Plant Extracts as Potential Acaricides for the Management of Red Spider Mite, Oligonychus coffeae Nietner (Acarina: Tetranychidae), in the Tea Ecosystem: An Eco-Friendly Strategy
Bhabesh Deka, Azariah Babu, Chittaranjan Baruah, Suman Sarkar
Abstract
The effects of the application of aqueous extracts of a selection of five traditional plants ( Murraya paniculata, Cassia tora, Amphineuron opulentum, Tithonia diversifolia , and Cassia alata ) were compared with that of synthetic acaricide in reducing the population of red spider mite ( Oligonychus coffeae ), a major tea pest, alongside their impact on natural enemies and green leaf yield. Analysis of large-scale field trials showed that all the five plants extract treatments resulted in similar yield; this was analogous to the application of synthetic acaricide. A reduction in the pest population was observed to be on par with the synthetic acaricide, with a higher number of natural enemies treated using the pesticide-plant-treated plot in comparison to the synthetic acaricide-treated plot, which indicated pesticidal plants had a lower impact on natural enemies. A phytotoxicity study on tea leaves indicated that aqueous extracts of selected plants are non-phytotoxic and do not impart any taint to the prepared tea samples. Therefore, the present investigation outlines how plant extracts used as a botanical pesticide display toxicity against red spider mite on tea plants without harming the beneficial insects, increasing the yield and avoiding any lethal consequence for the tea plants or consumers.