Rhaphiomidas

The mydid fly genus Rhaphiomidas contains fewer than 30 species/subspecies, all of them occurring in the desert regions of the southwestern United States and adjacent portions of northwestern Mexico. The adults are most commonly encountered in sand dune areas, and are typically only active for a few weeks each year, either in the spring or the fall; in some cases, more than one species can occur in the same dune system, but they are allochronic, each flying in different seasons. Almost nothing is known about their biology, though eggs or early instar larvae of some species are laid on the soil