P. macropilis when Tetranychus urticae is absent in the environment. Initially, we determined the predator’s food preference, and then evaluated the biology of P. macropilis studied on M. planki as prey. In food preference experiments, P. macropilis was given a choice between leaf discs with eggs of T. urticae or M. planki. For biology studies, common bean leaf discs were cut and placed on moistened filter paper in plastic plates. Our results suggest that M. planki is a suitable food for P. macropilis on native vegetation and in soybean crops in Rio Grande do Sul, Brazil.