Comprising about 17 500 described species, bees constitute a well-established clade of pollen-feeding Hymenoptera (Michener 2007). In the last 15 years, our understanding of bee phylogeny and evolution has made great progress due to increasing use of nucleotide sequences and model-based phylogenetic methods (Danforth et al. 2013). Molecular data have provided new insights into phylogenetic r…