Aquatic-beetle
Guides
Optioservus castanipennis
Optioservus castanipennis is a species of riffle beetle in the family Elmidae, first described by Fall in 1925. It belongs to a genus of small aquatic beetles inhabiting running water systems. The species is recognized as part of the Nearctic fauna and has been subject to taxonomic revision based on male genitalia and elytral characteristics.
Optioservus divergens
Optioservus divergens is a species of riffle beetle in the family Elmidae. The species was described by LeConte in 1874 and is currently accepted under this name, though it was formerly classified in the genus Heterlimnius. Riffle beetles in this family are aquatic insects typically associated with running water habitats.
Optioservus heteroclitus
Optioservus heteroclitus is a species of riffle beetle in the family Elmidae, described by White in 1978 as part of a taxonomic revision of Nearctic Optioservus. The species was distinguished based on male genitalia, elytral patterns and shape, and geographic distribution. Like other elmid beetles, it is associated with aquatic environments, specifically flowing water habitats.
Optioservus phaeus
Scott optioservus riffle beetle
Optioservus phaeus is a species of riffle beetle (family Elmidae) described by White in 1978. It belongs to a genus of small aquatic beetles inhabiting running waters. The species was described as part of a taxonomic revision based on male genitalia, elytral patterns, and geographic distribution. It is known from a highly restricted range in Kansas.
Optioservus quadrimaculatus
four-spotted riffle beetle
Optioservus quadrimaculatus is a species of riffle beetle in the family Elmidae, described by Horn in 1870. The species is found in North America, with records from Canadian provinces including Alberta, British Columbia, and Saskatchewan. Riffle beetles in this family are aquatic insects associated with running water habitats. The specific epithet "quadrimaculatus" refers to four spots, likely describing a distinctive elytral pattern.
Optioservus sandersoni
A species of riffle beetle in the family Elmidae, endemic to North America. First described by Collier in 1972. Taxonomic identification relies on male genitalia, elytral patterns, and body shape rather than variable external characters.
Optioservus seriatus
Optioservus seriatus is a species of riffle beetle in the family Elmidae, first described by LeConte in 1874. It is one of thirteen Nearctic species in the genus Optioservus, a group whose taxonomy was historically complicated by highly variable external morphology. The species occurs in North America, with records from western Canada including Alberta and British Columbia.
Oreodytes humboldtensis
Oreodytes humboldtensis is a species of predaceous diving beetle in the family Dytiscidae, described by Zimmerman in 1985. As a member of the genus Oreodytes, it belongs to a group of small diving beetles primarily associated with running water habitats. The species epithet suggests a connection to the Humboldt region, likely referring to Humboldt County or the broader Humboldt Bay area of coastal northern California. Like other Oreodytes species, it is presumed to be an aquatic predator in freshwater systems.
Oreodytes laevis
Oreodytes laevis is a species of predaceous diving beetle in the family Dytiscidae. It is distributed across North America, with records from Canada (Alberta, British Columbia) and the United States. As a member of the Hydroporinae subfamily, it inhabits aquatic environments where it functions as an active predator.
Oulimnius
Oulimnius is a genus of riffle beetles in the family Elmidae, containing approximately 15 described species. These beetles are aquatic and inhabit running water environments. The genus has been the subject of molecular phylogenetic studies, particularly for the O. tuberculatus species group, which revealed cryptic diversity and supported the re-validation of O. perezi as a distinct species.
Oulimnius latiusculus
Oulimnius latiusculus is a species of riffle beetle in the family Elmidae, first described by LeConte in 1866. Riffle beetles are aquatic insects typically associated with flowing water habitats. The species is known from North America, with records from Canada including New Brunswick and Newfoundland.
Pachydrus
Pachydrus is a genus of diving beetles in the family Dytiscidae, established by Sharp in 1882. The genus belongs to the tribe Pachydrini within the subfamily Hydroporinae. It contains nine described species distributed primarily in South America, with records from Colombia and surrounding regions. As with other dytiscids, members are aquatic predators inhabiting freshwater environments.
Paracymus confluens
Paracymus confluens is a species of water scavenger beetle in the family Hydrophilidae, described by Wooldridge in 1966. It is a small aquatic beetle found in freshwater habitats across parts of North America. Like other members of the genus Paracymus, it is associated with aquatic environments and contributes to nutrient cycling as a detritivore.
