The Toxicity and Physiological Effect of Unripe Husks of Juglans Regia on Teranychas Viennensis

Teranychas viennensis, a phytophagous mite with resistance, is responsible for reducing host vigor and yield losses of many crops and fruit trees. Botanical pesticides may reduce the potential of mite populations developing resistance. Isolation and identification of bioactive compounds from unripe Juglans regia husks is a potential approach for the development of new miticide. Laboratory experiments were carried out to investigate the acaricidal activities of unripe J. regia husks. Biologic active compounds were obtained through technique of extraction, chromatograph column and HPLC. Bioassay-guided fractionation of petroleum-ether extracts of walnut led to purity compound F7, which showed strong acaricidal activity at concentrations of 5 mg ml-1 and 10 mg ml-1 within 24 hr. Resistance mechanisms of mites to the compound include enhanced metabolic detoxification through some enzymes. Glutathione S-transferases (GSTs) catalyze conjugations by facilitating the nucleophilic attack of the sulfriydryl group of endogenous reduced glutathione on electrophilic centers of a vast range of xenobiotic compounds Elevated levels of GST exposed that Teranychas viennensis metabolized xenobiotic compounds and excreted them from body.