The structure of eusocial bee assemblages in Brazil

Social bee - food plant relationships have been studied extensively, especially in the Neotropics. This is, however, the first quantitative comparison and review of a large set (28) of studies. Patterns in social bee richness, niche breadth and associations between social bee taxa could be explained partly by species-specific differences in behaviour, foraging traits and response to interspecific competition. Bee assemblages contain higher percentages of social Apidae towards the equator. Medium-sized non-aggressive group foragers had the narrowest diet and the super-generalists the broadest diet. Niche breadth generally decreased with the number of social bee species in the assemblage indicating that interspecific competition influences diet choice. Cluster-analysis revealed two main groups in terms of food plant use: medium-sized non-aggressive group foragers and a group containing the aggressive group forager Trigona spinipes, the honeybee and three small scramblers. Four other taxa were not associated with any other taxa.