Diversity of Ascodipteron and Host-Associated Variation in Parasitism Among Hipposiderid Bats in Yunnan, China

Ascodipteron bat flies are specialized parasites of bats, but their diversity and parasite ecology in China remain poorly understood. We surveyed hipposiderid bats at ten localities in Yunnan Province, China, combining morphological identification, mitochondrial cytochrome c oxidase subunit I (COI) barcoding, and ecological analyses. Among 226 bats, 58 were infested; 72 neosomic females were collected, and 14 representative specimens were sequenced. Morphology, COI genetic distances, Assemble Species by Automatic Partitioning (ASAP), and maximum-likelihood phylogenetic analysis supported three taxa: A. phyllorhinae, A. sanmingense, and an undescribed Ascodipteron sp. Within-taxon COI distances were 0.199–0.512%, whereas between-taxon distances were 6.303–12.118%. Overall prevalence was 25.66%, and prevalence and mean parasite abundance varied among host species. Evidence for host-species differences in parasitism depended strongly on the absence of infestation in Hipposideros gentilis. Estimated associations of body condition with infestation occurrence and parasite abundance were positive but uncertain, and no clear associations were detected for the site-level environmental variables examined. These findings expand current knowledge of Ascodipteron diversity and host-associated parasitism in Yunnan and provide an integrative basis for further studies of species identification, host use, and parasite ecology in this genus.