CONICET | Buscador de Institutos y Recursos Humanos

Euglossini bees are among the main plant pollinators in tropical and subtropical forests of Central and South America: they have great flight capacity, being able to traverse over large open water bodies. Some authors have suggested that male Euglossa Latreille 1802, which are generally smaller than those of other Euglossini genera, would exhibit a smaller flight radius and therefore be less able to travel between forest fragments isolated by non-forested areas. Here, we tested this hypothesis by exploring patterns of genetic differentiation betweenEuglossa cordata males collected at two Atlantic Forest remnants located on the northern coast of São Paulo State, Brazil, apart from each other by at least 30 km: one on mainland, ?Núcleo Picinguaba? of Parque Estadual da Serra do Mar (44°49??44°50?W; 23°21?S; n = 174) and one on an island, Parque Estadual da Ilha Anchieta (45°02??45°05?W; 23°31??23°34?S; n = 377). Results of analyses based on genotypic information on 16 polymorphic microsatellites showed that: 1) allele frequencies differed significantly between both samples (genic Fisher?s tests P< 0.014, adjusted significance value); 2) the variation observed in males from island and mainland was best explained assuming two different genetic clusters (Bayesian analyses); 3) male bees from both sitesdiffered significantly in their genetic variation (Discriminant Analyses of Principal Components). Our results indicate significant genetic differentiation between Euglossa cordata populations from mainland and island, supporting the hypothesis that the bees may be less able to cross non-forested areas; alternatively, if dispersal does occur, other mechanism would be operating to restrict gene flow between these populations.