Comparison of the mitochondrial genomes of three geographical strains of indicates high genetic diversity in the black giant honeybee (Hymenoptera: Apidae).

is the largest honeybee that lives mainly on cliff faces, with strong migratory ability. In this study, we firstly sequenced and assembled two complete mitochondrial genomes of isolated from two distant locations in China (Chongqing and Shangri-La regions). Combined with the published mitochondrial genome of from Nepal, comparative genomic analyses were conducted to gain insight into the genetic diversity of giant honeybees from different geographical distributions. The mitochondrial genomes of from Chongqing and Shangri-La regions were 15,579 and 15,683 bp in length, respectively, both larger than that from Nepal with the length of 15,510 bp. Three mitochondrial genomes all harbor 37 common genes and present the same AT bias and the frequency of codon usage. However, the fragments including 1, SSUrRNA, LSUrRNA, and the AT-rich region of the mitochondrial genome from Shangri-La region demonstrate distinctive insertions and deletions compared to those from Chongqing and Nepal regions. Phylogenetic trees of mitochondrial genomes show that from Chongqing is most closely related to that from Nepal, rather than to Shangri-La. Genetic distance between Shangri-La and Chongqing or Nepal was even larger than that between the various subspecies of . Overall, these results unmark that in different geographical distributions can exhibit high genetic diversity at the mitochondrial genomic level, and therein, from Shangri-La may be the subspecies. All these studies will contribute to our understanding of the geographical distribution and genetic differentiation of black giant honeybee in Asian region.