Molecular phylogeny and morphology reveal cryptic species in Blackwellomyces and Cordyceps (Cordycipitaceae) from Thailand

Nine species in Cordyceps sensu lato producing orange to red stromata were discovered during diversity surveys of arthropod-pathogenic fungi in Thailand. The phylogenetic analyses of combined ITS, LSU, RPB1, RPB2 and TEF1 sequence data indicated four novel species belonging to Blackwellomyces and five novel species of Cordyceps. All Blackwellomyces species produce filiform ascospores with septations. Blackwellomyces aurantiacus and Blackwellomyces roseostromatus occur on lepidopteran larvae, and both species produce an Evlachovaea-like conidial arrangement of the anamorph and produce a red pigment that diffuses across agar medium. Blackwellomyces calendulinus and Blackwellomyces minutus are found on coleopteran larvae producing Acremonium-like and Mariannaea-like conidial arrangements of their anamorphs and do not produce any pigment. Novel members of Cordyceps include the species Cordyceps brevistroma, Cordyceps inthanonensis, Cordyceps neopruinosa, and Cordyceps parvistroma that are pathogenic on lepidopteran larvae and cocoons, whereas C. araneae is pathogenic on spiders. All Cordyceps species produce bola-shaped, whole ascospores, except for C. inthanonensis that produces ascospores dissociating into part-spores. A common feature of the novel Cordyceps species presented herein is the production of Evlachovaea-like or Mariannaea-like conidial arrangement of the anamorphs.