Leaves of Aegle marmelos Correa (Rutaceae): a potential source of acaricide for the management of Oligonychus coffeae (Nietner) (Acari: Tetranychidae)

Abstract

Leaves of Aegle marmelos Correa (Rutaceae) were extracted successfully with methanol (95%), ethyl alcohol (50 and 95%). These extracts were tested for their toxicity against eggs, larvae, protonymphs, deutonymphs and adults of Oligonychus coffeae (Nietner) (Tetranychidae: Acari) under laboratory conditions. In general, methanol extract was the most potent in terms of acaricidal activities against all life stages, followed by 95% ethyl alcohol and 50% ethyl alcohol extracts. The effect was stronger with increasing concentrations. The methanol extract effectively and significantly reduced the mite population in field trial, and its efficacy was comparable to synthetic pesticides and neem pesticides. With the availability and distribution of A. marmelos in and around tea growing areas of northeastern India, A. marmelos should be further developed as a potential plant-based acaricide for effective management of tea red spider mite.