Aquatic-insect
Guides
Epeorus punctatus
Epeorus punctatus is a species of flat-headed mayfly in the family Heptageniidae. The species was originally described by McDunnough in 1925 under the genus Iron before being transferred to Epeorus. It is known from North America within the Nearctic region. Like other members of the genus, it likely inhabits flowing water environments where the nymphs cling to submerged substrates.
Ephemera blanda
common burrower mayfly
Ephemera blanda is a species of burrower mayfly in the family Ephemeridae, characterized by its fossorial lifestyle in aquatic sediments. The species inhabits running waters in the southeastern Nearctic region. As with other members of the genus Ephemera, adults are short-lived and primarily focused on reproduction.
Ephemera guttulata
Eastern Green Drake, Shad Fly, Coffinfly
Ephemera guttulata, commonly known as the eastern green drake, is a burrowing mayfly species native to eastern North America. It is one of the largest mayfly species in the region and is highly significant to fly fishing, where its emergence events are eagerly anticipated. The species has a fully aquatic larval stage, followed by a winged subimago (dun) stage and a short-lived sexually mature adult (imago) stage. Its conservation status is G5 (secure) according to NatureServe.
Ephemera varia
Yellow Drake
Ephemera varia, commonly known as the Yellow Drake, is a species of burrower mayfly in the family Ephemeridae. It is native to North America, with documented presence in the northeastern United States including Vermont. Like other members of its genus, it is associated with aquatic environments and has a brief adult lifespan. The species is represented by 59 observations on iNaturalist, indicating it is documented but not extensively studied.
Ephemerella dorothea
Pale Dun
Ephemerella dorothea is a species of spiny crawler mayfly in the family Ephemerellidae, commonly known as the Pale Dun. It is native to North America, with documented occurrence in southwestern and northern Canada, the western United States, and Alaska. The species was first described by Needham in 1908 and includes two recognized subspecies: E. d. dorothea and E. d. infrequens.
Ephemerella dorothea infrequens
Pale Morning Dun
Ephemerella dorothea infrequens is a subspecies of mayfly in the family Ephemerellidae, commonly known as the Pale Morning Dun. It is an aquatic insect whose nymphal stage inhabits freshwater environments. The species is recognized as an important food source for trout and is frequently imitated by fly fishers using artificial flies. It was described by McDunnough in 1924 and is accepted as a valid subspecies within the Ephemerella dorothea complex.
Ephemerella excrucians
Pale Morning Dun
Ephemerella excrucians, commonly known as the pale morning dun, is a species of spiny crawler mayfly in the family Ephemerellidae. It is distributed across all of Canada and the continental United States. The species is of particular interest to fly fishers due to its importance as a trout food source and its frequent use as a model for artificial flies.
Ephemerella invaria
Sulphur Dun
Ephemerella invaria, commonly known as the sulphur dun, is a species of spiny crawler mayfly in the family Ephemerellidae. It occurs in headwater streams across eastern North America, from southeastern and northern Canada through the eastern United States. The species has been studied for population genetic impacts associated with deforestation of its stream habitats. As a member of the Ephemerellidae, it belongs to a group of mayflies characterized by distinctive spiny or tuberculate body features.
Ephemerella maculata
spiny crawler mayfly
Ephemerella maculata is a species of spiny crawler mayfly in the family Ephemerellidae. It exhibits a migratory life cycle involving upstream flight of adults, downstream drift of nymphs, and upstream crawling by nymphs to compensate for displacement. The species is found in North American streams.
Eucorethra underwoodi
Eucorethra underwoodi is a species of phantom midge in the family Chaoboridae, described by Underwood in 1903. As a member of this family, it belongs to a group of non-biting midges known for their aquatic larvae and transparent, reduced mouthparts in adults. The genus Eucorethra is a distinctive lineage within Chaoboridae. Specific ecological details for this species remain poorly documented in published literature.
