Typha angustifolia L. pollen as an alternative food for the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae)

Abstract

Neoseiulus californicus (McGregor) (Mesostigmata: Phytoseiidae) is considered a specialized predator of spider mites and has mainly been used to control Tetranychus urticae Koch (Acari: Tetranychidae). However, this phytoseiid is also able to feed and reproduce on certain pollens. In the present laboratory study, survival, development time, and reproduction of N. californicus were determined when reared on T. urticae, Typha angustifolia pollen, or on a combined diet of both foods. The immature stages of N. californicus developed faster when T. urticae was present in the diet. The total developmental time of females was longer when offered T. angustifolia pollen only (6.6 days), than when fed on T. urticae (4.5 days) or T. urticae + pollen (4.5 days). The oviposition rate of N. californicus was higher on the two diets containing T. urticae (3.1-3.3 eggs/female/day) than on T. angustifolia pollen alone (0.9 eggs/female/day). The intrinsic rates of natural increase (rm) were estimated to be 0.273, 0.268 and 0.149 females/female/day on T. urticae, T. urticae + T. angustifolia and T. angustifolia, respectively. Our results indicate that supplementing a T. urticae diet with T. angustifolia pollen would not improve population parameters. However, in the absence of spider mites, providing commercial pollen might help sustain populations of the phytoseiid in the field.