Pollen niche of Melipona (Michmelia) scutellaris Latreille, 1811 in the tropical forest: a palynological perspective.

Mutualistic interactions between plants and bees are essential for tropical forests. This study analyzes the spatiotemporal variation in the pollen niche of Melipona scutellaris, a generalist stingless bee native to the Atlantic Forest. Pollen was collected over 17 months at four replicates in the Michelin Ecological Reserve, Northeastern Brazil. Samples were processed using standard acetolysis, and ecological indices were analyzed. Sixty-one pollen types were found in this bee diet, with foraging concentrated on a few of them. Despite its generalist behavior, the concentration of pollen collection on a limited subset of the flora (with emphasis on Melastomataceae) indicates that certain floral sources play a prominent role in the maintenance of perennial colonies. Spatial modules in the interaction network were observed and corresponded to the replicates, indicating some effect of the spatial heterogeneity of the forest on the realized trophic niche. There was temporal variation in the richness of pollen sources used by this bee, practically unrelated to climate variables. Niche breadth and evenness values were low and presented asynchronous variation between replicates. These findings highlight the need to prioritize key floral resources in tropical forest conservation to sustain stingless bee populations and their essential pollination services.