Ophiocordyceps philippinensis Piskorski, Kisło & Ruszk.-Mich.

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 philippinensis Piskorski, Kisło & Ruszk.-Mich. , Persoonia 51: 345 (2023)

Fig. 4

Note.

The description and illustrations are based on specimens of O. philippinensis collected in Thailand.

Description.

Stromata stipitate, two to three stromata arising from the thorax region of host, beneath the wings, capitate, unbranched. Stipes cylindrical, smooth, brownish-orange (165 B), 5–8 mm long, 1–1.5 mm wide with a fertile apex. Sexual morph: Fertile head hemispherical to globoid, upper surface slightly convex, moderate orange yellow (164 C), located at the tip of stipes, 2–2.5 mm thick, 3–4 mm diam. Perithecia immersed, ovoid to obclavate, (720 –) 825–1017 (– 1100) × (240 –) 270–355 (– 400) μm (n = 30, 919.8 ± 97 × 313.4 ± 42 μm). Asci cylindrical, up to 300 μm long, 4–6 μm (n = 20, 5.3 ± 0.5) wide, with cap 4–6 μm thick. Ascospores filiform, multi-septate, breaking into 64 part-spores, cylindrical to fusoid, 10–12 × 1.5–2.5 μm (n = 50, 11 ± 1 × 2.1 ± 0.4 μm). Asexual morph: Synnemata arising from head, thorax, abdomen regions of host, solitary, multiple, cylindrical, unbranched, brown to dark brown at the base, light brown to grey towards the apex, 4–20 × 0.5–1 mm, fertile part located at the two-thirds length of the synnemata. Conidiogenous cells Hymenostilbe - like, phialidic, forming a hymenial layer. Phialides cylindrical with short crowded denticles, (10 –) 11.5–16.5 (– 20) × 3–3.5 (– 4) μm (n = 30, 14 ± 3 × 3.2 ± 0.4 μm). Conidia hyaline smooth-walled, fusiform, (5 –) 6 – 8 (– 10) × 2–2.5 (– 3) μm (n = 30, 7.1 ± 1 × 2.2 ± 0.4 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.

Robber fly ( Asilidae , Clephydroneura sp. )

Habitat.

Specimens were found on the twig of a tree in a forest.

Additional materials examined.

Thailand • Chaiyaphum Province, Phu Khiao Wildlife Sanctuary, Thung Ka Mang Nature Trail , on robber fly ( Asilidae , Clephydroneura sp. ) attached to the twig of a tree, 25 May 2006, K. Tasanathai, W. Chaygate, S. Mongkolsamrit, R. Ridkaew, B. Thongnuch, V. Sri-Indrasutdhi, MY 1294 ( BBH 17649 , BCC 22048 ) ; • idem, 12 August 2015, S. Mongkolsamrit, A. Khonsanit, W. Noisripoom, D. Thanakitpipattana, N. Kobmoo, P. Srikitikulchai, S. Wongkanoun, R. Promharn, MY 10790.01 ( BBH 41274 , BCC 79225 ), MY 10790.02 ( BBH 41274 , BCC 78339 ) ; • Chiang Mai Province, Kanlayaniwatthana district, on robber fly ( Asilidae , Clephydroneura sp. ) attached to the twig of a tree, 23 November 2015, K. Tasanathai, S. Mongkolsamrit, D. Thanakitpipattana, W. Noisripoom, R. Promharn, P. Srikitikulchai, S. Wongkanoun, MY 11132 ( BBH 42752 , BCC 79871 ), MY 11134 ( BBH 41232 , BCC 79872 ) .

Notes.

The multi-gene phylogenetic analysis (Fig. 1 ) revealed that the five Thai strains — BCC 79225, BCC 78339, BCC 79871, BCC 22048, and BCC 79872 — clustered with O. philippinensis , previously reported from the Philippines ( LOD PF 4565), with strong support (99 % MLB / 1 BPP). These species infect flies of the same family, Asilidae , but differ in their host genus. Ophiocordyceps philippinensis collected in Thailand infects Clephydroneura sp. , while O. philippinensis from the Philippines infects Asilus sp. A comparison of morphological features shows that the perithecia and asci of the Thai specimens are larger and longer than those of the Philippine specimens. The part-spores in the Thai specimens are mature, measuring 10–12 × 1.5–2.5 μm, whereas the part-spores in the Philippine specimens are immature (Table 2 ). Asexual morph reproductive structures, producing Hymenostilbe - like, were observed in the Thai specimen. Observations also revealed that the sexual and asexual morphs occur together on the same specimen, with synnemata emerging from the host’s abdominal region (Fig. 4 A ). If only the asexual morph is present, synnemata emerge from various parts of the host (Fig. 4 B ).

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 4. Ophiocordyceps philippinensis. A, B. Fungus on a robber fly (Asilidae, Clephydroneura sp.); C. Perithecium; D. Ascus; E. Part-spores; F. Synnema; G, H. Conidiogenous cells forming a hymenial layer; I. Conidia; J, K. Colonies on OA at 30 days (J obverse, K reverse); L, M. Colonies on PDA at 30 days (L obverse, M reverse). Scale bars: 15 mm (A, B); 300 µm (C); 20 µm (D, E); 1 mm (F); 15 µm (G, H); 10 µm (I); 10 mm (J – M).