Fungi associated with hives and castes of the Amazonian stingless bees Melipona interrupta and Melipona seminigra

Abstract The stingless bees Melipona interrupta and Melipona seminigra have great ecological importance as pollinators and economical importance for its honey production. They are associated with a great diversity of entomofauna and microbiota. To understand more about the microbiota associated with these species, this study carried out the morphological and molecular identification of fungi present in the internal hive environment and the brood cells of larvae and pupae (queen and workers) of M. interrupta and M. seminigra, during rainy and dry seasons. Isolated fungi were identified by two methods: analysis of morphological structures and sequencing of the rDNA ITS1-5.8S-ITS2 region. A total of 1.542 isolates were obtained. The filamentous fungi found were: Aspergillus sp., Aspergillus fumigatus, Aspergillus niger, Aspergillus nomius, Aspergillus ochraceus, Cladosporium cladosporioides, Monascus ruber and Penicillium citrinum. The yeasts found were: Cystobasidium minutum, Debaryomyces hansenii, Starmerella apicola, Starmerella etchellsii and Wickerhamiella versatilis. Yeasts were found only in brood cells. The greatest diversity of fungi was observed in the rainy season for M. seminigra, and in the dry season for M. interrupta. There was a high overlap of fungi species associated with both species, but there were also specific associations. Starmerella etchellsii was found only in worker cells of M. interrupta, while Cystobasidium minutum in worker cells of M. seminigra. These findings raise questions about the different types of relationships that microbial communities have with bees in their different microenvironments, as well as with their castes, opening new and intriguing avenues of investigation.