Genetic and morphometric variation in populations of Partamona cupira and Partamona mulata, stingless bees endemic to the Cerrado biome in Brazil

The Brazilian Cerrado biome stands out as a biodiversity hotspot, boasting a rich flora and endemic species. However, human activities have significantly altered nearly 80% of its area. Partamona cupira and Partamona mulata are stingless bees from the Cerrado that have received limited attention regarding their intraspecific variation. Our objective was to estimate the genetic and morphometric variation across the geographical distribution of these bees. We accomplished this by sequencing mitochondrial DNA (mtDNA) regions (COI and CytB genes) and obtaining phenotypic traits of wings using landmark-based approaches. Genetic analyses revealed a common pattern found in Partamona bees, characterized by high haplotype diversity, low nucleotide diversity, and the presence of exclusive low-frequency haplotypes. These characteristics support the hypothesis that stingless bees exhibit genetic structuring in their mtDNA due to their colony-dependent mode of reproduction. We observed an association between morphometric and geographical distances, suggesting that phenotypic gradients may be produced by environmental factors. The time to the most recent common ancestor for P. cupira and P. mulata was estimated at 147.8 and 284.0 kya, respectively. Demographic analyses suggested population equilibrium for both species, indicating that climatic fluctuations during the Pleistocene had no impact on the distributions of P. cupira and P. mulata.