Akanthomyces xixiuensis X. C. Peng & T. C. Wen, sp. nov.

Index Fungorum number: IF 900124; Mycobank number: MB 900124; Facesofungi number: FoF 13898; Figs. 1, 2

Etymology – xixiuensis (Lat.) referring to the collecting site “Xixiu District”.

Holotype – HKAS 125851.

Asexual morph: The host is ca. 14 mm long, moth (Lepidoptera). Several synnemata arising from adult of insect host, cylindrical, yellowish, 2‒6.5 mm long and 0.2‒0.7 mm wide. Phialides 6‒27×2‒4 µm (x̅=12.4×3.0 μm, n=15), cylindrical to ellipsoidal with papillate end. Conidia smooth-walled, fusoid to ovoid, 3.5‒5.6 × 2.2‒3.2 µm (x̅=4.3×2.6 μm, n=15).

Culture characteristics – Colonies on PDA, attaining a diameter of 17‒23 mm within 14 d at 20 ℃, dense, cottony, yellowish to white, reverse pale yellow. Mycelium smooth, branched, hyaline, 0.7‒4.8 μm diam. Conidia and reproductive structures not observed.

Habitat and distribution – The new species grow on the pine needle litter of mixed forest, and is currently only found in China.

Material examined – China, Guizhou Province, Xixiu District, 26°09′13.38′′ N, 106°05′13.19′′ E, 1293 m alt., on moth (Lepidoptera), 17 August 2021, X. C. Peng, XX21081764 (HKAS 125851, holotype); ex-type living culture XX21081764).

GenBank numbers – HKAS 125851: ITS= OP693461; SSU = OP693479; LSU = OP693481; TEF= OP838888; RPB1 = OP838890; RPB2 = OP838892. XX21081764: ITS = OP693460; SSU= OP693478; LSU = OP693480; TEF=OP838887; RPB1=OP838889; RPB2=OP838891.

Notes – Akanthomyces xixiuensis is characterized by gregarious synnemate with tapering gradually toward the apex, unbranched, obclavate, and yellowish. Two samples of Akanthomyces xixiuensis group together with strong statistical support (100/1), and form a separate clade at the basal portion of the Akanthomyces lineage. Akanthomyces xixiuensis is morphological similar to A. aculeatus, A. pyralidarum, and A. tortricidarum, and the host is Lepidoptera. However, the new species differs from Akanthomyces aculeatus in having shorter and wider synnemate, and fusoid conidia (Mains 1950), Akanthomyces tortricidarum has two kinds of structures of the synnemate, phialides, and conidia (Aini et al. 2020), while the asexual state of the Akanthomyces
pyralidarum is undetermined (Aini et al. 2020).

Figure 1 – Akanthomyces xixiuensis (HKAS 125851, holotype) a Habitat. b Fungus on the host. c-f Phialides from synnema. g, h Conidia. i, j Culture on PDA, lower surface (i) and upper surface (j). Scale bars: b=2 mm, c-f=10 µm, g=5 µm, h=2 µm, i, j=1 cm

Figure 2 – Phylogram generated from maximum likelihood analysis based on combined ITS, SSU, LSU, TEF, RPB1 and RPB2 sequence data representing Cordycipitaceae in Hypocreales. One hundred and four strains are included in the combined analyses which comprised 4633 characters (519 for ITS, 947 for SSU, 774 for LSU, 877 for TEF, 678 for RPB1 and 840 for RPB2) after alignment. Purpureocillium lilacinum CBS 431.87 and Purpureocillium lilacinum CBS 284.36 in Ophiocordycipitaceae were used as the outgroup taxa. The best scoring RAxML tree with a final likelihood value of − 44,136.925268 is presented. Estimated base frequencies were as follows: A=0.244444, C=0.269605, G=0.267391, T=0.218561; substitution rates: AC=1.445523, AG=3.809695, AT=0.889234, CG=0.984428, CT=8.185559, GT=1.000000; gamma distribution
shape parameter α=0.543314. Bootstrap support values for ML equal to or greater than 60 are given above the nodes (left side). Bayesian posterior probabilities (BYPP) equal to or greater than 0.7 are given above the nodes (right side). Bold black dots mean support for the two analyses were 100 and 1. Ex-type strains are in bold and newly generated sequences are in blue