A phylogenetic assessment of Akanthomyces sensu lato in Cordycipitaceae (Hypocreales, Sordariomycetes): introduction of new genera, and the resurrection of Lecanicillium

Abstract

During entomopathogenic fungal surveys conducted in Thailand, 15 specimens tentatively classified under Akanthomyces sensu lato were identified. To gain a comprehensive understanding of their taxonomy, molecular phylogenies using combined LSU, TEF1, RPB1, and RPB2 sequence data, together with morphological examination of several Akanthomyces spp. from previous studies were conducted. The analyses revealed distinct clades representing independent lineages within the Cordycipitaceae. These clades were further characterized by different asexual morph types and the respective hosts they parasitize. In this context, we resurrected the genus Lecanicillium to accommodate 12 known species previously classified under Akanthomyces sensu lato, found on diverse hosts. We propose four new genera - Corniculantispora, Corpulentispora, Zarea, and Zouia - from species previously identified as Lecanicillium. Notably, certain Akanthomyces species associated with spiders and parasitic on Ophiocordyceps sinensis were reclassified into the new genera Arachnidicola and Kanoksria, respectively. Moreover, we introduce four novel species in Akanthomyces sensu stricto found across a diverse range of moth families: Ak. buriramensis, Ak. fusiformis, Ak. niveus, and Ak. phariformis. Additionally, we provide descriptions and illustrations of the sexual morph linked to Ak. laosensis and Ak. pseudonoctuidarum, along with a second type of synnemata seen in Ak. noctuidarum and Ak. pseudonoctuidarum. To assist with their identification, keys to the genera Akanthomyces, Arachnidicola, and Lecanicillium are provided, but should not be used to replace molecular identification. Citation: Khonsanit A, Thanakitpipattana D, Mongkolsamrit S, Kobmoo N, Phosrithong N, Samson RA, Crous PW, Luangsa-ard JJ (2024). A phylogenetic assessment of Akanthomyces sensu lato in Cordycipitaceae (Hypocreales, Sordariomycetes): introduction of new genera, and the resurrection of Lecanicillium. Fungal Systematics and Evolution 14: 271-305. doi: 10.3114/fuse.2024.14.17.

Keywords: Cordycipitaceae; molecular phylogeny; new taxa; taxonomy.

Fig. 1A, B.

RAxML tree of Akanthomyces, Arachnidicola, Lecanicillium and related genera in the Cordycipitaceae from a combined LSU, TEF1, RPB1 and RPB2 dataset. Number on the nodes are ML bootstrap values/Bayesian posterior probability above 70 %. Bold lines mean support for the three analyses were 100 %. In yellow boxes are species with lecanicillium-like asexual morphs. ^T = ex-type culture.

Fig. 1A, B.

RAxML tree of Akanthomyces, Arachnidicola, Lecanicillium and related genera in the Cordycipitaceae from a combined LSU, TEF1, RPB1 and RPB2 dataset. Number on the nodes are ML bootstrap values/Bayesian posterior probability above 70 %. Bold lines mean support for the three analyses were 100 %. In yellow boxes are species with lecanicillium-like asexual morphs. ^T = ex-type culture.

Fig. 2

Akanthomyces buriramensis (A, C, D, G–N. BBH30240; E, F. BBH30245). A, B. Fungus on adult moths. C, D. Perithecia. E. Asci. F. Asci and ascicaps. G. Ascospores. H. Part-spores. I. Phialides and conidia. J. Conidia. K. Colony obverse on OA in 20 d. L. Colony reverse on OA in 20 d. M. Colony obverse on PDA in 20 d. N. Colony reverse on PDA in 20 d. Scale bars: A, B, K–N = 10 mm; C = 1 mm; D = 100 μm; E–G = 20 μm; H, I, F–L = 10 μm; J = 5 μm.

Fig. 3

Akanthomyces fusiformis (BBH27326). A, B. Fungus on adult moths. C. Perithecia. D. Asci. E. Asci-caps. F. Part-spores. G, H. Phialides and conidia on host. I. Conidia on host. J. Colony obverse on OA in 20 d. K. Colony reverse on OA in 20 d. L. Colony obverse on PDA in 20 d. M. Colony reverse on PDA in 20 d. Scale bars: A, B = 1 mm; C, D = 100 μm; E−I = 10 μm; J−M = 10 mm.

