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 populatio ns of the Mediterranean fruit fly, Ceratitis capitata, have been analy sed using markers produced by arbitrarily grimed polymerase chain reac tion (PCR). Populations sampled include various geographical localitie s around the world with established Mediterranean fruit fly population s and localities, such as California, where the status of the pest is controversial. Marker pattern relationships for these different popula tions have been used to determine genetic relatedness as well as to ex amine potential patterns of gene flow and movement of this pest specie s. Based on the extent to which markers are shared between these popul ations, it is clear that there is a range of genetic relationships. Sa mples from some regions, such as southern California and Guatemala. ap pear to be quite closely related to each other, whereas others, such a s those from Greece and Argentina, show relatively little in common wi th any ether sampled population. Multiple samplings from specific geog raphical sites within Guatemala and California have also been analysed in both spatial and temporal terms. The relationships among the infes tations within California from recent years are quite different compar ed with similar populations sampled within Guatemala. This indicates t hat they are more likely to represent multiple, independent infestatio n events.