Euholognatha
Guides
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-emergingmaintainlowhighdissolvedoxygenlevelsthroughoutyearUnitedStatesdistributioncenteredextendssoutheasternmonthstypicallythroughthisactivitygivesrisecommonnamedonotprovidesqualitymonitoringnodirecthabitatmorphologysizegenitalicNemouroidea
Rolled-winged Stoneflies, Forest Stoneflies, Winter Stoneflies
Nemouroidea is a superfamily of stoneflies (Plecoptera) within the suborder Arctoperlaria, comprising five families: Capniidae (winter stoneflies), Taeniopterygidae, Nemouridae, Notonemouridae, and Leuctridae. These stoneflies are predominantly found in freshwater habitats across the Northern Hemisphere. The group includes notable cold-adapted species such as snow flies that emerge during winter months.