Taxonomy

Cordycipitaceae Kreisel ex G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora, Stud. Mycol. 57: 48 (2007)

Arachnidicola Khons., Thanakitp. & Luangsa-ard, Fungal Syst. Evol. 14: 294, 2024

Arachnidicola fodingshanensis

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

925C9A42-759F-532C-8F78-8B87F00DCC21

861215

Fig. 5

Etymology.

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

Figure 5.: Arachnidicola fodingshanensisA. Infected spider; B, C. PDA culture plate showing top (B) and reverse (C) sides of the colony; D–G. Phialides and conidia on PDA. Scale bars: 10 mm (B, C) and 10 μm (D–G).

Type.

China, • Guizhou Province, Tongren City, Shiqian County, Fodingshan Nature Reserve (27°19'48"N, 108°4'48"E), on a dead spider (Araneae), under the rocks by the roadside, 11 July 2025, W.H. Chen, GZAC SQ5713, holotype; SQ57131, ex-type culture.

Diagnosis.

It differs from Arachnidicola kanyawimiae and A. sinensis by having longer phialides and ovoid to ellipsoidal conidia in culture.

Description.

The spider host was entirely covered by a white mycelial layer, with the hyphae closely adhering to the cuticle forming a dense, woolly felt. Several short, erect, whitish synnemata – slightly curved, columnar, and composed of compact parallel hyphae – arose from the mycelial mat. Colonies on PDA, attaining a diameter of 27–29 mm after 14 days at 25 °C, white, grayish-white in the middle part, consisting of a basal felt, floccose hyphal overgrowth; reverse light brown to yellowish. Hyphae septate, hyaline, smooth-walled, 1.8–1.9 μm wide. Conidiophores hyaline, smooth-walled, with single phialide or whorls of 2–5 phialides or paecilomyces-like formed directly from hyphae. Phialides narrowly obclavate, somewhat inflated base, 10.1–23.8 × 1.7–2.3 μm (x̄ = 18.9 × 2.0 μm, n = 50), tapering to a thin neck. Conidia hyaline, smooth-walled, ovoid to ellipsoidal, 2.4–3.2 × 1.5–2.0 μm (x̄ = 2.6 × 1.5 μm, n = 50). Sexual state and octahedral crystals not observed. Size and shape of phialides and conidia similar in culture on PDA and on natural substrate.

Host.

Spider (Araneae).

Habitat.

Near the road, under the rocks.

Additional strain examined.

China, • Guizhou Province, Tongren City, Shiqian County, Fodingshan Nature Reserve (27°19'48"N, 108°4'48"E), on a dead spider (Araneae), under the rocks by the roadside, 11 July 2025, W.H. Chen, GZAC SQ5713, holotype; SQ57132 (living culture).

Remarks.

Phylogenetic analysis of the concatenated dataset 1 (comprising ITS, LSU, rpb1, rpb2 and tef-1α sequences) and NCBI BLASTn searches demonstrated that Arachnidicola fodingshanensis (SQ57131 and SQ57132) formed a strongly supported terminal branch (100% ML/1.00 PP) within the genus Arachnidicola, closely related to A. kanyawimiae and A. sinensis. Morphologically, the new species differs from both A. kanyawimiae and A. sinensis in colony morphology (Table 2), and can be further distinguished from A. kanyawimiae by having longer phialides and ovoid to ellipsoidal conidia, and from A. sinensis by conidial shape and longer phialides. pairwise comparisons of five loci (Suppl. material 1) show limited divergence between A. fodingshanensis and A. kanyawimiae (e.g., 1.48% in ITS and 0.52% in rpb1), but this comparison is constrained by the substantially shorter sequences available for the latter in rpb2 and tef-1α, potentially underestimating true genetic distances. In contrast, A. fodingshanensis is clearly delineated from A. sinensis by marked divergence across multiple loci (1.56% in ITS, 0.79% in LSU, 3.87% in rpb2, and 0.91% in tef-1α). Furthermore, the PHI test revealed no significant recombination between the new species and its close relatives (Φw = 0.6876), supporting their phylogenetic independence. Collectively, the integrated evidence from morphology, phylogeny, nucleotide discrepancies, and recombination analysis robustly justifies the establishment of Arachnidicola fodingshanensis as a new species.

