Aquatic-insect
Guides
Hesperophylax magnus
northern caddisfly
Hesperophylax magnus is a species of northern caddisfly in the family Limnephilidae, described by Banks in 1918. It is native to North America and is one of seven recognized species in the genus Hesperophylax. Larvae are more predaceous than other Hesperophylax species and exhibit opportunistic omnivory. The species is univoltine with an extended flight period.
Heterelmis glabra
riffle beetle
Heterelmis glabra is a species of riffle beetle in the family Elmidae, found in Central America and North America. The largest known populations occur in springs associated with the upper Devils River in south-central Texas. As a spring-adapted organism, it has life-history patterns requiring surface habitat components, making it vulnerable to changes in spring flow. The species has been studied using N-mixture models to assess abundance and distribution across spring sources.
Heterelmis obscura
Heterelmis obscura is a species of riffle beetle in the family Elmidae, first described by Sharp in 1882. It inhabits freshwater environments in Central and South America. Like other elmid beetles, it is fully aquatic throughout its life cycle, with adults possessing a plastron—a layer of air trapped by body hairs that enables underwater respiration.
Heterelmis vulnerata
riffle beetle
Heterelmis vulnerata is a species of riffle beetle in the family Elmidae, first described by LeConte in 1874. It is distributed across Central America and North America. Riffle beetles are aquatic insects that inhabit fast-flowing, oxygen-rich waters where they spend their entire life cycle submerged. Adults possess a plastron—a layer of air trapped by body hairs that allows them to breathe underwater without surfacing.
Heterlimnius corpulentus
Corpulent Riffle Beetle
Heterlimnius corpulentus is a species of riffle beetle in the family Elmidae, commonly known as the Corpulent Riffle Beetle. It was described by LeConte in 1874 and is found in western North America, with records from the Canadian provinces of Alberta and British Columbia. Riffle beetles in this family are aquatic and associated with flowing water habitats.
Heterocerus pallidus
Heterocerus pallidus is a species of small, elongated beetle in the family Heteroceridae, commonly known as variegated mud-loving beetles. The species was described by Thomas Say in 1823. Members of this family are typically associated with moist, muddy habitats near water bodies. Heterocerus pallidus is one of approximately 250 species in the genus Heterocerus, which has a cosmopolitan distribution with highest diversity in tropical and subtropical regions.
Hexagenia
giant mayflies, burrowing mayflies, fishflies
Hexagenia is a genus of large burrowing mayflies in the family Ephemeridae, comprising eight recognized species. Nymphs construct distinctive U-shaped, ventilated burrows in soft aquatic sediments of lakes, streams, and ponds. Adults are notable for their synchronous mass emergences, which can produce swarms dense enough to appear on weather radar. The genus serves as an important bioindicator of water quality due to its intolerance of pollution and anoxia.
Hexagenia atrocaudata
Lake Hex
Hexagenia atrocaudata is a burrowing mayfly species in the family Ephemeridae, known from North American lakes and rivers. As a member of the common burrower mayflies, it spends the vast majority of its life as an aquatic nymph in bottom sediments, emerging as a short-lived winged adult for reproduction. Adults lack functional mouthparts and do not feed. Mass synchronous emergences can occur, producing swarms that attract fish and anglers alike. The species serves as an important indicator of clean freshwater ecosystems and provides substantial food resources for aquatic and terrestrial predators.
Hexagenia bilineata
Emergent Mayfly
Hexagenia bilineata is a burrowing mayfly native to the Upper Mississippi Valley of North America. The aquatic nymphs construct U-shaped burrows in mud and silt, filtering organic detritus for food. Adults emerge synchronously in enormous numbers during summer evenings, creating spectacular swarms that have caused documented traffic hazards and infrastructure damage. The species exhibits mixed voltinism, with some populations completing development in one year while others require two years.
