抄録
Absorption and degradation of propoxur in multiple-resistant and susceptible strains of the green rice leafhopper were investigated using 14C-labeled propoxur. Amounts of propoxur in the outer part of the treated insects dropped rapidly in both strains at low and high dosages (0.001 and 0.06 μg of propoxur applied topically on females). The absorption rates of propoxur were almost the same in the two strains. o-Isopropoxyphenyl N-hydroxymethylcarbamate was found as one of the metabolites in the leafhopper. At the low dosage, no symptom of poisoning was observed in either strain. Amount of propoxur equivalent in the organic phase was 2 times higher in the susceptible strain than in the resistant strain and that in the aqueous phase was reversely lower in the susceptible strain one hour after application. At the high dosage, no symptom was observed in the resistant strain, though the amount of propoxur equivalent in the organic phase was almost the same as that in the susceptible strain one hour after application, all leafhoppers of which were knocked down without restoration. On the basis of the previous and present observations, it is suggested that the somewhat high activity of degradation of propoxur in the resistant strain is one of the resistance factors to propoxur in addition to the main resistance factor, the insensitivity of acetylcholinesterase to inhibitors.
