Holarctic
Guides
Acalypta elegans
Acalypta elegans is a species of lace bug in the family Tingidae, order Hemiptera. The species was described by Horváth in 1906. Like other lace bugs, it possesses the characteristic reticulated, lace-like forewings that give the family its common name. It has a documented distribution across the Holarctic region.
Acanthocinus
Acanthocinus is a genus of longhorn beetles in the subfamily Lamiinae, described by Dejean in 1821. Species in this genus are associated with coniferous trees, particularly pines and spruces, where larvae develop in the phloem beneath bark. Several species exhibit cryptic coloration that provides camouflage against tree bark. The genus includes notable species such as Acanthocinus aedilis, A. nodosus, and A. princeps (the Ponderosa Pine Bark Borer).
Acemya
Acemya is a genus of tachinid flies (family Tachinidae) established by Robineau-Desvoidy in 1830. The genus belongs to the tribe Acemyini within the subfamily Tachininae. It includes approximately 11 described species distributed across multiple continents. As with other tachinid genera, members are presumed to be parasitoids, though specific host relationships for most species remain poorly documented.
Acericecis
maple gall midges
Acericecis is a genus of gall midges in the family Cecidomyiidae. The genus contains five described species, four extant and one known only from fossils. All extant species induce characteristic eyespot galls on maple (Acer) leaves. The genus was established by American entomologist Raymond Gagné in 1983, with Acericecis ocellaris as the type species. Species are restricted to the Holarctic region.
Acidota
A genus of rove beetles (Staphylinidae: Omaliinae: Anthophagini) established in 1829. Species occur across the Holarctic region, with documented presence in Eurasia and North America. The genus includes at least 10 described species, with recent taxonomic work clarifying species boundaries and geographic distributions in Russia and China.
Acidota crenata
Crenate Ocellate Rove Beetle
Acidota crenata is a species of rove beetle in the family Staphylinidae, subfamily Omaliinae. The species has a Holarctic distribution, occurring across northern and central Europe, extending eastward through Russia to East Asia, and present in North America including Canada and the United States. It is one of approximately 15 species in the genus Acidota, which are characterized by distinctive ocellate (eye-spotted) patterns on the elytra. The specific epithet 'crenata' refers to the crenate (scalloped or notched) margins characteristic of this species.
Acleris
Acleris is a large genus of tortrix moths in the family Tortricidae, containing approximately 241 species as of 2007. The genus includes several economically significant forest pests, notably the black-headed budworm complex (A. gloverana-variana), which causes periodic outbreaks in North American coniferous forests. Some species are also agricultural pests, such as A. comariana on strawberries. The genus has a Holarctic distribution with records from North America, Europe, and Asia.
Acleris effractana
Hook-winged Tortrix Moth
Acleris effractana is a tortricid moth with a Holarctic distribution, found across northern Europe, northwestern Russia, Japan, Canada, and the northwestern United States. It is externally indistinguishable from Acleris emargana, requiring genital examination for positive identification. Adults are active from July to October. The species has historically been underreported due to confusion with its more common congener.
Acmaeops
Acmaeops is a genus of longhorn beetles (Cerambycidae) in the subfamily Lepturinae. The genus contains several species distributed across the Holarctic region. Some species historically placed in Acmaeops have been reassigned to the genus Gnathacmaeops. Members of this genus are associated with coniferous forests.
Acrobasis
Acrobasis is a genus of small moths in the family Pyralidae, subfamily Phycitinae. Species in this genus are primarily known as pests of nut and fruit crops, with several economically significant species including the pecan nut casebearer (A. nuxvorella) and species affecting chokeberry, walnut, and hickory. Larvae typically bore into developing nuts or fruits, causing direct damage to yield. The genus has a Holarctic distribution with records from North America and Europe.
