Modifications of Phytoseiidae mite breeding methods to suppress spider mite

Abstract

Populations of mites from the Tetranychidae family are characterized as high-resistant to acaricides, which, in turn, leads to an increase in the pesticide load on the agrocenoses ecosystem. Carnivorous arthropods from the Phytoseiidae family can be used as an alternative pest control. Our research aimed at improving the methods of breeding, storage and use of predatory mites against Tetrahychus urticae Koch. In 2015–2018, work was being undertaken to define the optimum thickness of the substrate layer (2.0, 4.0 and 6.0 cm) for breeding the food object – Acaris farus Oud. We also assessed the effect of the fodder substrate composition (wheat bran – control, wheat bran + soybean meal – experimental variant) on the population density of Amblyseius andersoni Chant. In 2016–2019, experiments on the storage of Neoseiulus barkeri Hughes, Neoseiulus cucumeris Oud. and Amblyseius swirskii Athias-Henriot at 4 °C (control – no storage) were carried out. In 2018–2019, to control Tetrahychus urticae Koch. in the soybean field, a mixture of N. cucumeris and A. andersoni was used according to the method of introduction into natural foci of prey. The optimum thickness of the substrate layer was found to be 4 cm. In this case, it was possible to obtain 6,983 mites in 1 cm3 for 7 days. Soybean meal addition increased the number of A. andersoni by 22.3 % compared to control (263 ind. vs 204 ind. per cm3). 30–45 days – an effective storage period for N. barkeri, 30 days – for N. cucumeris, no more than 10 days – for A. swirskii. On average, in 2018–2019, N. cucumeris and A. andersoni mixture reduced the number of T. urticae. The number of spider mites in the control variant was 14.6, in the experimental one – 5.3 ind./leaf. No predatory activity was observed on eggs. To prevent the development of spider mites, it is necessary to use N. cucumeris and A. andersoni at least twice with an interval of 5–7 days.