Abstract
Ophiocordyceps is a heterogeneous, species-rich genus in the order Hypocreales (Sordariomycetes, Ascomycota) that includes invertebrate-pathogenic taxa. In this study, seven new species in Ophiocordyceps producing superficial perithecia infecting various insect hosts (Lepidoptera, Hemiptera) are described from Thailand - Ophiocordyceps brunneinigra, O. brunneiperitheciata, O. geometridicola, O. multiperitheciata, O. pauciovoperitheciata, O. pseudoacicularis and O. spataforae. Phylogenetic analyses based on multigene loci comprising the large subunit of the ribosomal DNA (LSU), partial sequences of elongation factor 1-alpha (TEF) and the largest and second largest subunit of the RNA polymerase (RPB1, PRB2) strongly support these new species of Ophiocordyceps in the Ophiocordycipitaceae. They differ from species previously described species Ophiocordyceps acicularis, O. atewensis, O. cochlidiicola, and O. crinalis, in the shape and sizes of distinguishing characters such as perithecia, ascospores and conidia. We also report a new record of O. macroacicularis in Thailand.