Bioinformatic analysis of the phylogenetic and haplotypic diversity of Varroa destructor using mt-CO1 gene sequences

Varroasis is a disease caused by the mite Varroa destructor, which inflicts serious damage on honey bees (Apis mellifera) worldwide. This parasite causes significantly greater harm than other arthropod-induced diseases and results in substantial economic losses in the beekeeping industry. In this study, Mitochondrial Cytochrome c Oxidase Subunit 1 (mt-CO1) gene sequences of V. destructor registered in the National Center for Biotechnology Information (NCBI) database were used to investigate the species' global phylogenetic relationships, haplotype diversity, genetic variation, and population structure through bioinformatic approaches. A total of 492 mt-CO1 gene sequences representing 20 different geographical regions were obtained from the NCBI database and analyzed. The analyses revealed 29 polymorphic region and 19 haplotype groups. Among them, Hap01 was identified as the major haplotype, comprising 288 sequences; in addition, 18 other distinct haplotypes were detected, 14 of which were singletons. The calculated haplotype diversity was 0,530 ± 0,014, indicating a moderate level of genetic diversity. Nucleotide diversity was found to be 0,00287 ± 0,00019, suggesting that the V. destructor population is genetically homogeneous overall. Tajima's D, Fu's Fs, Fu's LD, and Fu's LF neutrality tests all yielded negative values, indicating a recent population expansion. In terms of genetic differentiation between populations, the lowest fixation index value was found between Thailand and Vietnam, while the highest fixation index values were observed between Taiwan and Iran, France, Australia, Türkiye, South Korea and Argentina. In conclusion, the findings of this study demonstrate that V. destructor exhibits a certain level of genetic diversity on a global scale and that there are distinct genetic differentiations among some geographic populations. These genetic differences provide important insights into the dispersal patterns and adaptive capabilities of the species and contribute to the development of more effective control strategies.