Acronicta
Dagger Moths
Acronicta is a genus of approximately 150 noctuid moth species distributed primarily in the temperate Holarctic, with some species extending into adjacent subtropical regions. Adults are medium-sized moths commonly known as dagger moths due to distinctive black dagger-shaped markings on the forewings of most species; some species display a conspicuous dark ring marking instead. The genus was established by Carl Linnaeus in 1758.
Acrotona
Acrotona is a genus of rove beetles in the family Staphylinidae, first described by Thomson in 1859. The genus contains at least 30 described species. Recent taxonomic work has identified new species, including Acrotona brachyoptera from New Brunswick, Canada. Members of this genus belong to the subfamily Aleocharinae, a diverse group within the rove beetles.
Actebia fennica
Finnish Dart, black army cutworm, Eversmann's rustic
Actebia fennica is a noctuid moth with a Holarctic distribution spanning boreal regions of North America and Eurasia. Adults are active from July to September with a single generation per year. The species exhibits a documented behavioral response to landscape fire smoke, with females doubling egg production when exposed to volatiles from burning vegetation. Larvae feed on a diverse range of host plants including grasses, forbs, and woody species in coastal and disturbed habitats.
Aculepeira
Aculepeira is a genus of orb-weaver spiders in the family Araneidae, containing 26 species and two subspecies as of January 2026. The genus was established by Chamberlin and Ivie in 1942. North American species are primarily associated with high elevation and high latitude habitats, ranging from Alaska and the Yukon Territory to northern Mexico. Members of this genus construct typical orb webs and have been documented consuming pollen in addition to insect prey.
Aeshna
Hawkers, Mosaic Darners
Aeshna is a genus of large dragonflies in the family Aeshnidae, commonly known as hawkers in the Old World and mosaic darners in North America. The genus name was coined by Danish entomologist Johan Christian Fabricius in 1775, possibly from a printer's error in spelling the Greek 'Aechma' (spear). Species in this genus are characterized by their relatively large size, brown thoraces and abdomens with distinctive blue, yellow, or green markings. The genus has undergone significant taxonomic revision, with many Neotropical and other species reclassified into separate genera such as Rhionaeschna, Afroaeschna, and others based on phylogenetic studies.
Aeshna juncea
Common Hawker, Moorland Hawker, Sedge Darner
Aeshna juncea, known as the Common Hawker, Moorland Hawker, or Sedge Darner, is a large hawker dragonfly with a Holarctic distribution spanning the Palearctic from Ireland to Japan and northern North America. It is one of the larger Aeshna species and is strongly associated with acidic bog habitats, particularly in Scotland where it is a prominent bog specialist. The species has a flight period from June to early October. Recent genomic research has revealed that Alaskan populations underwent population bottlenecks during the most recent ice age, and the species has been used as a model for studying genome size variation in Odonata driven by transposons and repetitive elements.
Aethalura
Aethalura is a genus of geometrid moths (family Geometridae, subfamily Ennominae) containing four described species. The genus was erected by McDunnough in 1920. Species within this genus are primarily found in the Holarctic region, with records from Europe and North America. The most widely distributed species is Aethalura punctulata, commonly known as the grey birch.
Agabini
Agabini is a tribe of predaceous diving beetles in the family Dytiscidae, comprising approximately 500 species across six genera: Agabus, Ilybius, Platambus, Agabinus, Hydronebrius, and Ilybiosoma. Members are primarily aquatic predators found in lentic (standing water) and lotic (flowing water) habitats across the Holarctic region and beyond. The tribe exhibits diverse life cycle strategies, with variation in overwintering stages and habitat use between aquatic and terrestrial environments.
Agabus
Agabus is a large genus of predatory aquatic beetles in the family Dytiscidae, established by William Elford Leach in 1817. Adults range from 5 to 14 mm in length. The genus has a primarily Holarctic distribution, with limited representation in the Afrotropic and Neotropic realms. Some species are of conservation concern, with A. clypealis, A. discicollis, and A. hozgargantae listed as endangered by the IUCN.
