Bioindicators
Guides
Acroneuria
common stoneflies
Acroneuria is a genus of large-bodied stoneflies in the family Perlidae, containing more than 30 described species distributed across North America and Asia. Nymphs are predatory and inhabit streams and rivers, where they serve as important bioindicators of water quality. Adults are known for distinctive emergence behaviors, including arboreal emergence in some species. Several species in the genus are experiencing range contractions and population declines due to habitat degradation and climate change.
Annulipalpia
fixed-retreat makers
Annulipalpia is a suborder of Trichoptera (caddisflies) distinguished by the flexible, multi-ringed terminal segment of the adult maxillary palps. Larvae are aquatic and construct fixed retreats—stationary structures to which they remain attached—rather than portable cases. Some families build simple silken tubes anchored to the substrate, while others spin silken nets for filter feeding. The suborder includes families such as Psychomyiidae, Ecnomidae, Xiphocentronidae, Polycentropodidae, and Dipseudopsidae.
Arcynopterygini
springflies
Arcynopterygini is a tribe of springflies (Plecoptera) within the family Perlodidae. The tribe contains approximately 11 genera and more than 30 described species. Members are distributed across the Northern Hemisphere, with genera found in North America, Europe, and Asia. The tribe was established by Ricker & Scudder in 1975.
Aulogymnus
Aulogymnus is a genus of chalcidoid wasps in the family Eulophidae, first described by Förster in 1851. Members of this genus are small parasitoid wasps, part of a diverse family that primarily parasitizes other insects. The genus has been recorded from Europe and Asia. Specific biological details for the genus as a whole remain poorly documented in accessible literature.
parasitoidEulophidaeChalcidoideaHymenopteraPalearcticwaspsinsectsarthropodsentomologytaxonomyFörster-1851DenmarkSpainTibetChinaEuropeAsiaminute-waspschalcid-waspsEulophinaeTerebrantesApocritaHexapodaAnimaliaArthropodaInsectaAulogymnussmall-waspstiny-waspsparasitic-waspsbiological-controlinsect-parasitoidssystematicsmorphologyidentificationkeysNearcticOrientalXizangcitizen-scienceiNaturalistobservationsrecordsdistributionFörster1851genusacceptedvalidsynonymychalcidoidchalcidchalcidseulophideulophidseulophid-waspseulophinesparasitoid-waspsparasitic-Hymenopterabiological-control-agentsinsect-diversitybiodiversityfaunaentomologicalhymenopteranarthropodhexapodhexapodspterygotepterygotesendopterygoteendopterygotesholometabolousholometabolatiny-insectsminute-insectssmall-insectsmicrohymenopteramicro-waspsmicro-parasitoidsmicro-chalcidsmicro-eulophidswing-venationantennaethoraxdiagnostic-characterstaxonomic-keysidentification-keysgeneric-keysNearctic-faunaEuropean-faunaAsian-faunaTibetan-faunaSpanish-faunaDanish-faunapoorly-knowndata-deficientunderstudiedcryptic-diversityhost-unknownbiology-unknownlife-history-unknownecology-unknowndistribution-recordsoccurrence-recordsspecimen-recordsmuseum-recordsdatabase-recordsGBIFCatalogue-of-LifeNCBIWikipediaUniversal-Chalcidoidea-DatabaseKey-to-Nearctic-eulophid-generaliteraturesourcesreferencescitationsbibliographyoriginal-descriptiontype-speciestype-localitynomenclaturesystematic-entomologyhymenopterologychalcidologyparasitologybiological-control-researchintegrated-pest-managementIPMagricultural-entomologyforest-entomologymedical-entomologyveterinary-entomologyurban-entomologyconservation-entomologyinsect-ecologycommunity-ecologypopulation-ecologybehavioral-ecologyevolutionary-ecologyphylogeneticsphylogenymolecular-systematicsDNA-barcodingtaxonomy-and-phylogenyclassificationbiodiversity-informaticsbiogeographyhistorical-biogeographyphylogeographydispersalvicariancespeciationdiversificationevolutionadaptationnatural-selectionsexual-selectionlife-history-evolutionhost-parasitoid-interactionscoevolutiontritrophic-interactionsfood-websecosystem-servicesnatural-enemiesbiocontrolaugmentative-biological-controlclassical-biological-controlconservation-biological-controlinvasive-species-managementpest-managementsustainable-agricultureorganic-farmingagroecologyecosystem-healthenvironmental-monitoringbioindicatorsindicator-speciesclimate-changeglobal-changehabitat-lossfragmentationconservation-statusIUCNred-listnot-evaluatedresearch-needsknowledge-gapsfuture-researchprioritiesspecimen-collectionvoucheringmuseum-collectionsnatural-history-collectionsdigitizationdata-sharingopen-scienceFAIR-principlescitizen-science-contributionscommunity-sciencepublic-engagementscience-communicationeducationoutreachnatural-historyinsect-watchingwasp-watchingnature-observationbiodiversity-appreciationBaetidae
small mayflies, small minnow mayflies
Baetidae is the most species-diverse family of mayflies, comprising approximately 1,000 described species in 110-114 genera worldwide and representing about one-third of all mayfly diversity. Adults are among the smallest mayflies, rarely exceeding 10 mm in length excluding tails, with some species much smaller. The family has a cosmopolitan distribution except for New Zealand and occupies a relatively basal position in Ephemeroptera phylogeny.