Hexagenia orlando
Florida Hex
Hexagenia orlando is a burrower mayfly in the family Ephemeridae, described by Traver in 1931. The species is endemic to North America, with the common name "Florida Hex" suggesting a primary association with Florida. As a member of the genus Hexagenia, it exhibits the subterranean burrowing habits characteristic of this group during its nymphal stage. Adult mayflies in this genus typically emerge in synchronized swarms.
Hexagenia rigida
Great Olive-winged Drake
Hexagenia rigida is a burrowing mayfly (Ephemeroptera: Ephemeridae) native to North America. As a member of the common burrower mayfly genus, it spends most of its life as an aquatic nymph in lake and reservoir sediments, with adults emerging synchronously in large swarms. The species has a multi-year life cycle, typically requiring 3-4 years to complete development from egg to adult in northern climates. Laboratory studies indicate that larval growth and mortality are significantly influenced by food availability and density, with food limitation increasing size variation and mortality rates.
Himalopsyche
Himalopsyche is a genus of free-living caddisflies in the family Rhyacophilidae, containing more than 40 described species. The genus is primarily distributed in alpine to montane environments across Central and East Asia and North America, with its greatest diversity concentrated in the Himalayas and surrounding mountain ranges. Species within the genus have been divided into five morphological groups: kuldschensis, lepcha, navasi, phryganea, and tibetana. The genus has served as a model system for studying mountain biodiversity, gene flow, and the mountain-geobiodiversity hypothesis due to its endemic distribution in geologically dynamic regions.
caddisflyRhyacophilidaemountain-biodiversityTibeto-Himalayanaquatic-insectphylogeographygenome-assemblyindicator-speciesgene-flowHengduan-MountainsHimalayasalpinemontanerunning-waterfree-living-caddisflycocoon-makerpredatory-larvaewater-quality-monitoringadaptive-evolutionmountain-geobiodiversity-hypothesisHomophylax
Homophylax is a genus of caddisflies in the family Limnephilidae, described by Banks in 1900. It belongs to the tribe Chilostigmini within the subfamily Limnephilinae. As a limnephilid genus, its members are associated with freshwater habitats where larvae construct protective cases. The genus is poorly documented in public sources, with minimal observational records available.
Husseyella
Husseyella is a genus of small water striders in the family Veliidae, established by Herring in 1955. It belongs to the subfamily Microveliinae, a group of minute aquatic true bugs commonly known as riffle bugs or small water striders. Members of this genus inhabit aquatic environments where they skate on the water surface film. The genus is poorly known, with few documented observations and limited published biological information.
Hydaticus aruspex
Hydaticus aruspex is a predaceous diving beetle in the family Dytiscidae. It occurs across the Holarctic region, including North America and Eurasia. As a member of Hydaticus, it is adapted to aquatic life and functions as an active predator in freshwater systems.
Hydaticus bimarginatus
Hydaticus bimarginatus is a species of predaceous diving beetle in the family Dytiscidae, occurring across North America. The species is moderately well-documented with over 1,000 observations on iNaturalist, indicating established presence in aquatic habitats. As a member of Hydaticus, it is associated with lentic and lotic freshwater systems where it functions as an active predator.
Hydatophylax hesperus
Hydatophylax hesperus is a species of caddisfly in the family Limnephilidae, first described by Banks in 1914. The species belongs to the order Trichoptera, an insect group characterized by aquatic larval stages and terrestrial adults. As a member of the Limnephilidae family, it is part of one of the most diverse families of caddisflies, commonly known as case-making caddisflies. Very little specific biological information is available for this particular species.
Hydrellia
hydrilla leaf mining flies (unofficial, for some species)
Hydrellia is a large genus of shore flies (family Ephydridae) comprising more than 240 described species. The genus is notable for containing aquatic leaf-mining species whose larvae develop inside the tissues of submerged aquatic plants. Several species, particularly H. pakistanae and H. balciunasi, have been introduced to North America as biological control agents against the invasive aquatic weed Hydrilla verticillata. Other species, such as H. tarsata, mine leaves of Water Soldier (Stratiotes aloides) in Eurasian freshwater systems.