Euhrychiopsis
milfoil weevil
Euhrychiopsis is a genus of small aquatic weevils in the tribe Phytobiini, family Curculionidae. The genus contains at least one well-studied species, Euhrychiopsis lecontei, commonly known as the milfoil weevil. Members of this genus are fully submersed freshwater specialists that feed on watermilfoil plants (Myriophyllum species). The genus has gained attention for its potential use in biological control of invasive aquatic plants.
Euhrychiopsis lecontei
Milfoil Weevil
A small submersed aquatic weevil native to North America, investigated as a biological control agent for invasive Eurasian watermilfoil. Adults and larvae feed on watermilfoil species, with larvae acting as stem borers that damage plant tissue. Populations occur naturally on native northern watermilfoil and have expanded to exotic Eurasian watermilfoil. The species exhibits plastic host preferences influenced by rearing experience, with faster development and larger adult sizes observed on Eurasian watermilfoil despite higher larval survivorship on native hosts.
Euparyphus stigmaticalis
Euparyphus stigmaticalis is a species of soldier fly (Diptera: Stratiomyidae) described by Loew in 1866. It is known from eastern North America, where it occurs in specialized madicolous habitats—seepage areas on rock faces with thin films of flowing water. The species has been studied for its biology and immature stages, which are adapted to life in these thin water film environments.
Eurekapnia maculata
Spotted Snowfly
Eurekapnia maculata is a species of winter stonefly in the family Capniidae, commonly known as the Spotted Snowfly. It belongs to a group of small stoneflies adapted to cold environments, with adults typically emerging during winter months when temperatures are near freezing. The species is native to North America and shares characteristics typical of the Capniidae family, including reduced wing venation and small body size.
Eurylophella aestiva
spiny crawler mayfly
Eurylophella aestiva is a species of spiny crawler mayfly in the family Ephemerellidae. It was originally described by McDunnough in 1931 as Ephemerella aestiva. The species is known from North America and belongs to a genus characterized by distinctive spiny projections on the body. Like other members of Ephemerellidae, it exhibits the subimago stage typical of mayflies.
Eurylophella bicolor
bicolor spiny crawler mayfly
Eurylophella bicolor is a species of spiny crawler mayfly in the family Ephemerellidae, originally described as Ephemerella bicolor by Clemens in 1913. The species is distributed across the Nearctic region, particularly in North America. Like other members of the genus Eurylophella, it is associated with freshwater aquatic habitats during its nymphal stages.
Eurylophella funeralis
Eurylophella funeralis is a mayfly species in the family Ephemerellidae, described by McDunnough in 1925. Originally placed in the genus Ephemerella, it was later transferred to Eurylophella. The species is known from the Nearctic region, with records from North America including Vermont. As a member of the order Ephemeroptera, it has an aquatic larval stage and terrestrial adult stage, though specific ecological details for this species remain limited in available literature.
Eurylophella lodi
Eurylophella lodi is a species of spiny crawler mayfly in the family Ephemerellidae, described by Mayo in 1952. It belongs to a genus of mayflies found in North America. The species is known from limited observations, with only two documented occurrences in iNaturalist. Like other members of Ephemerellidae, it is likely associated with freshwater aquatic habitats during its immature stages.
Eurylophella prudentalis
spiny crawler mayfly
Eurylophella prudentalis is a species of spiny crawler mayfly in the family Ephemerellidae, first described by James Halliday McDunnough in 1931. As a member of the genus Eurylophella, it belongs to a group of mayflies commonly known as spiny crawlers, characterized by their distinctive body armature. The species is known from North America, with documented occurrences in the northeastern United States including Vermont. Like other Ephemerellidae, it completes its aquatic larval development in freshwater habitats before emerging as a short-lived adult.
Frenesia missa
Failed Northern Caddisfly
Frenesia missa is a rare species of northern caddisfly in the family Limnephilidae, first described by Milne in 1935. The species was originally placed in the genus Chilostigma as Chilostigma missum before being transferred to Frenesia. It is considered vulnerable to anthropogenic stressors and has a restricted distribution in North America.
