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.