Systematic-revision
Guides
Symmerus
Symmerus is a Holarctic genus of fungus gnats in the family Ditomyiidae (Diptera). The genus comprises approximately 16 described species distributed across the northern hemisphere, with records from Europe, North America, and Asia. A systematic revision recognized two subgenera: Symmerus s. str. and Psilosymmerus, the latter established with S. coqulus as type species. The genus has been subject to phylogenetic analysis using Hennig's phylogenetic systematics, with transantarctic relationships documented in the related genus Australosymmerus.