Frisonia
Frisonia is a genus of stoneflies in the family Perlodidae, established by Ricker in 1943. It belongs to the tribe Arcynopterygini within the subfamily Perlodinae. The genus is part of the diverse systellognathan stonefly assemblage, characterized by flexible gill structures and predatory habits in the nymphal stage.
Frisonia picticeps
Painted Springfly
Frisonia picticeps is a species of stonefly in the family Perlodidae, known by the common name Painted Springfly. It was originally described as Arcynopteryx picticeps by Hanson in 1942 before being transferred to the genus Frisonia. The species is distributed in western North America, with records from British Columbia through the Pacific Northwest to California and Nevada. As a member of the tribe Arcynopterygini, it belongs to a group of predatory stoneflies.
Galerucella nymphaeae
water-lily beetle, water lily leaf beetle
Galerucella nymphaeae is a univoltine skeletonizing leaf beetle in the family Chrysomelidae. Adults and larvae feed on aquatic and semi-aquatic host plants, primarily in the families Nymphaeaceae and Polygonaceae. The species exhibits a distinctive reproductive diapause strategy where adults mate in summer but delay oviposition until spring after overwintering. Populations show genetically based polymorphisms in morphology, size, and reproductive traits associated with host plant use, suggesting incipient host race formation.
Gerris buenoi
water strider
Gerris buenoi is a small water strider species native to North America, first described in 1911. Adults measure 8-10 mm in length and possess elongated mid-legs adapted for locomotion on water surfaces. The species exhibits wing polymorphism, with multiple wing forms corresponding to different seasons and environmental conditions. It has been extensively studied as a model organism for sexual conflict research and was the first water strider to have its genome sequenced.
Glaenocorisa propinqua
Glaenocorisa propinqua is a water boatman species (family Corixidae) found in lakes across Europe, Northern Asia (excluding China), and North America. Its abundance and distribution are strongly influenced by fish predation pressure, which primarily targets larvae. The species preys upon the water flea Holopedium gibberum, placing it as both predator and prey in lacustrine food webs.
Glossosoma nigrior
little black caddisfly
Glossosoma nigrior is a caddisfly species in the family Glossosomatidae, commonly known as the little black caddisfly. It is native to North America and has been extensively studied in Michigan trout streams and Alabama streams. The species exhibits respiratory adaptations to flowing water conditions and serves as a dominant benthic grazer in stream ecosystems.
Glossosomatidae
tortoise-case makers, saddle-case makers, little black caddisflies
Glossosomatidae is a family of caddisflies (order Trichoptera) containing 23 genera across three subfamilies. Larvae construct distinctive domed cases from pebbles bound with silk, giving rise to the common names "tortoise-case makers" or "saddle-case makers." The family has a worldwide distribution with particular diversity in the Americas. Larvae are primarily found in cool, fast-flowing streams where they serve as important bioindicators of water quality due to their sensitivity to pollution and long aquatic life stages.
Glossosomatinae
Glossosomatinae is a subfamily of caddisflies (order Trichoptera) in the family Glossosomatidae. Larvae construct distinctive dome-shaped or tortoise-like portable cases from sand grains and small stones, earning them the common name 'tortoise case makers.' The subfamily is distinguished from the other glossosomatid subfamily, Protoptilinae, primarily by adult genitalic characters and larval case morphology. Members are found in running waters across multiple continents, with larvae serving as important indicators of stream health due to their sensitivity to pollution and habitat disturbance.
Goeldichironomus
Goeldichironomus is a genus of non-biting midges in the family Chironomidae, containing approximately 14 described species. The genus is distributed across the Neotropical and Nearctic regions, with records from Argentina, Brazil, and Colombia. Species in this genus are notable for their short life cycles, tolerance to environmental stress, and colonization of ephemeral aquatic habitats as pioneer species. They serve as important bioindicators in water quality assessments and are widely used in laboratory toxicity studies. The type species Goeldichironomus holoprasinus has been extensively studied in laboratory conditions, completing development from egg to adult in approximately 13 days at 26°C.
