Genetic Profile of the Parasitic Varroan Mite (Arachnida: Mesostigmata: Varroidae) in Taiwan: a New Taiwanese Haplotype Intermediate Between the Highly Virulent Russian and Less Virulent Japanese Types Identified in the Honey Bee Host .

The Modern beekeeping industry is being challenged by the varroan mite and its transmitted pathogens. Various types of exhibit different levels of virulence toward honey bees, but only the Japanese (J) and Russian (R) types were found to infect . Type R was more highly virulent against in comparison with type J. Examining the genetic profile of Varroa species is therefore of crucial importance in apiary management. In this study, maternally inherited mitochondrial cytochrome oxidase I () and bisexual nuclear internal transcribed spacer (ITS) sequences of individuals from Taiwan were determined. All 168 sequences observed in populations obtained from were identical and belonged to type J, with one base difference to that of populations collected from ; the new type is named 'T type' (Taiwan type). ITS sequences of and its sister species were identical. A network analysis based on 611 sequences compiled from references indicated the presence of 27 haplotypes in . Epidemic history and relationship analyses of showed that the basal haplotypes were those from and many R-extending haplotypes infesting involving amino acid substitutions. Calibration dating based on analysis revealed that differentiated from its sibling lineage (occurring in Sri Lanka) prior to 1.3 million years ago (Mya). The ancestral haplotype retention and drift in that occurred locally during 0.10-0.64 Mya might be relevant to its host , which had been isolated geologically. The highly virulent type R was spreading quickly and could gradually outcompete the common and less virulent type J. Type T, being intermediate between types R and J, ought to be studied to better understand the pathogenic mechanism of in . Moreover, for areas where type R does not occur, such as Taiwan, quarantine requirements are crucial for reducing invasion risks.