Hydrometra martini
water measurer
Hydrometra martini is a species of water measurer in the family Hydrometridae. It is found in North America.
Hydropsyche alhedra
Hydropsyche alhedra is a species of caddisfly described by Ross in 1939. The species is currently recognized as a synonym of Ceratopsyche alhedra, reflecting taxonomic revisions that have moved this taxon to the genus Ceratopsyche. It belongs to the family Hydropsychidae, a group of net-spinning caddisflies known for constructing capture nets in flowing water.
Hydropsyche betteni
Common Netspinner
Hydropsyche betteni is a species of netspinning caddisfly in the family Hydropsychidae, described by Ross in 1938. It is one of the most widespread and commonly encountered members of its genus in North America. Like other hydropsychids, the larvae construct fixed capture nets to filter food from flowing water. The species is well-documented in freshwater biomonitoring studies due to its abundance and sensitivity to water quality.
Hydropsyche bifida
Hydropsyche bifida is a caddisfly species described by Banks in 1905, currently treated as a synonym of Ceratopsyche morosa. It belongs to the family Hydropsychidae, a group of net-spinning caddisflies whose larvae construct capture nets in flowing water to filter food particles. The species has been recorded from North America, specifically from Vermont in the United States.
Hydropsyche bronta
A net-spinning caddisfly species in the family Hydropsychidae. In summer-warm rivers of southern Ontario, populations exhibit trivoltine life cycles, completing three generations per year. Smaller than the sympatric H. morosa and overwinters in slightly older larval instars.
Hydropsyche incommoda
Hydropsyche incommoda is a species of net-spinning caddisfly in the family Hydropsychidae. Described by Hermann Hagen in 1861, this species is part of a large genus of aquatic insects whose larvae construct fixed capture nets in flowing water. Adults are nocturnal and attracted to light. The species is documented from North America.
Hydropsyche morosa
A net-spinning caddisfly species found in summer-warm rivers of southern Ontario. Has been observed to be bivoltine in lower river reaches where summer water temperatures exceed 24°C for extended periods. Larger-bodied than the sympatric Hydropsyche bronta, with which it shares habitat in the Credit and Humber river systems.
Hydropsyche oslari
Hydropsyche oslari is a species of caddisfly (order Trichoptera) in the family Hydropsychidae, first described by Banks in 1905. The species has been reclassified under the genus Ceratopsyche by some authorities, though it is still widely referenced as Hydropsyche oslari. It belongs to a group of net-spinning caddisflies that construct fixed retreats and capture nets in flowing water environments. Like other hydropsychids, the larvae are aquatic filter-feeders that play important roles in stream ecosystems.
Hydropsyche rossi
netspinning caddisfly
Hydropsyche rossi is a species of netspinning caddisfly in the family Hydropsychidae, described by Flint, Voshell & Parker in 1979. It is found in North America within the Nearctic region. As a member of the genus Hydropsyche, it belongs to a group of caddisflies known for constructing fixed retreats and capture nets to filter food from flowing water.
Hydropsyche scalaris
Hydropsyche scalaris is a species of net-spinning caddisfly in the family Hydropsychidae, first described by Hagen in 1861. It belongs to one of the largest genera of caddisflies, with larvae that construct fixed retreats and capture nets in flowing water to filter food particles. The species is documented from North America within the Nearctic region.
Hydropsyche simulans
Hydropsyche simulans is a species of net-spinning caddisfly in the family Hydropsychidae, described by Ross in 1938. Like other members of its genus, it is an aquatic insect whose larvae construct silk nets to capture food in flowing water. The species occurs in North America and is part of the diverse fauna of caddisflies that are ecologically important in freshwater ecosystems and relevant to fly fishing.
