Biodiversity of Metarhizium From Korea and Pathogenicity Screening of Two Unrecorded Species Metarhizium lepidiotae and Metarhizium robertsii

This study analyzed the biodiversity of entomopathogenic fungi Metarhizium species isolated from Korean soil samples and insect cadavers. Morphological characteristics and molecular phylogenetic analyses were used to analyze Korean species diversity. Concatenated datasets of three genes, the translation elongation factor 1-a (TEF), DNA-directed RNA polymerase II (RPB1), and internal transcribed spacer (ITS), were used for phylogenetic analyses using the following three methods: maximum parsimony (MP), Bayesian inference (BI), and maximum likelihood (ML). In addition, the TEF gene was used for molecular identification. As a result, five species were identified: Metarhizium pinghaense, Metarhizium robertsii, Metarhizium rileyi, Metarhizium pemphigi, and Metarhizium lepidiotae. In particular, M. robertsii and M. lepidiotae were identified in Korea for the first time in this study. The TEF gene was useful for species identification of Metarhizium species especially M. pinghaense and Metarhizium anisopliae. Among these fungi, only M. lepidiotae showed high pathogenicity against cotton aphids (Aphis gossypii) and lesser mealworm (Alphitobius diaperinus).