-Investigations on physiological and molecular mechanisms underlying developmental and reproductive differentiation in social bees center on the question of how different patterns of larval nutrition can affect hormonal dynamics and how these drive differential gene expression. Differential expression analyses and the generation of AFLP markers now enable us to re-examine the question of genetic caste determination in the genus Melipona. The comparison of vitellogenin expression in three species of stingless bees suggests divergence in regulatory mechanisms that directly relate to the mode of worker reproduction. As in honey bees, this indicates alternative functions for vitellogenin in the life cycle of adult workers. The diversity in life histories and their associated specific physiologies make the stingless bees a rich resource for information on evolutionary trajectories that have generated phenotypic plasticity in social Hymenoptera. stingless bee / caste development / juvenile hormone / vitellogenin / worker reproduction / Apidae / Meliponini

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Honey is a product with low water activity because of the great amount of sugars (fructose and glucose), and also it has antimicrobial compounds derived from flowers or because of its transformation process in the beehive. Despite all the honey microorganism barriers, some species of microorganisms are able to survive and may cause damage to honeybees or consumers. Techniques of pathogenic microorganism identification by DNA using PCR are recommended and required for sanitary and customs control. It is important to know the diversity of contaminating microorganisms in honey, especially due to disseminate pathogenic microorganisms in the international traded marketing. In contrast, beneficial microorganisms such as yeasts can remain latently in this product waiting for the moment in which the environment is suitable for their development. Among the beneficial bacteria found in honeybee products, we can mention some lactic acid bacteria that act as prebiotics when ingested. The microorganisms in the digestive tract of honeybees are important for their health. Thus, we present the knowledge of microbiota associated with honey from honeybees and stingless bees (Hymenoptera, Apidae) and the techniques available for the detection of microorganisms in honey.

Learning in insects has been extensively studied using different experimental approaches. One of them, the proboscis extension response (PER) paradigm, is particularly well suited for quantitative studies of cognitive abilities of honeybees under controlled conditions. The goal of this study was to analyze the capability of three eusocial bee species to be olfactory conditioned in the PER paradigm. We worked with two Brazilian stingless bees species, Melipona quadrifasciata and Scaptotrigona aff. depilis, and with the invasive Africanized honeybee, Apis mellifera. These three species present very different recruitment strategies, which could be related with different odor-learning abilities. We evaluated their gustatory responsiveness and learning capability to discriminate floral odors. Gustatory responsiveness was similar for the three species, although S. aff. depilis workers showed fluctuations along the experimental period. Results for the learning assays revealed that M. quadrifasciata workers can be conditioned to discriminate floral odors in a classical differential conditioning protocol and that this discrimination is maintained 15 min after training. During conditioning, Africanized honeybees presented the highest discrimination, for M. quadrifasciata it was intermediate, and S. aff. depilis bees presented no discrimination. The differences found are discussed considering the putative different learning abilities and procedure effect for each species.