Morphological and phylogenetic analyses reveal Conidiobolus longivillosus sp. nov., a new cryptic species with long villose conidia in the Conidiobolus coronatus species complex.

Conidiobolus coronatus (Cost.) Batko is the most common species within the genus Conidiobolus sensu stricto (s.s.). Historically, the presence of villose conidia in C. coronatus was considered a unique morphological characteristic distinguishing it from other Conidiobolus s.s. members. However, Conidiobolus lunulus, reported to infect leafcutter ants and produce half-moon-shaped microspores, was identified as the second species with villose conidia. These findings suggest that C. coronatus represents a species complex. In the present study, we isolated the third species with villose conidia, characterized by its long villi and named it Conidiobolus longivillosus sp. nov. Phylogenetic analyses based on single-gene phylogenies (nucLSU, nucSSU and ITS) and multi-gene phylogenies (nucLSU, nucSSU, TEF1, ITS and mtSSU), along with the pairwise homoplasy index test and Poisson tree processes analysis, were performed to recognize this cryptic species. The results not only support C. longivillosus as an independent species but also imply the existence of cryptic species within the C. coronatus species complex.