Baetiscidae
armored mayflies
Baetiscidae is a family of mayflies distinguished by their heavily armored nymphs bearing a robust, spiked thoracic notal shield that extends over part of the abdomen. The family contains a single extant genus, Baetisca, with approximately 12 species endemic to North America. Three extinct genera (Protobaetisca, Balticobaetisca, Koonwarrabaetisca) are known from Cretaceous and Eocene deposits, indicating a Pangean origin for the family by at least the Early Jurassic. Together with Prosopistomatidae, Baetiscidae forms the clade Carapacea, characterized by specialized larval armor.
Chironominae
non-biting midges
Chironominae is a subfamily of non-biting midges (Diptera: Chironomidae) containing over 2,000 described species across three tribes: Chironomini, Pseudochironomini, and Tanytarsini. Members are globally distributed and primarily aquatic in their immature stages. The subfamily includes economically and ecologically significant genera such as Chironomus, Polypedilum, and Tanytarsus. Adults are characterized by reduced mouthparts and do not feed; larvae are diverse in habitat specialization, ranging from freshwater lakes and rivers to marine environments and phytotelmata.
Chironomini
non-biting midges
Chironomini is a diverse tribe of non-biting midges within the family Chironomidae. Adults are mosquito-like in appearance but lack piercing mouthparts and are harmless to humans. Larvae are primarily aquatic and play significant roles in freshwater food webs. The tribe contains numerous genera distributed across multiple continents, with species occupying varied freshwater habitats from oligotrophic lakes to eutrophic waters.
Chironomus
nonbiting midges, bloodworms
Chironomus is a genus of nonbiting midges in the family Chironomidae, containing over 200 species. Several species are cryptic and distinguishable only by experts using giant chromosome characteristics. The genus is notable for larvae that inhabit oxygen-poor aquatic sediments, using hemoglobin-like proteins to survive in hypoxic conditions. Adults are recognized by their habit of raising and vibrating their front legs when at rest—a behavior that inspired the genus name derived from Greek 'cheironomos' meaning 'one who moves the hands'.
Chloroperlini
green stoneflies
Chloroperlini is a tribe of green stoneflies within the family Chloroperlidae. Members are characterized by their predominantly green coloration as adults and are associated with lotic freshwater habitats. The tribe contains multiple genera distributed across the Northern Hemisphere. Larvae are aquatic and typically found in cool, well-oxygenated streams.
Collembola
springtails
Collembola (springtails) are minute hexapods, traditionally grouped with insects but now recognized as a distinct class of non-insect hexapods. They are among the most abundant soil arthropods globally, with estimates of 200–1,800 individuals per cubic decimeter of forest soil. Most species measure 1–3 mm, though some reach 6 mm and the largest known species attains 17 mm. They occupy diverse habitats including soil, leaf litter, caves, rodent burrows, intertidal zones, ant and termite nests, freshwater surfaces, and snow fields. The group is defined by several unique morphological features: a ventral collophore on the first abdominal segment, a furcula (springing organ) on the third or fourth abdominal segment in most species, internal mouthparts (entognathy), and fused tibio-tarsal leg segments. They exhibit simple metamorphosis and continue molting throughout adult life, up to 50 times.