Paracymus nanus
Paracymus nanus is a species of water scavenger beetle (family Hydrophilidae) described by Fall in 1910. The species occurs in freshwater habitats across parts of the southeastern United States and the Caribbean region. As a member of the genus Paracymus, it belongs to a group of small aquatic beetles commonly known as water scavenger beetles that inhabit various freshwater environments.
Paracymus subcupreus
Paracymus subcupreus is a water scavenger beetle in the family Hydrophilidae. The species was described by Thomas Say in 1825. It is known from North America with records spanning Canada, the United States, and Mexico.
Peltodytes dietrichi
Peltodytes dietrichi is a species of crawling water beetle in the family Haliplidae, first described by Young in 1961. It belongs to a genus of small aquatic beetles adapted to life in shallow water environments. The species is known from North America, with confirmed records from Québec, Canada.
Peltodytes duodecimpunctatus
A small crawling water beetle in the family Haliplidae. Adults are recognized by the distinctive pattern of dark spots on the pale elytra. The species occurs in freshwater habitats across eastern and central North America. It is one of the more frequently encountered Peltodytes species in the region.
Peltodytes festivus
Peltodytes festivus is a species of crawling water beetle in the family Haliplidae. It occurs in North America. Members of this family are semi-aquatic, inhabiting the margins of ponds, lakes, and slow-moving streams where they feed on algae and detritus. The genus Peltodytes is distinguished from other haliplid genera by morphological features of the elytra and hind legs.
Peltodytes pedunculatus
Peltodytes pedunculatus is a species of crawling water beetle in the family Haliplidae. Members of this family are small, oval beetles adapted to aquatic environments with well-developed hind legs for swimming. The species was described by Clark in 1862 from North American material.
Peltodytes sexmaculatus
six-spotted crawling water beetle
Peltodytes sexmaculatus is a species of crawling water beetle in the family Haliplidae, first described by Roberts in 1913. The species name refers to the six-spotted pattern on its elytra. It is found in North America and is one of approximately 20 species in the genus Peltodytes. Like other haliplids, it inhabits aquatic environments and is capable of crawling through submerged vegetation.
Peltodytes simplex
Peltodytes simplex is a species of crawling water beetle in the family Haliplidae, first described by LeConte in 1852. It is one of approximately 20 species in the genus Peltodytes, which are characterized by their association with aquatic habitats and distinctive morphological adaptations for swimming. The species occurs in North America and Middle America, though detailed biological information remains limited in published literature.
Plateumaris diversa
Plateumaris diversa is a species of leaf beetle in the family Chrysomelidae, subfamily Donaciinae. The species was described by C. Schaeffer in 1925. It is one of numerous Plateumaris species associated with wetland habitats, particularly those supporting emergent vegetation. Records indicate presence in central and eastern Canada, with observations from Manitoba, Ontario, and Québec.
Plateumaris frosti
Frost's reed beetle
Plateumaris frosti is a species of aquatic leaf beetle in the subfamily Donaciinae, commonly known as Frost's reed beetle. It is distributed across North America with records from Canada (Alberta, British Columbia, Manitoba) and the United States. Like other members of the genus Plateumaris, it is associated with wetland and riparian habitats. The species was described by C. Schaeffer in 1925.
Plateumaris germari
Germar's reed beetle
Plateumaris germari is an aquatic leaf beetle in the family Chrysomelidae, subfamily Donaciinae. It occurs in western North America, with records extending from western Canada through the western United States. The species is associated with wetland and riparian habitats where emergent vegetation provides food and substrate for larval development. Like other members of the genus, it is believed to complete its life cycle in close association with aquatic or semi-aquatic plants.
Plateumaris metallica
Metallic reed beetle
Plateumaris metallica is an aquatic leaf beetle in the family Chrysomelidae, known by the common name Metallic reed beetle. It is native to North America, with confirmed records from Canada (New Brunswick, Nova Scotia, Ontario) and the United States. As a member of the genus Plateumaris, it is associated with wetland habitats and aquatic vegetation.
