A predatory mite as potential biological control agent of Bemisia tabaci on tomato plants

Several natural enemies are known as predators of the whitefly Bemisia tabaci, which is one of the most invasive pests worldwide and has developed high resistance to pesticides. However, biological control of this pest on tomato is often difficult because the plant’s glandular trichomes release substances that are toxic to arthropods and hinder the foraging of natural enemies. Therefore, adaptation of natural enemies to this crop is one of the selection criteria for potential biocontrol agents. We collected predatory mites from wild and feral tomato plants and found the species Amblyseius herbicolus and A. tamatavensis. Whereas the latter is known to feed on B. tabaci eggs, we investigated the ability of A. herbicolus to develop and reproduce when feeding on this prey stage, and assessed whether both species can feed and develop on B. tabaci crawlers. To verify the adaptation of these predators to tomato, we assessed their ability to disperse on tomato plants and their establishment on clean tomato plants with pollen as an alternative food. Finally, we evaluated whether the predators were effective in controlling B. tabaci on tomato plants with different pollen dosages as alternative food. We show that both predators fed and reproduced on B. tabaci immatures. A. herbicolus established and dispersed better on tomato plants supplemented with cattail pollen than A. tamatavensis and only A. herbicolus was able to control B. tabaci in two population dynamics experiments. Our results suggest that A. herbicolus is better adapted to tomato than A. tamatavensis and may therefore be a promising biocontrol agent on tomato.