Winter-stonefly
Guides
Allocapnia
winter stoneflies
Allocapnia is a genus of small winter stoneflies in the family Capniidae, comprising at least 40 described species. Adults emerge during winter months, typically from December through March. Nymphs inhabit stream substrates and exhibit vertical movement within the hyporheic zone, often retreating to deeper substrate during summer diapause and returning to surface layers in autumn.
Allocapnia maria
Two-knobbed Snowfly
Allocapnia maria, the two-knobbed snowfly, is a small winter stonefly in the family Capniidae. The species was described by Hanson in 1942 and occurs in eastern North America. Like other winter stoneflies, it is active during cold months when most other insects are dormant.
Allocapnia nivicola
brook snowfly
Allocapnia nivicola is a small winter stonefly in the family Capniidae, commonly known as the brook snowfly. It is native to North America and has been documented across the eastern and midwestern United States. As a member of the winter stonefly group, it is active during cold months when most other insects are dormant. The species is one of approximately 40 described species in the genus Allocapnia.
Allocapnia pygmaea
Pygmy Snowfly
Allocapnia pygmaea, commonly known as the pygmy snowfly, is a small winter stonefly in the family Capniidae. It is one of the smallest members of its genus and is found across eastern and midwestern North America. As a winter stonefly, it is active during cold months when most other insects are dormant.
Allocapnia recta
Eastern Snowfly
Allocapnia recta, commonly known as the eastern snowfly, is a small winter stonefly in the family Capniidae. The species exhibits a univoltine slow-season life cycle with adult emergence occurring during January-February. It inhabits karst headwater streams, where it has been observed at higher densities in intermittent flow sections compared to permanent flow sections. The species is found in eastern North America.
Allocapnia rickeri
Midwest Snowfly
Allocapnia rickeri is a small winter stonefly in the family Capniidae, commonly known as the Midwest Snowfly. It is one of numerous small, dark stoneflies in the genus Allocapnia that emerge during cold months when few other insects are active. The species has been documented across the central and eastern United States. Like other capniids, it is associated with clean, cold streams and is an important indicator of water quality.
winter-stoneflybioindicatorcoldwaterPlecopteraCapniidaeAllocapnialoticemergencebrachypteryapterygenitalia-identificationFrison-1942Midwestsoutheastern-USclean-water-indicatorJanuary-Marchsmall-stoneflywingless-femalestream-insectshreddergathererseasonal-resourcewater-qualityaquatic-insectterrestrial-adultshort-lived-adultovipositionsubmerged-eggshigh-dissolved-oxygenlow-temperaturecentral-USeastern-USAlabamaArkansasDelawareGeorgiaIllinoishexapodhemimetabolousEuholognathaNemouroideaArctoperlariaInsectaArthropodaAnimaliaGBIFCatalogue-of-LifeiNaturalistNCBItaxonomyaccepted-species1942FrisonRickerMidwest-Snowflysnowflysmall-dark-stoneflyclean-streamsriverswell-oxygenatedlotic-habitatcold-monthswinter-activitywing-reductionfemale-apterymale-flightepiproctparaproctterminaliataxonomic-revisioncongenersdistribution-recordsobservations9-observationseukaryotemetazoanarthropodinsectstoneflywinter-emergingJanuaryFebruaryMarchcold-weathernear-freezingbelow-freezingwater-surfacesubmerged-substratesallochthonous-organic-materialstream-ecosystemsseasonal-food-resourceinsectivorous-birdspredatorsscarce-preyunpollutedno-economic-importancestream-monitoringwater-quality-indicatorhigh-quality-coldwatermicroscopic-examinationtaxonomic-keysmale-terminaliareliable-separationgenitalic-examinationoverlapping-distributionsimilar-habitatsmall-sizeunder-10-mmbody-lengthreduced-wingsabsent-wingsfully-developed-wingsspecific-identificationpublished-descriptionsillustrationssubsequent-revisionscharacteristicfamily-Capniidaecommon-nameextended-nymphal-periodone-to-two-yearsshort-liveddoes-not-feedaquatic-nymphclean-cold-streamslow-temperaturesyear-roundwinter-monthsJanuary-through-Marchfamilycentered-Midwestextends-southeasternUnited-Statesdocumentedappearsmost-reliablydistinguishedsubtle-differencesterminal-abdominal-structuresshould-be-comparedagainstpublishedsubsequentgenus-levelcharacterizedreducedabsentfemalesfully-developedmalesrequires-examinationmale-genitaliastructureparaproctsreliableseparationoverlapssimilarmanyexternallydefinitivereliesmicroscopicexaminationcomparisonkeysusedbiologicalindicatorprogramspresenceindicatescoldconditionsno-directeconomicimportanceshreddersgatherersprocessingallochthonousorganicmaterialstreamecosystemsseasonalfoodresourceinsectivorousbirdsotherwhenalternativepreyscarceserveshigh-qualityhabitatsdevelopmentaquaticnymphalstagesterrestrialadultstagenymphsdevelopstreamsextendedperiodlikelyonetwoyearsbasedrelatedspeciesadultsdo-notfeedactiveduringweatherairtemperaturesmaynearbelowfreezingwingedcapableflightwinglessshort-wingedremainwatersurfacematingoccurwinterenteringdepositeggssubmergedsubstratessmallcommonlyknownnumerousdarkemergefewinsectscentraleasternassociatedcleanimportantundermmbodylengthmembersgenuswingspossessfullydevelopedspecificidentificationlevelwithinrequiresmalegenitaliaparticularlymostreliablysubtledifferencestheseterminalabdominalstructuresshouldcompareddescriptionstaxonomicrevisionswinter-emergingmaintainlowhighdissolvedoxygenlevelsthroughoutyearUnitedStatesdistributioncenteredextendssoutheasternmonthstypicallythroughthisactivitygivesrisecommonnamedonotprovidesqualitymonitoringnodirecthabitatmorphologysizegenitalicAllocapnia vivipara
Shortwing Snowfly, short-wing snowfly
Allocapnia vivipara, commonly known as the shortwing snowfly, is a species of small winter stonefly in the family Capniidae. It is native to North America and has been recorded from multiple states in the central United States. The species was originally described as Capnella vivipara by Claassen in 1924 before being transferred to Allocapnia. As a winter stonefly, it belongs to a group adapted to cold-season activity.
Bolotoperla
winter stonefly
Bolotoperla is a genus of winter stoneflies in the family Taeniopterygidae, containing a single described species, B. rossi. The genus was established by Ricker & Ross in 1975. Winter stoneflies are active during cold months, distinguishing them from most other stonefly groups.
Bolotoperla rossi
Smoky Willowfly
Bolotoperla rossi is a species of stonefly in the family Taeniopterygidae, commonly known as the Smoky Willowfly. Originally described as Brachyptera rossi by Frison in 1942, it was later transferred to the genus Bolotoperla. This species belongs to the winter stonefly group, which are active during cold months when most other insects are dormant.
Capnia lineata
Straight Snowfly
Capnia lineata is a species of small winter stonefly in the family Capniidae. It is known from scattered records in western North America, including California and Idaho. As a member of the Capniidae, it belongs to a group commonly called "small winter stoneflies" or "snowflies" that are typically active during cold months. The species was described by Hanson in 1943. Very little detailed biological information has been published specifically for this species.
Capnia promota
Pacific Snowfly
Capnia promota is a species of small winter stonefly in the family Capniidae. It is commonly known as the Pacific Snowfly due to its distribution along the Pacific coast of North America. The species was described by Frison in 1937. Like other Capniidae, it is active during the winter months when most other insects are dormant.
Capnia umpqua
Umpqua Snowfly
Capnia umpqua, commonly known as the Umpqua Snowfly, is a small winter stonefly species in the family Capniidae. It was described by Frison in 1942. The species occurs in western North America, with documented records from California and Oregon. As a member of the Capniidae, it belongs to a group of stoneflies adapted to cold-water environments and winter-emergence patterns.
Capnia zukeli
Idaho snowfly
Capnia zukeli, known as the Idaho snowfly, is a small winter stonefly species in the family Capniidae. It was described by Hanson in 1943. The species is known from Idaho and the broader Nearctic region of North America. As a member of Capniidae, it belongs to a group of cold-adapted stoneflies active during winter months.
