Type: — CHINA. Anhui Province: Shitai County, Guniujiang National Nature Reserve, on a spider, 1 August 2020, Mingjun Chen & Ting Wang, holotype GNJ20200814-46. GenBank sequence data for GNJ20200814-46: SSU = MW969660, LSU = MW969673, TEF = MW961413, RPB1 = MW980146.

Asexual morph: white to yellowish-white mycelial mat, completely covering the host spider. Synnemata 1.9–2.5 × 0.2–0.5 mm, clustered in the back of host, slightly narrowing toward the tip. Conidiophores arising along the entire length of the outer hyphae of synnemata and from the mycelia covering the host, verrucose, 33.5–123.5(–182.5) × (3–)4–9.5(–11.5) μm, tapering suddenly to a short distinct neck, enlarging into an ellipsoid to globose vesicle, 6–9(–12) × (5–)6–8(–9) μm; several metulae born on each vesicle, obovoid to broadly obovoid, (4.5–)5.5–7 × 3.5–5.5 μm, bearing a few narrowly obovate to clavate phialides with papillate apices, 5.5–7×1.5–2.5 μm. Conidia fusiform, (2.5–)3–4(– 5.5) × 1–2(–3) μm; vesicle, metulae, phialide forming a spherical head, (28–)34.5–44(–51) μm in diam. Sexual morph: Perithecia arising from the cream to yellow mycelial mat, superficial or partly embedded, gregarious, elongatedellipsoidal, with dark orange papillate ostioles, cream to orange, 290–380 × 98–130 μm. Asci cylindrical, 8-spored, up to 130–220 × 5 μm, ascus cap 5 × 2.5–3.5 μm. Ascospores hyaline, smooth, filiform, 130–170 × 2.5 μm, readily disarticulating into part-spores; part-ascospores bacilliform with apices rounded, 4.5–7.5 × 2.5 μm. Granulomanus-like asexual morph absent.

Etymology: — flava named after the colour in the sexual morph specimen.

Additional material examined: — CHINA. Anhui Province: Shucheng County, Wanfoshan National Forest Park, on a spider, June 2019, Mingjun Chen & Bo Huang WFS20190625-25; Shucheng County, Wanfoshan National Forest Park, June 2009, on a spider, Mingjun Chen & Bo Huang WFS20190625-01. GenBank sequence data for WFS20190625-25: SSU = MW036749, LSU = MW084343, TEF = MW091325, RPB1 = MW384883.

Known distribution: —Shucheng County, Anhui Province, China.

Notes: —According to descriptions of both sexual and asexual morphs for Gibellula pulchra from Mains (1950) and from the phylogenetic analysis, G. pulchra is the most closely related species with the new species. However, G. pulchra differs from G. flava in having longer verrucose conidiophores (150–600 μm) with slightly longer metulae (6–12 μm), phialides (6–10 μm) and conidia (2.5–6.4 μm). The sexual morph of G. flava produces superficial and elongate ellipsoidal small perithecia with shorter asci. The perithecia of G. pulchra are ovoid in shape and the asci are 600–660 × 5–7 μm.