Genetic diversity of woolly apple aphid Eriosoma lanigerum (Hemiptera: Aphididae) populations in the Western Cape, South Africa.

The woolly apple aphid Eriosoma lanigerum (Hausmann) is one of the most damaging apple pests in South Africa. Information on its genetic diversity is lacking and this study, in which the genetic structure of parthenogenetic E. lanigerum populations was characterized in the Western Cape Province of South Africa, represents the first local study of its kind. A total of 192 individuals from four different regions were collected and analysed using amplified fragment length polymorphism (AFLP). Using five selective AFLP primer pairs, 250 fragments were scored for analysis. Results indicated that a low level of genetic variation was apparent in E. lanigerum populations in the Western Cape (H = 0.0192). Furthermore, populations collected from geographically distant regions were very closely related, which can partly be explained by the fact that agricultural practices were responsible for dissemination of populations from a common ancestor to geographically distant areas. The low level of variation found indicated that the possibility of controlling E. lanigerum in the Western Cape using host plant resistance is favourable. This is the first report of AFLP being used to characterize the genetic structure of an aphid species. Results indicate that this marker may be useful for analysis of other aphid species.