Ophiocordyceps muscae Mongkolsamrit, Liangsiri, Thanakitpipattana & Luangsa-ard, 2025

Mongkolsamrit, Suchada, Thanakitpipattana, Donnaya, Noisripoom, Wasana, Tasanathai, Kanoksri, Liangsiri, Kanraya, Jaiyen, Somruetai, Rungjindamai, Nattawut, Stadler, Marc & Luangsa-ard, Jennifer, 2025, Multi-locus molecular phylogenetic analysis reveals four new species and a new record of Ophiocordyceps (Ophiocordycipitaceae, Hypocreales) on dipteran hosts in Thailand, MycoKeys 119, pp. 235-261 : 235-261

Ophiocordyceps muscae Mongkolsamrit, Liangsiri, Thanakitpipattana & Luangsa-ard sp. nov.

Fig. 3

Etymology.

Named after the host genus, Musca domestica .

Typus.

Thailand • Nakhon Ratchasima Province, Khao Yai National Park, Mo Singto Nature Trail , on housefly ( Musca domestica ) attached to the underside of a dicotyledonous leaf of forest plant, 9 July 2014, K. Tasanathai, S. Mongkolsamrit, A. Khonsanit, W. Noisripoom, D. Thanakitpipattana, R. Somnuk, MY 9689.01 (holotype BBH 41168 , ex-type culture BCC 73616 ) .

Description.

Stromata stipitate, usually two stromata arising from the thorax region of host, beneath the wings, capitate, unbranched. Stipes cylindrical, smooth, brownish-orange (165 B), 4–8 mm long, 0.5–1.5 mm wide with a fertile apex. Sexual morph: Fertile heads hemispherical to globoid, upper surface slightly convex, moderate orange yellow (164 B – C), located at the terminal part of stipes, 1–2 mm thick, 1.5–2 mm diam. Perithecia immersed, ovoid to obclavate, (820 –) 875–1020 (– 1100) × (320 –) 350–390 (– 400) μm (n = 20, 947.3 ± 71.2 × 367.5 ± 19 μm). Asci cylindrical, up to 720 μm long, 4–5 μm (n = 20, 4.4 ± 0.5 μm) wide, with cap 3–5 μm thick. Ascospores filiform, multi-septate, breaking into 64 part-spores, cylindrical to fusoid, 10–12 (– 13) × 1.5–2 μm (n = 50, 10.8 ± 0.8 × 1.8 ± 0.2 μm). Asexual morph: Synnemata usually arising from posterior abdomen region of host, solitary, cylindrical, unbranched, brown to dark brown at the base, light brown to grey towards the apex, 5–12 × 0.5–1.5 mm, fertile region located at about two-thirds of the synnema length. Conidiogenous cells Hymenostilbe - like, phialidic, forming a hymenial layer. Phialides cylindrical with short crowded denticles, (12 –) 14–17.5 (– 20) × 3–4 μm (n = 30, 15.4 ± 1.9 × 3.3 ± 0.4 μm). Conidia hyaline smooth-walled, fusoid, (5 –) 6–8 (– 10) × 1.5–3 μm (n = 30, 6.8 ± 1.1 × 2.1 ± 0.2 μm).

Culture characteristics.

Colonies on OA attaining a diam. of 7–10 mm in 30 days, mycelium sparse, white, reverse pale yellow (165 D). Conidia and reproductive structures not observed. Colonies on PDA attaining a diam. of 7–10 mm in 30 days, high mycelium density, white, reverse pale yellow (165 D). Conidia and reproductive structures not observed.

Host.

Housefly ( Muscidae , Musca domestica ).

Habitat.

The specimens were found on the underside of a dicotyledonous leaf from a forest plant.

Additional materials examined.

Thailand • Nakhon Ratchasima Province, Khao Yai National Park, Mo Singto Nature Trail , on housefly ( Musca domestica ) on the underside of a dicotyledonous leaf of a forest plant, 9 July 2014, K. Tasanathai, S. Mongkolsamrit, A. Khonsanit, W. Noisripoom, D. Thanakitpipattana, R. Somnuk, MY 9670 (paratype BBH 38888 , ex-paratype culture BCC 73607 ) ; • idem, 28 May 2014, K. Tasanathai, S. Mongkolsamrit, A. Khonsanit, W. Noisripoom, D. Thanakitpipattana, R. Somnuk, MY 9584.01 ( BBH 30660 , culture BCC 48932 ) ; • idem, 30 April 2014, K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, A. Khonsanit, W. Noisripoom, K. Sansatchanon, MY 9568 ( BBH 40602 , culture BCC 72871 ) ; • Phetchabun Province, Nam Nao National Park, Headquarters Nature Trail , 3 October 2015, K. Tasanathai, S. Mongkolsamrit, W. Noisripoom, N. Kobmoo, R. Promharn, MY 10980 ( BBH 41221 ), MY 10981 ( BBH 41222 ) ; • Tak Province, Wat Phothi Khun Nature Trail , on housefly ( Musca domestica ) on the underside of a dicotyledonous leaf of a forest plant, 20 August 2024, MY 13633, K. Tasanathai, S. Mongkolsamrit, W. Noisripoom, K. Liangsiri .

Notes.

The two strains, NHJ 12170.02 and MRCIF 71, originally identified as Ophiocordyceps dipterigena , were collected from Thailand and have their sequences available in the NCBI database (Table 1 ). The sequence data for NHJ 12170.02 were submitted by Luangsa-ard et al. (2011), while MRCIF 71 was deposited by Aung and colleagues in 2008. However, based on our analysis and the phylogenetic results presented in Fig. 1 , we found that these strains clustered with BCC 72871, BCC 73616, and BCC 73607, supporting their re-identification as Ophiocordyceps muscae .

Figures

Figure 1. RAxML tree of the Ophiocordyceps dipterigena complex (highlighted in pink) and related species of entomopathogenic fungi in Ophiocordyceps, based on a combined ITS, LSU, TEF 1, and RPB 2 dataset. Numbers at the major nodes indicate maximum likelihood bootstrap values (MLB ≥ 70 %) and Bayesian posterior probabilities (BPP ≥ 0.70).

Figure 3. Ophiocordyceps muscae. A, B. Fungus on housefly (Musca domestica, Holotype BBH 41168); C. Perithecia; D. Asci; E. Ascus; F. Ascus cap; G. Part-spores; H. Synnema; I, J. Conidiogenous cells forming a hymenial layer; K. Conidia; L, M. Colonies on OA at 30 days (L obverse, M reverse) N, O. Colonies on PDA at 30 days (N obverse, O reverse). Scale bars: 5 mm (A, B); 350 µm (C); 100 µm (D, E); 10 µm (F, J, K); 20 µm (G, I); 1 mm (H); 10 mm (L – O).