Holarctic
Guides
Callomyia
Callomyia is a genus of flat-footed flies (Diptera: Platypezidae) comprising approximately 24 described species distributed across the Holarctic and Oriental regions. The genus is distinguished by a setulose R1 wing vein and enlarged female antennae. Larvae are xylobiont, developing under bark of fallen trees where they feed on fungal mycelia. Adults are typically found in forested habitats and are active from spring through autumn.
Caloptilia stigmatella
Willow Leafcone Caterpillar Moth
A small leaf-mining moth in the family Gracillariidae with a wingspan of 12–14 mm. Adults display distinctive red-brown forewings with a triangular white median costal blotch marked with blackish dots, and grey hindwings. The species has two adult flight periods annually and larvae feed on leaves of willows, poplars, and bog myrtle. It occurs across the Holarctic region, excluding the Balkan Peninsula.
Calvia quatuordecimguttata
cream-spot ladybird, cream-spotted ladybird, polkadot ladybird, eighteen spot ladybird
A small Holarctic ladybird measuring 4–5.5 mm, highly variable in coloration across its range. In Europe it appears maroon-brown with fourteen cream spots; in North America and eastern Asia, color forms range from black with white spots to yellow or pink with eighteen large blotches. It inhabits deciduous woodlands, hedgerows, and ruderal areas, overwintering in bark crevices and leaf litter.
Campaea
Campaea is a genus of geometer moths in the family Geometridae, subfamily Ennominae, established by Lamarck in 1816. The genus contains approximately 30 described species distributed across the Holarctic region, with records from Europe, North America, and parts of Asia. Best-known members include Campaea margaritata (light emerald) and Campaea perlata (pale beauty). Species in this genus are characterized by broad wings, often with green or pale coloration that frequently fades post-emergence, and larvae that feed on deciduous tree foliage.
Canalidion montanum
Canalidion montanum is a small tangle-web spider (family Theridiidae) and the sole species in the monotypic genus Canalidion. Originally described as Theridion montanum by James Emerton in 1882, it was transferred to its own genus by J. Wunderlich in 2018 based on distinctive cheliceral dentition and male genitalic morphology. The species has a holarctic distribution, occurring across northern North America and Eurasia.
Capniidae
small winter stoneflies, winter stoneflies
Capniidae, the small winter stoneflies, is one of the largest families in the order Plecoptera, comprising approximately 300 species distributed throughout the Holarctic region. Adults are active during winter months, often observed on snow-covered stream banks when most other insects are dormant. The family exhibits notable adaptations to cold environments, including antifreeze compounds and winglessness in some species, which has led to high endemism and restricted distributions. Their closest relatives are the rolled-winged stoneflies (Leuctridae).
Capsus cinctus
Capsus cinctus is a species of plant bug in the family Miridae, a group commonly known as plant bugs or mirids. The species has a Holarctic distribution, occurring across Europe, Northern Asia (excluding China), and North America. As a member of the Miridae, it possesses the characteristic piercing-sucking mouthparts typical of true bugs. Specific details regarding its biology, host associations, and ecology remain poorly documented in the available literature.
Carabinae
ground beetles
Carabinae is a subfamily of ground beetles in the family Carabidae, comprising approximately 1,400 described species across ten genera. The subfamily is divided into two tribes: Cychrini and Carabini, with the latter further subdivided into subtribes Carabina and Ceroglossina. Notable genera include Carabus, Calosoma, and Ceroglossus. The group has been extensively studied phylogenetically, with molecular data covering over 90% of carabid genera.
Carabus maeander maeander
Carabus maeander maeander is a subspecies of ground beetle described by Fischer von Waldheim in 1820. It belongs to the genus Carabus, one of the most species-rich genera of ground beetles. The subspecies occurs across a broad Holarctic range including parts of North America and Asia. As a member of the Carabidae family, it is presumed to be a predatory beetle based on the well-documented feeding ecology of the genus, though specific studies on this subspecies are limited.
