Large-flies
Guides
Mydidae
Mydas flies, Mydaid flies
Mydidae, or mydas flies, are a small cosmopolitan family of large to very large flies within the superfamily Asiloidea. With approximately 471 described species, they represent one of the most distinctive dipteran groups due to their exceptional size—Gauromydas heros is the largest known fly species—and their frequent mimicry of stinging hymenopterans, particularly spider wasps. Most species inhabit arid and semiarid regions globally. The family is poorly studied, with larval biology documented for only a handful of species.
Rhaphiomidinae
Rhaphiomidinae is a subfamily of mydid flies (Diptera: Mydidae) comprising the genus Rhaphiomidas and its close relatives. These are among the largest flies in North America, with adults reaching substantial body sizes. The group is notable for its extreme rarity, highly restricted geographic distributions, and brief adult activity periods concentrated in desert spring or fall seasons. Several species are of significant conservation concern due to habitat specialization on sand dune systems.