Trichothecium sinense W. H. Chen, Y. F. Han, J. D. Liang & J. H. Zhao, 2025

Chen, Wan-Hao, Shu, Hui-Lin, Li, Dan, Liang, Jian-Dong, Ren, Xiu-Xiu, Wijayawardene, Nalin N., Han, Yan-Feng & Zhao, Jie-Hong, 2025, Morphological and phylogenetic evidence reveals three new arthropod-associated species of Hypocreales (Clavicipitaceae, Bionectriaceae, and Myrotheciomycetaceae) from karst habitats in Guizhou, China, MycoKeys 123, pp. 319-353 : 319-353

Trichothecium sinense W. H. Chen, Y. F. Han, J. D. Liang & J. H. Zhao sp. nov.

Fig. 7

Etymology.

Referring to its location, China, where the fungus was first discovered.

Type.

China • Guizhou Province, Qiannan Buyi and Miao Autonomous Prefecture, Duyun City, Mayao River Valley ( 26°21'24.71"N, 107°22'48.22"E). On a dead spider ( Araneae ), on or under rocks, 1 May 2022, Wanhao Chen, GZAC DY 0546 , holotype; DY 05461 , ex-type .

Diagnosis.

Differs from Trichothecium crotocinigenum by its shorter phialides, larger conidia and spider host.

Description.

Colonies on PDA, attaining a diameter of 86–90 mm after 14 days at 25 ° C, white, consisting of a basal felt, floccose hyphal overgrowth; reverse light yellow. Conidiophores solitary, (sub-) erect, arising directly from submerged or superficial hyphae, 14.3–23.1 × 1.4–2.6 μm (x ̄ = 17.7 × 1.8 μm, n = 30). Phialides lateral or terminal, cylindrical, occasionally swollen in the lower part, hyaline, thick-, smooth-walled, 32.8–55.1 × 1.9–3.0 μm (x ̄ = 46.9 × 2.6 μm, n = 30). Conidia aseptate, cylindrical, oblong or ovoid, rounded at both ends, hyaline, thin-, smooth-walled, 4.8–5.8 × 1.2–2.9 μm (x ̄ = 5.5 × 2.4 μm, n = 30), arranged in slimy heads. Chlamydospores not observed. Sexual morph not observed.

Host.

Spider ( Araneae ).

Habitat.

Near the road, located on or under rocks.

Additional material examined.

China • Guizhou Province, Qiannan Buyi and Miao Autonomous Prefecture, Duyun City, Mayao River Valley ( 26°21'24.71"N, 107°22'48.22"E). On a dead spider ( Araneae ), on or under rocks, 1 May 2022, Wanhao Chen, DY 05462 (living culture); GZAC DY 0559 (specimen), DY 05591 , DY 05592 (living culture) .

Remarks.

Trichothecium sinense was identified as Trichothecium , based on the BLASTn result in NCBI and the phylogenetic analysis of the combined datasets 1 and 4 (Figs 1 , 4 ). It clustered into an independent clade with a close relationship with Trichothecium crotocinigenum with high statistical values (99 % ML / 1 PP). Compared with the typical microscopic characteristics, Trichothecium sinense can be distinguished from T. crotocinigenum by its shorter phialides (32.8–55.1 × 1.9–3.0 μm vs. 168 μm long), larger conidia [4.8–5.8 × 1.2–2.9 μm vs. 3–8 (– 11) × 2–3 μm] and its substrates (mushroom vs. spider). Thus, the morphological characteristics and molecular phylogenetic results support T. sinense as a new species.

Figures

Figure 1. Phylogram retrieved from IQ-TREE to confirm the familial placements of the new strains using the combined dataset of ITS, LSU, RPB 2 and tef - 1 α gene regions. The statistical values are provided at nodes as ML / PP (ML value above 70 % and BI value above 0.70). The tree is rooted with Gelasinospora tetrasperma (AFTOL-ID 1287), Neurospora crassa (ICMP 6360) and Sordaria fimicola (AFTOL-ID 216). Ex-types and new strains are indicated by the superscript “ T ” and in bold, respectively.

Figure 4. Phylogram retrieved from IQ-TREE of the placement of new strains in Trichothecium s. str. using the combined dataset of ITS, LSU, RPB 2 and tef - 1 α gene regions. The statistical values are provided at nodes as ML / PP (ML value above 70 % and BI value above 0.70). The tree is rooted with Clonostachys phyllophila (CBS 921.97) and Clonostachys spinulosispora (CBS 133762). Ex-types, new strains are indicated by the superscript “ T ” and in bold, respectively.

Figure 7. Trichothecium inense A. Infected spider; B, C. PDA culture plate showing the top (B) and reverse (C) sides of the colony; D – L. Phialides and conidia. Scale bars: 10 mm (B, C) and 10 μm (D – L).