The superfamily Byrrhoidea includes a number of beetle families, most of which are either aquatic or associated with a semi-aquatic habitat. Other than the superfamily Hydrophiloidea, the majority of the remaining Polyphagan beetles which are aquatic are in this superfamily. These families were traditionally grouped as a separate superfamily, the Dryopoidea, which is no longer recognized. The vast majority of species are small (<1 cm), and predominantly dull brown or black.
|Pill beetles and allies|
Byrrhidae - pill beetles
Byrrhidae, the pill beetles, is a family of beetles in the superfamily Byrrhoidea. These beetles are common in the forests of the Northern Hemisphere. They feed mainly on moss. Populations increase after wildfires.There are about 450 species in this family.Genera include:
Callirhipidae is a family of beetles in the superfamily Byrrhoidea. It was described by Emden in 1924.Chelonariidae
Chelonariidae or turtle beetles is a family of beetles in the superfamily Byrrhoidea. It was described by Blanchard in 1845.Cneoglossidae
Cneoglossidae is a family of beetles, in the large suborder Polyphaga.
It contains nine species in a single genus:
Genus Cneoglossa Guérin-Méneville, 1843
Cneoglossa brevis Champion, 1897
Cneoglossa collaris Guérin-Méneville, 1849
Cneoglossa elongata Pic, 1916
Cneoglossa gournellei Pic, 1916
Cneoglossa lampyroides Champion, 1897
Cneoglossa longipennis (Pic, 1915)
Cneoglossa peruviana Pic, 1916
Cneoglossa rufifrons Pic, 1916
Cneoglossa testacericollis Pic, 1916Dryopidae
Dryopidae is a family of beetles, commonly named long-toed water beetles, in the superfamily Byrrhoidea. It was described by Gustaf Johan Billberg in 1820.Elateriformia
Elateriformia is an infraorder of polyphagan beetles. The two largest families in this group are buprestids, of which there are around 15,000 described species, and click beetles, of which there are around 10,000 described species.
The infraorder consists of five superfamilies :
Buprestoidea — the metallic wood-boring beetles
Byrrhoidea — families including long-toed water beetles, moss beetles and mud-loving beetles
Elateroidea — including the click beetles and soldier beetles
Elmidae, commonly known as riffle beetles, is a family of beetles in the superfamily Byrrhoidea described by John Curtis in 1830. There are more than 150 genera and 1,500 described species in Elmidae.Eulichadidae
Eulichadidae is a family of forest stream beetles in the order Coleoptera. There are about 5 genera and more than 40 described species in Eulichadidae.Helichus
Beetles of the genus Helichus are found worldwide apart from in Australia and Antarctica. Adults reach 1–8 millimetres (0.04–0.31 in) long and live in aquatic or riparian environments. The larvae are land-dwelling which may be unique in water living insects.Heterelmis
Heterelmis is a genus of beetles in the riffle beetle family Elmidae.Species include:
Heterelmis vulnerataHeterelmis stephani
Heterelmis stephani was a rare species of aquatic beetle known by the common name Stephan's riffle beetle. It was endemic to Arizona in the United States, where it occurred in the Santa Rita Mountains before being declared presumed extinct. It was brown in color with small black dots on its wings.Heteroceridae
The Heteroceridae, or variegated mud-loving beetles, are a widespread and relatively common family of beetles. They occur on every continent except for Antarctica.
Around two hundred and fifty species of heterocerids are known to occur worldwide. They are most diverse in tropical and sub-tropical regions. Currently, 87 species are known from the New World, including 34 from the United States.Variegated mud-loving beetles are brownish, dorsoventrally depressed shoreline inhabitants. Superficially they resemble small scarabs with the tibiae armed with rows of robust flattened spines. The beetles live in shallow tunnels that they dig in damp soil around fresh and brackish lakes, rivers and ponds. Heterocerids have been reported to live in intertidal sandflats, making them one of the few groups of coleopterans with marine representatives. The uniform way in which they live seems to have favored the conservation of a "phenotypical uniformity in external morphology". Consequently, it is often quite difficult to identify one of these beetles to species relying on external morphology alone. Therefore, male genitalia are most often relied upon to identify species. Although few studies have been conducted on their ecology, heterocerids have been shown to be an important prey group for passerine birds and frogs (Schmidt et al., 2003; Turner, 1959), and they appear to play a significant role in seed dispersal and burial in sandy soils.In the most recent revision of the family, Francisco Pacheco (1964) split the heterocerids into 20 different genera, erecting 17 new generic names based almost entirely on the features of male genitalia. Most systematists have found Pacheco’s system complex and impractical because the ratio of genera to species is high and females cannot be identified. Consequently, his generic circumscriptions have not been widely accepted.Limnichidae
Limnichidae is a family of minute marsh-loving beetles in the order Coleoptera. There are at least 30 genera and 350 described species in Limnichidae.Lutrochidae
Lutrochidae is a family of water beetles sometimes known as "travertine beetles", since in North America they are common in springs and streams depositing travertine.
