Functional evaluation of Mentha suaveolens and Phlomis fruticosa as reservoir plants of Typhlodromus (Anthoseius) recki (Acari: Phytoseiidae) in tomato biological control strategies.

Effective pest management requires alternative strategies to reduce pesticide use. This study investigates the potential of Mentha suaveolens and Phlomis fruticosa, to act as reservoir plants for the predatory mite Typhlodromus (Anthoseius) recki in tomato crops. Two experiments were conducted in controlled conditions: the first to assess the suitability of these plants for four tomato pests (Tuta absoluta, Trialeurodes vaporariorum, Tetranychus urticae, and T. turkestani) and a second to evaluate the influence of the reservoir plant species, the presence of tetranychid mites on them, and infestation by Aculops lycopersici of nearby tomato plants on predator and tetranychid mites development and dispersal. In experiment 1, neither of the two reservoir plants was favorable to T. absoluta and T. vaporariorum. Mentha suaveolens was favorable to both Tetranychus species, while P. fruticosa was favorable to T. turkestani but much less T. urticae. In the experiment 2, Typhlodromus (A.) recki reproduced and developed on both reservoir plants, even without prey, with higher densities on M. suaveolens. Predators dispersed to tomato plants in all treatments, with consistently higher densities found on tomato plants infested by A. lycopersici. A higher dispersal seems also to better occur when M. suaveolens is the reservoir plant vs. P. fruticosa. The numbers of tetranychid mites remained very low on both reservoir plants and adjacent tomato plants, likely due to efficient predation. These results indicate that both plants can act as reservoirs for T. (A.) recki, even in the absence of prey, but that M suaveolens would be more favorable to adjacent tomato colonization. Further research is needed to optimize predator density and improve reservoir plant configurations for enhanced dispersal.