Goeldichironomus carus
Goeldichironomus carus is a species of non-biting midge in the family Chironomidae. The species was described by Townes in 1945. It belongs to the tribe Chironomini within the subfamily Chironominae. As with other members of this genus, it is likely associated with freshwater aquatic habitats, though specific ecological details remain limited in published literature.
Gomphidae
Clubtails, Club-tailed Dragonflies
Gomphidae is a family of dragonflies commonly known as clubtails, containing approximately 90 genera and 900 species worldwide. The family name derives from the Greek 'gomphos' meaning 'bolt' or 'nail,' referring to the club-like widening of abdominal segments 7-9, though this feature is reduced in females and absent in some species. Clubtails are distinguished from other dragonfly families by their small, widely separated compound eyes—a trait shared only with Petaluridae and damselflies. The family is the sole member of the superfamily Gomphoidea and has a global distribution across North and South America, Europe, Asia, Australia, and Africa.
Grammotaulius
Grammotaulius is a genus of caddisflies in the family Limnephilidae, established by Kolenati in 1848. The genus contains species distributed across Europe and North America, including at least two recognized species: G. alascensis and G. bettenii. As limnephilid caddisflies, members of this genus are aquatic in their larval stages and terrestrial as adults.
Graphoderus perplexus
predacious diving beetle
Graphoderus perplexus is a predaceous diving beetle in the family Dytiscidae, described by Sharp in 1882. It is distributed across the Holarctic region, occurring in both North America and the Palearctic. Like other members of its genus, it is an aquatic predator inhabiting freshwater environments. The species is part of the tribe Aciliini, which includes other medium to large diving beetles.
Graptocorixa californica
Graptocorixa californica is a species of water boatman in the family Corixidae, first described by Hungerford in 1925. It belongs to the tribe Graptocorixini within the subfamily Corixinae. The species is known to occur in North America, with its specific epithet suggesting a California distribution. Water boatmen in this family are aquatic insects found in freshwater habitats.
Gumaga
bushtailed caddisflies
Gumaga is a genus of bushtailed caddisflies in the family Sericostomatidae, established by Tsuda in 1938. The genus comprises approximately six described species distributed across East Asia and North America. The type species is Gumaga okinawaensis M. Tsuda. Species within this genus are characterized by their association with the bushtailed caddisfly group, a morphologically distinct lineage within Trichoptera.
Gyretes sinuatus
Gyretes sinuatus is a whirligig beetle (family Gyrinidae) inhabiting freshwater systems of North America. Like other gyrinids, it lives on the water surface where it feeds and forms aggregations. The genus Gyretes represents the third North American gyrinid genus alongside Dineutus and Gyrinus, and has been documented across the Ozark region and Arkansas. This species was described by LeConte in 1852.
Gyrinus pugionis
whirligig beetle
Gyrinus pugionis is a species of whirligig beetle in the family Gyrinidae, found in North America. Like other members of the genus, it inhabits the surface of freshwater bodies where it exhibits characteristic erratic, circular swimming patterns. The species was described by Fall in 1922. Specific details regarding its biology and ecology remain limited in published literature.
Habrophlebia vibrans
pronggilled mayfly
A small stream-dwelling mayfly with a 2-year life cycle, notable for its extended development compared to most mayflies. Adults emerge synchronously in June. Nymphs inhabit gravel substrates and show distinct drift patterns across life stages. The species has been studied in Québec populations, where it reaches final sizes of approximately 5 mm before emergence.
Halesochila taylori
Halesochila taylori is a species of northern caddisfly in the family Limnephilidae. It is a small to medium-sized caddisfly with a Nearctic distribution, documented primarily from North America. The species was originally described as Halesus taylori by Banks in 1904 and later transferred to the genus Halesochila. As a member of the Limnephilidae, it is presumed to have an aquatic larval stage and terrestrial adult stage, though specific life history details remain poorly documented in published literature.
