Ophiocordyceps linyphiidarum Y. Yang, K.D. Hyde & Y.P. Xiao, 2025

Ophiocordyceps linyphiidarum Y. Yang, K.D. Hyde & Y.P. Xiao sp. nov. Fig. 2 View FIGURE 2

Index Fungorum IF 904156, Facesoffungi FoF 17626

Etymology:— linyphiidarum refers to its host in the arachnid family Linyphiidae .

Sexual morph: undetermined. Asexual morph: Hymenostilbe -like. Synnemata 2–7 mm long, 0.3–0.5 mm wide, arising from the abdomen of the host spider; multiple, cylindrical, white to cream when fresh, light greyish-brown to pale yellow when dried, smooth, lacking an enlarged globose fertile head at the apex. Phialides along synnemata, arranged in clusters of 2–3, sharing a common base, stout, protuberant, hyaline, polyblastic, clavate or cylindrical, apically crowned with denticles 16.5–22.7 × 2.2–3.8 µm ( x = 19.6 × 3.0 µm, n = 60). Conidia smooth-walled, hyaline, one-celled, long-obovoid to ellipsoidal or elongate-ellipsoidal, with slightly rounded ends, some appear slightly fusiform or curved, 6.5–8.6 × 2.3–3.2 μm ( x = 7.6 × 2.7 µm, n = 60).

Material examined:— CHINA. Guizhou Province: Bijie City , Weining County, at 2490 m, 104.103 E, 26.863 N, 3 August 2023, coll. Yu Yang, WN 23168 (HKAS 132197, holotype) GoogleMaps ; ibid., on tree bark, same collecting details WN23166 (HKAS 132196). CHINA. Guizhou Province: Liupanshui City , Shuicheng County, at 2093 m, 104.811 E, 26.460 N, 31 July 2022, coll. Yuanpin Xiao, LPS05 (HKAS 132260) GoogleMaps .

Notes:— Phylogenetic analysis based on the combined dataset of SSU, LSU, ITS, tef-1α, rpb1, and rpb2 genes revealed that our collections form a distinct branch and are sister to the clade comprising Ophiocordyceps borealis and O. purpureostromata ( Fig. 1 View FIGURE 1 ). While O. borealis and O. purpureostromata infect larvae of Elateroidea, O. linyphiidarum parasitizes spiders ( Linyphiidae ) ( Kobayasi & Shimizu 1980, Zha et al. 2021). Ophiocordyceps linyphiidarum is distinct from other species in having slender, white to cream synnemata without an enlarged fertile head, clustered phialides with denticulate apices, and long-obovoid to ellipsoidal conidia. Base differences between O. linyphiidarum and its closest relatives are as follows: compared to O. borealis , 3.8% (37/968) in SSU, 6.7% (56/832) in LSU, 4.6% (22/472) in ITS, and 5.9% (53/896) in tef-1α; and compared to O. purpureostromata , 3.4% (34/978) in SSU, 6.6% (55/833) in LSU, 6.7% (54/802) in tef-1α, and 9.8% (69/698) in rpb1. Both morphological and molecular phylogenetic analyses support that O. linyphiidarum represents a distinct species.