Induction of aldrin epoxidation and glutathione S‐transferase in the mite Rhizoglyphus robini

The extent of induction of aldrin epoxidation and glutathione S‐transferase (GST) in the bulb mite Rhizoglyphus robini was dependent on the ingested plant material or on the type of inducer. GST was strongly induced in mites fed on garlic or exposed to trans‐stilbene oxide as well as by the pesticides fenpropathrin and propoxur. Several phytochemicals such as 3‐indoleacetonitrile, flavone, chalcone and pulegone were potent GST inducers stimulating the enzyme activity by 2–4‐fold. Other toxicants, pesticides and allelochemicals yielded moderate to slight stimulation and a few were even inhibitory. In general, aldrin epoxidation was moderately stimulated by plant materials and xenobiotics. The epoxidation activity was increased in mites fed on garlic and carrot, or exposed to toxicants such as pentobarbital and δ‐hexachlorocyclohexane, pesticides like chlordimeform, propoxur, carbaryl and lindane, as well as allelochemicals such as flavone, β‐carotene, indole‐3‐carbinol and safrole. The relevance of the study vis‐à‐vis adaptation of herbivorous arthropods to their habitats and acquirement of tolerance to chemical control agents, is discussed. 1991 The Netherlands Entomological Society