Ovicillium zunyiense 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

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

Fig. 5

Etymology.

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

Type.

China • Guizhou Province, Zunyi City, Honghuagang District, Dabanshui National Forest Park ( 27°46'35.904"N, 106°48'30.89"E). On a dead larva ( Lepidoptera ), on the leaf litter, 2 September 2023, Wanhao Chen, GZAC ZY 0927 , holotype; ZY 09271 , ex-type .

Diagnosis.

Differs from Ovicillium oosporum by its shorter conidiophore, smaller conidia and its insect substrate. Differs from O. subglobosum by its shorter phialides, smaller ovoid to subglobose conidia and insect substrate. Differs from O. theobromae by its shorter conidiophores, shorter phialides and insect substrate. Differs from O. variecolor by its shorter conidiophores, shorter phialides, absence of sessile conidia and insect substrate.

Description.

Colonies on PDA, attaining a diameter of 42–45 mm after 14 days at 25 ° C, grayish-white to light brown, consisting of a basal felt, floccose hyphal overgrowth; reverse light brown to brown. Hyphae septate, hyaline, smooth-walled, 1.6–1.7 μm wide. Conidiophores hyaline, smooth-walled, with single phialide or whorls of 2–4 phialides or verticillium-like from hyphae directly, 17.4–26.2 × 2.3–3.0 μm (x ̄ = 20.8 × 2.6 μm, n = 30). Phialides cylindrical, somewhat inflated base, 21.6–33.3 × 1.2–2.6 μm (x ̄ = 28.2 × 1.7 μm, n = 30), tapering to a thin neck. Conidia hyaline, smooth-walled, ovoid to subglobose, 2.3–3.7 × 1.7–2.6 μm (x ̄ = 2.7 × 2.1 μm, n = 30). Sexual state not observed.

Host.

Larva ( Lepidoptera ).

Habitat.

Near the road, located on the leaf litter.

Additional strain examined.

China • Guizhou Province, Zunyi City, Honghuagang District, Dabanshui National Forest Park ( 27°46'35.904"N, 106°48'30.89"E). On a dead larva ( Lepidoptera ), on the leaf litter, 2 September 2023, Wanhao Chen, ZY 09272 (living culture) .

Remarks.

Based on BLASTn results, strains ZY 09271 and ZY 09272 were identified as members of Ovicillium s. str., and the phylogenetic analysis of the combined datasets 1 and 2 (Figs 1 , 2 ). It clustered into an independent clade with a close relationship with Ovicillium oosporum , O. subglobosum , O. theobromae and O. variecolor with a high support value (98 % ML / 1 PP). Compared with the typical characteristics, Ovicillium zunyiense can be distinguished from O. oosporum by its shorter conidiophores (17.4–26.2 × 2.3–3.0 μm vs. 20–50 × 1.2–2.2 μm), smaller conidia (2.3–3.7 × 1.7–2.6 μm vs. 4–6 × 2.5–4.0 μm) and its substrates (insect vs. plant). Ovicillium zunyiense can be distinguished from O. subglobosum by its short phialides (21.6–33.3 × 1.2–2.6 μm vs. 25–55 × 1.5–2.2 μm), smaller ovoid to subglobose conidia (2.3–3.7 × 1.7–2.6 μm vs. 3.5–5.5 × 3.5–4.5 μm) and its substrates (insect vs. soil). Ovicillium zunyiense can be distinguished from O. theobromae by its short conidiophores (17.4–26.2 × 2.3–3.0 μm vs. 460 × 1.5–3.2 μm), short phialides (21.6–33.3 × 1.2–2.6 μm vs. 28.4–65.5 × 1.2–1.8 μm) and its substrates (insect vs. plant). Ovicillium zunyiense can be distinguished from O. variecolor by its short conidiophores (17.4–26.2 × 2.3–3.0 μm vs. 290 μm long), short phialides (21.6–33.3 × 1.2–2.6 μm vs. 18–95 × 1–2 μm), absence of sessile conidia and its substrates (insect vs. soil). Thus, the morphological characteristics and molecular phylogenetic results support to establishment of O. zunyiense 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 2. Phylogram retrieved from IQ-TREE for establishing the new species in the genus Ovicillium 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 Acremonium alternatum (CBS 407.66) and A. egyptiacum (CBS 114785). Ex-types and new strains are indicated by the superscript “ T ” and in bold, respectively.

Figure 5. Ovicillium zunyiense A. Infected larva; B, C. PDA culture plate showing the top (B) and reverse (C) sides of the colony; D – J. Phialides and conidia. Scale bars: 10 mm (B, C) and 10 μm (D – J).