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1. The resource partitioning hypothesis states that sympatric, morphologically, and functionally similar species can coexist by temporal separation or low food overlap. Also, the interindividual variations about the use of resources, i.e. individual specialisation, can promote the resilience and stability of their populations when an environmental disturbance affects food availability.2. Two sympatric and polylectic species of carpenter bees to test both the hypotheses of food niche partitioning and the occurrence of individual specialisation were used.3. The study was conducted in two Brazilian Savanna areas and the trophic niches of Xylocopa grisescens and X. frontalis were determined by the diversity of pollen types obtained from larval food samples. Individual-resource networks were constructed to elucidate the patterns of resource use by the individuals of each species.4. The populations of the two bee species moderately overlapped their trophic niche. Xylocopa grisescens mainly used the pollen of non-poricidal plants, whereas X. frontalis used pollen from plants with poricidal anthers. Individual-resource networks of both species are weakly connected, highly specialised, and modular.5. In conclusion, the results suggest that the coexistence between Xylocopa grisescens and X. frontalis probably occurs due to food resource partitioning. Furthermore, the results about individual-resource networks of both species seem to reveal the occurrence of interindividual variations regarding food resource foraging.

A consolidação em uma área do conhecimento acontece principalmente quando as informações acerca de um determinado fato ou fenômeno são sistematizadas na forma de uma teoria explicativa, capaz de gerar novas hipóteses testáveis. Na biologia da polinização, o teste de diversas hipóteses ecológicas permitiu ampliar o entendimento sobre os processos que originam, mantêm, alteram ou ainda excluem as interações entre plantas e visitantes florais, gerando os padrões observados na natureza. Visando sintetizar esse panorama teórico e oferecer condições para que novas questões relacionadas ao funcionamento de interações de polinização sejam geradas, compilamos aqui um conjunto de 25 hipóteses, ideias e teorias ecológicas que fornecem aporte conceitual para a área. Essas ideias estão relacionadas a aspectos reprodutivos, morfológicos, cognitivos, macroecológicos e de coexistência, de acordo com a especialização das interações entre as plantas e seus polinizadores. Ao apresentarmos essas ideias principais, esperamos promover a utilização de uma abordagem teórico-conceitual explícita no planejamento e desenvolvimento de estudos em biologia da polinização. Concluímos com a expectativa de que essa contribuição direcione os estudos em biologia da polinização no Brasil e contribua para o avanço e internacionalização das pesquisas desenvolvidas no país. Palavras-chave: Fundamentação teórica, interação planta-polinizador, sucesso reprodutivo, ecologia cognitiva. AbstractA particular research area can be significantly improved when information is systematized in explanatory theories able to generate testable hypotheses. In pollination biology, such systematization contributed to several ecological theories and expanded the understanding of the patterns and processes that originated, maintain, or exclude ecological interactions. Here, we compiled a set of 25 ecological ideas that have already received conceptual contribution from pollination biology. These ideas are related to reproduction, morphology, cognition, macroecology and species coexistence. We hope to promote the use of an explicit conceptual and theoretical approach when planning and developing studies in this research field by presenting these main ideas. We conclude that this contribution will boost studies in pollination biology in Brazil and contribute to the advancement and internationalization of such research developed in the country.

Approximately 20,000 species of flowering plant offer mainly pollen to their pollinators, generally bees. Stamen dimorphism, a floral trait commonly present in some pollen flowers, is thought to be associated with exclusive pollen provision for highly effective bee pollinators. Notwithstanding, little is known about how stamen dimorphism is related to other floral morphological traits and, consequently, plant-pollinator interactions at the community scale. Here we investigated the relationship between stamen dimorphism and other floral morphological traits, as well as the interactions with pollinators in plants of Melastomataceae.• We characterized each plant species as stamen dimorphic or stamen isomorphic according to differences in size and shape between stamen sets. Data on interactions between the plants and their bee pollinators were analysed as quantitative bipartite networks.• We found that petal and style size and shape were correlated to stamen dimorphism.Stamen dimorphic species present larger flowers and less variable style shapes than stamen isomorphic species. Furthermore, stamen dimorphism is associated with higher richness of visiting bees, i.e. higher ecological generalization.• During the evolutionary history of Melastomataceae, the dependence on pollinators for fruit set has possibly favoured the evolution of larger flowers with dimorphic stamens, which in turn are able to make use of a larger spectrum of pollen-collecting bees, leading to ecological generalization.