Aquatic-beetle
Guides
Acidocerinae
Acidocerinae is a cosmopolitan subfamily of water scavenger beetles (Hydrophilidae) containing over 500 species in 23-24 genera, making it one of the largest and most morphologically heterogeneous lineages in the family. The subfamily occupies a key phylogenetic position as sister to the largely terrestrial Cylominae+Sphaeridiinae clade. Recent taxonomic revisions (2013, 2021) have substantially restructured generic boundaries, establishing new genera such as Colossochares, Novochares, Aulonochares, Ephydrolithus, and Primocerus while synonymizing former subgenera of Helochares.
Acilius confusus
Acilius confusus is a species of predaceous diving beetle in the family Dytiscidae, described by Bergsten in 2006. It is found in North America. As a member of the genus Acilius, it is an aquatic predator. The species was separated from related taxa based on morphological and molecular evidence.
Acilius semisulcatus
Woods Predaceous Diving Beetle
Acilius semisulcatus is a species of predaceous diving beetle in the family Dytiscidae. It is found in North America, with records from Canada (Alberta, British Columbia) and the United States. The species is known by the common name Woods Predaceous Diving Beetle.
Acneus beeri
Beer's false water penny beetle
Acneus beeri is a species of aquatic beetle in the family Psephenidae, known from a single female specimen collected east of Cascadia, Oregon in July 1940. The species belongs to the false water penny beetles, a group characterized by their flattened, oval body form adapted for clinging to submerged surfaces in flowing water. No additional specimens have been reported in the more than 80 years since its original description, making it one of the most poorly known North American beetle species.
Agabus ambiguus
Agabus ambiguus is a predaceous diving beetle in the family Dytiscidae, belonging to the North American endemic ambiguus species group. Adults are active in open water year-round, including throughout winter. The species occurs across the United States and Canada, where it inhabits depositional areas of springs, streams, and stream-fed ponds.
Agabus bicolor
Agabus bicolor is a species of predaceous diving beetle in the family Dytiscidae. It was originally described by Kirby in 1837 under the basionym Colymbetes bicolor. The species is found in North America, with records from Alberta and British Columbia in Canada. As a member of Dytiscidae, it is an aquatic predator.
Agabus cordatus
Agabus cordatus is a species of predaceous diving beetle in the family Dytiscidae, originally described by LeConte in 1853. It is currently treated as a synonym of Ilybiosoma cordatum, a genus distinguished from Agabus by subtle morphological features of the male genitalia and body proportions. Like other members of the subfamily Agabinae, it is an aquatic beetle inhabiting freshwater systems. Records indicate presence in North America.
Agabus discolor
Agabus discolor is a predaceous diving beetle in the family Dytiscidae, first described by Harris in 1828. The species has a broad geographic distribution spanning North America and the Palearctic region. As a member of the predaceous diving beetles, it is an aquatic predator inhabiting freshwater environments. The species was originally described under the genus Colymbetes before being transferred to Agabus.
Agabus griseipennis
Agabus griseipennis is a predaceous diving beetle described by LeConte in 1859. It belongs to the genus Agabus, a large group of aquatic beetles in the family Dytiscidae. The species is recorded from North America, with specific distribution records from western Canada including Alberta and British Columbia.
Agabus pisobius
Agabus pisobius is a predaceous diving beetle in the family Dytiscidae. The species was described by Leech in 1949. It is known from North America, with records from western Canada including Alberta and British Columbia. As a member of the genus Agabus, it is adapted to aquatic environments.
Agabus punctatus
Agabus punctatus is a predaceous diving beetle in the family Dytiscidae, first described by F.E. Melsheimer in 1844. The species is known from North America, though specific details regarding its ecology, habitat preferences, and life history remain poorly documented in the available literature. As a member of the genus Agabus, it is presumed to be aquatic in the adult stage, though this has not been explicitly confirmed for this particular species.
Agabus semipunctatus
Agabus semipunctatus is a predaceous diving beetle in the family Dytiscidae. The species was originally described as Colymbetes semipunctatus by Kirby in 1837 before being transferred to the genus Agabus. It is recorded from North America, with specific distribution records from Alberta and British Columbia in Canada. As a member of the predaceous diving beetles, it is adapted to aquatic habitats.