Capnura
small winter stoneflies
Capnura is a genus of small winter stoneflies in the family Capniidae, established by Banks in 1900. The genus contains approximately seven described species distributed primarily in North America. These stoneflies are part of the winter-emerging group of Plecoptera, with adults typically active during cold months when most other insects are inactive.
Capnura manitoba
Manitoba snowfly
Capnura manitoba, commonly known as the Manitoba snowfly, is a small winter stonefly in the family Capniidae. It is one of several species in the genus Capnura, which are characterized by their cold-season activity patterns. The species was first described by Claassen in 1924 from Manitoba. Like other members of the Capniidae, it is adapted to cold-water environments and exhibits winter-emergence behavior typical of this stonefly family.
Eucapnopsis brevicauda
short-tailed snowfly
Eucapnopsis brevicauda is a small winter stonefly in the family Capniidae, commonly known as the short-tailed snowfly. It has a transpacific distribution spanning North America and eastern Asia, with confirmed records from Canada, the United States, Mongolia, Russia, and South Korea. Adults emerge during late winter to spring and are typically found in association with cold, running water in sub-montane stream habitats. The species was previously misidentified as E. quattuorsegmentata in Korean records.
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.
Oemopteryx
winter stoneflies, willowflies
Oemopteryx is a genus of winter stoneflies in the family Taeniopterygidae, established by Klapálek in 1902. The genus comprises approximately six described species distributed primarily in the Nearctic region, with some records from Europe. Species are commonly known as willowflies, including the dark willowfly (O. contorta) and Canadian willowfly (O. glacialis). Recent taxonomic work has described additional Nearctic species from the southeastern United States using integrated morphological and molecular data.
Oemopteryx contorta
Dark Willowfly
Oemopteryx contorta, commonly known as the dark willowfly, is a species of winter stonefly in the family Taeniopterygidae. The species was described by Needham and Claassen in 1925. It is native to North America, with documented records from Alabama, Connecticut, Georgia, Kentucky, and Maine. As a member of the order Plecoptera, it belongs to a group of aquatic insects whose nymphal stages develop in freshwater environments.
Oemopteryx glacialis
Canadian willowfly
Oemopteryx glacialis, commonly known as the Canadian willowfly, is a winter stonefly species in the family Taeniopterygidae. It is one of several North American stoneflies adapted to cold-weather activity, with adults emerging during winter months when most other insects are inactive. The species has been recorded from the northeastern United States and adjacent Canada, including Connecticut, Michigan, Minnesota, New York, and Ontario.
Paracapnia
small winter stoneflies
Paracapnia is a genus of small winter stoneflies in the family Capniidae, native to North America. The genus contains at least five described species, including the angulate snowfly (Paracapnia angulata) and the northeastern snowfly (Paracapnia opis). Members of this genus are notable for their tolerance of acidic stream conditions, with some species increasing in abundance in waters affected by acid precipitation.
Paracapnia angulata
angulate snowfly
Paracapnia angulata is a small winter stonefly in the family Capniidae. The species occurs in headwater streams across eastern North America, with documented populations in Appalachian streams affected by acid precipitation. Research indicates it tolerates a wide pH range (4.5–7.5) and can achieve high secondary production in acidic conditions due to increased abundance and biomass, despite lower individual growth rates. Nymphs serve as prey for steelhead trout.
Paracapnia boris
Colusa Snowfly
Paracapnia boris is a species of winter stonefly in the family Capniidae, described by Stark & Baumann in 2004. It is known from California and is commonly referred to as the Colusa Snowfly. Like other capniids, it is likely active during cold months when few other insects are present. The species name honors someone named Boris, presumably a colleague or contributor to stonefly research.
Paracapnia humboldta
Redwood Snowfly
Paracapnia humboldta is a species of small winter stonefly in the family Capniidae, described from California in 2007. It belongs to a genus of snowflies that are active during cold months. The species epithet references Humboldt County, where the type specimen was collected. It is one of the more recently described members of this genus in western North America.