Hedriodiscus truquii
Hedriodiscus truquii is a soldier fly (family Stratiomyidae) whose larval ecology has been studied in thermal spring habitats. The species was described by Bellardi in 1859 and occurs in North and Central America. A detailed 4-year ecological study documented its role as a dominant herbivore in two thermal spring communities in Washington State, where larvae feed on algae and serve as a significant energy conduit in these extreme ecosystems. Larvae are aquatic and subject to heavy predation pressure, particularly from spiders on newly emerged adults.
Helicopsyche
Speckled Peter, Spiral Caddisflies
Helicopsyche is a genus of caddisflies (Trichoptera: Helicopsychidae) containing more than 230 species with highest diversity in tropical and sub-tropical regions. The genus is represented on all major faunal regions worldwide. Larvae construct distinctive helical, snail-shell-like cases from sand grains and silk. Adults are known to fly fishers as the 'Speckled Peter'. The genus was first described by Siebold in 1856.
Helopicus subvarians
vernal springfly
Helopicus subvarians is a species of springfly in the family Perlodidae, described by Banks in 1920. It is commonly known as the vernal springfly. Records indicate occurrence in the eastern United States. Like other Plecoptera, it is associated with aquatic habitats during immature stages.
Heptagenia flavescens
flatheaded mayfly
Heptagenia flavescens is a species of flatheaded mayfly in the family Heptageniidae. The species has been documented in North America and Central America, with records indicating a southwestern range extension. As with other members of Heptageniidae, it possesses the characteristic flattened head morphology associated with this group of mayflies.
Heptagenia marginalis
Margined Flat-headed Mayfly
Heptagenia marginalis is a species of flatheaded mayfly in the family Heptageniidae, first described by Banks in 1910. It belongs to a family characterized by dorsoventrally flattened body forms adapted to clinging in fast-flowing water. The species is known from North America, though detailed biological information remains limited in available literature.
Hesperocorixa interrupta
Hesperocorixa interrupta is a species of water boatman in the family Corixidae, first described by Thomas Say in 1825. It belongs to a genus of aquatic true bugs distributed across North America. Water boatmen in this family are characterized by their oar-like hind legs adapted for swimming and their aquatic lifestyle in freshwater habitats.
Hesperocorixa lucida
Hesperocorixa lucida is a species of water boatman in the family Corixidae, described by Abbott in 1916. The species is recorded from North America and belongs to a genus of aquatic true bugs commonly found in freshwater habitats. Like other corixids, it is adapted to life in water with oar-like hind legs modified for swimming.
Hesperocorixa michiganensis
Hesperocorixa michiganensis is a species of water boatman (family Corixidae) described by Hungerford in 1926. It belongs to a genus of aquatic true bugs found in freshwater habitats. The species is recorded from North America, specifically within the Nearctic region. Like other Corixidae, it is adapted to underwater life with modified hind legs for swimming.
Hesperocorixa semilucida
Hesperocorixa semilucida is a species of water boatman in the family Corixidae, described by Walley in 1930. It belongs to a genus of aquatic true bugs found in freshwater habitats. The species is documented from North America. Like other Corixidae, it is an aquatic insect adapted to life in ponds, lakes, and slow-moving waters.
Hesperoperla pacifica
golden stonefly, Golden Stone
Hesperoperla pacifica, commonly known as the golden stonefly, is a species of common stonefly in the family Perlidae. It is native to western North America, with documented populations in Colorado streams and broader distribution across Alberta, Arizona, Alaska, British Columbia, and California. The species has been studied for its life history responses to varying flow regimes and serves as an indicator of stream health in its aquatic habitats.
Hesperophylax
Hesperophylax is a genus of northern caddisflies (Trichoptera: Limnephilidae) comprising seven described species distributed across western North America. The genus is characterized by morphological plasticity and broad habitat tolerance compared to other Trichoptera. Larvae construct portable protective cases and exhibit chemically-mediated antipredator behaviors. All species appear to be univoltine with extended adult flight periods.