ESTERASE VARIATION IN JAPANESE POPULATIONS OF MYZUS-PERSICAE (SULZER) (HOMOPTERA, APHIDIDAE), WITH SPECIAL REFERENCE TO RESISTANCE TO ORGANOPHOSPHORUS INSECTICIDES

The esterase activity of 153 clones of Myzus persicae (Sulzer) from field populations and 95 F1 and F2 clones from some interclonal crosses was examined by polyacrylamide gel electrophoresis. A total of 15 esterases, including one known to be associated with organophosphorus resistance, were detected. Some of them, including the resistance- associated esterase (RAE), were concentrated mainly in the body fluid and the others in the alimentary canal. Interclonal variation was found at the RAE locus and at 4 others. From segregating ratios in Fl the genetic basis for inheritance of each variant at the polymorphic esterase loci was discussed. No indication was found for linkage between RAE activity and any other polymorphic esterase loci. RAE activity appears to be also independent of the body colour, the life-cycle category and the presence or absence of the trans-location. A known association between RAE activity and resistance was generally chromosomal confirmed in testing 20 clones for susceptibility to malathion. © 1979, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.