Carabus truncaticollis
blunt-collared worm and slug hunter
Carabus truncaticollis is a ground beetle in the family Carabidae distributed across the northern Holarctic. The species occurs in mesic tundra environments, including moist meadows. Multiple subspecies have been described, primarily from Russia and Mongolia. The common name 'blunt-collared worm and slug hunter' reflects its presumed predatory habits, though specific dietary documentation is limited.
Carsia sororiata
Manchester Treble-bar, Manchester Treble-bar Moth
Carsia sororiata is a geometrid moth with a Holarctic distribution spanning northern and central Europe through Siberia to the Russian Far East and northern Mongolia, with a separate North American range from Alaska to Newfoundland and New Hampshire. Adults are active from July to August. The species exhibits notable wing pattern variation across its range, with several described subspecies.
Carterocephalus
skipperlings, chequered skippers, Arctic skippers
Carterocephalus is a Holarctic genus of small skipper butterflies (skipperlings) in the family Hesperiidae. The genus contains approximately 20 described species, with the majority endemic to China. The most widely distributed species, C. palaemon (chequered skipper), has been the focus of conservation efforts in Europe following its extinction in England in 1976 and subsequent reintroduction from Belgium in 2018.
Caryocolum pullatella
Caryocolum pullatella is a small gelechiid moth with a broad distribution spanning the Holarctic region. The species is characterized by its small size, with forewings measuring 5–6.5 mm. Adults are active from mid-May through mid-October, likely with a single annual generation. The species belongs to a genus whose larvae are specialized feeders on plants in the carnation family (Caryophyllaceae).
Cassida flaveola
pale tortoise beetle
Cassida flaveola, known as the pale tortoise beetle, is a brownish leaf beetle in the family Chrysomelidae. It was historically considered an introduced Palearctic species in North America, but recent evidence indicates it is at least in part native with a Holarctic distribution. The species has been newly recorded in Nova Scotia and Prince Edward Island in the Maritime Provinces of Canada.
Catharosia
Catharosia is a genus of tachinid flies established by Rondani in 1868. The genus comprises approximately twelve described species distributed across the Holarctic region. Species within this genus are classified in the tribe Catharosiini within the subfamily Phasiinae.
Catocala
underwing moths, underwings
Catocala is a large Holarctic genus of moths in the family Erebidae, containing over 250 species. Adults are medium to large with cryptic forewings that conceal brightly colored hindwings when at rest. The genus is renowned among collectors for its diversity of hindwing patterns in orange, red, white, blue, or black. The common name "underwings" derives from the habit of hiding the colorful hindwings beneath the dull forewings. The genus name combines Greek words meaning "beautiful below" or "beautiful hindwings."
Catops
Catops is a genus of small carrion beetles in the family Leiodidae, subfamily Cholevinae, established by Paykull in 1798. The genus comprises approximately 16 described species distributed across the Holarctic region. Several species are associated with cave habitats, including the Iranian endemic Catops farsicus.
Catops alsiosus
Catops alsiosus is a small carrion beetle in the family Leiodidae. It has a Holarctic distribution spanning Europe, northern Asia, and North America. The species is one of approximately 60 described species in the genus Catops, which are generally associated with decomposing organic matter.
Catotricha
Catotricha is a genus of non-biting midges (family Cecidomyiidae) established by British entomologist Frederick Wallace Edwards in 1938. The genus comprises five described species distributed in the Holarctic region. Catotricha is the type genus of the subfamily Catotrichinae.
Cavariella
Willow-Umbellifer Aphids
Cavariella is a genus of aphids in the family Aphididae, tribe Macrosiphini. It is distinguished from other Macrosiphini genera by a supra-caudal process on abdominal tergite VIII bearing two distal setae. The genus has a Holarctic distribution with approximately half its species occurring in Asia. Species in this genus exhibit a characteristic life cycle involving primary hosts in Salicaceae (willows) and secondary hosts in Apiaceae (umbellifers), making them economically significant as pests of carrot and other crops.
Centromerus
dwarf spiders
Centromerus is a genus of dwarf spiders in the family Linyphiidae, containing approximately 88 species and two subspecies. The genus has a broad distribution spanning the Holarctic region, with species recorded across Europe, North America, Asia, and North Africa. Many species exhibit restricted geographic ranges, while a few such as C. sylvaticus have exceptionally wide distributions. The genus was established by Dahl in 1886.
