Pleurocordyceps longiphialis Q. Y. Dong & C. D. Xu 2026, sp. nov.

Pleurocordyceps longiphialis Q. Y. Dong & C. D. Xu sp. nov. Fig. 2 Etymology. The specific epithet longiphialis refers to the characteristically elongated phialides, which distinguish this species from its closely related congeners. Holotype. China, • Guizhou Province, Qiandongnan Miao and Dong Autonomous Prefecture, Shibing County, Chengguan Town, on the larva of Scarabaeoidea, 25 March 2025, Quanying Dong (holotype CXAC 0017; ex-holotype living culture, CXCC 0017). Stromata morph. Host a Scarabaeoid larva, 47–32.5 × 3–5 mm, swollen, cylindrical, black. Stromata arise from the head and thoracic region of the host, solitary or paired, simple or branched, clavate, yellow to brown, 47–142.5 × 1.5–3.5 mm. In some specimens, the stromatal apex expands into a fist to globose-shaped head, occasionally fissuring into two or three lobes; in others, it divides into two segments, one longer and thicker, the other shorter and narrower. Certain stromata bear a black stipe, 6.5–17 mm long. Sterile. Culture characters. Colony on PDA attaining a diameter of 42–44 mm after one month at 25 ° C. Colony cottony, fluffy, with high mycelial density, central pale brownish-white umbonate, surrounded by successive concentric rings: an inner dark brown band, a broader light to dark brown zone, a distinct yellow ring, and an off-white periphery with a yellowish tint; reverse dark brown center and creamy-white margin. Hyphae smooth walled, branched, septate, hyaline, 1–2.5 µm wide. Synnemata emerging after two months, clavate or with a mucronate apex, solitary, unbranched, and 2–5 mm long, 0.5–2.5 mm wide, yellowish to yellow, emerging on the middle part of the synnemata or on the top, with conidial masses on the surface (Fig. 2 E). Terminal portion of a synnemata covered by a viscous mass. Cultures readily produced phialides and conidia on potato dextrose agar after 14 days at 25 ° C. Conidiophores are cylindrical, hyaline, smooth-walled, simple to verticilate form 1–3. Phialides have two types, α-phialides solitary, cylindrical or lanceolate, tapering gradually from base to apex, 9.5–101 × 2–3.5 µm, 2–3.5 µm wide (base), 1–2 µm wide (apex). β-phialides terminal on solitary on hyphae; lageniform or subulate, tapering abruptly from the base to the apex, 7.5–15.5 × 1–2.5 µm, 1–2.5 µm wide (base), 0.5–1.5 µm wide (apex). α-conidia one-celled, hyaline, smooth, subglobose, ovoid to ellipsoidal, 2–3 × 2–3 µm. β-conidia one-celled, hyaline, smooth, fusiform, oblong-elliptical to ellipsoidal, 4.5–8.5 × 1.5–3.5 µm, solitary or aggregated in long chains. Host. Scarabaeoidea larva Known distribution. Guizhou Province, China. Additional specimens examined. China, • Guizhou Province, Qiandongnan Miao and Dong Autonomous Prefecture, Shibing County, Chengguan Town, on the larva of Scarabaeoidea, 25 March 2025, Quanying Dong (paratype CXAC 0018; ex-paratype living culture, CXCC 0018). China, • Guizhou Province, Qiandongnan Miao and Dong Autonomous Prefecture, Shibing County, Baiduo Township, isolated from the larva of Scarabaeoidea, 1 April 2025, Quanying Dong (paratype CXAC 0019, CXAC 0020; ex-paratype living culture, CXCC 0019, CXCC 0020). Commentary. The diagnostic morphology of Pleurocordyceps longiphialis conforms to the generic concept of Pleurocordyceps. The species produces dimorphic, often verticillately branched phialides, comprising two types: α-phialides, verticillate with a cylindrical to subulate base tapering into a long neck, and β-phialides, solitary, narrow, lageniform to subulate, and tapering abruptly. Conidia are also dimorphic: α-conidia are globose to subglobose or ellipsoidal, while β-conidia are fusiform and occur solitary or in chains. The species can be distinguished by the following combination of morphological characteristics: α-phialides cylindrical to lanceolate, 9.5–101 × 2–3.5 μm; β-phialides lageniform to subulate, 7.5–15.5 × 1–2.5 μm; α-conidia subglobose, ovoid to ellipsoidal, 2–3 × 2–3 μm; and β-conidia fusiform, oblong-elliptical to ellipsoidal, 4.5–8.5 × 1.5–3.5 μm, occurring solitary or aggregated in long chains. Furthermore, this species was isolated from a Scarabaeoidea larva. Phylogenetically, Pleurocordyceps longiphialis is strongly supported (BS = 100 %, PP = 1) and clusters with P. litangensis (strains YFCC 06109293 and YFCC 06109295) and an undescribed Pleurocordyceps sp. (strains NBRC 109987, 109988, 109990, and 110224). However, it forms a distinct clade separate from these taxa (Fig. 1). Morphologically, P. longiphialis differs from related species in several aspects. P. litangensis, described from Litang County, Sichuan Province, China, possesses aculeate and relatively shorter α-phialides (11.2–12.8 μm vs. 9.5–101 μm in P. longiphialis), longer β-phialides (9.9–27.8 μm vs. 7.5–15.5 μm), larger α-conidia (3.2–6.1 × 1.8–3.9 μm vs. 2–3 × 2–3 μm), and smaller β-conidia (3.5–6.1 × 1.4–2.5 μm vs. 4.5–8.5 × 1.5–3.5 μm). Ecologically, P. litangensis is reported from the host Ophiocordyceps sinensis (Ophiocordycipitaceae), whereas P. longiphialis is associated with a Scarabaeoidea larva (Liu et al. 2024 b). Table 4 lists all hosts, substrates, and geographical locations of Samsoniella.