Agabus smithi
Agabus smithi is a species of predaceous diving beetle in the family Dytiscidae. It is found in North America, with records from Alberta and British Columbia in Canada. As a member of the genus Agabus, it is an aquatic predator, though specific ecological details for this species remain limited in available literature.
Agabus triton
Agabus triton is a species of predaceous diving beetle in the family Dytiscidae, described by Fall in 1922. The species is currently treated as a synonym of Agabus amnicola. It has been recorded from Europe, Northern Asia (excluding China), and North America. As a member of the Dytiscidae, it belongs to a family of aquatic beetles adapted to life in freshwater habitats.
Agna
Agna is a genus of water scavenger beetles in the family Hydrophilidae, subfamily Sphaeridiinae. The genus was established by Smetana in 1978 and is classified within the tribe Megasternini. Members of this genus are small beetles associated with aquatic or moist habitats, though specific ecological details remain poorly documented in available sources.
Ametor latus
Ametor latus is a species of water scavenger beetle in the family Hydrophilidae. It is native to western North America, with documented occurrences in British Columbia, Canada, and several western U.S. states including California, Idaho, Oregon, and Washington. The species was first described by Horn in 1873 under the basionym Hydrobius latus. As a member of the Hydrophilidae, it belongs to a family of beetles primarily associated with aquatic and semi-aquatic habitats.
Ametor scabrosus
Ametor scabrosus is a water scavenger beetle (family Hydrophilidae) found across northern and western North America, with additional records from East Asia including China, Korea, and the Russian Far East. The species was described by Horn in 1873. Like other members of the genus Ametor, it inhabits aquatic environments where it contributes to decomposition processes.
Amphizoa striata
trout-stream beetle
Amphizoa striata is a species of trout-stream beetle in the family Amphizoidae, found in western North America. It measures 13–15 millimeters in length and possesses distinctive morphological features on its front tarsi, including a well-developed groove on the posterior surface and grooves bearing long hair-like setae. The species inhabits cold, fast-flowing streams in the Pacific Northwest.
Ampumixis
Ampumixis is a monotypic genus of riffle beetles in the family Elmidae, containing the single species Ampumixis dispar. The genus was described by Sanderson in 1954 and is endemic to the Western United States, specifically the region between California and Oregon. Adults are small, measuring approximately 2.1–2.5 mm in length.
Anacaena
Anacaena is a genus of small water scavenger beetles in the tribe Anacaenini, containing at least 150 species worldwide. Adults range 1.5–3.3 mm in length. The genus is characterized by a slightly expanded second maxillary palpomere relative to the third, lack of metallic lustre on the dorsal head, slight hydrofuge pubescence on proximal metafemora, and a non-carinate prosternum. Species-level identification relies primarily on aedeagus morphology.
Anacaena limbata
Anacaena limbata is a water scavenger beetle in the family Hydrophilidae. It is native to Europe and parts of Northern Asia, and has been introduced to North America. As a member of the genus Anacaena, it inhabits aquatic and semi-aquatic environments.
Bagous magister
snout beetle, bark beetle
Bagous magister is a species of weevil in the family Curculionidae, first described by John Lawrence LeConte in 1876. It is a small beetle with the characteristic elongated snout (rostrum) typical of the genus Bagous. The species occurs in North America, with records from the United States and Canada (Ontario). As a member of the Bagous genus, it is associated with aquatic or semi-aquatic habitats, though specific ecological details for this species remain poorly documented.
Berosus aculeatus
Berosus aculeatus is a species of hydrophilid beetle first described by John Lawrence LeConte in 1855. It is native to the eastern United States and Cuba, with records spanning from Florida to New England and west to Iowa and Wisconsin. The species is distinguished by its prolonged elytral apices—a diagnostic morphological feature. Like other members of the genus Berosus, it is associated with aquatic or semi-aquatic habitats, though specific ecological details remain poorly documented.
Berosus hatchi
Berosus hatchi is a species of water scavenger beetle in the family Hydrophilidae, described by D.C. Miller in 1965. It is found in North America, with distribution records from Canada and the United States. As a member of the genus Berosus, it belongs to a group of aquatic beetles commonly known as water scavenger beetles.
