Elmidae, commonly known as riffle beetles, is a family of beetles in the superfamily Byrrhoidea described by John Curtis in 1830. Both adults and larvae are usually aquatic, living under rocks in fast-flowing shallow areas of streams, such as riffles, feeding on algae and biofilms. There are more than 150 genera and 1,500 described species in Elmidae. The oldest record of the group is Cretohypsilara from the Cenomanian aged Burmese amber.
Elminae is a subfamily of riffle beetles in the family Elmidae. There are at least 120 genera and more than 1,300 described species in Elminae.
Elmini is a tribe of riffle beetles in the family Elmidae. There are more than 90 genera and 1,200 described species in North America.
Optioservus was a genus of riffle beetles in the family Elmidae; as of 2021 it is a junior synonym of Heterlimnius. There were about 13 described species in Optioservus.
Bryelmis is a genus of riffle beetles in the family Elmidae. There are at least three described species in Bryelmis.
Oulimnius is a genus of riffle beetles in the family Elmidae. There are about 15 described species in Oulimnius.
Hexacylloepus is a genus of riffle beetles in the family Elmidae. There are about 19 described species in Hexacylloepus.
Heterlimnius dietrichi is a species of riffle beetles in the family Elmidae that occurs in the southeastern United States. It was formerly the only species in the genus Gonielmis.
Neoelmis is a genus of riffle beetles in the family Elmidae. There are more than 50 described species in Neoelmis.
Phanocerus is a genus of riffle beetles in the family Elmidae. There are about seven described species in Phanocerus.
Ordobrevia is a genus of riffle beetles in the family Elmidae. There are about 11 described species in Ordobrevia.
Zaitzevia is a genus of riffle beetles in the family Elmidae. There are about 19 described species in Zaitzevia. The genus is named after the Russian entomologist Filipp Zaitsev.
Neocylloepus is a genus of riffle beetles in the family Elmidae. There are about eight described species in Neocylloepus.
Atractelmis is a genus of riffle beetles in the family Elmidae. There is one described species in Atractelmis, A. wawona.
Promoresia is a genus of riffle beetles in the family Elmidae. There are at least two described species in Promoresia.
Ampumixis is a genus of riffle beetles in the family Elmidae. There is one described species in Ampumixis, A. dispar.
Cleptelmis is a genus of riffle beetles in the family Elmidae. There are at least two described species in Cleptelmis.
Huleechius is a genus of riffle beetles in the family Elmidae. There are at least two described species in Huleechius.
Larainae is a subfamily of riffle beetles in the family Elmidae. There are more than 20 genera and 160 described species in Larainae.
Macronychini is a tribe of riffle beetles in the family Elmidae. There are more than 20 genera and 80 described species in Macronychini.
