Previously, only two species of Hercostomus Loew were known to occur in Inner Mongolia. Here two species from Inner Mongolia are described as new to science, namely Hercostomuschifengensis sp. nov. and Hercostomustriangulatus sp. nov. Three new records of Hercostomus in Inner Mongolia are added. A key to the species of Hercostomus in Inner Mongolia is provided.
Keywords: Identification key; long-legged flies; new records; taxonomy.
Xingyang Qian, Ning Wang, Ding Yang.