Unveiling the genetic structure and ecological niche diversification of the stingless bee Tetragonisca angustula (Meliponini) in Peruvian Amazon

Aim: Tetragonisca angustula, one of the most widespread stingless bees in the Neotropics, is commonly reared for meliponiculture. In this work we aimed to shed light on the genetic structuring of this species in Peru, define the ecological niches of the spatially distributed genetic groups, and relate the observed patterns to Miocene/Pleistocene events. Location: Peru (Departments: Amazonas, Ayacucho, Cajamarca, Cusco, Huánuco, Junín, Loreto, Pasco and San Martín). Taxon: Tetragonisca angustula (Hymenoptera: Apidae: Meliponini). Methods: We sampled 121 T. angustula specimens across Peru to obtain mtDNA (COI, Cytb) and (18 loci) microsatellite data. Genetic polymorphism analyses, coalescent inferences and niche modelling were conducted to reveal the genetic structure, migration patterns, and niche diversification among T. angustula Peruvian matrilineages. Results: T. angustula was geographically structured in Peru, showing isolation-by-distance. We identified 3 (COI) matrilineages/haplogroups: the ancestral Hapl. II (also shared with Brazil) plausibly spread in the Amazon basin during the Middle/Late Miocene, whereas Hapl. I (the most widespread) and Hapl. III (the southernmost located) likely evolved in Peruvian Pleistocene Refugia. Microsatellites revealed that male dispersal favoured the introgression of nucDNA from Hapl. I to Hapl. II, owing to the specialisation of the former to more arid conditions. Similarly, Hapl. III isolated and adapted to a wider temperature range and landscape complexity. Main Conclusions: Miocene/Pleistocene events shaped the genetic and ecological diversification of T. angustula in Peru, with range expansion operated by males belonging to the more recently and locally evolved matrilineages. We remark that the genetic and ecological distinctiveness of the so-revealed groups of T. angustula should be preserved in the future from the detrimental effects of possible human-induced population mixing or reduction due to meliponiculture and deforestation.