Taxonomic and phylogenetic insights into dipteran-parasitizing Ophiocordyceps: Descriptions of two new species and a new record from China and Laos

Ophiocordyceps species are renowned for their ecological roles and medicinal potential, yet their diversity on dipteran hosts remains insufficiently documented. Here, we investigated the diversity of dipteran-parasitizing Ophiocordyceps from China and Laos, describing two novel taxa— O. calliphoridarum and O. laosensis —and reporting O. muscae as a new record for Laos. Phylogenetic analyses based on a five-locus dataset (ITS, nr LSU, tef-1α , rpb1 , and rpb2 ) strongly support the recognition of the two new species within the O. dipterigena complex of the hymenostilboid clade. Ophiocordyceps calliphoridarum is closely related to O. muscidarum but differs by parasitizing Lucilia caesar (Calliphoridae) rather than the housefly (Muscidae) and by possessing significantly larger asci and part-spores. O. laosensis closely resembles O. muscae but can be distinguished by its elongated perithecial ostioles and large asci and part-spores. Additionally, the asexual morph of O. muscidarum was newly described. These findings broaden our knowledge of the taxonomy and diversity of dipteran-parasitizing Ophiocordyceps , and further corroborate the phylogenetic monophyly of this lineage, thereby offering valuable insights into the co-evolutionary relationships between Ophiocordyceps fungi and their dipteran hosts.