RAPD PCR CONFIRMS ABSENCE OF GENETIC-VARIATION BETWEEN INSECTICIDE RESISTANT VARIANTS OF THE GREEN PEACH APHID, MYZUS-PERSICAE (HOMOPTERA, APHIDIDAE)

Previous allozyme analysis has revealed an apparent absence of enzyme variability in the green peach aphid, Myzus persicae (Sulzer). We are interested in determining the genetic relatedness of individual M. per sicae clones carrying different numbers of esterase 4 (E4) gene copies conferring resistance to insecticides, in order to determine how many times and in what geographic locations resistance via gene duplicatio n may have evolved. We have therefore extended the analysis of genetic variability in M. persicae to the DNA level using random amplificatio n of polymorphic DNA(RAPD) with single 10 mer oligonucleotide primers. Here we report a lack of variability between resistant clones in Wisc onsin populations even at the DNA level. Further, 'fast' E4 (FE4) vari ants appear to be absent from Wisconsin populations, despite FE4 varia nts of moderate resistance (R(1)) being the most common clones in the United Kingdom. These results suggest that resistance in M. persicae m ay have evolved a very few times and that North American populations m ay differ from those in Europe by founder effects.