Phoxim is an organophosphate insecticide that inhibits acetylcholinesterase (AchE) activity in the nervous system of insects. It is used in veterinary medicine for the treatment of ectoparasitic mites. It is toxic to aquatic organisms and may affect cytochrome P450 enzyme (CYP1A) activity and its expression levels in fish liver microsomes. In addition, sub-lethal doses of phoxim affected detoxification enzyme activities of adult mulberry whitefly, such as changes in the activities of glutathione S-transferase (GST), carboxylesterase (CarE) and acetylcholinesterase (AchE).