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.

KEYWORDS:

• Plant-feeding mites
• predators
• abundance
• IPM
• GC-MS

Acknowledgments

The Applied Centre of Entomonematodes, the Faculty of Agriculture, Cairo University, Giza, Egypt is grateful for offering many facilities used to complete the current work. Thanks are to Dr Ahmad Said Sanad (Vegetable and Aromatic Plant Mites Department, Plant Protection Research Institute, Agricultural Research Centre, Egypt) for providing the two-spotted spider mite laboratory strain and Phytoseiuls persimilis source used in the bioassay experiment. Dr Ashraf Said Elhalawany (Fruit Tree Mite Department, Plant Protection Research Institute, Agricultural Research Centre, Egypt) is also thanked for identifying the eriophyid mite specimens collected in the current study. Special thanks are to Dr Bruce Halliday (Australian National Insect Collection, CSIRO, Australia), for help with the English language editing.

Disclosure statement

No potential conflict of interest was reported by the authors.