Abstract
The genus Gibellula (Cordycipitaceae, Hypocreales) comprises highly specialized, obligate pathogens that exclusively parasitize spiders. In this study, five new species were delimited based on morphological and phylogenetic evidence from a six-locus dataset (nrSSU, ITS, nrLSU, tef-1α, rpb1, rpb2). Specimens were collected from northeastern (Jilin and Liaoning Provinces) and southwestern (Yunnan Province) China. Phylogenetic analyses resolved these collections into five distinct, well-supported lineages, described as G. baishanensis, G. jilinensis, G. kunmingensis, G. paralongispora, and G. yunnanensis spp. nov. Among these, G. baishanensis and G. jilinensis were identified as sister taxa, whereas G. kunmingensis formed an independent lineage. Gibellula paralongispora was recovered as a sister to G. longispora, and G. yunnanensis as a sister to G. attenboroughii; both new species are supported by significant morphological distinctions (e.g., conidiophore length and conidial shape). This study provides detailed descriptions, illustrations, and morphological comparisons for these taxa, thereby enriching the taxonomy of Gibellula. Furthermore, the records from Jilin and Liaoning represent only the second documented occurrence of the genus in northeastern China, significantly expanding its known geographic range.