Agabus arcticus
Agabus arcticus is a predaceous diving beetle in the family Dytiscidae with a Holarctic distribution, occurring in North America and the Palearctic region. It belongs to the arcticus-group of Agabus species, which is characterized by specific morphological and ecological traits adapted to northern environments. The species has three described larval stages and is known from reared material collected in northern Sweden.
Agabus clavicornis
Agabus clavicornis is a predaceous diving beetle in the family Dytiscidae. It is distributed across the Holarctic region, occurring in both North America and the Palearctic. The species was described by Sharp in 1882. Like other members of the genus Agabus, it is an aquatic predator.
Agabus confinis
predaceous diving beetle
Agabus confinis is a predaceous diving beetle in the family Dytiscidae, belonging to the confinis-group within the subgenus Acatodes. The species has a Holarctic distribution, occurring in North America and the Palearctic region. Larval stages have been described from reared material in northern Sweden, with morphological characters enabling separation from other European Agabus species. It is one of approximately 36 species in the confinis-group, which has been subject to taxonomic revision in North America.
Agabus elongatus
Agabus elongatus is a predaceous diving beetle in the family Dytiscidae. It belongs to the elongatus-group, one of three species groups within the confinis-group complex of North American Agabus. The species has a Holarctic distribution, occurring in both North America and the Palearctic region. It is one of two species in the elongatus-group, alongside A. inexspectatus.
Agabus fuscipennis
Agabus fuscipennis is a diving beetle species in the family Dytiscidae, belonging to the fuscipennis-group as defined by Larson (1989). It is characterized by a holarctic distribution, occurring across both the Palearctic and Nearctic regions. In North America, it is transcontinental in boreal regions. In Europe, it has a restricted distribution, recorded from Austria, Belarus, Czech Republic, Denmark, Estonia, Finland, Germany, Italy, Kaliningrad, Latvia, Lithuania, Norway, Poland, Russia, Sardinia, Sicily, Slovakia, Sweden, and Ukraine.
Agabus tristis
Agabus tristis is a predaceous diving beetle in the family Dytiscidae. It belongs to the tristis species group, which has a Holarctic distribution. The species occurs in North America and the Palearctic region. It is one of two North American members of the tristis group, alongside A. leptapsis.
Aglais
Tortoiseshells
Aglais is a Holarctic genus of brush-footed butterflies commonly known as tortoiseshells. The genus contains several well-known European species including the small tortoiseshell (A. urticae) and the peacock butterfly (A. io). Taxonomic placement remains somewhat contentious, with some authorities treating Aglais as a subgenus of Nymphalis rather than a separate genus. Species in this genus are characterized by their distinctive wing patterns and adult hibernation behavior.
Agnocoris
Agnocoris is a genus of plant bugs in the family Miridae, established by Reuter in 1875. The genus contains seven described species distributed across the Holarctic region. Members are small, soft-bodied true bugs with the characteristic hemelytra of mirids. The genus has been documented from Europe and North America based on specimen records.
Agonum gratiosum
Gracious Ground Beetle
Agonum gratiosum is a ground beetle species in the Platyninae subfamily, first described by Mannerheim in 1853. It has a trans-Beringian distribution spanning the Russian Far East (Chukotka and Kamchatka) and western North America (Alaska). The species belongs to a large genus of small to medium-sized predatory beetles commonly found in moist habitats.
Agonum nigriceps
Agonum nigriceps is a ground beetle species in the family Carabidae, first described by LeConte in 1846. It occurs across the Holarctic region, with records from North America (including Alaska, Canada, and the contiguous USA), Europe, and Northern Asia (excluding China). As a member of the genus Agonum, it belongs to a diverse group of ground beetles commonly associated with moist habitats.
