Molecular phylogeny of the large carpenter bee Xylocopa aestuans from North West India

Xylocopa aestuans (L.), a key large carpenter bee associated with pollination in both managed and natural ecosystem, belong to one of the largest subgenera, Koptortosoma Gribodo under the genus Xylocopa Latreille. This paper presents molecular variation and phylogeny of this species deploying partial cytochrome oxidase I (COI) and cytochrome b (cytb) sequences of mitochondrial genome. This study is the first report of X. aestuans mitochondrial genes with respect to amplicon regions. It was observed that both the sequences showed high A-T bias with 80.67% and 81.54% in CO1 and cytb, respectively. The BLASTN similarity search of the obtained sequences showed a maximum similarity of 97% with Xylocopa pubescens Spinola accession. A separate phylogenetic analysis of both the sequences showed appropriate subgenus clustering of tested Xylocopa sequences. The study also showed the evolutionary association of X. aestuans with X. pubescens. Interestingly, Koptortosoma sp. showed two separate clusters supporting the polyphyletic nature of the subgenus. The evolutionary distances of Koptortosoma sequences showed that differences were larger than expected and showed probability of substitution from one base to another instantaneously. The study illustrates a complex genetic variation coupled with highly structured evolutionary divergences within species of Xylocopa, especially X. aestuans.