Gibellula scorpioides Tasanathai, Khonsanit, Kuephadungphan & Luangsa-ard, 2020

Kuephadungphan, Wilawan, Tasanathai, Kanoksri, Petcharad, Booppa, Khonsanit, Artit, Stadler, Marc & Luangsa-ard, J. Jennifer, 2020, Phylogeny- and morphology-based recognition of new species in the spider-parasitic genus Gibellula (Hypocreales, Cordycipitaceae) from Thailand, MycoKeys 72, pp. 17-42 : 17

Gibellula scorpioides Tasanathai, Khonsanit, Kuephadungphan & Luangsa-ard sp. nov. Figure 5

Typification.

Thailand, Nakhon Ratchasima, Khao Yai National Park, Mo Sing To Nature Trail, 14°711'N, 101°421'E; on Portia sp. attached to the underside of unidentified dicot leaf; 1 June 2011; K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, A. Khonsanit, K. Sansatchanon, W. Noisripoom (Holotype no. BBH 31439, ex-type culture no. BCC 47975, isolated from ascospores and BCC 47976, isolated from conidia) GenBank (BCC 47976): ITS = MT477078, LSU = MT477066, TEF1 = MT503335, RPB1 = MT503325, RPB2 = MT503339.

Etymology.

Refers to the outer appearance of the fungus resembling the posture of a scorpion.

Description.

White to grayish- or brownish-white mycelial mat velvety, completely covering the spider host, firmly attaching the underside of living leaf by the mycelia covering its legs (Fig. 5a, b ). Synnema solitary, arising from the posterior of the host abdomen, cylindrical, consisting of a compact bundle of parallel hyphae, 15-20 mm long with blunt tip. Conidiophores arising laterally from synnema, stout, smooth, mostly biverticillate, 20-29(-30) × 4 μm (Fig. 5d ). Vesicles absent or hardly developed, bearing multiple metulae. Metulae obovoid, slightly broadening toward the base, (7-)9.5-12.5(-15) × (2-)3-5(-7) μm (Fig. 5e ). A number of phialides borne on each metula, broadly cylindrical, abruptly tapering toward the apex, forming thickened distinct short neck, (9-)10-12.5(-14) × (2-)2.5-3.5(-4) μm, each bearing a conidium (Fig. 5e ). Conidia fusiform, 5-7(-9) × (1.5-)2-3 μm (Fig. 5f ). Sexual morph occasionally present. Perithecia occurring on the mycelial mat covering the host legs, occasionally on synnema particularly at base, superficial, mostly arranged in groups, ovoid, reddish yellow or light honey-brown, one-third immersed in the loose network of mycelia, 750-836(-870) × 310-361(-380) μm (Fig. 5c ). Asci over 550 μm in length, (3-)4-5.5(-7) μm in width, ascus tip (4-)4.5-5 × 3-3.5(-4) μm (Fig. 5g, h ). Ascospores often breaking into part-spores. Part-spores bacilliform, (9-)10-15(-22) × 1.5-2 μm (Fig. 5i ). Granulomanus -like asexual morph absent.

Culture characteristics.

Colonies derived from conidia, on PDA slow-growing, attaining a diam of 1.5 ± 0.1 cm in 4 weeks at 25 °C, floccose, forming irregular margin, white, reverse cream, darkening toward center with age (Fig. 5l ). Sporulation occurring after 3-4 months with the absence of synnema, forming a group of conidiophores, grey and scatter. Conidiophores biverticillate. Vesicles absent or hardly developed. Metulae obovoid, (10-)11-14.5(-16) × 3-5.5(-7) μm, each bearing cylindrical phialides, (10-)11.5-14(-16) × 3-4 μm. Conidia fusiform, 5-6(-7) × 3-3.5(-4) μm.

Additional specimens examined. Thailand, Chumphon, Phato District, Phato Watershed Conservation and Management Unit; 9°784'N, 98°699'E; on Portia sp., underside of unidentified dicot leaf; 10 March 2011; K. Tasanathai, P. Srikitikulchai, A. Khonsanit, K. Sansatchanon, D. Thanakitpipattana (BBH 30499, BCC 47530). Nakhon Ratchasima, Khao Yai National Park, Mo Sing To Nature Trail; 14°711'N, 101°421'E; on Portia sp., underside of unidentified dicot leaf; 1 June 2011; K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, A. Khonsanit, K. Sansatchanon, W. Noisripoom (BBH 29669, BCC 43298).

Notes.

The morphology of G. scorpioides appeared to be very close to G clavulifera var. clavulifera ( Samson and Evans 1977), G clavulifera var. major ( Tzean et al. 1997) and G clavulifera var. alba ( Humber and Rombach 1987). The penicillate conidiophores were largely absent from the whip-like stroma in G clavulifera var. alba but distinctly present on a synnema of G. scorpioides . Based on a comparison of microscopic characteristics among G. scorpioides , varieties clavulifera , major and alba , the latter three were found to produce much longer conidiophores (up to 100 μm) than G. scorpioides (20-29(-30) × 4 μm) while the other characters such as metulae, phialides as well as conidia were considered to be not significantly different in both shape and size. Considering the presence of the torrubiella-like sexual morph, perithecia of G clavulifera var. alba were produced sparingly and separately on the host abdomen while those of G. scorpioides distinctly appeared in groups, only on the spider’s legs and basally on synnema. Nevertheless, an examination of additional specimens has led us to conclude that the sexual morph is not always present in G. scorpioides .

Figures

Figure 5. Gibellula scorpioides a fungus on a spider (BBH 29669) b fungus on a spider (BBH 31439) c perithecia (BBH 31439) d conidiophores arising on synnema (BBH 29669) e penicillate conidiophore (BBH 29669) f conidia (BBH 29669) g asci (BBH 31439) h ascus with apical apparatus (BBH 31439) i ascospores (BBH 31439) j penicillate conidiophore produced on PDA k conidia on PDA l colonies obverse and reverse on PDA at 25 ° C after 4 months. Scale bars: 500 μm (c); 50 μm (d, g); 20 μm (e, h-j); 10 μm (f, k).