Abstract
The metabolism of 14C-isoafenphos was examined in the housefly and the cupreous chafer. Isofenphos penetrated more rapidly into the housefly than into the cupreous chafer. It was rapidly metabolized in the insects and the distribution of 14C-compounds into the aqueous fraction increased gradually. The transformation to water soluble metabolites was faster in the housefly than in the cupreous chafer. No difference in kinds of metabolites was found between the two insects, and as those of isofenphos, isofenphos-oxon, aminoisofenphos, des N-isopropyl isofenphos, desphenyl isofenphos, desN-isopropyl isofenphos-oxon, desphenyl isofenphos-oxon, O-ethyl hydrogen phosphoramidate and O-ethyl dihydrogen phosphate were identified. The main metabolic pathway was proposed to be the formation of the water soluble metabolites through isofenphos-oxon. Water soluble metabolites were dominantly formed through the cleavage of P-O-aryl linkage.