Berosus peregrinus
Berosus peregrinus is a water scavenger beetle (Hydrophilidae) native to North America and the Caribbean. It inhabits freshwater environments including marshes, ponds, and sluggish streams. Like other members of its genus, it is adapted to aquatic life and contributes to decomposition of organic material in aquatic ecosystems.
Berosus pugnax
Berosus pugnax is a species of water scavenger beetle in the family Hydrophilidae, native to the United States. It was described by John Lawrence LeConte in 1863. The species is distinguished by having emarginate (notched) apices on its elytra. Like other members of the genus Berosus, it is associated with aquatic or semi-aquatic habitats.
Berosus rugulosus
Berosus rugulosus is a species of water scavenger beetle in the family Hydrophilidae. It is found in arid and semi-arid regions of the southwestern United States and Mexico. Like other members of the genus Berosus, it is associated with aquatic or semi-aquatic habitats. The species was described by George Henry Horn in 1873.
Berosus sayi
Berosus sayi is a species of water scavenger beetle in the family Hydrophilidae, native to North America. First described by Thomas Say in 1825 as Berosus striatus, it was later renamed Berosus sayi by Hansen in 1999. The species is characterized by a distinctive morphological trait in females: a small tooth on the suture near the apex of each elytron.
Berosus stylifer
Stylish Water Scavenger Beetle
Berosus stylifer is a water scavenger beetle in the family Hydrophilidae, described by Horn in 1873. It is found across western and central North America from Canada to Mexico. The species is part of a diverse genus of aquatic beetles commonly associated with freshwater habitats.
Bryelmis
Bryelmis is a genus of riffle beetles in the family Elmidae, established by Barr in 2011. The genus contains three described species, all described in the same 2011 publication: Bryelmis idahoensis, Bryelmis rivularis, and Bryelmis siskiyou. As members of Elmidae, these beetles are aquatic and associated with flowing water habitats. The genus is relatively newly described and appears to be restricted to western North America based on species epithets.
Celina angustata
Celina angustata is a species of predaceous diving beetle in the family Dytiscidae. The species was described by Aubé in 1838. It occurs across North and South America.
Celina imitatrix
Celina imitatrix is a predaceous diving beetle in the family Dytiscidae, described by Young in 1979. The species is known from North America and the Neotropics. Like other members of the genus Celina, it is aquatic and predatory. Very few specific observations or studies have been published for this particular species.
Celina occidentalis
Celina occidentalis is a predaceous diving beetle described by Young in 1979. It belongs to the family Dytiscidae, a group of aquatic beetles adapted for underwater predation. The species is known from North America and the Neotropics, though specific details about its biology remain limited in published literature.
Cercyon assecla
Cercyon assecla is a small water scavenger beetle in the family Hydrophilidae. The species was described by Smetana in 1978 and is known from North America, with records across much of the United States and parts of Canada. It belongs to a genus of beetles typically associated with moist or aquatic environments where they feed on decaying organic matter.
Cercyon limbatus
Cercyon limbatus is a small water scavenger beetle in the family Hydrophilidae, first described by Mannerheim in 1843. It belongs to the genus Cercyon, a diverse group of beetles commonly found in moist or aquatic environments. The species has been documented across much of North America, with records from Canada and the western and northern United States.
Cercyon marinus
Cercyon marinus is a water scavenger beetle in the family Hydrophilidae. It has a Holarctic distribution spanning Europe, Northern Asia, North America, and parts of Southern Asia. The species inhabits aquatic and semi-aquatic environments where it contributes to organic matter decomposition.
Cercyon mendax
Cercyon mendax is a small water scavenger beetle in the family Hydrophilidae. It inhabits moist or aquatic environments in North America, where it contributes to nutrient cycling as a detritivore. The species was described by Smetana in 1978 and remains poorly known in terms of detailed biology.
Cercyon roseni
Cercyon roseni is a small water scavenger beetle in the family Hydrophilidae, first described by Knisch in 1922. It belongs to the genus Cercyon, a diverse group of beetles commonly found in moist or aquatic environments. The species is documented across much of North America, with records spanning from Canada to the United States.