Centromerus sylvaticus
sheetweb spider, money spider
Centromerus sylvaticus is a small sheetweb spider in the family Linyphiidae, commonly known as money spiders. The species has a broad Holarctic distribution spanning North America, Europe, and Asia. Adults measure 2.2–4 mm in body length. Two subspecies are recognized: the nominate C. s. sylvaticus and C. s. paucidentatus described from Bulgaria.
Cercyon littoralis
Cercyon littoralis is a small water scavenger beetle in the family Hydrophilidae. It has a broad distribution across the Holarctic region, occurring in Europe, Northern Asia (excluding China), and North America. The species has also been introduced to oceanic islands including the Azores and Tristan da Cunha.
Cercyon marinus
Cercyon marinus is a water scavenger beetle in the family Hydrophilidae. It has a Holarctic distribution spanning Europe, Northern Asia, North America, and parts of Southern Asia. The species inhabits aquatic and semi-aquatic environments where it contributes to organic matter decomposition.
Cerophytidae
Rare Click Beetles
Cerophytidae is a small family of elateroid beetles commonly known as rare click beetles. The family contains approximately 23 extant species distributed across five genera, with the majority of diversity concentrated in the Neotropics. Adults possess a clicking mechanism convergent with Elateridae, though they are less specialized for jumping and better adapted for rapid walking and flight. The family has a significant fossil record extending to the Early Jurassic, with 17 fossil species in seven genera documented.
Cerophytum
rare click beetles
Cerophytum is a genus of rare click beetles in the family Cerophytidae, established by Latreille in 1809. The genus contains at least four described species distributed across the Holarctic region (Europe, Asia, and North America). Members are characterized by their clicking mechanism, which represents convergent evolution with the true click beetles (Elateridae). A fifth species, Cerophytum lii, was described in 2025 from Yunnan Province, China, representing the first record of the family in that country.
Ceutorhynchinae
Minute Seed Weevils
Ceutorhynchinae is a large subfamily of minute seed weevils within Curculionidae, comprising over 150 genera and more than 1,000 described species worldwide. The subfamily is predominantly phytophagous and exhibits strong associations with Brassicaceae, though host plant relationships vary across genera. The genus Ceutorhynchus is particularly diverse and includes significant agricultural pests such as the cabbage seedpod weevil (Ceutorhynchus obstrictus), as well as species with potential for biological control of weeds. The subfamily shows highest diversity in the Holarctic region, especially the Palaearctic.
Ceutorhynchus querceti
Ceutorhynchus querceti is a small weevil in the family Curculionidae. The species was described by Gyllenhal in 1813. It is part of a large genus of seed weevils, many of which are associated with brassicaceous plants.
Chaitophorini
Chaitophorini is a tribe of aphids in the subfamily Chaitophorinae, established by Mordvilko in 1909. Members are generally associated with woody host plants, particularly in the families Salicaceae and Aceraceae. The tribe includes several genera, with Chaitophorus being the most diverse and well-known. These aphids are characterized by specific morphological features of the antennae and siphunculi that distinguish them from other aphid tribes.
Chaoborus flavicans
phantom midge
Chaoborus flavicans is a phantom midge (Diptera: Chaoboridae) whose larval stages are important aquatic predators in lake ecosystems. Recent taxonomic revision indicates it represents a complex of at least four species, with C. flavicans sensu stricto primarily inhabiting lakes across the Holarctic region. Larvae are notable for their diel vertical migration behavior, which changes ontogenetically and serves as a predator avoidance mechanism against fish predation.
Chersotis juncta
stirrup dart moth, spear dart moth, Stirrup and Spear Dart
Chersotis juncta is a noctuid moth with a Holarctic distribution spanning Europe, northern Asia, and North America. The species is known by multiple common names referencing its wing pattern. It is a member of the cutworm or dart moth group within the family Noctuidae.
