Population genetic structure of economically important Tortricidae (Lepidoptera) in South Africa: a comparative analysis.

Comparative studies of the population genetic structures of agricultural pests can elucidate the factors by which their population levels are affected, which is useful for designing pest management programs. This approach was used to provide insight into the six Tortricidae of major economic importance in South Africa. The population genetic structure of the carnation worm E. acerbella and the false codling moth T. leucotreta, analyzed using amplified fragment length polymorphism (AFLP) analysis, is presented here for the first time. These results were compared with those obtained previously for the codling moth Cydia pomonella, the oriental fruit moth Grapholita molesta, the litchi moth Cryptophlebia peltastica and the macadamia nut borer T. batrachopa. Locally adapted populations were detected over local geographic areas for all species. No significant differences were found among population genetic structures as result of population history (whether native or introduced) although host range (whether oligophagous or polyphagous) had a small but significant effect. It is concluded that factors such as dispersal ability and agricultural practices have the most important effects on genetically structuring populations of the economically important Tortricidae in South Africa.