Supergroup F Wolbachia bacteria parasitise lice (Insecta: Phthiraptera).

We studied six species of lice from three of the four suborders of lice. These lice were infected with Wolbachia bacteria from supergroups A and F. This is the first report of an infection of supergroup F Wolbachia in lice. To date, Wolbachia from supergroup F have been found in filarial nematodes, Mansonella spp., and, rarely, in insects. We inferred the phylogeny of the Wolbachia from lice and representatives of all Wolbachia supergroups, with nucleotide sequences from the small subunit ribosomal RNA gene (SSU rRNA). There was no evidence of congruence between the taxon of louse and the Wolbachia bacteria that infect lice. There is no evidence that Wolbachia and their louse hosts co-evolved at least at the level of Wolbachia supergroups. We propose a novel mechanism for the horizontal transfer of Wolbachia between different species of lice from birds: transfer of Wolbachia during phoresis by hippoboscid flies.