Estuarine floodplains harbor greater diversity of orchid bees (Hymenoptera: Apidae: Euglossini) than mangroves in coastal Amazonia

Variations in vegetation types in a given location, including the availability of floral resources, can directly influence the composition of orchid bee (Euglossini) communities. A diverse range of vegetation types are found along the coast of the Brazilian Amazon, with Mangrove (MANG) and Estuarine Floodplain (FE) forests being the predominant types. With the exception of dryland forests, taxonomic information and distribution of Euglossini in MANG and EF in the coastal Amazon are still incipient. Based on this, we investigated the role of these vegetation types in maintaining Euglossini bee communities on the coast of the Brazilian Amazon. We sampled bees using aromatic baits in 48 locations, 23 in EF and 25 in MANG, comparing the abundance, richness, diversity, and composition of bees. We collected a total of 1017 specimens from four genera and 22 species of Euglossini bees. Abundance and richness were, on average, greater in EF. Species composition differed statistically but was weakly explained by vegetation type. We also identified three indicator bee species for EF and one for MANG. Apparently, floristic diversity in EF is the main predictor for greater abundance and richness of Euglossini bees in the studied region. Our findings reinforce the importance of conserving native vegetation along the Amazon coast, considered one of the most threatened on the planet, to maintain the biodiversity of its pollinators.