Fig. 4

Akanthomyces niveus (A. BBH27294; B–K. BBH40778). A, B. Fungus on adult moths. C, D. Perithecia. E. Asci. F. Asci-caps. G. Part-spores. H. Colony obverse on OA in 20 d. I. Colony reverse on OA in 20 d. J. Colony obverse on PDA in 20 d. K. Colony reverse on PDA in 20 d. Scale bars: A = 1 mm; B = 5 mm; C = 500 μm; D = 100 μm; E = 200 μm; F = 20 μm, G = 10 μm; H−K = 10 mm.

Fig. 5

Akanthomyces phariformis (BBH30086). A. Fungus on adult moth. B, C. Perithecia. D. Asci. E. Part-spores. F. Colony obverse on OA in 20 d. G. Colony reverse on OA in 20 d. H. Colony obverse on PDA in 20 d. I. Colony reverse on PDA in 20 d. Scale bars: A = 5 mm; B = 1 mm; C = 100 μm; D = 20 μm; E = 10 μm; F−I = 10 mm.

Fig. 6

Akanthomyces laosensis (A, D, E, H–T. BBH31282; B, F, G. BBH32436; C. BBH37641). A–C. Fungus on adult moths. D, E. Perithecia. F. Asci and asci-caps. G. Ascospores. H. Synnema. I. Phialides and conidia on host. J. Conidia on host.. K. Colony obverse on OA in 20 d. L. Colony reverse on OA in 20 d. M, N. Phialides and conidia on OA. O. Conidia on OA. P. Colony obverse on PDA in 20 d. Q. Colony reverse on PDA in 20 d. R, S. Phialides and conidia on PDA. T. Conidia on PDA. Scale bars: A−C = 5 mm; D = 1 mm; E = 100 μm; F = 20 μm; G, I, J, M−O, R, T = 10 μm; H = 500 μm; K, L, P, Q = 10 mm; S = 50 μm.

Fig. 7

Akanthomyces noctuidarum (MY12641). A. Fungus on adult moth. B–D. Perithecia on stipe. E. Asci. F. Asci-caps. G, H. Ascospore. I. Short synnemata. J. Phialides and conidia from short synnemata. K. Conidia from short synnemata. L, M. Phialides and conidia from long synnemata. N. Conidia from long synnemata. O. Colony obverse on OA in 20 d. P. Colony reverse on OA in 20 d. Q. Colony obverse on PDA in 20 d. R. Colony reverse on PDA in 20 d. Scale bars: A, O−R = 10 mm; B, C = 1 mm; D = 200 μm; E, I = 100 μm; F−H, J, K, M, N = 10 μm; L = 50 μm.

Fig. 8

Akanthomyces pseudonoctuidarum (A, O–P. BBH38012; B. BBH30698; C, D. BBH37920; E–N. BBH40318). A–C. Fungus on adult moths. D, E. Perithecia. F. Asci. G. Asci-caps. H. Ascospore. I. Short synnemata, J. Phialides and conidia from short synnemata. K. Conidia from short synnemata. L. Long synnemata. M. Phialides and conidia from long synnemata, N. Conidia from long synnemata. O. Colony obverse on OA in 20 d. P. Colony reverse on OA in 20 d. Q. Colony obverse on PDA in 20 d. R. Colony reverse on PDA in 20 d. Scale bars: A, O−R = 10 mm; B, C = 5 mm; D, L = 500 μm; E, J = 200 μm; F = 50 μm; G, H, J, K, M, N = 10 μm.

Fig. 9

Types of conidiogenous cells and conidia of known and new genera. A. Akanthomyces aculeatus on host after Seifert et. al. (2011), plate 84C. B. Arachnidicola sulphurea on culture media adapted from fig. 3 in Mongkolsamrit et al. (2018). C. Corniculantispora psalliotae on culture media adapted from fig. 12 in Zare & Gams (2001). D. Corpulentispora magnispora on culture media adapted from fig. 30 in Zhang et al. (2020). E. Kanoksria zaquensis on culture media adapted from fig. 3 in Wang et al. (2023). F. Lecanicillium lecanii on culture media adapted from fig. 3 in Zare & Gams (2001). G. Zarea fungicola on culture media adapted from fig. 3 in Zare & Gams (2008). H. Zouia cauligalbarum on culture media adapted from fig. 3 in Zhou et al. (2018). Line drawings by P. Wongpitakchai (B–E, G–H).