Hydropsyche sparna
Hydropsyche sparna is a species of net-spinning caddisfly in the family Hydropsychidae. It has been studied primarily for its behavioral responses to suspended particles and deposited bedload sediment in flowing water environments. The species is currently treated as a synonym of Ceratopsyche sparna in some taxonomic databases. Research on this species has contributed to understanding how filter-feeding aquatic insects modify their foraging behaviors in response to changing environmental conditions.
Hydropsyche walkeri
Hydropsyche walkeri is a species of net-spinning caddisfly in the family Hydropsychidae. Originally described by Betten and Mosely in 1940, it is currently treated as a synonym of Ceratopsyche walkeri. The species belongs to a diverse genus of aquatic insects whose larvae construct elaborate silk nets to capture food in flowing water. Like other hydropsychids, it is associated with freshwater lotic habitats.
Hydropsychinae
net-spinning caddisflies
Hydropsychinae is a subfamily of caddisflies (Trichoptera) within the family Hydropsychidae, commonly known as net-spinning caddisflies. Larvae construct fixed capture nets in flowing water to filter food particles. The subfamily is taxonomically diverse, with generic revisions documented in multiple regions including New Zealand and the Americas.
Hydropsychoidea
net-spinning caddisflies
Hydropsychoidea is a superfamily of caddisflies (order Trichoptera) first described by Curtis in 1835. The constituent families, particularly Hydropsychidae, are commonly known as net-spinning caddisflies due to the distinctive capture nets constructed by their larvae. These insects are predominantly aquatic in their immature stages and are among the most frequently observed caddisflies in stream environments worldwide.
Hydroptila arctia
Hydroptila arctia is a species of microcaddisfly in the family Hydroptilidae, first described by Ross in 1938. It belongs to the diverse genus Hydroptila, which comprises numerous small caddisfly species found across various aquatic habitats. The species is known from North America and has been recorded in both Nearctic and Neotropical regions.
Hydroptila grandiosa
microcaddisfly
Hydroptila grandiosa is a species of microcaddisfly in the family Hydroptilidae, described by Ross in 1938. As a member of the order Trichoptera, it belongs to a group of aquatic insects closely related to moths and butterflies. The species is recorded from North America. Microcaddisflies in this genus are generally small-bodied and associated with freshwater habitats.
Hydroptila rono
microcaddisfly
Hydroptila rono is a species of microcaddisfly (family Hydroptilidae) described by Ross in 1941. As a member of the order Trichoptera, it is an aquatic insect with larvae that develop in freshwater habitats. The species is known from North America, though specific details about its ecology and biology remain limited in available literature.
Hydroptiloidea
microcaddisflies, purse-case caddisflies
Hydroptiloidea is a superfamily of caddisflies (Trichoptera) containing the family Hydroptilidae. Members are distinguished by their minute size, rarely exceeding 5 mm, and the distinctive purse-shaped larval cases constructed only in the final instar. The group has a worldwide distribution and represents one of the most species-rich lineages within Trichoptera.
Hydrovatus
Hydrovatus is a genus of diving beetles in the family Dytiscidae, subfamily Hydroporinae, and tribe Hydrovatini. The genus comprises approximately 214 species globally, with documented presence across Asia, Europe, and the Americas. Members are aquatic beetles inhabiting lentic and slow-moving lotic freshwater environments. The genus was established by Motschulsky in 1853.
Hylogomphus apomyius
Banner Clubtail
Hylogomphus apomyius, commonly known as the Banner Clubtail, is a dragonfly species in the family Gomphidae. It is one of several small clubtail species within the genus Hylogomphus, characterized by relatively modest abdominal clubbing compared to larger gomphids. The species was described by Donnelly in 1966 and occurs in eastern North America. It is associated with riverine habitats and is considered uncommon throughout its range.