Cercyon variegatus
Cercyon variegatus is a small water scavenger beetle in the family Hydrophilidae, first described by Sharp in 1882. The species has a broad distribution across the Americas, ranging from the southeastern United States through Central America to South America. Like other members of the genus Cercyon, it is associated with moist or aquatic environments where it contributes to decomposition processes. The specific epithet 'variegatus' refers to variable or mottled coloration, though detailed morphological descriptions are limited in available sources.
Chaetarthria ochra
Chaetarthria ochra is a species of water scavenger beetle in the family Hydrophilidae. It was described by D.C. Miller in 1974. The species is known from Central America and North America, with records from the southwestern United States (Arizona and California) and Mexico. As a member of the Chaetarthriinae subfamily, it belongs to a group of small hydrophilid beetles often associated with aquatic or semi-aquatic habitats.
Clarkhydrus roffii
Clarkhydrus roffii is a species of predaceous diving beetle in the family Dytiscidae, subfamily Hydroporinae. It belongs to a genus of small diving beetles distributed in the Western Hemisphere. The species was described by Clark in 1862 and is known from limited collection records in North and Middle America. Like other members of Dytiscidae, it is an aquatic predator, though specific ecological details remain poorly documented.
Clarkhydrus spectabilis
Clarkhydrus spectabilis is a diving beetle species in the family Dytiscidae, described by Zimmerman in 1982. The genus Clarkhydrus belongs to the tribe Hydroporini within the subfamily Hydroporinae. As a member of the Dytiscidae family, this species is adapted to aquatic habitats. The specific epithet 'spectabilis' suggests notable or showy characteristics, though detailed biological information remains limited in available sources.
Cleptelmis
Cleptelmis is a genus of riffle beetles in the family Elmidae, established by Sanderson in 1954. The genus contains at least two described species: Cleptelmis addenda and Cleptelmis ornata. Riffle beetles in this family are aquatic insects associated with flowing water habitats.
Coelostoma
Coelostoma is a diverse genus of water scavenger beetles in the family Hydrophilidae, first described by Brullé in 1835. The genus comprises approximately 111 described species and is considered one of the most species-rich genera within Hydrophilidae. Members are found across the Old World, primarily in the Oriental, Afrotropical, and Palearctic regions, with limited representation in the Australian region. The genus is absent from the Nearctic and Neotropical regions, where related genera occupy similar ecological niches.
Colymbetes densus
Colymbetes densus is a predaceous diving beetle (family Dytiscidae) found in North America. The species was described by LeConte in 1859 and includes two recognized subspecies: C. d. densus and C. d. inaequalis. As a member of the genus Colymbetes, it belongs to a group of medium to large diving beetles adapted to aquatic habitats.
Colymbetes exaratus
Colymbetes exaratus is a predaceous diving beetle (family Dytiscidae) described by LeConte in 1862. The species occurs in North America, with records from Canada (Alberta, British Columbia) and the United States. Like other members of the genus Colymbetes, it is an aquatic predator inhabiting freshwater systems. Two subspecies are recognized: C. e. exaratus and C. e. incognitus.
Contacyphon cooperi
Contacyphon cooperi is a small marsh beetle in the family Scirtidae, a group of aquatic and semi-aquatic beetles commonly known as marsh beetles or minute marsh beetles. The species was described by Schaeffer in 1931 and is documented from North America. Scirtidae larvae are typically found in moist or aquatic habitats, often in decaying vegetation or mud, while adults are frequently collected at lights or in vegetation near water.
Contacyphon neopadi
Contacyphon neopadi is a species of marsh beetle in the family Scirtidae, a group of small beetles commonly associated with moist or aquatic habitats. The species was described by Klausnitzer in 1976 and is known from North America. Marsh beetles in this genus are typically encountered near water or in humid microhabitats.
Contacyphon perplexus
marsh beetle
Contacyphon perplexus is a species of marsh beetle in the family Scirtidae, found in North America. The species was described by Blatchley in 1914. As a member of Scirtidae, it belongs to a family of small beetles commonly associated with moist or aquatic habitats, though specific ecological details for this species remain limited.
Contacyphon punctatus
Contacyphon punctatus is a species of marsh beetle in the family Scirtidae. Members of this family are small beetles commonly found in moist habitats near water. The genus Contacyphon is characterized by small body size and association with aquatic or semi-aquatic environments. The specific epithet "punctatus" suggests the presence of punctate (dotted) surface sculpturing on the body.