Holarctic
Guides
Deuterophlebiidae
Mountain Midges
Deuterophlebiidae is a monotypic family of Diptera containing the single genus Deuterophlebia, considered the most plesiomorphic extant dipteran family based on morphological and molecular evidence. Commonly known as mountain midges, these insects inhabit cold, fast-flowing streams across the Holarctic region. Adults possess striking morphology including extremely long antennae in males, broad fan-shaped wings, and highly reduced mouthparts. Larvae are specialized for life in torrential waters with reversible crocheted pseudopods for attachment to smooth stones. The family exhibits a complex life cycle with extended larval and pupal periods and extremely brief adult longevity lasting only a few hours.
Devia prospera
Devia prospera is a rove beetle (Staphylinidae: Aleocharinae) described by Erichson in 1839. The species has a Holarctic distribution, occurring naturally across northern Eurasia from Europe through Russia to Japan, and has been introduced to North America where it is now established across Canada and the northern United States. As a member of the diverse rove beetle family, it inhabits various terrestrial environments where these beetles are typically found.
Diacheila
Diacheila is a genus of ground beetles in the family Carabidae, subfamily Elaphrinae. The genus comprises at least four described species, including one extinct species. Members are distributed across Holarctic regions, with some species restricted to Central Asia. The genus is notable for its Arctic and Subarctic specialization, particularly the well-studied D. polita, which exhibits photoperiod-driven life cycle timing.
Diacheila arctica
Arctic Diacheila
Diacheila arctica is a species of ground beetle in the family Carabidae. It has a Holarctic distribution, occurring in Europe, Northern Asia (excluding China), and North America. The species is classified within the subfamily Elaphrinae, a group of small to medium-sized carabid beetles often associated with moist habitats. Two subspecies are recognized: D. a. arctica (Gyllenhal, 1810) and D. a. amoena (Faldermann, 1835).
Diachrysia
burnished brass moths
Diachrysia is a genus of noctuid moths comprising approximately eleven species, distributed across the Holarctic region. The genus is best known for the burnished brass (D. chrysitis), which displays striking structural coloration on its forewings. Species in this genus are characterized by metallic golden or brassy wing patches produced by nanoscale multilayer structures rather than chemical pigments. The taxonomic relationship between D. chrysitis and the closely related D. stenochrysis remains unresolved in some populations.
Diaphorus nigricans
Diaphorus nigricans is a species of long-legged fly in the family Dolichopodidae, first described by Meigen in 1824. The species has a broad distribution across the Holarctic realm, extending southward into the Neotropics. Records indicate presence in Europe (Belgium, Denmark, Norway, Sweden), Brazil (Minas Gerais, Rio de Janeiro), and other regions. As a member of Dolichopodidae, it shares the family's characteristic elongated legs and metallic coloration typical of long-legged flies.
Dicheirotrichus cognatus
Kindred Ground Beetle
Dicheirotrichus cognatus is a ground beetle species in the family Carabidae with a broad holarctic distribution spanning Europe, Northern Asia, and North America, including Alaska and Canada. The species has also been recorded in Central America. It is known from 52 observations on iNaturalist and is recognized by the common name "Kindred Ground Beetle."
Dichelotarsus flavimanus
Yellow-handed Soldier Beetle
Dichelotarsus flavimanus is a soldier beetle in the family Cantharidae, characterized by yellowish-orange legs that contrast with its darker body. The species was described by Motschulsky in 1860 and is known from the Holarctic region with documented records in several Canadian provinces. As a member of Cantharidae, it likely shares general traits of the family including soft-bodied form and association with flowers and foliage. The specific epithet 'flavimanus' refers to the yellow-handed appearance.
Dicosmoecinae
northern caddisflies
Dicosmoecinae is a subfamily of caddisflies within the family Limnephilidae, comprising approximately 19 genera and at least 80 described species. The group is commonly referred to as "northern caddisflies," reflecting its predominantly Holarctic distribution. The subfamily was established by Schmid in 1955, with Dicosmoecus as its type genus. Members are case-making caddisflies, with larvae constructing portable shelters from plant materials.
Dictyna alaskae
Alaska mesh web weaver
Dictyna alaskae is a small spider species in the family Dictynidae, commonly known as mesh web weavers. The species was described in 1947 and has a Holarctic distribution spanning boreal and subarctic regions. It constructs irregular, mesh-like webs to capture prey. The specific epithet references Alaska, where the species was first described.
Dicymbium
dwarf spiders
Dicymbium is a genus of dwarf spiders in the family Linyphiidae, established by Anton Menge in 1868. The genus name refers to the distinctive male palpal morphology, specifically a cup-shaped projection on the palpal tibia that surrounds the cymbium dorsally. The genus contains eight species and one subspecies distributed across the Northern Hemisphere, including Europe, Asia, and North America.
