Ovicidal and residual effects of Moringa oleifera leaf ethanol extract on Tetranychus merganser (Trombidiformes: Tetranychidae)

Red spider mite, Tetranychus merganser (Trombidiformes: Tetranychidae), is considered a pest in Mexican agriculture. It has also spread to the USA, China, and Thailand. Currently, the control of red spider mites depends mainly on agrochemicals such as pesticides. It is necessary to find sustainable strategies to manage T. merganser with low environmental impact and reduced risks for human health. The aim of this study is to assess the effects of Moringa oleifera leaf ethanolic extract at different concentrations (0.1, 0.5, 1, 5, 10, 15, and 20% (v/v)) against T. merganser eggs and its residual effect on immature hatched from treated eggs. Eggs treated with 0.1 and 20% (v/v) of the extract showed mortality of 3.11 (0.1% (v/v)) to 72.58% (20% (v/v)), as compared to the control treatment, respectively. The number of dead larvae and nymphs emerging from the treated eggs, as well as their feeding rates, depended on extract concentration, which led to a reduction in the population of red spider mites. This pioneering investigation reveals the ovicidal and residual activities of the M. oleifera leaf ethanolic extract against T. merganser . Further research is needed, including the assessment of the phytotoxicity of the extract against T. merganser under greenhouse and field conditions, as well as studying the extract’s effect on natural enemies.