Polystromomyces araneae Mongkolsamrit, Noisripoom, Sakolrak & Himaman, 2022

Mongkolsamrit, Suchada, Noisripoom, Wasana, Tasanathai, Kanoksri, Kobmoo, Noppol, Thanakitpipattana, Donnaya, Khonsanit, Artit, Petcharad, Booppa, Sakolrak, Baramee & Himaman, Winanda, 2022, Comprehensive treatise of Hevansia and three new genera Jenniferia, Parahevansia and Polystromomyces on spiders in Cordycipitaceae from Thailand, MycoKeys 91, pp. 113-149 : 113

Polystromomyces araneae Mongkolsamrit, Noisripoom, Sakolrak & Himaman sp. nov.

Fig. 8

Typification.

Thailand, Tak Province, Umphang Wildlife Sanctuary, 15°55'36.33"N, 98°45'12.15"E, on spider egg sac ( Araneidae sensu lato) attached to the underside of a dicot leaf, 6 December 2020, B. Sakolrak, MY12684 (BBH 49054, holotype), ex-type culture BCC 93301 isolated from ascospores.

Etymology.

From Latin, “aranea” refers to a spider host.

Description.

Hosts covered by dense pale yellow mycelium (162D). Sexual morph: Stromata stipitate, arising from the host, multiple, cylindrical at the base, slightly enlarged midway to the terminal stipe below the fertile head, moderate yellow (162A-B), 8-12 mm long, 1-3 mm broad. Fertile head disc-shaped, upper surface slightly convex, 3-4 × 2-3.5 mm. Perithecia completely immersed, narrowly ovoid, 1000-1400 × 200-350 µm, ostiole pale brownish-orange (165B). Asci cylindrical, 8-spored, 400-1000 µm long, 3.5-6 µm broad, with cap 2-5 µm thick. Ascospores hyaline, dissociating into 128 part-spores, cylindrical, 2-6 × 1-3 µm.

Culture characteristics.

Colonies on OA attaining a diam. of 8-10 mm in 21 d, mycelium sparse, white, reverse pale yellow (161C). Conidia forming on vegetative hyphae or by microcyclic conidiation, hyaline, clavate to cylindrical, 2-10 × 1-5 µm.

Colonies on PDA attaining a diam. of 8-10 mm in 20 d, mycelium sparse, white, reverse pale yellow (161C). Conidia forming on vegetative hyphae or by microcyclic conidiation, hyaline, clavate to cylindrical, 2-12 × 1-5 µm.

Host.

Spider egg sac.

Habitat.

Specimen was found on the underside of a dicot leaf of a forest plant.

Notes.

Based on natural specimens, Po. araneae closely resembles H. nelumboides and H. novoguineensis by producing fertile heads at the end of the stipes. The perithecia of these species are completely immersed. The ascospores of Po. araneae and H. nelumboides are filamentous, multiseptate ascospores disarticulating into part-spores, whereas H. novoguineensis produces filiform, whole ascospores. However, Po. araneae differs from H. nelumboides in the size of the perithecia. In Po. araneae , perithecia are larger than those reported for H. nelumboides (1000-1400 × 200-350 µm vs. 535-545 × 180-190 µm) (Table 2 ). Polystromomyces araneae produces microcycle conidiation from conidia on culture, while the microcyclic sporulation is often seen in discharged ascospores in Metarhizium phuwiangense Luangsa-ard, Mongkols., Himaman, Thanakitp. & Samson and Purpureomyces khaoyaiensis (Hywel-Jones) Luangsa-ard, Samson & Thanakitp ( Mongkolsamrit et al. 2020a).

Figures

Figure 8. Polystromomyces araneae a fungus on a spider egg sac (BBH 49054) b fertile heads c perithecia d asci e ascus tip f part-spores g, h colonies on OA at 21 days (g obverse, h reverse) i conidium formation from a hypha on OA j microcycle conidiation on OA k, l colonies on PDA at 21 days (k obverse, l reverse) m conidia formation from a hypha on PDA n microcycle conidiation on PDA. Scale bars: 10 mm (a); 3 mm (b); 200 µm (c, d); 10 µm (e, f, i, j, m, n).