Plateumaris pusilla
Little reed beetle
Plateumaris pusilla is a species of aquatic leaf beetle in the family Chrysomelidae. It is known from North America, with records from Canada including Alberta, British Columbia, and Labrador. As a member of the subfamily Donaciinae, it is associated with wetland habitats. The species is commonly referred to as the Little reed beetle.
Plateumaris robusta
Robust reed beetle
Plateumaris robusta is a species of aquatic leaf beetle in the family Chrysomelidae, subfamily Donaciinae. It is found in North America, with records from western Canadian provinces including Alberta, British Columbia, and Manitoba. As a member of the reed beetle genus Plateumaris, it is associated with freshwater wetland habitats.
Postelichus immsi
Postelichus immsi is a species of long-toed water beetle described by Hinton in 1937. It belongs to the family Dryopidae, a group of aquatic beetles commonly found in flowing water habitats. The species is known from North America. Very few observations exist in citizen science databases, suggesting it is either rare, poorly sampled, or cryptic in its habits.
Prionocyphon discoideus
Disk-shaped Marsh Beetle
Prionocyphon discoideus is a species of marsh beetle in the family Scirtidae, found in eastern North America. The species is associated with moist habitats and has been documented in Canada and the United States. Like other members of Scirtidae, it likely has aquatic or semi-aquatic larval stages.
Rhantus binotatus
Double-marked Swimming Beetle
Rhantus binotatus is a predaceous diving beetle in the family Dytiscidae. The species occurs in North America, with records from Canada (Alberta, British Columbia) and the United States. As a member of the genus Rhantus, it inhabits aquatic environments where it functions as an active predator. The common name 'Double-marked Swimming Beetle' refers to distinctive markings used in identification.
Rhantus gutticollis
Rhantus gutticollis is a predaceous diving beetle in the family Dytiscidae. The species occurs across a broad geographic range spanning North America, Central America, and the Caribbean. Like other members of its genus, it inhabits aquatic environments and functions as an active predator. The specific epithet "gutticollis" refers to spotted or marked neck/throat region characteristics.
Rhantus sericans
Rhantus sericans is a predaceous diving beetle in the family Dytiscidae, first described by Sharp in 1882. The species is distributed across North America and has been recorded from the Holarctic region, including the Canadian province of Alberta. As a member of the genus Rhantus, it belongs to a group of diving beetles adapted to aquatic environments. The species is represented by 88 observations on iNaturalist, indicating it is documented but not exceptionally common in citizen science records.
Rhantus suturellus
Rhantus suturellus is a predaceous diving beetle in the family Dytiscidae. It is distributed across the Holarctic region, occurring in both North America and the Palearctic. The species is part of a genus of aquatic beetles adapted to freshwater environments.
Sanfilippodytes brumalis
Sanfilippodytes brumalis is a small predaceous diving beetle in the family Dytiscidae, described by Brown in 1930. The species belongs to the subfamily Hydroporinae, a group of generally small dytiscids. It occurs in northern North America, with records from Labrador and Québec in Canada. As a member of Dytiscidae, it is aquatic and predatory, though specific natural history details remain poorly documented.
Sanfilippodytes pseudovilis
Sanfilippodytes pseudovilis is a species of predaceous diving beetle in the family Dytiscidae. It was described by Young in 1953. The species is known from North America, with confirmed records from the Canadian provinces of Alberta and British Columbia. As a member of the Hydroporinae subfamily, it belongs to a group of small diving beetles.
Sanfilippodytes terminalis
Sanfilippodytes terminalis is a species of predaceous diving beetle in the family Dytiscidae, first described by Sharp in 1882. It is one of several species in the genus Sanfilippodytes, a group of small diving beetles within the subfamily Hydroporinae. The species is known from North America, with records from British Columbia, Canada. Like other members of its family, it is adapted to aquatic habitats.
Scirtes orbiculatus
Red-sutured Marsh Beetle
Scirtes orbiculatus is a species of marsh beetle in the family Scirtidae, commonly known as the Red-sutured Marsh Beetle. It is a small beetle native to North America, with documented records from Canada (Nova Scotia, Ontario, Québec) and the United States. The species has been the subject of life history studies, though detailed ecological information remains limited in publicly available sources. As a member of Scirtidae, it is associated with moist or aquatic environments where larvae typically develop.