Agrenia bidenticulata
Agrenia bidenticulata is the type species of the genus Agrenia, a springtail in the family Isotomidae. It belongs to the bidenticulata species group, characterized by the presence of a mucronal seta. Populations show considerable morphological variation across their range, with Buryatian mountain forms differing from typical arctic populations in claw length. The species exhibits sexual polymorphism (epitoky) and cyclomorphosis.
Agroeca
Agroeca is a genus of liocranid sac spiders first described by Niklas Westring in 1861. The genus contains 35 recognized species distributed across Africa, Asia, Europe, North America, and South America. Species in this genus are ground-dwelling hunters with nocturnal activity patterns. The genus shows a notably broad geographic distribution, with multiple species endemic to East Asia.
Agrotis ruta
Subarctic Dart
Agrotis ruta is a noctuid moth with a Holarctic distribution, first described by Eduard Friedrich Eversmann in 1851. It is primarily found in northern regions of North America and Eurasia. The species has a wingspan of 40–46 mm. Agrotis patula was synonymized with this species in 1989.
Agyneta olivacea
Agyneta olivacea is a species of sheet-web spider (family Linyphiidae) described by James Henry Emerton in 1882. It has a Holarctic distribution, occurring across northern regions of North America and Eurasia. The species was originally described under the basionym Microneta olivacea. As a member of the sheet weaver family, it constructs flat, horizontal webs rather than aerial orb webs.
Alaptus
Alaptus is a genus of minute egg parasitoid wasps in the family Mymaridae, commonly known as fairyflies. The genus contains approximately 17 described species in the Holarctic region, with several new species described from North America and Russia in recent taxonomic revisions. These wasps are specialized parasitoids of psocid eggs (barklice), with some species also associated with scale insects and other small arthropod eggs. Alaptus species are among the smallest insects, with body lengths typically under 1 mm.
Alexeter
Alexeter is a genus of ichneumonid wasps in the subfamily Ctenopelmatinae, tribe Mesoleiini. First described by Förster in 1869, the genus has a primarily Holarctic distribution with highest diversity in temperate regions, though species also occur in mountainous areas of the Oriental and Neotropical regions. Species are koinobiont endoparasitoids of sawfly larvae (Tenthredinoidea).
Allomengea
dwarf spiders
Allomengea is a genus of dwarf spiders in the family Linyphiidae, first described by Embrik Strand in 1912. The genus contains six species with a primarily Holarctic distribution, ranging from North America across Eurasia to East Asia. Species occur in diverse habitats including boreal and temperate regions, with some showing broad transcontinental ranges while others are restricted to specific regions such as the Korean Peninsula or China.
Alloperla
Alloperla is a genus of stoneflies in the family Chloroperlidae. Species within this genus inhabit running water environments, including the hyporheic zones of gravel-bed rivers. Some species exhibit extended larval development periods and specialized feeding habits. The genus has a broad distribution across the Holarctic region.
Alydus calcaratus
ant bug
Alydus calcaratus is a large, dark plant bug in the family Alydidae with a Holarctic distribution spanning Europe, Asia, and northern North America. It is the sole representative of its family in northern Central Europe outside the Alps. Adults are 10–12 mm, blackish with an orange-red dorsal abdomen visible only in flight, and exhibit wasp-like resemblance. Nymphs are convincing ant mimics with an unclear relationship to ant nests. The species feeds primarily on fallen legume seeds, with carrion-feeding also observed.
Amara
Sun Beetles
Amara is a large genus of ground beetles in the family Carabidae, commonly known as sun beetles. The genus has a primarily Holarctic distribution, with most species occurring in the Northern Hemisphere. A few species extend into the Neotropics and eastern Asia. Members of this genus are active predators and are frequently observed in open, sunny habitats.
Amara alpina
Amara alpina is an arctic-alpine ground beetle in the family Carabidae, first described by Gustaf von Paykull in 1790. It inhabits cold regions at high altitudes and high latitudes across the Holarctic, with populations in Scandinavia, Siberia, Mongolia, Alaska, and Canada. Molecular genetic evidence indicates that Beringian populations persisted throughout the Pleistocene, while other regions were recolonized following glacial retreat. The species has been observed feeding on dead insects on snowfields and is associated with specific alpine vegetation.
