Molecular characterization and phylogeny of four new species of the genus Trichonympha (Parabasalia, Trichonymphea) from lower termite hindguts.

Members of the genus Trichonympha are among the most well-known, recognizable and widely distributed parabasalian symbionts of lower termites and the wood-eating cockroach species of the genus Cryptocercus. Nevertheless, the species diversity of this genus is largely unknown. Molecular data have shown that the superficial morphological similarities traditionally used to identify species are inadequate, and have challenged the view that the same species of the genus Trichonympha can occur in many different host species. Ambiguities in the literature, uncertainty in identification of both symbiont and host, and incomplete samplings are limiting our understanding of the systematics, ecology and evolution of this taxon. Here we describe four closely related novel species of the genus Trichonympha collected from South American and Australian lower termites: Trichonympha hueyi sp. nov. from Rugitermes laticollis, Trichonympha deweyi sp. nov. from Glyptotermes brevicornis, Trichonympha louiei sp. nov. from Calcaritermes temnocephalus and Trichonympha webbyae sp. nov. from Rugitermes bicolor. We provide molecular barcodes to identify both the symbionts and their hosts, and infer the phylogeny of the genus Trichonympha based on small subunit rRNA gene sequences. The analysis confirms the considerable divergence of symbionts of members of the genus Cryptocercus, and shows that the two clades of the genus Trichonympha harboured by termites reflect only in part the phylogeny of their hosts.