Metabolism of imidacloprid in houseflies

Metabolism of imidacloprid in the housefly Musca domestica was investigated. After the injection of C-14-labeled imidacloprid, radioactivity decreased to approximately 20% of the initial level within 24 hr. Most of the C-14 in the excreta as well as that in the insect body was accounted for by an olefin derivative of imidacloprid. The pre-application of piperonyl butoxide or propargyl propyl phenylphosphonate as a synergist suppressed the degradation of imidacloprid and delayed the excretion of insecticidal components from houseflies. These results suggested that the insecticidal activity of imidacloprid was affected by oxidative metabolic processes.