Mite biodiversity on vegetables in plastic-houses and the efficacy of an essential oil mixture on Tetranychus urticae and Phytoseiulus persimilis

ABSTRACT We surveyed the mite fauna on three vegetable crops (cucumber, eggplant, and pepper) in plastic-houses throughout the autumn of 2020 by taking weekly leaf samples. These samples revealed several plant-feeding and predatory mites belonging to 13 species in ten genera and five families, as well as some insect pests. Tetranychus urticae Koch (Tetranychidae) was a significant pest in all three crops and Integrated Pest Management (IPM) control was used for its control. A bioassay was performed to evaluate the effect of a mixture of essential oils (clove, lavender, eucalyptus, and sweet orange) on T. urticae and its associated predator, Phytoseiulus persimilis Athias-Henriot (Phytoseiidae). The lethal concentration of this essential oil mixture determined by laboratory bioassay, was used on eggplant and cucumber crops in plastic-houses. The active ingredients of the tested oil mixture were determined using GC-MS analysis of the mixed essential oil. The total constituents of the mixed essential oil were identified as 43 compounds, primarily d-limonene, but also monoterpenes, sesquiterpens, diterpens, sestetraterpens, triterpens, and tetraterpens.