The evolutionary and phylogenetic relationships of the diverse and important crop-pollinated bees in the genus Megachile (Anthophila; Megachilidae) in Southeast Asia have never been explored, despite the abundant presence and wide distribution of the genus in the region. This study focuses on using the integrative taxonomic approach to resolve some evolutionary questions relating to the Megachile found in Thailand. 315 Thai Megachile specimens were examined, whereas 103 were used for molecular analyses. The initial COI phylogeny obtained from this study shows that most Megachile putative species are grouped within monophyletic clades suggesting congruence between the morphological and molecular evidence, whereas the relationships among the subgenera are unresolved due to low supporting values. The color patterns of the mesothoracic and metathoracic hairs overlapping among the subgenera are usually found in many sympatric species. This may suggest that the color patterns in Thai and possibly Southeast Asian Megachile may be driven by convergent evolution. Further studies using more genetic markers are expected to resolve other questions relating to sexual dimorphism and genetic variations among the wide spread species in Megachile.
Species and evolutionary relationships in the diverse bee genus of Megachile, Latreille, 1802 (Megachilidae: Megachilini) in Thailand