Ophiocordyceps longistipes Y.B. Wang, T. Yang, Q. Fan & Zhu L. Yang, 2024

Fan, Qi, Yang, Tao, Li, Hui, Wang, Xue-Mei, Liao, He-Fa, Shen, Pei-Hong, Yang, Zhu-Liang, Zeng, Wen-Bo & Wang, Yuan-Bing, 2024, Molecular phylogeny and morphology reveal two new entomopathogenic species of Ophiocordyceps (Ophiocordycipitaceae, Hypocreales) parasitic on termites from China, MycoKeys 103, pp. 1-24 : 1

Ophiocordyceps longistipes Y.B. Wang, T. Yang, Q. Fan & Zhu L. Yang sp. nov.

Fig. 2

Etymology.

Referring to the long stipe of stromata.

Type.

Holotype: China, Yunnan Province, Ruili City , 26°1.07'N, 97°51.33'E, alt. 1140 m, on a termite buried in soil, 2 July 2022, Tao Yang (holotype HKAS 126185, ex-type culture KUNCC 5224). Ex-type sequences (ITS: OR015962, nrLSU: OR015967, nrSSU: OR082949, tef-1α: OR030530, rpb1: OR062224, rpb2: OR113082) .

Description.

Stromata arising from the back of termites buried in soil, solitary, unbranched, cylindrical, flexible, leathery, 17-24 cm long, 0.5-1.0 mm wide, grayish white to yellowish brown. Fertile parts cylindrical, yellowish brown, 3-5.5 cm long, generating toward the upper part of stromata, covered by a spinous surface, with a sterile tip of 11-28 × 0.5-1.0 mm. Perithecia superficial, pale yellow at early stage, brown at maturity, pyramidal to oval, densely distributed in the upper of stromata, arranged in a disordered manner, 390-420 × 295-350 µm. Asci 8-spored, filiform, hyaline, 160-195 × 4.5-6.5 µm, with hemispheric apical cap. Ascospores whole, hyaline, filiform, tapering at both ends, 70-85 × 3.5-4.5 µm, multiseptate, septa 4.5-13.8 μm long.

Anamorph.

hirsutella-like. Colonies on PDA growing very slowly, reaching 3-3.5 cm diam after six weeks at 25 °C, felty, irregularly convex, cream, reverse pale brown to dark brown. Hyphae hyaline, branched, septate, smooth-walled, 2-3 µm wide. Conidiogenous cells arising from aerial mycelia, monophialidic or rarely polyphialidic, on hyphae laterally or terminally, hyaline, smooth, flask-shaped, 29-60 μm long, with a swollen base, 4-4.5 μm wide, tapering sharply into a thin neck, 0.5-0.8 μm wide. Conidia borne directly on the tip of phialides, hyaline, one-celled, solitary, smooth-walled, citriform or oval, 7-10 × 4.5-7 µm, with a mucous sheath.

Additional specimens examined.

China, Yunnan Province, Ruili City , 26°1.07'N, 97°51.33'E, alt. 1140 m, on a termite buried in soil, 2 July 2022, Tao Yang (HKAS 126186), sequences (ITS: OR015960, nrLSU: OR015966, nrSSU: OR082947, tef-1α: OR030531, rpb1: OR062225). Ibid., (HKAS 126187), sequences (ITS: OR015961, nrLSU: OR015965, nrSSU: OR082948, tef-1α: OR030529, rpb1: OR062223) .

Habitat and ecology.

Parasitic on termites buried in soil of the subtropical evergreen broad-leaved forests, emerging from fallen leaves on the forest floor.

Known distribution.

Ruili City, Yunnan Province, China.

Notes.

Ophiocordyceps longistipes is characterized by solitary stromata, superficial and pyramidal to oval perithecia, filiform asci, and filiform ascospores, hirsutella-like anamorph with monophialidic or rarely polyphialidic, flask-shaped conidiogenous cells, and citriform or oval conidia embedded in a mucous sheath. Phylogenetically, all specimens of O. longistipes are clustered in the H. thompsonii subclade of Hirsutella lineages and form a monophyletic clade, which is placed sister to O. fusiformis with maximum support (Fig. 1 ). However, O. longistipes exhibits significant morphological differences from O. fusiformis in its both teleomorph and anamorph. For the teleomorph, O. longistipes produce longer stromata of 17-24 cm (up to 6 cm long for O. fusiformis ), larger perithecia of 390-420 × 295-350 µm (300-360 × 180-270 µm for O. fusiformis ). For the anamorph, O. longistipes possess both monophialidic and polyphialidic conidiogenous cells, but O. fusiformis is only monophialidic. Moreover, O. longistipes produces oval conidia, while O. fusiformis produces narrower fusiform conidia (Table 3 ).

Figures

Figure 1. Phylogenetic tree based on the combined dataset of nrSSU, nrLSU, tef- 1 α, rpb 1, rpb 2, and ITS showing the relationship of two new species on termites from China with other Ophiocordyceps species. Values at the nodes before and after the backslash are BI posterior probabilities (BI-PP greater than 0.60) and ML bootstrap proportions (ML-BP greater than 70 %), respectively. New species described in this paper are shown in bold red.

Figure 2. Ophiocordyceps longistipes A, B stromata of fungus arising from termites C fertile part D perithecia E colony on PDA (obverse and reverse) F, G ascospores H, I asci J-L conidiogenous cells and conidia. Scale bars: 1 cm (A, B, E); 2 mm (C); 100 µm (D); 20 µm (F-L).