Fungal pathogens occurring on Orthopterida in Thailand.

Two new fungal genera and six species occurring on insects in the orders Orthoptera and Phasmatodea (superorder Orthopterida) were discovered that are distributed across three families in the Hypocreales. Sixty-seven sequences generated in this study were used in a multi-locus phylogenetic study comprising SSU, LSU, TEF, RPB1 and RPB2 together with the nuclear intergenic region (IGR). These new taxa are introduced as Metarhizium gryllidicola, M. phasmatodeae, Neotorrubiella chinghridicola, Ophiocordyceps kobayasii, O. krachonicola and Petchia siamensis. Petchia siamensis shows resemblance to Cordyceps mantidicola by infecting egg cases (ootheca) of praying mantis (Mantidae) and having obovoid perithecial heads but differs in the size of its perithecia and ascospore shape. Two new species in the Metarhizium cluster belonging to the M. anisopliae complex are described that differ from known species with respect to phialide size, conidia and host. Neotorrubiella chinghridicola resembles Torrubiella in the absence of a stipe and can be distinguished by the production of whole ascospores, which are not commonly found in Torrubiella (except in Torrubiella hemipterigena, which produces multiseptate, whole ascospores). Ophiocordyceps krachonicola is pathogenic to mole crickets and shows resemblance to O. nigrella, O. ravenelii and O. barnesii in having darkly pigmented stromata. Ophiocordyceps kobayasii occurs on small crickets, and is the phylogenetic sister species of taxa in the 'sphecocephala' clade.