Paracapnia opis
Northeastern Snowfly
Paracapnia opis, the northeastern snowfly, is a small winter stonefly in the family Capniidae. It was the first species described in the genus Paracapnia, established by Edward Newman in 1839. The species is found in North America, with records from the northeastern United States and adjacent Canada. It is synonymous with Paracapnia curvata, described by Hanson in 1946.
Strophopteryx
mottled willowfly (for S. fasciata)
Strophopteryx is a genus of winter stoneflies comprising seven described species. Members are found in the Holarctic region, with records from North America and the Russian Far East. The genus belongs to the family Taeniopterygidae, a group characterized by adult emergence during cold months. Strophopteryx fasciata, the mottled willowfly, is the most well-known species and has been the subject of mitochondrial genome sequencing.
Taenionema
winter stoneflies
Taenionema is a genus of winter stoneflies (Plecoptera: Taeniopterygidae) comprising approximately 14 described species. The genus was established by Banks in 1905 with Taenionema analis as the type species. Species are distributed across the Nearctic and eastern Palearctic regions, with 13 species native to North America and one species (T. japonicum) ranging across Japan, Korea, Mongolia, Russia and northeastern China. A second Eastern Hemisphere species, T. sinensis, was described in 2023 from southeastern China.
Taenionema atlanticum
Atlantic willowfly
Taenionema atlanticum, known as the Atlantic willowfly, is a species of winter stonefly in the family Taeniopterygidae. It was described by Ricker & Ross in 1975. The species is known from a limited number of observations and records in eastern North America.
Taenionema californicum
California willowfly
Taenionema californicum, commonly known as the California willowfly, is a species of winter stonefly in the family Taeniopterygidae. It is native to North America, with documented presence in California. As a member of the order Plecoptera, it is associated with freshwater habitats. The species was first described by Needham and Claassen in 1925.
Taenionema oregonense
Oregon Willowfly
Taenionema oregonense, commonly known as the Oregon Willowfly, is a species of winter stonefly in the family Taeniopterygidae. The species was described by Needham & Claassen in 1925. It belongs to the order Plecoptera, a group of aquatic insects whose nymphs develop in freshwater habitats.
Taeniopteryx burksi
Eastern Willowfly
Taeniopteryx burksi, commonly known as the eastern willowfly, is a winter stonefly species in the family Taeniopterygidae. It was described by Ricker and Ross in 1968 and is distributed across eastern and central North America. The species belongs to a group of stoneflies adapted to cold-water environments and winter emergence patterns.
Taeniopteryx nivalis
boreal willowfly
Taeniopteryx nivalis, commonly known as the boreal willowfly, is a winter stonefly species in the family Taeniopterygidae. It is native to North America and has been recorded from multiple regions including Alberta, California, Connecticut, Delaware, and Idaho. As a member of the order Plecoptera, it belongs to a group of aquatic insects whose nymphs develop in freshwater habitats. The species was first described by Fitch in 1847.
Utacapnia
small winter stoneflies
Utacapnia is a genus of small winter stoneflies in the family Capniidae. The genus contains approximately 11 described species, most of which were first described by entomologists Alan V. Nebeker and Arden R. Gaufin during the 1960s. Species in this genus are primarily distributed in the Rocky Mountains of North America. As winter stoneflies, members of this genus are active during cold months, a trait characteristic of the family Capniidae.
Utacapnia logana
Logan Snowfly
Utacapnia logana is a small winter-emerging stonefly in the family Capniidae, commonly known as the Logan Snowfly. It is native to the Rocky Mountain region of the western United States, where it inhabits cold, clean mountain streams. Adults emerge during winter months, a trait characteristic of the Capniidae family. The species was originally described as Capnia logana in 1965 before being transferred to the genus Utacapnia.
Utacapnia trava
Yellowstone Snowfly
Utacapnia trava, commonly known as the Yellowstone snowfly, is a small winter stonefly in the family Capniidae. It is one of approximately 16 species in the genus Utacapnia, which is endemic to western North America. The species was originally described as Capnia trava in 1965 before being transferred to Utacapnia. Like other winter stoneflies, adults are active during cold months when most other insects are dormant.