Phylogenetic comparison between nycteribiid bat flies and their host bats

Abstract

We inspected 97 specimens of bat flies of the family Nycteribiidae parasitizing wild bats in Japan. Bat flies representing 8 species of 4 genera (Basilia spp., Nycteribia spp., Penicillidia spp. and Phthiridium sp.) were obtained from bats representing 11 species of 5 genera (Barbastella sp., Miniopterus spp., Myotis spp., Plecotus sp. and Rhinolophus spp.). We also surveyed past reports on bat flies in Japan wherein host bat species and number of insects collected from them are explicitly recorded. On the basis of these data, we identified 3 bat flies primarily associated with a single host bat, and 4 bat flies associated with 2 congenic host bats. Only 1 species, B. truncata endoi, was associated with 4 bat species representing 3 genera, although these bats were placed in a well-defined clade in the bat phylogeny. Hence, the nycteribiid bat flies generally exhibit di#erent levels of specificity to their host bats, which may be species-specific, genus-specific or genus-group-specific. Meanwhile, when the molecular phylogeny of the bat flies was compared with that of the host bats, no co-speciating pattern was observed, suggesting that host shifts must have occurred at a considerable frequency in the evolutionary course of the bat flies.