They are distinguished by their ovate bodies, 2–6 mm long and yellowish in color, and short antennae in which the first two antennomeres are longer than the others. The larvae are elongate, 4–10 mm in length, with short but well-developed legs.
Both adults and larvae are found in fast-moving water, feeding on algae and wood.
The family is known only from the New World, and consists of 12 species in a single genus Lutrochus, although it is likely that the genus will be divided upon review. The genus has been variously classified under Dryopidae and Limnichidae, but has more recently been given its own family.Podabrocephalus
Podabrocephalus is the only genus in the beetle family Podabrocephalidae. Its only species is Podabrocephalus sinuaticollis.Polyphaga
Polyphaga is the largest and most diverse suborder of beetles. It comprises 144 families in 16 superfamilies, and displays an enormous variety of specialization and adaptation, with over 300,000 described species, or approximately 90% of the beetle species so far discovered.
Key characteristics of Polyphaga are that the hind coxa (base of the leg), does not divide the first and second abdominal/ventral plates which are known as sternites. Also, the notopleural suture (found under the pronotal shield) is not present.Ptilodactylidae
Ptilodactylidae is a family of toe-winged beetles in the order Coleoptera. There are about 6 genera and 15 described species in Ptilodactylidae.Stenelmis
Stenelmis is the largest and most widespread genus of beetles in the family Elmidae. It contains the following species:
Stenelmis antennalis Sanderson, 1938
Stenelmis beameri Sanderson, 1938
Stenelmis bicarinata LeConte, 1852
Stenelmis calida Chandler, 1949
Stenelmis canaliculata (Gyllenhal, 1808)
Stenelmis concinna Sanderson, 1938
Stenelmis consobrina Dufour, 1835
Stenelmis cheryl Brown, 1987
Stenelmis convexula Sanderson, 1938
Stenelmis crenata (Say, 1824)
Stenelmis decorata Sanderson, 1938
Stenelmis douglasensis Sanderson, 1938
Stenelmis exigua Sanderson, 1938
Stenelmis exilis Sanderson, 1938
Stenelmis florala Schmude
Stenelmis fuscata Blatchley, 1925
Stenelmis gammoni White & Brown, 1976
Stenelmis grossa Sanderson, 1938
Stenelmis harleyi Schmude
Stenelmis hungerfordi Sanderson, 1938
Stenelmis knobeli Sanderson, 1938
Stenelmis lariversi Schmude, 1999
Stenelmis lateralis Sanderson, 1938
Stenelmis mera Sanderson, 1938
Stenelmis mirabilis Sanderson, 1938
Stenelmis occidentalis Schmude and Brown, 1991
Stenelmis puberula Reitter, 1887
Stenelmis quadrimaculata Horn, 1870
Stenelmis sandersoni Musgrave, 1940
Stenelmis sexlineata Sanderson, 1938
Stenelmis sinuata LeConte, 1852
Stenelmis vittipennis Zimmermann, 1869
Stenelmis xylonastis Schmude and Barr in Schmude, Barr and Brown, 1992Water-penny beetle
Water-penny beetles are a family (the Psephenidae) of 272 species (in 35 genera) of aquatic beetles found on all continents, in both tropical and temperate areas. The young, which live in water, resemble tiny pennies. The larvae feed – usually nocturnally – on algae on rock surfaces. The presence of water penny larvae in a stream can be used as a test for the quality of the water, as they are pollution-sensitive. They cannot live in habitats where rocks acquire a thick layer of algae, fungi, or inorganic sediment. Therefore, their presence along with other diverse phyla signifies good-quality water. They are around 6 to 10 millimeters in length.A water penny larva's shell is oval-shaped to almost circular and is commonly a copper color, which explains the name, 'water penny.' Water pennies obtain oxygen through their membrane and through feathery gills located at the base of the abdomen. They are typically found in riffles in streams with a moderate to fast current, clinging to the underside of logs or rocks. Occasionally, they can be found on rocks along the shores of lakes. Attached to the legs are scrapers, which are used to scrape the algae from the surface of a log or rock.
In North America, they are usually found in the Northeast, and occasionally discovered in the Southwest. Some genera in the US:
Psephenus: the Northeast and the west coast (from Oregon to California; usually below 4,000 feet elevation in California).
Eubrianax: California, up to 6,000 feet elevation.
Ectopria: the northeastern and Central U.S..
Acneus: California and Oregon up to 4,000 feet.As adults, water pennies become terrestrial. Adults are relatively short-lived and eat little to nothing.
Extant Coleoptera families