Corydalinae
Dobsonflies
Corydalinae is a subfamily of large megalopteran insects commonly known as dobsonflies. Adults are among the largest winged insects in their range, with males of some species possessing dramatically elongated mandibles used in intraspecific combat. Larvae, called hellgrammites, are aquatic predators inhabiting clean, fast-flowing streams. The subfamily contains nine genera distributed across the Americas, Asia, and South Africa, with notable Oriental genera including Neurhermes and Nevromus. Some Corydalinae species exhibit striking coloration patterns that likely represent Batesian mimicry of diurnal toxic moths.
Drunella
Blue-winged Olives, Spiny Crawler Mayflies
Drunella is a genus of spiny crawler mayflies in the family Ephemerellidae, comprising at least 20 described species. These mayflies are aquatic insects with nymphs that inhabit stream environments and are significant components of freshwater food webs. Adults are important to fly fishermen, who commonly refer to them as "Blue-winged Olives" and imitate them with artificial flies. Some species, such as Drunella grandis (the green drake), are particularly valued as trout food sources.
Dubiraphia
riffle beetles
Dubiraphia is a genus of riffle beetles in the family Elmidae, established by Sanderson in 1954. The genus contains approximately 11 described species distributed in North America. These beetles are aquatic or semi-aquatic, inhabiting flowing water environments. Species within Dubiraphia are distinguished by morphological features of the elytra and male genitalia.
Ephemeridae
Burrowing Mayflies
Ephemeridae is a family of large mayflies comprising approximately 150 described species distributed worldwide except Australia and Oceania. Adults range up to 35 mm in length and possess either two or three elongated caudal filaments. Many species exhibit distinctively patterned wings. The family is commonly known as "burrowing mayflies" due to the fossorial adaptations of their nymphs, which inhabit silty or sandy substrates in freshwater systems. Nymphs possess specialized morphological features including spur-like projections on foretibiae, dorsally positioned plumose and lanceolate abdominal gills, and mandibular tusks that facilitate burrowing behavior.
Ephemeroptera
mayflies, Canadian soldiers, shadflies, fishflies, up-winged flies
Mayflies (Ephemeroptera) represent the oldest known winged insects, with fossil evidence dating to approximately 350 million years ago in the lower Carboniferous. The order contains over 3,000 described species across more than 400 genera and 42 families worldwide. Adults are characterized by short lifespans—typically hours to days—and a unique subimaginal stage where the winged but sexually immature subimago undergoes a final molt to become a reproductive imago. Larvae are exclusively aquatic and serve as important indicators of water quality in freshwater ecosystems.
Folsomia
Folsomia is a genus of elongate-bodied springtails in the family Isotomidae, containing more than 110 described species. Members of this genus are primarily soil-dwelling and are among the most commonly studied Collembola in ecotoxicological research. The genus has a cosmopolitan distribution spanning multiple continents and biomes.
Gyrininae
whirligig beetles, gyrinine beetles
Gyrininae is the largest subfamily of Gyrinidae, containing over 740 described extant species. These beetles are commonly known as whirligig beetles for their characteristic circling behavior on water surfaces. The subfamily comprises three tribes: Dineutini, Gyrinini, and Orectochilini, with genera distributed across all major biogeographic regions. Members occupy diverse freshwater habitats from lentic to lotic systems.
Helopicus
springflies
Helopicus is a genus of springflies (order Plecoptera) in the family Perlodidae, established by Ricker in 1952. The genus contains at least four described species distributed across eastern North America and parts of Asia. Species in this genus are part of the stonefly group Systellognatha, characterized by their predatory or omnivorous feeding habits as nymphs.
Heptageniidae
Stream Mayflies, Flat-headed Mayflies
Heptageniidae is a family of mayflies comprising over 500 described species, commonly known as stream mayflies or flat-headed mayflies. Members are generally small with three long tails, clear wings with prominent venation, and males possess large compound eyes that are not divided into upper and lower parts. The family is primarily distributed across the Holarctic, Oriental, and Afrotropical regions, with additional presence in Central American tropics and extreme northern South America. Nymphs are flattened in shape, typically dark in coloration, and inhabit fast-flowing streams where they exhibit diverse feeding strategies including herbivory, scavenging, and predation.
Hydropsychidae
Net-spinning Caddisflies
Hydropsychidae, commonly known as net-spinning caddisflies, is a family of aquatic insects in the order Trichoptera. Larvae construct silk nets at the openings of their retreats to capture food particles from flowing water. The family is globally distributed in freshwater habitats and serves as important bioindicators of stream health. Larvae exhibit unique behaviors including territorial defense through stridulation and competitive interactions for retreat ownership.
