Regular or covert sex defines two lineages and worldwide superclones within the leaf-curl plum aphid (Brachycaudus helichrysi, Kaltenbach)

Asexual reproduction occurs widely in plants and animals, particularly in insects. Aphid species usually reproduce by cyclic parthenogenesis, but many species include obligate asexual lineages. We recently showed that the leaf-curl plum aphid, Brachycaudus helichrysi, actually encompasses two lineages, B. helichrysi H1 and H2. Ecological data suggest that these lineages have different life cycles. We conducted a large population genetic study, based on 14 microsatellite loci, to infer their respective life cycles and investigate their population structure and geographic distribution. Brachycaudus helichrysi H1 displayed the genetic signature of cyclical parthenogenesis, using plum trees as primary hosts for sexual reproduction, as classically described for B. helichrysi. This global survey showed that the Central Asian population of H1 was clearly differentiated from American - European populations. By contrast, B. helichrysi H2 displayed the typical signature of obligate asexual reprod...