RESUMEN
Bat flies are obligate ectoparasitic dipterans that are highly specialised to bats and have apomorphic characteristics, such as absent or reduced wings, and specialised legs and claws, which contribute to their survival. They are often associated with fungi and harbour a fungal diversity that is still poorly understood. Fungi were found in association with the bat flies in a cave of the Caatinga dry forest in Brazil. In total, 43% of the captured bat flies were associated with fungi. Seventy-six flies were collected. DNA sequence analyses of 39 isolates showed that the isolates belonged to 13 species within nine genera, with 38 isolates belonging to Ascomycota and one isolate to Basidiomycota, and Aspergillus was the most frequently isolated genus. Most of the genera found have also been isolated from bat bodies and other substrates/hosts in caves in different regions of the world. Based on morphological and multi-locus phylogenetic analyses, two new species of Ascomycota were described: Allophoma brasiliensis sp. nov. and Pyrenochaetopsis cecavii sp. nov.