Laccobius
water scavenger beetles
Laccobius is a diverse genus of water scavenger beetles in the family Hydrophilidae, with more than 80 described species worldwide. Species are classified into several subgenera including Microlaccobius, Hydroxenus, Glyptolaccobius, and Dimorpholaccobius. They are found across multiple continents including Europe, Asia, Africa, and North America, inhabiting a variety of freshwater marginal habitats.
Megaloptera
alderflies, dobsonflies, fishflies
Megaloptera is a small order of holometabolous insects containing approximately 300 described species across two extant families: Corydalidae (dobsonflies and fishflies) and Sialidae (alderflies). Adults are characterized by large, membranous wings that fold over the abdomen, and many species have short adult lifespans during which they do not feed. Larvae are exclusively aquatic, predatory, and serve as important indicators of stream health due to their sensitivity to pollution. The order was formerly classified within Neuroptera but is now recognized as a distinct order within the superorder Neuropterida.
Nemoura
spring stoneflies
Nemoura is a genus of spring stoneflies in the family Nemouridae, with more than 190 described species. The genus belongs to the subfamily Nemourinae within the superfamily Nemouroidea. Species in this genus are part of the EPT (Ephemeroptera, Plecoptera, Trichoptera) complex, a group of aquatic insects with significant ecological importance in freshwater ecosystems.
Nemouridae
spring stoneflies, brown stoneflies, forestflies, tiny winter blacks
Nemouridae is a family of stoneflies (Plecoptera) comprising over 700 described species, primarily distributed in the Holarctic region. Members are commonly known as spring stoneflies, brown stoneflies, or forestflies, and are important indicators of water quality in aquatic ecosystems. The family is characterized by small size, with adults typically measuring 5–8 millimeters in body length. Nemouridae occupy diverse flowing-water habitats, though they are most prevalent in smaller streams.
Nymphomyiidae
nymph flies
Nymphomyiidae are a family of minute (approximately 2 mm), delicate flies with highly reduced morphology. They are considered among the most archaic living Diptera, sometimes placed in their own suborder Archidiptera. Larvae are strictly aquatic, inhabiting cold, fast-flowing streams in northern and high-altitude regions. Adults are short-lived, non-feeding, and form aggregative swarms; their wings fracture at the base after mating. The family contains approximately one dozen extant species, currently classified in the single genus Nymphomyia.
Oniscidae
sow bugs, woodlice
Oniscidae is a family of terrestrial isopods (woodlice) within the suborder Oniscidea. The family includes the common woodlouse Oniscus asellus and at least six confirmed genera: Oniscus, Oroniscus, Phalloniscus, Rabdoniscus, Rodoniscus, and Sardoniscus. Members are detritivores that contribute to decomposition and nutrient cycling in terrestrial ecosystems. Some species exhibit behavioral sensitivity to environmental contaminants, suggesting potential use as bioindicators.
Ostrocerca
forestflies
Ostrocerca is a genus of spring stoneflies (Plecoptera) in the family Nemouridae, containing six described species distributed in eastern North America. Members are small to medium-sized stoneflies commonly known as forestflies. The genus was established by Ricker in 1952. Species are distinguished by subtle morphological differences in wing venation and genitalia.
Panorpidae
scorpionflies, common scorpionflies
Panorpidae is the largest family of scorpionflies (order Mecoptera), comprising more than 480 species across approximately 70% of the order's diversity. Adults range 9–25 mm in length and possess four membranous wings, threadlike antennae, and elongated faces with chewing mouthparts. The family is characterized by males having enlarged genital claspers that curve upward like a scorpion's tail, giving the group its common name. The fossil record extends to the Eocene, with the extinct genus Baltipanorpa known from Baltic amber.
Peltoperlidae
roach-like stoneflies, roachflies
Peltoperlidae is a family of stoneflies comprising 11 genera and approximately 46 known species. Larvae are dorsoventrally flattened with expanded thoracic plates, giving them a distinctive roach-like appearance. The family exhibits semivoltine life cycles lasting one to two years, with adult emergence typically occurring from April through June. Members are classified as shredder-detritivores, playing a significant role in leaf litter decomposition in lotic systems.
