Semiaquatic
Guides
Epimetopus
hooded shore beetles
Epimetopus is a New World genus of semiaquatic beetles commonly known as hooded shore beetles, comprising 56 species ranging from Argentina to Arizona and Arkansas. The genus was revised in 2012, with 36 new species described and new collection records provided for 15 previously described species. Species diversity is concentrated in South America (37 species) and areas north of South America (17 species), with only two species known from both regions. The genus is absent from the Amazon basin and is divided into seven species groups based on morphological characters.
Gerrinae
Typical Water Striders
Gerrinae is a subfamily of water striders (Gerridae) comprising thirteen extant genera in two tribes, plus three fossil genera. Members are characterized by long, slender bodies and hydrophobic leg microhairs that enable locomotion on water surfaces. The subfamily includes some of the best-known gerrid species and the largest water strider, Gigantometra gigas. Gerrinae species inhabit inland freshwaters and some brackish environments, with documented adaptations to different flow regimes.
Gerroidea
Water Striders and Ripple Bugs
Gerroidea is a superfamily of semiaquatic true bugs (Hemiptera: Heteroptera) comprising at least three families—Gerridae (water striders), Veliidae (smaller water striders or riffle bugs), and Hermatobatidae—with over 2,000 described species. Members are specialized for life on the water surface, utilizing water-repellent legs and surface tension to remain afloat. The group occupies diverse aquatic habitats ranging from freshwater ponds and streams to marine coastal environments including mangroves and open ocean. Recent research has documented significant undescribed diversity in tropical regions and novel bacterial symbiont associations.
Gerromorpha
semiaquatic bugs, shore-inhabiting bugs, water striders, water measurers, velvet water bugs, water treaders, riffle bugs
Gerromorpha is an infraorder of true bugs (Hemiptera: Heteroptera) comprising approximately eight families in four superfamilies. Members are commonly called semiaquatic or shore-inhabiting bugs, though many species are specifically adapted to exploit the water surface film. The group includes well-known taxa such as Gerridae (water striders), Hydrometridae (water measurers), Hebridae (velvet bugs), and Veliidae (riffle bugs). Gerromorphans are distributed globally and are frequently used as bioindicators of aquatic habitat quality.
Hebridae
Velvet Water Bugs
Hebridae, known as velvet water bugs, is a small family of semiaquatic Heteroptera within the infraorder Gerromorpha. The family comprises approximately 220 species in 9 genera and 2 subfamilies, distributed worldwide. Members are characterized by their small size, plump body form, and dense covering of setae that gives them a velvety appearance. They inhabit humid terrestrial and marginal freshwater habitats, including mossy areas, pond margins, and stream banks with abundant vegetation.
Hebroidea
Velvet Water Bugs
Hebroidea is a superfamily of Heteroptera (true bugs) established by Amyot & Serville in 1843, containing the family Hebridae. Members are known as velvet water bugs and represent the smallest group within the infraorder Gerromorpha. They inhabit semiaquatic environments with dense vegetation.
Husseyella turmalis
Husseyella turmalis is a small water strider in the family Veliidae, originally described as Microvelia turmalis by Drake & Harris in 1933. It belongs to the subfamily Microveliinae, a group of minute semiaquatic bugs that inhabit the surface film of freshwater habitats. The genus Husseyella is a small group within the Veliidae, and this species appears to have a limited number of documented observations.
Hydrometridae
marsh treaders, water measurers
Hydrometridae is a family of semiaquatic true bugs comprising over 147 species across seven genera and three subfamilies. Members are characterized by extremely elongated, slender bodies and heads that give them a measuring-stick appearance. They inhabit water surface margins of lakes, ponds, and wetlands worldwide, with greatest diversity in tropical regions. Some lineages have independently evolved terrestrial habits in insular Pacific habitats.
Mesovelia amoena
water treader
Mesovelia amoena is a species of water treader (family Mesoveliidae), a group of semiaquatic true bugs adapted to life at the water surface. The species was described by Uhler in 1894 and has a remarkably broad distribution spanning five continents. Water treaders in this family are characterized by their ability to walk on water using surface tension, aided by their hydrophobic body covering and specialized leg structure.
Metrobates anomalus
Metrobates anomalus is a water strider species in the family Gerridae, described by Hussey in 1948. It belongs to the genus Metrobates, a group of semiaquatic bugs known for their ability to walk on water surfaces using hydrophobic leg adaptations. The species is part of the subfamily Trepobatinae and tribe Metrobatini, which are primarily associated with running water habitats. Very little specific biological information is documented for this particular species.
Microvelia
small water striders, riffle bugs
Microvelia is a large genus of small semiaquatic bugs comprising at least 230 described species distributed worldwide. These insects inhabit nearshore areas of stagnant or slow-flowing freshwater, where they move on the water surface using surface tension. The genus exhibits wing dimorphism, with populations containing both fully winged (macropterous) and short-winged (brachypterous) individuals. Several subgenera have been recognized including Austromicrovelia, Barbivelia, Pacificovelia, and Picaultia, based on phylogenetic and morphological analyses.