Chesiadini
Chesiadini is a tribe of geometer moths within the subfamily Larentiinae, established by Stephens in 1850. The tribe comprises approximately 12 recognized genera distributed primarily in the Holarctic region. Members are small to medium-sized moths with relatively broad wings and often subdued coloration. The tribe includes economically and ecologically significant species such as those in the genus Aplocera.
Chionea
Snow Flies, Snow Crane Flies
Chionea is a genus of wingless crane flies in the family Limoniidae, commonly known as snow flies. The genus contains approximately 37-40 recognized species distributed across the northern hemisphere, with two subgenera: the Holarctic Chionea and the Palearctic Sphaeconophilus. Adults are uniquely adapted to cold environments and are active during winter months, walking across snow surfaces at sub-zero temperatures. The wingless condition is associated with energy conservation in freezing conditions, with flight muscles replaced by expanded egg storage capacity in females.
Chionodes continuella
Spring Oak Leafroller Moth
Chionodes continuella is a small gelechiid moth with a Holarctic distribution spanning Europe, Asia, and North America. Adults are active during summer months in western Europe. The species has been misnamed 'spring oak leafroller' despite larvae feeding on conifers and lichens rather than oak.
Chirocephalidae
fairy shrimp
Chirocephalidae is the second largest family of fairy shrimp (Anostraca), characterized by a reduced or vestigial maxilla, more than two setae on the fifth endite, divided pre-epipodites, and widely separated seminal vesicles. The family includes nine genera: Artemiopsis, Branchinectella, Chirocephalus, Dexteria (extinct), Eubranchipus, Linderiella, Parartemiopsis, Polyartemia, and Polyartemiella. Former families Linderiellidae and Polyartemiidae are now included within Chirocephalidae. Most species are distributed in the Holarctic region.
Chlamydatus
Chlamydatus is a genus of plant bugs (Miridae: Phylinae) established by Curtis in 1833, containing more than 30 described species. The genus is distributed across the Holarctic region, with records from Europe (Denmark, Norway, Sweden) and North America. One species, Chlamydatus ruficornis, has been documented feeding on prostrate knotweed (Polygonum aviculare) in Wyoming, USA.
Chloropinae
grass flies
Chloropinae is a subfamily of grass flies (family Chloropidae) containing approximately 76 genera and hundreds of species. Members are found across diverse landscapes from boreal regions to arid coastal environments. Larval biology varies considerably, with some species associated with grasses and sedges while others develop in decaying organic matter or as inquilines. The subfamily is taxonomically well-documented in northern Europe and Asia, with ongoing work clarifying species boundaries and distributions.
Chrysocharis nephereus
Chrysocharis nephereus is a minute parasitoid wasp in the family Eulophidae, first described by Walker in 1839. It has been studied in Northern England, where its biology was examined alongside allied species. The species is recorded across multiple Canadian provinces, suggesting a Holarctic distribution. As a member of Chrysocharis, it likely functions as a parasitoid of leaf-mining insects, though specific host associations for this species remain poorly documented.
Chrysoclista
Chrysoclista is a genus of small moths within the family Elachistidae, though its familial placement has been historically disputed. The genus was described by Henry Tibbats Stainton in 1854 and contains approximately twelve described species distributed across the Holarctic region. Species within this genus exhibit metallic coloration, reflected in the name derived from Greek roots meaning 'golden' and 'hair'. The taxonomy of Chrysoclista has been contentious, with various authors assigning it to Agonoxenidae, Cosmopterigidae, Elachistidae, or Momphidae.
Chrysolina subsulcata
Chrysolina subsulcata is a leaf beetle species in the family Chrysomelidae, first described by Mannerheim in 1853. It has a Holarctic distribution, occurring across Europe, Northern Asia (excluding China), and North America. The species is one of approximately 150 recognized species in the genus Chrysolina, a group of leaf beetles often associated with specific host plants.
Cimberidini
Cimberidini is a small tribe of leaf-rolling weevils (Attelabidae) distinguished by their association with coniferous host plants, primarily in the family Pinaceae. The tribe contains the genus Cimberis, whose species are specialized on conifer foliage and cones. These weevils exhibit the characteristic leaf-rolling or leaf-folding behavior of the subfamily Attelabinae, though modified for conifer hosts. The tribe has a Holarctic distribution with species found in North America and Eurasia.
