Ophiocordyceps globiceps Y.P. Xiao, T.C. Wen & K.D. Hyde

Xiao, Yuan-Pin, Hongsanan, Sinang, Hyde, Kevin D., Brooks, Siraprapa, Xie, Ning, Long, Feng-Yao & Wen, Ting-Chi, 2019, Two new entomopathogenic species of Ophiocordyceps in Thailand, MycoKeys 47, pp. 53-74 : 53

Ophiocordyceps globiceps Y.P. Xiao, T.C. Wen & K.D. Hyde sp. nov. Fig. 2

Etymology.

The specific epithet refers to the feature of the secondary hemispherical to globoid fertile head.

Sexual morph: Stromata 4-8 mm long × 0.5-1 mm diam., one or several from the host, stipitate, capitate, unbranched, cinnamon to yellow. Stipe 3.5-7.5 mm long, 0.2-0.5 mm diam., yellow, cylindrical, with a fertile apex. Fertile head 1-1.5 mm long, 1-1.2 mm diam., cinnamon to yellow, single, hemispherical to globoid. Perithecia 538-663 × 182-247 μm (x̄= 600 × 214 µm, n = 60), immersed, ovoid to elongated pyriform, thick-walled, vertical with the ostioles opening on the upper surface of the head. Peridium 17-22 µm (x̄ = 20 µm, n = 90) wide, hyaline, of textura porrecta to textura prismatica to textura angularis. Asci 373-454 × 5.7-8.2 μm (x̄ = 413 × 7 µm, n = 90), 8-spored, hyaline, filiform, with a thick apex. Apical cap 4.4-6.4 × 4.9-5.7 μm (x̄ = 5.4 × 5.3 µm, n = 60), thick, with a small channel in the centre. Ascospores 240-303 × 1.8-2.3 μm (x̄ = 272 × 2.1 µm, n = 60), filiform, hyaline, multiseptate. Secondary ascospores 4-5.4 × 1.2-1.9 μm (x̄ = 4.7 × 1.6 µm, n = 90) cylindrical to fusoid, 1-celled, straight, hyaline, smooth-walled. Asexual morph: Undetermined.

Culture characteristics.

growing on PDA, reaching 5 cm diam., after 6 weeks at 25 °C, superficial cottony, whitened, loose, reverse yellow. After 10 weeks at 25 °C, reaching 6 cm diam., no conidiogenous structures observed.

Material examined.

THAILAND, Ranong, Tambon Khao Niwet, parasitise on fly ( Muscidae , Diptera ) 7 mm long, 3 mm wide, brown to dark brown, without hyphae on the surface, collected on the grass stem, 19 July 2015, YuanPin Xiao, (MFLU 18-0661, holotype, ex-type living culture, MFLUCC 18-0495); Chiang Mai, Thailand, on adult fly ( Diptera ), 6.5 mm long, 2.7 mm wide, brown to dark brown, without hyphae on the surface, collected on the grass, 19 July 2017, YuanPin Xiao, (MFLU 18-0662, paratypes, living culture MFLUCC 18-0496).

Notes.

In the phylogenetic tree, Ophiocordyceps globiceps is closely related to O. dipterigena (Berk. & Broome) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafor. (Thailand) and O. hemisphaerica Mafalda-Freire, Reck & Drechsler-Santos (Brazil), which infect flies ( Luangsa-ard et al. 2008, Hyde et al. 2016). Ophiocordyceps globiceps also groups with Ophiocordyceps sp. (FMF147) (106bp ITS differ), which was introduced by ITS sequence data and without any other detail ( Freire 2015). Ophiocordyceps globiceps has 60 bp that differ from O. dipterigena (MY621, Thailand) in the ITS region, 19 bp in TEF1α. It has 87 bp that differ from Hymenostilbe dipterigena Petch (NHJ12170, Thailand, asexual morph of O. dipterigena ) in the ITS region and 20 bp in TEF1α. Ophiocordyceps globiceps also has 94 bp (ITS) that differ from O. dipterigena (MRCIF71, Thailand), which only has ITS and without any details. Ophiocordyceps globiceps has 104 bp that differ from O. hemisphaerica (FLOR 59525) in the ITS region and has 21 bp in nrSSU, 97 bp in nrLSU, 74 bp in TEF1α that differ from O. dipterigena (OSC 151913).

We compared the new species with other Ophiocordyceps species which infect flies ( Diptera ) or are morphologically similar to O. globiceps (Table 2). Ophiocordyceps globiceps differs from three records of O. dipterigena found in Sri Lanka, Japan and Thailand by producing single smaller stroma, smaller and shorter perithecia, shorter asci and smaller ascospores (Table 2). Cordyceps sakishimensis Kobayasi & Shimizu, Ophiocordyceps discoideicapitata (Kobayasi & Shimizu) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora, Ophiocordyceps forquignonii ( Quél.) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora, Ophiocordyceps hemisphaerica Mafalda-Freire, Reck & Drechsler-Santos, Ophiocordyceps lacrimoidis Mafalda-Freire, Reck & Drechsler-Santos and Cordyceps muscicola Möller (= Ophiocordyceps muscicola ) have been reported as fly infected taxa ( Saccardo 1891, Möller 1901, Kobayasi and Shimizu 1982, Freire 2015, Hyde et al. 2016), but their morphology is different from O. globiceps (see Table 2). Cordyceps sakishimensis is distinct from O. globiceps in having white, longer, cylindrical stromata and larger superficial perithecia. Ophiocordyceps discoideicapitata differs from O. globiceps by producing smaller stromata, pyriform, larger perithecia and longer part-spores (Table 2) ( Kobayasi and Shimizu 1982). Ophiocordyceps forquignonii is distinct from O. globiceps in having a cylindrical fertile apex and oval secondary ascospores (Table 2) ( Saccardo 1891). Molecular data indicate that the new species has 26 bp in nrSSU and 89 bp in nrLSU that are different from O. forquignonii . Ophiocordyceps hemisphaerica is different from O. globiceps in having longer stomata, larger obpyriform perithecia, longer asci and longer fusoid part-spores ( Hyde et al. 2016). Ophiocordyceps lacrimoidis ( Diptera infected species) was not considered in our phylogenetic sampling as the DNA (ITS) sequence did not align well with other species, but its DNA sequence differed by 154 bp in the ITS region from the sequence of O. globiceps . However, Ophiocordyceps lacrimoidis is morphologically different from our new species in producing longer stipe, obpyriform, slightly curved perithecia, longer asci and longer part spores. Cordyceps muscicola was revised as Ophiocordyceps muscicola by Freire (2015), while it is different from O. globiceps in having longer stromata, larger pyriform perithecia, longer asci and longer part-spores ( Möller 1901, Freire 2015). We would like to introduce Ophiocordyceps globiceps as a new species based on the phylogenetic and morphological analyses.