Ophiocordyceps cystidiata X. Zou, Zhong S. Xu & Y. D. Dai sp. nov.

Fig. 3

Etymology.

Cystidiata refers to the saccate mucous sheath that envelopes the conidium.

Holotype.

GZUIFR-2023 XY-OA 5 (Fig. 3 b), China • Guizhou Province: Baishi Mountains, Baiwanyao Village, Xingyi City (25°4'12"N, 99°10'12"E; altitude, 1720 m). These specimens were found on a larva of Hepialidae, buried in soil, collected in July 2023 by Zhongshun Xu, Binghui Zhou, Yongdong Dai, Huiling Tian, and Xiao Zou (ex-holotype: GZUIFR-2023 XY-OA 5 C). (The GenBank accession numbers: nrSSU, PQ 497594; nrLSU, PQ 497634; rpb 1, PQ 516632; rpb 2, PQ 516636).

Host.

The larvae of Hepialidae ( Lepidoptera).

Description.

Stromata: Arising from the head the host, lignified, solitary, rarely branched, brown to yellow-brown, 60–146 mm long. Fertile part: Cylindrical, yellowish, without a sterile tip, surface spinous due to protruding ostioles, up to 18 × (0.8 -) 1.44 mm.

Perithecia: Immersed, ovoid to oblong-ovate, 355–434 × 178–220 μm. Asci: Cylindrical, hyaline, eight-spored ascus, 133–224 × 5–7 μm, apex thickened to form an ascus cap, hemispherical, 4.7–5.6 × 3.6–4.0 μm. Ascospores: Filiform, hyaline, irregular, multi-septate, non-disarticulating, 13.2–25.2 × 1.5–2.6 μm, with septa.

Asexual morph: Hirsutella - like

Colonies: On PDA, reaching 13–16 mm in diameter after two weeks at 20 ° C, round, irregularly swollen, initially light yellow, gradually changing color with an outer layer of white, an inner layer of rose red, and a central white protrusion. The back of the colony is rose red. Hyphae: The basal hyphae are hyaline, smooth-walled, and septate; the apical hyphae are verrucose (2.5–3.3 μm wide). Conidiogenous cells: Growing from verrucose apical hyphae, monophialidic, 22–56 µm long. The base is cylindrical, with an inflated structure near the bottom, tapering gradually into a slender neck. The base width measures 2.4–3.3 µm, and the neck width measures 0.9–1.4 µm. Conidia: Arising solitarily from the apex of conidiogenous cells, fusiform or orange-like shape, usually solitary, hyaline, smooth-walled, measuring 10–12 × 2.5–3.2 µm, often enveloped in a hyaline mucous sheath (1.5–3.0 µm thick).

Distribution and habitat.

The karst-landform forest of Xingyi City, Guizhou Province, China.

Additional specimens examined.

GZUIFR-2023 XY-OA 2, 3, 6, 7, 8, 9, 10, 11 (Fig. 3 f). Location: China. Guizhou Province: Baishi Mountains, Baiwanyao Village, Xingyi City (25°4'12"N, 99°10'12"E; altitude: 1710–1730 m). These specimens were found on a larva of Hepialidae sp. buried in soil, collected in July 2023 by Zhongshun Xu, Binghui Zhou, Yong-dong Dai, Huiling Tian, and Xiao Zou .

Notes.

O. cystidiata is closely related to O. fenggangensis (Peng et al. 2024), O. musicaudata (Peng et al. 2024), O. alboperitheciata (Fan et al. 2021), and H. kuankuoshuiensis (Qu et al. 2021) . Morphologically, O. cystidiata is similar to O. fenggangensis and O. musicaudata in the shape of the stromata, fertile part, and perithecia but it differs by its inconspicuous separate ascospores (Table 3). It also resembles H. kuankuoshuiensis in asexual morphology but differs in having phialides with a verrucose apex and conidia enveloped by a thickened mucous sheath.