Gibellula pigmentosinum Tasanathai, 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 pigmentosinum Tasanathai, Kuephadungphan & Luangsa-ard sp. nov. Figure 4

Typification.

Thailand. Nakhon Ratchasima, Khao Yai National Park, Mo Sing To Nature Trail; 14°711'N, 101°421'E; on Storenomorpha sp., attached to underside of unidentified dicot leaf; 10 February 2010; K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, T. Chohmee, R. Ridkaew, A. Khonsanit (Holotype no. BBH 28509, ex-type culture no. BCC 41203, isolated from ascospores and BCC 41204, isolated from conidia). GenBank (BCC 41203): ITS = MT477071, TEF1 = MT503330, RPB1 = MT503323.

Etymology.

Refers to the capability of the fungus to produce pigmentosins.

Description.

Spider host completely covered by white to yellowish-white mycelial mat. Synnemata solitary or in pairs, cylindrical, white, becoming yellowish-white at the base (Fig. 4a ). Conidiophores arising along the entire length of the outer hyphae of synnemata and from the mycelia covering the host, crowded, smooth to verrucose, (55-)97.5-170(-226) × (5-)7-10(-12.5) µm, narrowing to a slender apex, and terminating in a swollen vesicle, metulae, phialides bearing conidia, forming a spherical conidial head (Fig. 4a, f ). Conidial heads (25-)30-39(-45) µm diam (Fig. 4g ). Vesicles mostly globose, (4.5-)5.5-9(-10) µm diam (Fig. 4g ). Metulae borne on a vesicle, broadly obovoid, (5.5-)6-8(-10) × (3-)4-6(-7.5) µm (Fig. 4g ), bearing phialides. Phialides obovoid to clavate, with a distinct short neck, (5-)5.5-8(-9) × 2-3(-4.5) µm (Fig. 4g ). Conidia produced on a phialide, obovoid with an acute apex, (2.5-)3.5-5(-5.5) × 1-2(-3) µm (Fig. 4h ). Perithecia produced on the mycelial mat on the head and body of the spider, scattered, superficial with loose mycelia covering only the bottom one-fourth of the perithecium, ovoid, reddish-yellow, (790-)882-1,117(-1,150) × 300-443(-475) μm (Fig. 4a, b ). Asci cylindrical, 700-750 μm long, (4.5-)5-6(-7) μm wide, ascus cap (4-)5.5-6.5(-7) × 3.5-4(-5.5) μm (Fig. 4c ). Ascospores filiform, multiseptate, arranged in parallel rows, (666-)670-727(-730) × 2-3 μm, often breaking into 128 part-spores (Fig. 4d ). Part-spores bacilliform with apices rounded, (3.5-)4-7(-9) × 1-1.5(-3) μm (Fig. 4e ). Granulomanus -like asexual morph occasionally present, forming irregularly branched hyphae bearing mono- or polyblastic phialides. Phialides irregularly in shape, mostly smooth, with one or more conspicuous denticles. A conidium borne on each denticle, long, filiform, (16-)16.5-21.5(-22.5) × 1-1.5 μm (Fig. 4i ).

Culture characteristics.

Colonies derived from ascospores, on PDA slow-growing, attaining a diam of 1.5 ± 0.2 cm in 4 weeks at 25 °C, white, floccose; reverse light brown, darkening with age toward center (Fig. 4j ). Sporulation not observed.

Additional specimens examined. Thailand, Nakhon Ratchasima, Khao Yai National Park, Mo Sing To Nature Trail; 14°711'N, 101°421'E; on Storenomorpha sp., underside of unidentified dicot leaf; 13 August 2009; K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, T. Chohmee, R. Ridkaew (BBH 26516, BCC 38246 and BCC 38955); on Araneida , underside of unidentified dicot leaf; 11 September 2009; K. Tasanathai, P. Srikitikulchai, S. Mongkolsamrit, T. Chohmee, R. Ridkaew (BBH 27081, BCC 39707 and BCC 39708); on Storenomorpha sp., underside of unidentified dicot leaf; 7 April 2010; K. Tasanathai, S. Mongkolsamrit, T. Chohmee, A. Khonsanit, R. Ridkaew (BBH 28533, BCC 41870 and BCC 41871).

Notes.

Gibellula pigmentosinum shares similarity with G pulchra ( Mains 1950) in producing cylindric, yellowish white synnemata bearing aspergillate conidiophores with fusoid-ellipsoid conidia and superficial, reddish brown, ovoid perithecia containing bacilliform part-ascospores. The synnemata in G pulchra are more copious and sometimes more violaceous than in G. pigmentosinum . Remarkably, G. pigmentosinum distinctly differs from G pulchra in having a granulomanus-like conidial state.

Figures

Figure 4. Gibellula pigmentosinum a fungus on spider (BBH 28509); b perithecia; c an ascus with an apical apparatus; d ascospore; e part-spores; f conidiophores; g conidial heads; h conidia; i granulomanus-like asexual morph; j colonies obverse and reverse on PDA at 25 ° C after 28 days. Scale bars: 1 mm (b); 500 μm (d); 100 μm (f); 50 μm (g); 20 μm (c, i); 10 μm (e, h).