Effect of biorationals and Predatory Mites incontrolling the Two-Spotted Spider Mite (Tetranychus urticae L) on Eggplant field in the Greenhouse

Abstract

The Two-Spotted Spider Mite (TSSM) is a prevalent mite pest found worldwide and is extensively distributed in Mongolian greenhouses. In this study, we conducted a field experiment using predatory mites and botanical pesticides on eggplants infested by TSSM. We observed promising results in terms of reducing pest populations and achieving overall improved outcomes. The experiment took place in a 120 sq.m. greenhouse located at the "Agropark" training-research center of the Mongolian University of Life Sciences. The aim of this experiment was to test the effectiveness of the following treatments in controlling Two-Spotted Spider Mite (TSSM): Treatment A (predatory phytoseiid mites at a ratio of 1:5), Treatment B (predatory phytoseiid mites + Neem), Treatment C (Neem alone), Treatment D (Neem + BEB), and Treatment E (untreated control). The experiment utilized a total of 20 plots, each with a size of 6 square meters, and 24 plants were grown in each plot, resulting in a total of 480 plants. Each plot was replicated four times. To assess TSSM control, mortality rates of TSSM were calculated for each treatment as follows: - Treatment A (Predatory phytoseiid mites): 44.4% to 94.7% - Treatment B (Predatory phytoseiid mites - 1:5 + Neem - 30ml/4.5L of water): 76.3% to 96.3% - Treatment C (Neem - 30ml/4.5L of water): 61.8% to 90.8% - Treatment D (Neem - 30ml/4.5L of water + BEB - 20ml/10L of water): 68.6% to 88.2%. The combination of all these treatments have shown apromising results in controlling TSSM in the greenhouse, significantly reducing the TSSM population, according to our research findings. However, it is important to release the predatory mites after a 5-day interval following the application of botanicals (Neem). We recommend a release of predatory mites (Phytoseiilus persimilis and Amblyseius swirskii) either alone or in combination with botanicals for controlling TSSM in the greenhouse, because it is effective and a safe plant protection measurement to use in the greenhouse.