Perlodidae
perlodid stoneflies, stripetails, springflies, Stripetail and Springfly Stoneflies
Perlodidae is a family of stoneflies comprising at least 50 genera and over 350 species, with fossil records extending to the Triassic. Adults are commonly known as stripetails or springflies and typically emerge from April to June. The family is characterized by larvae with flattened bodies, patterned heads and thoraces, long tails, and divergent hind wing pads that lack the branching thoracic gills found in similar stonefly families.
Plecoptera
stoneflies
Plecoptera, commonly known as stoneflies, comprises approximately 3,500 described species worldwide. This order represents one of the most primitive groups of Neoptera, with fossil relatives dating to the Carboniferous and Lower Permian periods, though modern diversity appears to be of Mesozoic origin. Stoneflies are found on every continent except Antarctica, with distinct populations in the Northern and Southern Hemispheres. All species are aquatic in their immature stages and are highly sensitive to water pollution, making them important bioindicators of stream and river health.
Psephenidae
Water Penny Beetles, Water Pennies
Psephenidae, commonly known as water penny beetles, is a family of aquatic beetles in the order Coleoptera. The family comprises approximately 272 species in 35 genera distributed across all continents in both tropical and temperate regions. Larvae are fully aquatic and bear a distinctive flattened, circular shape resembling a penny, from which the common name derives. Adults are typically terrestrial, short-lived, and non-feeding. The family is divided into two subfamilies: Eubriinae and Psepheninae.
Psychodomorpha
Psychodomorpha is a nematoceran infraorder of flies comprising three families—Psychodidae, Blephariceridae, and Tanyderidae—plus the superfamily Scatopsoidea (Canthyloscelidae, Scatopsidae, Valeseguyidae). These flies are generally small to minute with hairy or scaled wings and long, often multi-segmented antennae. The group includes moth flies, sand flies, and other obscure dipterans with diverse aquatic and semi-aquatic larval habitats.
Stratiomyomorpha
Soldier Flies and Allies
Stratiomyomorpha is a parvorder of brachyceran flies comprising approximately 3,000 species, dominated by the family Stratiomyidae (soldier flies) with two smaller associated families. The group is characterized by broad morphological diversity ranging from slender to robust body forms. Larvae occupy varied aquatic and semi-aquatic habitats. Adults are often conspicuous, frequently displaying metallic coloration.
Sweltsa
green stoneflies
Sweltsa is a genus of green stoneflies in the family Chloroperlidae, established by Ricker in 1943. The genus comprises more than 50 described species worldwide, with documented diversity in North America and Asia. Species are small to medium-sized stoneflies recognized by their characteristic green or yellow-green wing coloration. Adults are typically collected in mid-summer months in mountainous stream habitats.
Sympetrum
meadowhawks, darters
Sympetrum is a genus of small to medium-sized skimmer dragonflies comprising over 50 species. Most species inhabit the temperate zone of the Northern Hemisphere, with 11 species native to Europe and 15 to North America; a few species occur in tropical Africa and South America, but none are native to Australasia. Most species are active in late summer and autumn, breeding in ponds and foraging over meadows. Juveniles are typically yellow-gold, with mature males and some females developing bright red or orange-red coloration; the Holarctic Sympetrum danae is an exception with black males lacking red.
Tanytarsini
Tanytarsini is a diverse tribe of non-biting midges (Chironomidae: Chironominae) comprising over 20 genera and approximately 1,000 described species. The tribe is divided into two subtribes: Tanytarsina and Zavreliina. Members occupy a wide range of aquatic habitats including freshwater lotic and lentic systems, hygropetric seepages, and marine intertidal zones. The genus Pontomyia represents truly marine chironomids within this tribe, with specialized life history adaptations including flightless, larviform females and short-lived non-feeding adults.
Torrenticolidae
torrent mites
Torrenticolidae is a family of water mites (Acari: Hydrachnidia) in the order Trombidiformes. Members are tiny, heavily sclerotized, crawling arthropods found in running freshwater habitats. The family contains approximately 5 genera and more than 400 described species, with the genus Torrenticola being the most diverse and widespread. Species diversity is highest in tropical regions, though the family occurs on all continents except Antarctica.
Trichoptera
Caddisflies
Caddisflies are an order of approximately 14,500 described species of insects with aquatic larvae and terrestrial adults. The order is divided into two principal suborders: Integripalpia, whose larvae construct portable protective cases while foraging, and Annulipalpia, whose larvae build fixed retreats and wait for food to arrive. Caddisflies are widely distributed globally and are recognized as important bioindicators of freshwater ecosystem health due to their sensitivity to water quality changes.