Disentangling cryptic species with isaria-like morphs in Cordycipitaceae

ABSTRACT

A new genus and eight new species, all with isaria-like phialides, are described in Cordycipitaceae from Thailand. The new genus, Samsoniella, is segregated from Akanthomyces based on morphological and molecular evidence. Samsoniella differs from Akanthomyces 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 Paecilomyces farinosus (Isaria farinosa), and CBS 262.58, originally identified as Penicillium alboaurantium, respectively, is made in Samsoniella. Two new species, Samsoniella aurantia and S. inthanonensis, are described from lepidopteran larvae. Two new species of Cordyceps, C. blackwelliae and C. lepidopterorum, 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 Cordyceps javanica (= Isaria javanica) on lepidopteran larvae. Four new species, Akanthomyces kanyawimiae, A. sulphureus, A. thailandicus, and A. waltergamsii, were pathogenic on spiders, with some strains of A. kanyawimiae also found on unidentified insect larvae. These four species of Akanthomyces occur on the underside of leaves and produce white to cream white powdery conidia, whereas S. aurantia and S. inthanonensis were found in leaf litter and produce bright orange stromata and synnemata with white conidia. Another new combination, Akanthomyces ryukyuensis, 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 (TEF1), and the genes for RNA polymerase II largest (RPB1) and second-largest (RPB2) subunits strongly support the delimitation of these new species of Cordyceps, Akanthomyces, and in a new genus Samsoniella in Cordycipitaceae.

KEYWORDS:

• Akanthomyces
• Cordyceps
• Hypocreales
• Isaria
• Samsoniella
• taxonomy
• 11 new taxa

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Corrigendum

ACKNOWLEDGMENTS

The authors would like to thank Prof. Morakot Tanticharoen, Drs. Kanyawim Kirtikara, Lily Eurwilaichitr, and Supawadee Ingsriswang, and Ms. Rungsima Tantalakha for their support of the program Biodiversity Studies of Entomopathogenic Fungi in Thailand. We are grateful to Ms. Jirawan Kumsao (Chief of Research and Development Division Ban Hua Thung Village) for her kind cooperation. We thank Khun Suchin, the owner of the orchard, for his kind cooperation, as well as Dr. Sasitorn Hasin for insect host identification. We also thank Mr. Artit Khonsanit and Mr. S. Wongkanoun for photos of the natural samples. We are indebted to the Department of National Parks, Wildlife and Plant Conservation for their cooperation and support of our project research. We are grateful to the two anonymous reviewers and editors whose suggestions and comments helped improve the manuscript.

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Funding

This study was supported by the National Science and Technology Development Agency, Cluster and Program Management Office (grant no. P15-51452).