Reappraisal of the phylogenetic relationships of hirsutella-like fungi across Ophiocordycipitaceae and Polycephalomycetaceae (Hypocreales, Sordariomycetes), and the description of seven new species

Abstract

Entomopathogens constitute a unique and specialized trophic group of fungi, most of which belong to Hypocreales (Sordariomycetes, Ascomycota). In this study, eight species were collected and isolated from China and Thailand. Through comprehensive morphological analyses and multigene phylogenetic studies (ITS, nrSSU, nrLSU, tef 1 - α, rpb 1, rpb 2), seven novel species (Ophiocordyceps jinguangensis sp. nov., O. northeastensis sp. nov., Polycephalomyces bannaensis sp. nov., Po. chiangraiensis sp. nov., Pleurocordyceps shibingensis sp. nov., Pl. tengchongensis sp. nov., and Dingleyomyces yunnanensis sp. nov.) and one known species (O. formicarum) were identified.

Additionally, the pairwise homoplasy index (PHI) test results and morphological differences between the new species and their closely related taxa are provided. Notably, as the number of reported hirsutella-like species continues to increase, their phylogenetic placement has become increasingly unclear in previous classifications. To address this issue, this paper presents the first comprehensive summary of the distribution of hirsutella-like species within the families Ophiocordycipitaceae and Polycephalomycetaceae, along with an analysis of the similarities and differences in their phialidic characteristics.

These findings significantly expand our knowledge of the diversity, taxonomy, and phylogenetic relationships of entomopathogenic fungi in these families, providing a valuable framework for future studies on their ecology and evolution.