Genetic marker analysis of spatial and temporal relationships among existing populations and new infestations of the Mediterranean fruit fly (Ceratitis capitata)

Genetic relationships among temporally and spatially defined populations of the Mediterranean fruit fly, Ceratitis capitata, have been analysed using markers produced by arbitrarily primed polymerase chain reaction (PCR). Populations sampled include various geographical localities around the world with established Mediterranean fruit fly populations and localities, such as California, where the status of the pest is controversial. Marker pattern relationships for these different populations have been used to determine genetic relatedness as well as to examine potential patterns of gene flow and movement of this pest species. Based on the extent to which markers are shared between these populations, it is clear that there is a range of genetic relationships. Samples from some regions, such as southern California and Guatemala, appear to be quite closely related to each other, whereas others, such as those from Greece and Argentina, show relatively little in common with any other sampled population. Multiple samplings from specific geographical sites within Guatemala and California have also been analysed in both spatial and temporal terms. The relationships among the infestations within California from recent years are quite different compared with similar populations sampled within Guatemala. This indicates that they are more likely to represent multiple, independent infestation events.