Ophiocordyceps radiata (Petch) S. W. Xie, D. P Wei & T. C. Wen, 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 radiata (Petch) S. W. Xie, D. P Wei & T. C. Wen comb. nov.

Fig. 4

Basionym.

Hirsutella radiata Petch , Trans. Br. Mycol. Soc. 19 (3): 184 (1935) [1934].

Description.

Anamorph: Synnemata up to 5.4 mm long, 0.04 mm wide, emerging from neck and leg joints of the host, multiple, unbranched, brown, filiform, slender, wiry, gradually attenuating toward the apex. Subiculum forming from leg joints of the host, white, composed of interlaced hyphae. Phialides laterally formed along synnemata or produced from subiculum, hyaline, aseptate, smooth-walled, cylindrical, 4–16 × 3–7 (x ̄ = 10 × 4, n = 30) μm at the base, nrowing rapidly into a long neck 10–40 × 0.8–2 (x ̄ = 19 × 1, n = 30) μm. Conidia 6–10 × 2–5 (x ̄ = 9 × 3, n = 20) μm, hyaline, cymbiform, one-celled, smooth-walled, enveloped in a mucous sheath, forming a globose head 8–13 (x ̄ = 10, n = 10) μm in diameter. Teleomorph: Undetermined.

Material examined.

China • Yunnan Province, Honghe Prefecture, Amushan natural reserve , on fly (Diptera) attached to lower side of a living fern leaf, Shi-Wen Xie, TSQ 13 ( HKAS 135613 ) .

Notes.

In the phylogenetic analyses, our new collection clustered with Hirsutella radiata and H. fusiformis , forming a monophyletic clade with high statistical support (97 % ML / 1 PP, Fig. 1 ). Hirsutella radiata was initially found infecting a small fly attached to a leaf from Great Britain. It was characterized by filiform, brown, branched synnemata; phialides with conical to cylindrical bases and stout necks; cymbiform to oval conidia; and oval conidial masses ( Petch 1935). Hirsutella fusiformis was introduced by Speare (1920) from a cricket in Hawaii. It has erect, straight, unbranched, nearly black synnemata; simple phialides with inflated basal portions tapering to a neck; and fusoid-cylindrical conidia. For the first time, Simmons et al. (2015 b) used the DNA sequences of LSU, SSU, tef 1 - a, and rpb 1 gene regions of ‘ H. radiata ’ (from a specimen occurring on Diptera in Poland) and H. fusiformis (from a specimen occurring on Brachyderes incanus in the Netherlands) in their phylogenetic analyses. However, these sequences have not been linked to any morphological description, and epitypes were not designated. The close phylogenetic relationship between H. radiata and H. fusiformis was observed in this study and that of Simmons et al. (2015 b), while it is undetermined whether they are conspecific. Morphologically, our specimen shares similarities with H. radiata in the association with a dipteran host, the filiform brown synnemata, and the cymbiform conidia; thus, we concluded our collection was H. radiata . According to our knowledge, this is the first geographical record of H. radiata in China. Besides, for the first time, we created the linkage between molecular data and the morphological characteristics of this species, thereby formally synonymizing H. radiata as Ophiocordyceps radiata .

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 4. Ophiocordyceps radiata a, b synnemata growing from the fly host c synnema-bearing conidiophores d, i sporodochia emerging from leg joints of host e, f synnema g, j – l conidia mass on tip of phialides h phialides m conidia mass n – q conidia. Scale bars: 2 mm (a, b); 200 μm (c – e); 50 μm (f); 15 μm (g – l); 5 μm (m – q).