Scirtes tibialis
Red-legged Marsh Beetle
Scirtes tibialis is a species of marsh beetle in the family Scirtidae, commonly known as the Red-legged Marsh Beetle. It is native to North America with records from Canada (Alberta, Manitoba, New Brunswick) and the United States. The species has been the subject of life history studies, though detailed biological information remains limited in publicly available sources.
Spanglerogyrus
Spanglerogyrus is a monotypic genus of whirligig beetles (family Gyrinidae) containing the single species S. albiventris. It represents the only living member of the subfamily Spanglerogyrinae, the earliest diverging extant lineage of gyrinid beetles. The genus was described in 1979 from specimens collected in southern Alabama, making it a rare example of a relictual aquatic beetle lineage in North America.
Stenelmis concinna
riffle beetle
Stenelmis concinna is a species of riffle beetle in the family Elmidae, described by Sanderson in 1938. Riffle beetles are aquatic insects that inhabit flowing water environments. The species is known from North America, with distribution records including Québec, Canada. As a member of the genus Stenelmis, it shares the family characteristic of being fully aquatic in both larval and adult stages.
Stenelmis grossa
riffle beetle
Stenelmis grossa is a species of riffle beetle in the family Elmidae, described by Sanderson in 1938. Riffle beetles are aquatic insects typically associated with running water habitats. The species is known from North America, though specific details regarding its biology, ecology, and distribution within that range remain limited in published literature.
Stenelmis lignicola
riffle beetle
Stenelmis lignicola is a species of riffle beetle in the family Elmidae, described in 1992. The specific epithet "lignicola" derives from Latin roots meaning "wood-dweller," suggesting an association with woody substrates. As a member of the riffle beetle family, it is adapted to aquatic or semi-aquatic environments with flowing water. The species is known from North America.
Stenelmis mera
Stenelmis mera is a species of riffle beetle in the family Elmidae, first described by Sanderson in 1938. It belongs to a genus of small, aquatic beetles commonly found in running water habitats. The species is documented from eastern North America, with records from New Brunswick and Nova Scotia in Canada. Like other elmid beetles, it is associated with freshwater stream environments where larvae develop in submerged substrates.
Stenelmis mirabilis
riffle beetle
Stenelmis mirabilis is a species of riffle beetle in the family Elmidae, described by Sanderson in 1938. Riffle beetles are aquatic insects typically associated with flowing water habitats. The species is recorded from North America, though specific details about its biology and ecology remain limited in published literature.
Stenelmis parva
Stenelmis parva is a species of riffle beetle in the family Elmidae, described by Sanderson in 1938. The species occurs in North America. Like other members of the genus Stenelmis, it inhabits aquatic environments with flowing water.
Stenelmis sinuata
riffle beetle
Stenelmis sinuata is a species of riffle beetle in the family Elmidae, described by LeConte in 1852. It is found in North America. Riffle beetles are aquatic beetles that inhabit flowing water environments.
Stenus laccophilus
Stenus laccophilus is a rove beetle in the subfamily Steninae, first described by Casey in 1884. Members of this genus possess specialized hunting adaptations including the ability to eject mouthparts using blood pressure to capture prey. The species occurs across northern North America including Canada and the northern United States.
Suphisellus bicolor
Suphisellus bicolor is a species of burrowing water beetle in the family Noteridae, subfamily Noterinae. It was described by Thomas Say in 1830 and is known from the United States. As a member of the Noteridae, it belongs to a family of small aquatic beetles adapted to burrowing in muddy substrates of freshwater habitats.
Suphisellus gibbulus
Suphisellus gibbulus is a species of burrowing water beetle first described by Aubé in 1838. It belongs to the family Noteridae, a group of small aquatic beetles adapted to burrowing in muddy substrates. The species is known from the United States, though specific details about its biology remain poorly documented.
Suphisellus semipunctatus
Suphisellus semipunctatus is a small burrowing water beetle in the family Noteridae, measuring 2.3–2.6 mm in length. The species was originally described as Suphis semipunctatus by LeConte in 1878 and has also been placed in the genus Pronoterus. It occurs in the eastern United States, ranging west to Texas and Michigan.