Ophiocordyceps keqinii S. W. Xie, T. C. Wen & D. P Wei, 2025

Xie, Shi-Wen, Wei, De-Ping, Qiu, Jun-Zhi, Peng, Xing-Can, Kang, Ji-Chuan, He, Zhang-Jiang, Li, Zeng-Zhi, Li, Chun-Ru, Huang, Shi-Ke, Zhang, Xian, Liu, Zhong-Liang, Bu, Jing, Wijayawardene, Nalin N. & Wen, Ting-Chi, 2025, Overview of hirsutella-like anamorphs in Ophiocordyceps (Sordariomycetes, Ophiocordycipitaceae): introducing two new species and one new record from China, MycoKeys 119, pp. 95-121 : 95-121

Ophiocordyceps keqinii S. W. Xie, T. C. Wen & D. P Wei sp. nov.

Fig. 3

Etymology.

Named after an eminent Chinese mycologist, Prof. Ke-Qin Zhang, who has made a significant contribution to the studies of fungi in China.

Description.

Anamorph: Stromata extending from the head of the lepidopteran larva, 15–90 × 0.3–1.1 mm, irregularly branched at upper part, cylindrical, fibrous, dark brown at base, becoming white toward the apex due to the formation of hymenium. Phialides exclusively formed at the apical region of stromata, hyaline, smooth-walled, cylindrical at the base 4–12 × 2–4 (x ̄ = 7 × 3, n = 20) μm, narrowing rapidly to a long neck 6–16 × 0.7–2 (x ̄ = 11 × 1, n = 20) μm. Conidia 3–12 × 2–5 (x ̄ = 9 × 4, n = 20) μm, hyaline, semielliptical, ovoid with a round apex and obvious scars at base, one-celled, smooth-walled. Teleomorph: Undetermined.

Material examined.

China • Yunnan Province, Honghe Prefecture, Amushan natural reserve , on a dead larva of Lepidoptera on the ground, Shi-Wen Xie, Y 08 ( HKAS 135614 , holotype) .

Notes.

Phylogenetic analyses revealed that O. keqinii is sister to a clade comprising O. macroacicularis and Hirsutella changbeisanensis , with strong statistical support (89 % ML / 0.99 PP, Fig. 1 ). Ophiocordyceps macroacicularis was found infecting lepidopteran larvae in Japan ( Ban et al. 2015). According to the studies by Ban et al. (2015) and Zhou et al. (2015), they identified polyphialidic phialides in their strains of O. macroacicularis , which were absent in our collection. The comparison of nucleotide sequences showed that there are 17 bp differences (5 bp in ITS, 12 bp in tef 1 - a) between O. keqinii and O. macroacicularis , suggesting they are separate species.

Hirsutella changbeisanensis was initially discovered on leafhoppers ( Hemiptera ) by Liang (1991) and restudied by Qu et al. (2017) based on a new collection occurring on Cicadellidae (Homoptera) . Hirsutella changbeisanensis is distinct from O. keqinii in having a verruculose neck, which is smooth-walled in our collection ( Qu et al. 2017). Additionally, there are 23 bp differences in nucleotides (6 bp in ITS, 17 bp in tef 1 - a) between O. keqinii HKAS 135612 and H. changbeisanensis GZUIFR-hir 160527, suggesting they are not conspecific. Hence, based on the differences in morphological characteristics (Table 3 ), multi-locus phylogenetic analyses, and base pair differences, we introduce O. keqinii as a new species of Ophiocordyceps .

Figures

Figure 1. Phylogram generated from maximum likelihood analysis based on combined SSU, LSU, ITS, tef 1 - a, and rpb 1 sequence data. ML bootstrap values equal to or greater than 50 % and PP values equal to or greater than 0.90 are given above each node. The newly generated sequences are indicated in red.

Figure 3. Ophiocordyceps keqinii (HKAS 135614, holotype) a, b stromata growing from the insect larva c, d close-up of stromata e stromata covered with hymenium f – h phialides i – k conidia. Scale bars: 200 μm (c – e); 15 μm (f – h); 5 μm (i – k).