Toxicological and physiological activity of lemongrass and peppermint essential oils on life-table parameters of Oligonychus mangiferus and its predatory mite, Cydnoseius negevi

Abstract

Abstract The use of synthetic pesticides has raised concerns about environmental safety and human health. As a result, eco-friendly biopesticides such as essential oils are being used in combination with biocontrol agents within IPM programs. In this study, the effects of LC50 of lemongrass and peppermint essential oils were evaluated on the demographic parameters of Oligonychus mangiferus (Rahman & Sapra) and its predatory mite, Cydnoseius negevi (Swirskii & Amitai). The effects of these oils were assessed in terms of measuring the activity of antioxidant and detoxifying enzymes. GC-MS was used to identify the chemical components of these oils. The main compounds identified by GC–MS in lemongrass and peppermint essential oils were (D-Limonene (45.06%), β-Citral (10.30%), α-Citral (9.90%)) and (Menthol (32.03%), Menthone (30.18%), p-Menthan-3-one (11.53%)), respectively. The results showed that lemongrass and peppermint were more toxic to O. mangiferus than to C. negevi. Exposure of O. mangiferus to the LC50 of these oils caused a significant increase in peroxidase and catalase enzymes, but it inhibited the detoxifying enzymes, α-esterase, β-esterase, and glutathione s-transferase. Also, these oils had disruptive effects on survival, longevity, and fecundity of O. mangiferus; as they reduced its demographic parameters such as (R0), (GRR), (rm) and (λ). However, they did not show any substantial change in the development time and demographic parameters of C. negevi. On the contrary, they improved its enzymes activity. According to these findings, these essential oils can be used in combination with biological control agents in the integrated pest management strategies against the mango spider mite, O. mangiferus.