Amara bokori
Amara bokori is a ground beetle species in the family Carabidae, described by Csiki in 1929. It belongs to the large genus Amara, which contains numerous species distributed across the Northern Hemisphere. The species has been recorded from holarctic regions including Alaska, Canada, Russia, and the contiguous United States.
Amara brunnea
Amara brunnea is a ground beetle species in the family Carabidae, genus Amara. The species was described by Letzner in 1852. It is distributed across the Holarctic region with records from Alaska, Belarus, Belgium, Bulgaria, and other areas. As a member of the genus Amara, it belongs to a group of small to medium-sized carabid beetles often associated with open habitats. The species is listed as an accepted name in GBIF, though Catalogue of Life notes it as an ambiguous synonym of Amara (Amara) communis.
Amara hyperborea
Amara hyperborea is a seed-eating ground beetle in the subfamily Harpalinae. The species has a Holarctic distribution spanning boreal and subarctic regions of the Northern Hemisphere. It is known from northeastern China, southern Mongolia, Finland, and across northern North America including Alaska and Canada.
Amara interstitialis
Amara interstitialis is a seed-eating ground beetle in the family Carabidae. It is distributed across the Holarctic region, with records from Europe, Northern Asia (excluding China), and North America. The species belongs to a genus known for granivorous feeding habits among ground beetles.
Amara lunicollis
Mesophile Sunshiner
Amara lunicollis is a seed-eating ground beetle in the family Carabidae. It has a Holarctic distribution, occurring across Europe, Northern Asia (excluding China), and North America. The species is commonly known as the Mesophile Sunshiner. Like other members of the genus Amara, it is primarily associated with open, sunny habitats.
Amarochara
A genus of rove beetles (Staphylinidae: Aleocharinae: Oxypodini) established by C.G. Thomson in 1858. The genus comprises approximately 25 valid species distributed across the Holarctic region, with the majority described or redescribed in a comprehensive 2002 revision. Holarctic species are organized into five species groups based on phylogenetic analysis, replacing the previous subgeneric classification system.
Amarochara fenyesi
Fenyes's Minute Rove Beetle
A small rove beetle in the genus Amarochara, described by Blatchley in 1910. It is one of 25 valid species recognized in the Holarctic revision of the genus. The species belongs to a group characterized by specific morphological traits and shares the genus-wide trait of apparently utilizing subterranean habitats for reproduction and hibernation.
Amarochara forticornis
Amarochara forticornis is a rove beetle species in the tribe Oxypodini, originally described by Lacordaire in 1835. It is one of 25 valid species recognized in the Holarctic revision of the genus Amarochara. The species has undergone taxonomic clarification, with previous synonymies resolved. It is assigned to one of five species groups established for Holarctic representatives of the genus.
Amaurobius
Lace web spiders, Tangled nest spiders
Amaurobius is a genus of araneomorph spiders in the family Amaurobiidae, first described by Carl Ludwig Koch in 1837. The genus contains approximately 68 species with primarily Holarctic distribution. Members are commonly known as lace web spiders or tangled nest spiders due to their characteristic web architecture. The genus includes notable species such as Amaurobius ferox, which exhibits the rare behavioral phenomenon of matriphagy, where offspring consume the mother after hatching.
Amaurobius similis
Lace-Weaver Spider, lace-webbed spider
Amaurobius similis is a small spider in the family Amaurobiidae, commonly known as the lace-weaver spider. It is frequently found in human dwellings, particularly near windows and in wall crevices. The species is visually similar to A. fenestralis, with which it has been historically confused, and reliable identification requires microscopic examination of genitalia. It has a Holarctic distribution, native to Europe and the Caucasus, and has been introduced to North America.