Development and reproduction of four predatory mites (Parasitiformes: Phytoseiidae) feeding on the spider mites Tetranychus evansi and T. urticae (Trombidiformes: Tetranychidae) and the dried fruit mite Carpoglyphus lactis (Sarcoptiformes: Carpoglyphidae)

The tomato red spider mite, Tetranychus evansi, a notorious crop pest, invaded New Zealand in 2020. In an effort to identify potential biological control agents for this species, we investigated the capabilities of four phytoseiid predators found in New Zealand—Amblyseius herbicolus, Amblyseius lentiginosus, Amblydromalus limonicus, and Neoseiulus californicus. For comparison, we also used the two-spotted spider mite, T. urticae, and the dried fruit mite, Carpoglyphus lactis, as prey for these predators. In our first experiment we monitored immature development and oviposition rate (over the first 5 days) of the phytoseiid predators when presented with the three prey species. While all four species of predators could develop and reproduce on the factitious (alternative and easily available) prey species C. lactis, they had limited success when feeding on T. evansi and T. urticae. Amblyseius herbicolus, A. lentiginosus, and Amblyd. limonicus were unable to reach adulthood when feeding on T. evansi and T. urticae in the presence of the protective webbing spun by the mites. While N. californicus matured when exposed to T. evansi reared on black nightshade leaves, it did not lay eggs—indicating potential limitations in prey suitability. In our second experiment, gravid females of all four predators failed to maintain their reproduction when provided with T. evansi in the presence of webbing. Neoseiulus californicus exhibited phenotypic plasticity in its developmental time, body size, and oviposition rate when feeding on the three prey species. This suggests that N. californicus has the flexibility to switch diets to survive during food scarcity, especially when their primary prey, T. urticae, is limited. This study is also the first to offer life history information about A. lentiginosus. Our findings underscore the difficulties of controlling T. evansi using phytoseiid predators and highlight the need for diversified pest management strategies, including the use of alternative insect predators or entomopathogenic fungi.