Hylogomphus viridifrons
Green-faced Clubtail
Hylogomphus viridifrons, commonly known as the Green-faced Clubtail, is a dragonfly species in the family Gomphidae. It is a medium-sized clubtail characterized by distinctive green facial coloration. The species is found in eastern North America, where it inhabits clean, flowing streams and rivers.
Integripalpia
Integripalpia is a suborder of caddisflies (Trichoptera) distinguished by adults having unringed terminal segments on their maxillary palps. Larvae are aquatic and construct portable protective cases from debris beginning in the first instar, enlarging them through subsequent developmental stages. Case construction is often highly specific, with distinctive architectural patterns characteristic of particular families and genera. The suborder includes diverse lineages distributed across aquatic habitats worldwide.
Ironodes
Ironodes is a genus of mayflies in the family Heptageniidae, first described by Traver in 1935. Members of this genus are part of the diverse Heptageniidae family, commonly known as flat-headed mayflies due to their distinctive head morphology. The genus is represented by relatively few observations, suggesting it may be uncommon, geographically restricted, or underreported in surveys.
Ironodes nitidus
Ironodes nitidus is a species of flat-headed mayfly in the family Heptageniidae. The species was described by Eaton in 1885. It belongs to a genus of mayflies found in North America, with records from the Nearctic region including Middle America and North America. The genus Ironodes is part of the diverse Heptageniidae family, which contains many species adapted to running water habitats.
Ironoquia lyrata
eastern boxed-wing sedge
Ironoquia lyrata is a species of caddisfly (order Trichoptera) in the family Limnephilidae, commonly known as the eastern boxed-wing sedge. It was described by Ross in 1938 and is found in North America. The species belongs to the subfamily Dicosmoecinae, a group of northern caddisflies.
Ironoquia parvula
northern caddisfly
Ironoquia parvula is a species of caddisfly in the family Limnephilidae, described by Banks in 1900. It is classified within the subfamily Dicosmoecinae and is one of the species in the genus Ironoquia. The species is known to occur in North America.
Ironoquia punctatissima
northern caddisfly
Ironoquia punctatissima is a species of northern caddisfly in the family Limnephilidae. Its life cycle has been documented from populations in temporary streams of southern Ontario, including a description of its previously undescribed pupal stage. The species occurs in North America within the Nearctic region.
Isogenoides frontalis
Hudsonian springfly
Isogenoides frontalis, known as the Hudsonian springfly, is a stonefly species in the family Perlodidae. It is one of several species in the genus Isogenoides found in North America. The species has been documented in the northern United States and Canada, including Michigan, Minnesota, Maine, and Manitoba. Research on the genus indicates that Isogenoides species exhibit complex vibrational communication (drumming) behaviors and extended egg diapause lasting up to several years.
Isonychia
Slate Drakes, Brushlegged Mayflies
Isonychia is a genus of mayflies comprising over 30 described species, commonly known as Slate Drakes or brushlegged mayflies. The genus is the sole member of the family Isonychiidae. Nymphs are notable for possessing raptorial forelegs adapted for predation, a trait uncommon among mayflies. Some species exhibit habitat generalist ecology while others are specialized to intermittent streams.
Isonychia arida
arid howdy mayfly
Isonychia arida is a species of brushlegged mayfly in the family Isonychiidae. It was described by Thomas Say in 1839, originally as Baetis arida. The species is found in North America and is known by the common name "arid howdy mayfly." Like other members of the genus Isonychia, it belongs to a group commonly referred to as "slate drakes" by anglers.
Isonychia bicolor
mahogany dun
Isonychia bicolor, commonly known as the mahogany dun, is a species of brushlegged mayfly in the family Isonychiidae. It is found in southeastern Canada and the eastern United States. Like all mayflies, it undergoes incomplete metamorphosis with aquatic nymphal stages and short-lived winged adults. The species is part of the EPT (Ephemeroptera-Plecoptera-Trichoptera) biological index used to assess water quality.