Microvelia albonotata
Microvelia albonotata is a small water strider species in the family Veliidae, first described by Champion in 1898. It belongs to a genus of minute semiaquatic bugs commonly found on the water surface film. The species has been documented across a broad Neotropical and Nearctic range including the Caribbean, Middle America, North America, and South America. Like other Microvelia species, it is adapted to life at the air-water interface.
Microvelia beameri
Microvelia beameri is a small water strider in the family Veliidae, described by McKinstry in 1937. The species belongs to a genus characterized by small body size and the ability to skate on water surfaces. Records indicate presence across Caribbean, Middle America, and North America. Very few observations exist in public databases, suggesting either rarity or underreporting due to its minute size.
Microvelia buenoi
smaller water strider
Microvelia buenoi is a small semiaquatic bug in the family Veliidae, commonly known as smaller water striders. The species was described by Drake in 1920 and occurs across a broad transcontinental range spanning Europe, Northern Asia (excluding China), and North America. Like other members of the genus Microvelia, it inhabits the surface film of freshwater habitats where it moves with characteristic rapid, darting movements. The specific epithet honors entomologist Erika Bueno's family name, though this appears coincidental rather than commemorative.
Microvelia cerifera
Microvelia cerifera is a species of small water strider in the family Veliidae, described by McKinstry in 1937. The species belongs to the genus Microvelia, a diverse group of semiaquatic bugs commonly found on the surface film of freshwater habitats. Like other veliids, it is adapted for life on water surfaces using hydrophobic setae and specialized leg morphology. The species is known from North America.
Microvelia cubana
Microvelia cubana is a small semiaquatic true bug described from Cuba in 1951. As a member of the family Veliidae, it belongs to a group of insects commonly known as small water striders or riffle bugs. The species inhabits freshwater environments in the Caribbean region. Limited published information exists regarding its biology and ecology.
Microvelia pulchella
smaller water strider
Microvelia pulchella is a semiaquatic predatory bug in the family Veliidae, distributed throughout the American continents from Canada to Argentina. It is the type species of the genus Microvelia and one of the most common species in the Neotropical Region. Laboratory studies demonstrate its potential as a biological control agent against disease-vector mosquitoes and agricultural pests in rice fields. The species serves as a model organism for behavioral and ecological research due to its convenient rearing characteristics and measurable traits.
Nostima
Nostima is a genus of shore flies (family Ephydridae) established by Coquillett in 1900. These are minute flies measuring 0.72–1.72 mm in body length, characterized by distinctive microtomentum patterns on the body and wings. The genus contains 11 described species distributed across the Holarctic region, with larvae occupying semiaquatic habitats where they feed on blue-green algae.
Ochthebius lineatus
Ochthebius lineatus is a species of minute moss beetle in the family Hydraenidae. The species was described by J.L. LeConte in 1852. It has a broad distribution across the Americas, with records from North America, Central America, and South America. As a member of the Hydraenidae, it belongs to a family of small aquatic or semiaquatic beetles commonly known as minute moss beetles or water scavenger beetles.
Platyvelia
smaller water striders
Platyvelia is a genus of smaller water striders in the family Veliidae, established by J. Polhemus and D. Polhemus in 1993. The genus contains seven described species distributed in the Americas. These insects are small semiaquatic true bugs that inhabit the surface film of water bodies.
Rhagovelia choreutes
Rhagovelia choreutes is a species of small water strider in the family Veliidae. It belongs to the infraorder Gerromorpha, a group of semiaquatic true bugs adapted to life on the water surface. The species was described by Hussey in 1925. It occurs in running water habitats in parts of North and Central America.
Rhagovelia torreyana
Rhagovelia torreyana is a species of small water strider in the family Veliidae, described by Bacon in 1956. It belongs to the genus Rhagovelia, a diverse group of semiaquatic bugs commonly found in running water habitats. The species is known from North America, though detailed biological information remains limited in available sources. Like other members of the family Veliidae, it is adapted to life on the water surface, using surface tension to move and forage.
Stenus
rove beetles, water-gliding rove beetles
Stenus is a genus of semiaquatic rove beetles comprising approximately 3100 described species, making it one of the largest genera in the animal kingdom. These beetles are specialist predators of small arthropods, particularly Collembola. They possess distinctive adaptations including a protrusible adhesive labium for prey capture and pygidial gland secretions that enable rapid water surface locomotion via the Marangoni effect. The genus occurs worldwide across diverse habitats from aquatic margins to terrestrial leaf litter.
Stilobezzia
Stilobezzia is a genus of predaceous biting midges in the family Ceratopogonidae, comprising more than 330 described species worldwide. Adult females are predators of other small insects. Immature stages develop in aquatic and semiaquatic habitats. The genus is absent from Antarctica and some islands.