Abstract
The karst regions of southwest China are rich in biodiversity and have critically threatened ecosystems, harboring unique species that could be new to science. During the investigations of arthropods associated-fungi, several fungal strains were collected. Among these, three new species, Conoideocrella tiankengensis sp. nov. (Clavicipitaceae), Ovicillium zunyiense sp. nov. (Bionectriaceae) and Trichothecium sinense sp. nov. (Myrotheciomycetaceae), isolated from a dead scale insect, larva and spider, respectively, were introduced as novel taxa, based on the morphological characteristics and DNA-based phylogenetic analyses. This is the first time that a species from Myrotheciomycetaceae is reported from the karst habitats. In addition, the genus Myrotheciomyces is treated as a synonym of Trichothecium based on the phylogenetic analysis, and the type species of the former is transferred to the latter genus.