Acaricidal Properties of Essential Oils from Moroccan Thyme Against Oriental Red Mite, <i>Eutetranychus Orientalis</i> (Klein) (Acari: Tetranychidae)
Mohamed Ouknin, Hassan Alahyane, Houda Aboussaid, Khalid Oufdou, S. El Messoussi, Jean Costa, Lhou Majidi
Abstract
Essential oils (EOs) from three species of the Lamiaceae family growing in several areas in Morocco, were evaluated for their acaricidal properties against the oriental red mite, Eutetranychus orientalis (Klein) (Acari: Tetranychidae). In this study, different concentrations of thyme oils including Thymus satureioides Coss., T. maroccanus Ball. and T. atlanticus Ball. EOs were used to assess the adulticidal, larvicidal effect by leaf paint method. In addition, the ovicidal effect was evaluated by the leaf disc sprayer method. The obtained results showed that all the EOs tested induce significant mortality to E. orientalis adult females and larvae, and the mortality was increased with increasing the concentration of EOs. In addition, adult females treated with EOs lay fewer eggs than untreated females. Moreover, the highest ovicidal effect on E. orientalis, was induced by T. maroccanus and the lowest effect was induced by T. satureioides and T. atlanticus, respectively at the lowest concentration. The GC/MS analysis showed that the major compounds of T. satureioides EO were borneol (22.7 %), thymol (18.2 %), p-cymene (17.3 %), and α-pinene (6.7 %). The main compounds of T. atlanticus and T. maroccanus EOs are carvacrol (47.1-65.5 %), p-cymene (7.5-20.7 %) and α-pinene (3.7-5.5 %). The results proved that all EOs tested could be used in the integrated pest management of E. orientalis.