Hidden species behind Ophiocordyceps ( Ophiocordycipitaceae , Hypocreales ) on termites: four new species from Thailand

Four new species of Ophiocordyceps pathogenic to termites, Ophiocordyceps fusiformis , O . globosa , O . isopterae and O . radiciformis , were collected from community forests and described based on morphological characters and molecular phylogenetic data. Ophiocordyceps globosa has pseudo-immersed perithecia and globose conidia, while O. fusiformis , O. isopterae and O. radiciformis share similarities of having ovoid superficial perithecia, filiform asci, and filiform, whole, septate ascospores but differ in their sizes. Ophiocordyceps radiciformis possesses the largest size of all the aforementioned characters followed by O. fusiformis and O. isopterae , respectively. Ophiocordyceps fusiformis produces Hymenostilbe -like asexual morph and O. globosa , O. isopterae and O. radiciformis produce Hirsutella -like asexual morph. The phylogenetic analyses based on the ITS rDNA barcode and 4-gene dataset comprising LSU, TEF1 , RPB1 and RPB2 supported these four new species in Ophiocordyceps .