Cinara obscura
Dark Spruce Stem Aphid
Cinara obscura is a species of large aphid in the family Aphididae, commonly known as the Dark Spruce Stem Aphid. It is a conifer-feeding aphid that infests spruce trees (Picea species). Like other members of the genus Cinara, it possesses a long piercing-sucking beak adapted for tapping into phloem tissues. The species overwinters as eggs on host needles. It produces honeydew, which attracts ants and wasps and supports sooty mold growth.
Cladotanytarsus
Cladotanytarsus is a genus of non-biting midges (Chironomidae) containing over 80 described species with worldwide distribution, particularly diverse in the Holarctic region. The genus comprises two subgenera: Cladotanytarsus s. str. and Lenziella. Species are primarily lacustrine, with adults often associated with lake surroundings and larvae inhabiting freshwater sediments. Several species have been described from experimentally acidified lakes in North America, demonstrating tolerance to varying pH conditions. One species, C. lewisi, is a significant human allergen source in Sudan.
Cleopomiarus
Cleopomiarus is a genus of weevils in the tribe Mecinini (Curculionidae), established by Pierce in 1919. The genus comprises approximately 21 Holarctic species, including two North American and 19 Palaearctic species, with additional species described from China. Species are associated with Campanulaceae host plants. Cleopomiarus was historically conflated with the genus Miarus but has been reinstated as distinct based on morphological characters of adults and immature stages.
Clivinematini
Clivinematini is a tribe of ichneumon wasps within the subfamily Tryphoninae. Members of this tribe are parasitoid wasps that target sawfly larvae (Hymenoptera: Symphyta) as hosts. The tribe is characterized by specific morphological features of the ovipositor and associated structures that distinguish it from related tryphonine tribes. Clivinematini represents a relatively small and specialized lineage within the diverse Ichneumonidae.
Cloeon dipterum
Pond Olive
Cloeon dipterum is a small mayfly species with a Holarctic distribution, widespread across Europe, Asia, and North America. It is the most common mayfly in ponds of the British Isles, occurring in approximately 40% of all ponds and 70% in southern regions. The species is notable for being the only ovoviviparous mayfly in Europe: females retain eggs internally for 10–14 days after mating, and nymphs hatch immediately upon contact with water. Males possess distinctive turbinate eyes—dorsal "turban-shaped" superposition eyes that aid in locating females during mating swarms. The species has been established as a laboratory model for studying insect evolution, development, and ecotoxicology.
Clostera
Clostera is a genus of moths in the family Notodontidae, subfamily Pygaerinae, containing approximately 30 described species distributed across the Holarctic and Oriental regions. Multiple species, including C. anachoreta, C. anastomosis, C. fulgurita, and C. cupreata, are recognized as significant defoliators of poplar (Populus) trees in forestry contexts across China, India, Europe, and Japan. The genus has been extensively studied for its economic impact and as a target for biological control and Bt toxin research.
Clubiona trivialis
Clubiona trivialis is a small sac spider in the family Clubionidae, characterized by its reddish-brown coloration and holarctic distribution. Unlike the longlegged sac spiders in the genus Cheiracanthium (now Eutichuridae), which are frequently encountered indoors, Clubiona species are less commonly found inside human dwellings. Adults are present year-round and occupy exposed positions on low vegetation.
Cnemogonini
minute seed weevils
Cnemogonini is a tribe of minute seed weevils within the weevil family Curculionidae. The tribe comprises 15 genera, including economically notable genera such as Auleutes and Cnemogonus. Members are small beetles associated with seeds of various plants. The tribe is primarily distributed in the Nearctic and Palearctic regions.
Cochylini
Cochylini is a tribe of tortrix moths (Tortricidae) containing approximately 1,000 described species in about 80 genera. Formerly classified as the subfamily Cochylinae, molecular research by Regier et al. (2012) suggests it may represent a monophyletic lineage within Euliini, warranting subtribe rank as Cochylina. The tribe has a global distribution with highest diversity in the Holarctic and Neotropical realms.