Species | Colony | Phialide (μm) | Conidia (μm) | Habitat | Distribution | Reference
A. fodingshanensis | white, grayish-white in the middle part | 18.9 × 2.0 | ovoid to ellipsoidal, 2.6 × 1.5 | under the rocks | Guizhou, China | This study
A. kanyawimiae | white, turning pale yellow in the center | 9–12 × 2–3 | cylindrical to ellipsoidal, 2.5–3.5 × 2 | on the stem of dicotyledonous plant | Phetchabun, Thailand | Mongkolsamrit et al. 2018
A. sinensis | white | 17.4 × 1.9 | subglobose to ellipsoidal, 2.7 × 2.2 | on or under the rock | Guizhou, China | Chen et al. 2025b

Simplicillium W. Gams & Zare, Nova Hedwigia 73(1–2): 38, 2001

Simplicillium fodingshanense

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

673BCACD-B2C3-593D-A0FC-98E75BEEE270

861217

Fig. 6

Etymology.

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

Figure 6.: Simplicillium fodingshanenseA. Infected cocoon; B, C. PDA culture plate showing top (B) and reverse (C) sides of the colony; D–H. Phialides and conidia on PDA. Scale bars: 10 mm (B, C) and 10 μm (D–H).

Type.

China, • Guizhou Province, Tongren City, Shiqian County, Fodingshan Nature Reserve (27°19'48"N, 108°4'48"E), on a dead cocoon (Lepidoptera), located on the leaf litter, 11 July 2025, W.H. Chen, GZAC SQ5710, holotype; SQ57101, ex-type culture.

Diagnosis.

It differs from Simplicillium shiqianense by its shorter phialides (18.6–33.1 × 0.7–1.6 μm). It differs from S. subtropicum by its absence of octahedral crystals and slime head of conidia in culture.

Description.

A dense, woolly, pure white mycelial mat was produced on the lower-middle region of the pupal body, with numerous white aerial hyphae extending radially outward from its surface. Colonies on PDA, attaining a diameter of 30–31 mm after 14 days at 25 °C, white, consisting of a basal felt, floccose hyphal overgrowth; reverse yellowish. Hyphae septate, hyaline, smooth-walled, 1.2–1.4 μm wide. Single phialide from hyphae directly. Phialides cylindrical, somewhat inflated base, 18.6–33.1 × 0.7–1.6 μm (x̄ = 25.2 × 1.0 μm, n = 50), tapering to a thin neck. Conidia, hyaline, smooth-walled, 1-celled, ellipsoidal to ovoid, 2.0–4.8 × 1.0–1.5 μm (x̄ = 3.3 × 1.3 μm, n = 50). Octahedral crystals, slime head of conidia and sexual state not observed.

Host.

Cocoon (Lepidoptera).

Habitat.

Located on the leaf litter.

Additional strain examined.

China, • Guizhou Province, Tongren City, Shiqian County, Fodingshan Nature Reserve (27°19'48"N, 108°4'48"E), on a dead cocoon (Lepidoptera), located on the leaf litter, 11 July 2025, W.H. Chen, GZAC SQ5710, holotype; SQ57102 (living culture).

Remarks.

Molecular characterization through NCBI BLASTn alignment and phylogenetic reconstruction of dataset 2 (comprising ITS, LSU, rpb1 and tef-1α sequences) revealed that Simplicillium fodingshanense (SQ57101 and SQ57102) was nested within Simplicillium and formed a strongly supported independent lineage (100% ML/1.00 PP), closely related to S. shiqianense and S. subtropicum. Morphologically (Table 3), S. fodingshanense can be distinguished from S. shiqianense by its shorter phialides and different host, and from S. subtropicum by the absence of both octahedral crystals and conidial slime heads, as well as by its distinct host/substrate. Pairwise comparisons of the reliable gene regions (ITS, LSU, and tef-1α; Suppl. material 1) revealed that S. fodingshanense differs from S. shiqianense by 6/581 bp (1.03%) in ITS, 8/882 bp (0.90%) in LSU, and 19/1005 bp (1.89%) in tef-1α, and from S. subtropicum by 9/581 bp (1.54%) in ITS, 2/770 bp (0.25%) in LSU, and 14/923 bp (1.51%) in tef-1α. Furthermore, the PHI test revealed no significant recombination between the new species and its close relatives (Φw = 0.1587), further supporting their phylogenetic independence. Collectively, the integrative evidence from morphology, ecology, molecular phylogeny, nucleotide divergence, and the PHI test substantiates the recognition of Simplicillium fodingshanense as a novel species.

