Samsoniella hymenopterorum W.H. Chen, Y.F. Han & Z.Q. Liang, 2020

Chen, Wan-Hao, Han, Yan-Feng, Liang, Jian-Dong, Tian, Wei-Yi & Liang, Zong-Qi, 2020, Morphological and phylogenetic characterisations reveal three new species of Samsoniella (Cordycipitaceae, Hypocreales) from Guizhou, China, MycoKeys 74, pp. 1-15 : 1

Samsoniella hymenopterorum W.H. Chen, Y.F. Han & Z.Q. Liang sp. nov. Fig. 4

Diagnosis.

Differs from Samsoniella inthanonensis and S. aurantia by having smaller, fusiform to ovoid conidia and a host in the family Vespidae .

Type.

China, Guizhou Province, Xishui County, at 28°29'56.70"N, 106°24'31.04"E, July 2018, Jiandong Liang, holotype GZAC A1952, ex-type culture GZAC A19522. Sequences from isolated strain A19522 have been deposited in GenBank with accession numbers: ITS = MN128224, RPB1 = MT642603, RPB2 = MT642604 and TEF = MN101588.

Description.

Colonies on PDA, 6.2-6.4 cm diam. in 14 d at 25 °C, white, consisting of a basal felt and cottony, floccose hyphal overgrowth, reverse yellowish. Prostrate hyphae smooth, septate, hyaline, 1.1-1.6 μm diam. Erect conidiophores usually arising from aerial hyphae, Isaria -like with phialides in whorls of three to four. Phialides 6.5-10.6 × 1.2-2.0 μm, with a cylindrical basal portion, tapering to a distinct neck. Conidia in chains, hyaline, fusiform to ovoid, 1-celled, 1.9-2.5 × 1.5-2.1 μm. Chlamydospores and synnemata not observed. Size and shape of phialides and conidia similar in culture and on natural substratum. Sexual state not observed.

Host.

Bee, family Vespidae .

Distribution.

Xishui County, Guizhou Province, China.

Etymology.

Referring to its insect host, order Hymenoptera .

Remarks.

Samsoniella hymenopterorum was identified as belonging to Samsoniella , based on the phylogenetic analyses (Fig. 1 ). Comparing with the typical characteristics of the three species (Table 2 ), S. hymenopterorum has a close relationship with S. inthanonensis by a having cylindrical basal in phialide and similar in size. However, it is distinguished from S. inthanonensis by having smaller, fusiform to ovoid conidia and a host in the family Vespidae . Based on combined dataset of ITS, RPB1, RPB2 and TEF sequences, S. hymenopterorum is phylogenetically close to S. aurantia and S. inthanonensis (Fig. 2 ). However, S. hymenopterorum has smaller fusiform to ovoid conidia and a different host.

Figures

Figure 1. Phylogenetic relationships of the genus Samsoniella in Cordycipitaceae, based on multigene dataset (ITS, RPB 1, RPB 2 and TEF). Statistical support values (≥ 50 % / 0.5) are shown at the nodes for ML bootstrap support / BI posterior probabilities.

Figure 2. Phylogenetic relationships between the genus Samsoniella and closely-related species, based on multigene dataset (ITS, RPB 1, RPB 2 and TEF). Statistical support values (≥ 50 % / 0.5) are shown at the nodes for ML bootstrap support / BI posterior probabilities.

Figure 4. Samsoniella hymenopterorum A infected insect (Hymenoptera) B, C top (B) and underside (C) of a colony cultured on PDA medium at 14 d D-H, J phialides and conidia in chains K conidiophore and phialides I conidia. Scale bars: 10 mm (B, C); 10 μm (D-K).