Morphology and phylogeny of four new species within Polycephalomycetaceae (Hypocreales) parasitising Ophiocordyceps species

Species of the family Polycephalomycetaceae grow on insects or entomopathogenic fungi and are distributed from tropical to subtropical regions. This study proposed four new species of hyperparasitic fungi from China based on six molecular markers (ITS, SSU, LSU, TEF-1α, RPB1 and RPB2) phylogenetic analyses and morphological characteristics. The four new species, i.e. Pleurocordyceps litangensis, Polycephalomyces jinghongensis, Po. multiperitheciatae and Po. myrmecophilus, were described and illustrated. Pl. litangensis, exhibiting a hyperparasitic lifestyle on Ophiocordyceps sinensis, differed from Pleurocordyceps other species in producing subulate β-phialides and ovoid or elliptic α-conidia. Po. jinghongensis was distinct from Polycephalomyces other species, being parasitic on Ophiocordyceps sp., as producing oval or long oval-shaped α-conidia and columns of β-conidia. Po. multiperitheciatae differed from Polycephalomyces other species as having synnemata with fertile head, linear β-conidia and parasitic on Ophiocordyceps multiperitheciata. Po. myrmecophilus was distinct from Polycephalomyces other species, being parasitic on the fungus Ophiocordyceps acroasca, as producing round or ovoid α-conidia and elliptical β-conidia without synnemata from the colonies. These four species were clearly distinguished from other species in the family Polycephalomycetaceae by phylogenetic and morphological characteristics. The morphological features were discussed and compared to relevant species in the present paper.