Disentangling cryptic species with isaria-like morphs in Cordycipitaceae

A new genus and eight new species, all with isaria-like phialides, are described in Cordycipitaceae from Thailand. The new genus, <i>Samsoniella</i>, is segregated from <i>Akanthomyces</i> based on morphological and molecular evidence. <i>Samsoniella</i> differs from <i>Akanthomyces</i> in producing orange cylindrical to clavate stromata with superficial perithecia and orange conidiophores with isaria-like phialides and white to cream conidia. A new combination for CBS 240.32, originally identified as <i>Paecilomyces farinosus</i> (<i>Isaria farinosa</i>), and CBS 262.58, originally identified as <i>Penicillium alboaurantium</i>, respectively, is made in <i>Samsoniella</i>. Two new species, <i>Samsoniella aurantia</i> and <i>S. inthanonensis</i>, are described from lepidopteran larvae. Two new species of <i>Cordyceps, C. blackwelliae</i> and <i>C. lepidopterorum</i>, were also found on coleopteran and lepidopteran larvae. Both produce isaria-like morphs with globose phialides and attenuated long necks and white mycelium in culture. The authors established a sexual-asexual link for <i>Cordyceps javanica</i> (= <i>Isaria javanica</i>) on lepidopteran larvae. Four new species, <i>Akanthomyces kanyawimiae, A. sulphureus, A. thailandicus</i>, and <i>A. waltergamsii</i>, were pathogenic on spiders, with some strains of <i>A. kanyawimiae</i> also found on unidentified insect larvae. These four species of <i>Akanthomyces</i> occur on the underside of leaves and produce white to cream white powdery conidia, whereas <i>S. aurantia</i> and <i>S. inthanonensis</i> were found in leaf litter and produce bright orange stromata and synnemata with white conidia. Another new combination, <i>Akanthomyces ryukyuensis</i>, is proposed. Phylogenetic analyses based on a combined data set comprising the nuc rDNA region encompassing the internal transcribed spacers 1 and 2 along with the 5.8S rDNA (ITS), nuc 28S rDNA (28S), partial sequences of translation elongation factor 1-α gene (<i>TEF1</i>), and the genes for RNA polymerase II largest (<i>RPB1</i>) and second-largest (<i>RPB2</i>) subunits strongly support the delimitation of these new species of <i>Cordyceps, Akanthomyces</i>, and in a new genus <i>Samsoniella</i> in Cordycipitaceae.