Samsoniella sapaensis H. Yu bis, Y. Wang & Z.Q. Wang, 2023

Wang, Yao, Wang, Zhi-Qin, Thanarut, Chinnapan, Dao, Van-Minh, Wang, Yuan-Bing & Yu, Hong, 2023, Phylogeny and species delimitations in the economically, medically, and ecologically important genus Samsoniella (Cordycipitaceae, Hypocreales), MycoKeys 99, pp. 227-250 : 227

Samsoniella sapaensis H. Yu bis, Y. Wang & Z.Q. Wang sp. nov.

Fig. 6

Etymology.

Named after the location Sa Pa District where the species was collected.

Type.

Vietnam, Lao Cai Province, Sa Pa District, Hoang Lien National Park (22°19′30″N, 103°46′50″E, 2178 m above sea level), on a larva of Lepidoptera buried in soil, 26 October 2017, collected by Hong Yu (holotype: YHH 873; ex-type living culture: YFCC 873) .

Description.

Teleomorph: Stromata arising from the whole body of lepidopteran pupae or larvae, gregarious, generally unbranched, up to 22-38 mm long. Stipes fleshly, flexuous, yellowish to orange, cylindrical to clavate, 7.5-14.5 × 0.7-4.6 mm. Fertile parts yellowish to reddish orange, clavate, lateral side usually have a longitudinal section without producing perithecia, 1.5-21.3 × 1.0-2.8 mm. Perithecia crowded, superficial, narrowly ovoid to fusiform, 383.2-412.1 × 125.4-156.9 µm. Asci cylindrical, hyaline, 282.5-444.5 × 2.6-3.9 µm, with a hemispheric apical cap of 1.8-2.2 × 2.6-3.0 µm. Ascospores not observed. Anamorph: Synnemata arising from lepidopteran insects. Synnemata flexuous, irregularly branched, white or pale orange, 9-58 × 0.2-1.6 mm, Isaria -like morph producing a mass of conidia at the branches of synnemata, powdery and floccose. Colonies on PDA moderately fast-growing, 36-40 mm diameter in 14 days at 25 °C, white to pale pink, cottony, sporulating abundantly, reverse yellow to orange. Hyphae smooth-walled, branched, septate, hyaline, 1.0-1.9 µm wide. Conidiophores smooth-walled, cylindrical, solitary or verticillate, 6.5-17.5 × 1.0-1.6 µm. Phialides verticillate, usually in whorls of two to three, or solitary on hyphae, 2.8-7.6 µm long, basal portion cylindrical to narrowly lageniform, tapering gradually or abruptly toward the apex, from 0.8-1.5 µm wide (base) to 0.6-0.9 µm wide (apex). Conidia smooth and hyaline, fusiform or oval, one-celled, 1.2-1.5 × 0.8-1.0 µm, often in chains. Size and shape of phialides and conidia similar in culture and on natural substratum.

Distribution.

At present, known only in Sa Pa District, Lao Cai Province, Vietnam.

Additional materials examined.

Vietnam, Lao Cai Province, Sa Pa District (22°21′4″N, 103°46′29″E, 1931 m above sea level), on a pupa of Limacodidae in a cocoon buried in soil, 31 October 2016, collected by Hong Yu (YHH 872; living culture: YFCC 872) . Vietnam, Lao Cai Province, Sa Pa District, Hoang Lien National Park (22°19′30″N, 103°46′50″E, 2178 m above sea level), on larvae of Lepidoptera buried in soil, 26 October 2017, collected by Yuan-Bing Wang (YHH 900-YHH 906) .

Commentary.

Samsoniella sapaensis was identified as belonging to Samsoniella based on the phylogenetic analyses and was shown to resolve closely to S. haniana (Fig. 2 ). Morphologically, S. sapaensis is similar to S. haniana in sharing Isaria -like asexual conidiogenous structure which produces phialides with cylindrical to narrowly lageniform basal portion, fusiform or oval conidia ( Wang et al. 2022). However, two samples of S. sapaensis were clustered together and formed a separate clade from S. haniana with strong statistical support (BI posterior probabilities = 1, ML bootstrap = 100%). Our morphological observation revealed some differences between them. Phialides on PDA of S. sapaensis (2.8-7.6 µm) are shorter than those of S. haniana (5.4-12.1 μm). Furthermore, conidia on PDA of S. sapaensis (1.2-1.5 × 0.8-1.0 μm) are smaller than those of S. haniana (2.3-3.7 × 1.2-2.8 μm).

Figures

Figure 2. Phylogenetic tree of Samsoniella based on Bayesian inference and Maximum Likelihood analyses of a 4 - locus (5 P _ TEF, 3 P _ TEF, RPB 1 and MCM 7) dataset. No significant differences in topology are observed between BI and ML (IQ-TREE) phylogenies. Numbers at the branches indicate support values (BI-PP / RAxML-BS / IQ-TREE-BS) above 0.7 / 70 % / 70 %. Isolates in bold type are those analyzed in this study.

Figure 6. Samsoniella sapaensis A stromata of fungus arising from lepidopteran larva B, C stromata and synnemata arising from lepidopteran insects D synnemata of fungus E, F perithecia G, H asci I, J colony as obversed and its backside on PDA K-M conidiophores, phialides and conidia on PDA N conidia on PDA. Scale bars: 10 mm (A, C); 5 mm (B); 20 mm (D); 100 µm (E, F, G); 50 µm (H); 20 mm (I); 30 mm (J); 5 µm (K, N); 10 µm (L, M).