Species | Phialide (μm) | Conidia (μm) | Host/ Substrate | Habitat | Distribution | Notes | Reference
S. fodingshanense | 25.2 × 1.0 | Ellipsoidal to ovoid, 3.3 × 1.3 | Cocoon | On the leaf litter | Guizhou, China |  | This study
S. shiqianense | 39.4 × 1.2 | Cylindrical to ellipsoidal, 3.6 × 1.4 | Spider | Under the rocks | Guizhou, China |  | This study
S. subtropicum | 20–42 × 1.0–2.3 | Subglobose to ellipsoidal, 2.3–4.0 × 1.5–3.3 | Soil | Under various plants | Tokyo, Japan | Slime head and octahedral crystals present | Nonaka et al. 2013

Simplicillium shiqianense

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

4E5FA66A-8BFB-5D51-AE96-D47EB0CE5DE7

861218

Fig. 7

Etymology.

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

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

Type.

China, • Guizhou Province, Tongren City, Shiqian County, Fodingshan Nature Reserve (27°19'48"N, 108°4'48"E), on a dead spider (Araneae), under the rocks by the roadside, 11 July 2025, W.H. Chen, GZAC SQ5711, holotype; SQ57111, ex-type culture.

Diagnosis.

Differs from S. fodingshanense by its longer phialides. Differs from S. subtropicum by its absence of octahedral crystals, cylindrical to ellipsoidal conidia in culture and spider host.

Description.

The spider host was covered by a dense white mycelial layer growing closely appressed to its body surface. A short, pure white, columnar synnema emerged upright from above the cephalothorax, composed of numerous parallel hyphae. Colonies on PDA, attaining a diameter of 29–30 mm after 14 days at 25 °C, white, consisting of a basal felt, floccose hyphal overgrowth; reverse light brown to yellowish. Hyphae septate, hyaline, smooth-walled, 1.2–1.4 μm wide. Single phialide from hyphae directly. Phialides cylindrical, somewhat inflated base, 28.4–54.9 × 0.6–1.7 μm (x̄ = 39.4 × 1.2 μm, n = 50), tapering to a thin neck. Conidia, hyaline, smooth-walled, 1-celled, variable in shape, mostly cylindrical, ellipsoidal to subglobose, 2.4–4.3 × 1.1–1.7 μm (x̄ = 3.6 × 1.4 μm, n = 50). Octahedral crystals, slime head of conidia and sexual state not observed.

Host.

Spider (Araneae).

Habitat.

Under the rocks by the roadside.

Additional strain examined.

China, • Guizhou Province, Tongren City, Shiqian County, Fodingshan Nature Reserve (27°19'48"N, 108°4'48"E), on a dead spider (Araneae), under the rocks by the roadside, 11 July 2025, W.H. Chen, GZAC SQ5711, holotype; SQ57112 (living culture).

Remarks

. Molecular characterization through NCBI BLASTn alignment and phylogenetic reconstruction of dataset 2 (comprising ITS, LSU, rpb1 and tef-1α sequences) revealed that Simplicillium shiqianense (SQ57111 and SQ57112) was nested within Simplicillium and formed a strongly supported independent lineage (100% ML/1.00 PP), closely related to S. fodingshanense and S. subtropicum. Morphologically and ecologically (Table 3), S. shiqianense can be distinguished from S. fodingshanense by its longer phialides and different host, and from S. subtropicum by the absence of octahedral crystals and conidial slime heads, as well as by its conidial shape and distinct host/substrate. At the nucleotide level, pairwise comparisons of the reliable gene regions (ITS, LSU, and tef-1α; Suppl. material 1) revealed that Simplicillium shiqianense differs from S. fodingshanense by 6/581 bp (1.03%) in ITS, 8/882 bp (0.90%) in LSU, and 19/1005 bp (1.89%) in tef-1α, and from S. subtropicum by 7/581 bp (1.20%) in ITS, 2/770 bp (0.25%) in LSU, and 14/924 bp (1.51%) in tef-1α. Furthermore, the PHI test revealed no significant recombination between the new species and its close relatives (Φw = 0.1587), further supporting their phylogenetic independence. Collectively, the integrative evidence from morphology, ecology, molecular phylogeny, nucleotide divergence, and the PHI test substantiates the recognition of Simplicillium shiqianense as a novel species.