Didea
lucent flies
Didea is a Holarctic genus of hoverflies (Syrphidae) commonly known as lucent flies. Adults are large-bodied, measuring 10–15 mm, with distinctive black and yellow coloration. The genus is notable for its late-season flight activity and predatory larvae that feed on arboreal aphids.
Didea alneti
Didea alneti is a Holarctic hoverfly species with a wide distribution spanning Europe, Asia, and North America. Adults are arboreal, descending to visit flowers of various herbaceous plants and shrubs. The larvae are arboreal predators that feed on aphids associated with trees including Larix, Prunus, Salix, and Quercus.
Dinaraea angustula
Rove beetle
Dinaraea angustula is a small rove beetle (Staphylinidae) first described by Gyllenhal in 1810. Originally placed in Aleochara, it was later transferred to Dinaraea. The species has a Holarctic distribution, occurring naturally across Europe and northern Asia, with introduced populations established in North America. It is one of many aleocharine rove beetles characterized by reduced elytra and a compact body form.
Dinera
Dinera fly
Dinera is a genus of tachinid flies established by Robineau-Desvoidy in 1830. The genus comprises approximately 24 described species distributed across the Holarctic region, with notable diversity in China. Larvae of most species are parasitoids of scarab beetles (Scarabaeidae), making this genus economically relevant for biological control of certain beetle pests.
Dioctria
Dioctria is a genus of robber flies (family Asilidae) in the subfamily Dasypogoninae, forming the tribe Dioctriini alongside Bohartia, Dicolonus, Echthodopa, Eudioctria, and Metadioctria. The genus contains multiple species distributed across the Holarctic region, with documented occurrences in Europe, North America, and Turkey. Species within Dioctria are generally small to medium-sized predatory flies that hunt other insects.
Dioctria hyalipennis
Stripe-legged Robber Fly
Dioctria hyalipennis is a small Holarctic robber fly (10–14 mm) in the family Asilidae, characterized by distinctive black-and-yellow leg patterning and hyaline wings. Adults are active predators that feed primarily on small wasps, bees, and other insects. The species occupies meadows, hedgerows, and forest edges with shrubs or conifers, and has been introduced to eastern North America from Europe.
Diplazon pectoratorius
Diplazon pectoratorius is a species of ichneumon wasp in the family Ichneumonidae. It belongs to the genus Diplazon, a group of parasitoid wasps that target hoverfly (Syrphidae) larvae. The species has been recorded in northern Europe and northeastern North America. As with other Diplazon species, it likely functions as a specialist parasitoid of aphidophagous hoverfly larvae.
Diplazontinae
Hover Fly Parasitoid Wasps
Diplazontinae is a subfamily of ichneumonid wasps comprising approximately 19 genera, with highest diversity in the Holarctic region. Members are specialized koinobiont endoparasitoids of hover flies (Syrphidae), with oviposition into host eggs or larvae and emergence from the puparium. The subfamily exhibits distinctive morphological features including three-toothed mandibles and a box-like first abdominal tergite. Several genera have undergone recent taxonomic revision, with Syrphoctonus split into multiple genera to restore monophyly.
Diplocentria bidentata
dwarf spider
Diplocentria bidentata is a species of dwarf spider in the family Linyphiidae, first described by Emerton in 1882. It is a small-bodied spider with a broad geographic distribution spanning the Holarctic region. The species has been recorded across North America, Europe, Russia (from European Russia to the Far East), and China. As a member of Linyphiidae, it is presumed to construct small sheet webs, though specific behavioral observations remain limited.
Diplocentria rectangulata
Diplocentria rectangulata is a sheet web spider in the family Linyphiidae, first described by Emerton in 1915. The species occurs across northern regions of the Northern Hemisphere, including North America and Eurasia. As with other linyphiids, it constructs horizontal sheet webs to capture prey. It is among the smaller spiders, consistent with the dwarf spider morphology typical of this family.
Diplocephalus subrostratus
dwarf spider
Diplocephalus subrostratus is a dwarf spider in the family Linyphiidae, first described by O. Pickard-Cambridge in 1873. The species exhibits a Holarctic distribution spanning North America, Greenland, and a broad range across Russia from Europe to the Far East, including Mongolia. Like other linyphiids, it is a small-bodied spider, though specific morphological and ecological details remain poorly documented in published literature.
Diplocolenus abdominalis
Diplocolenus abdominalis is a leafhopper species in the family Cicadellidae, subfamily Deltocephalinae. The species was described by Fabricius in 1803 and is currently placed in the genus Diplocolenus, tribe Paralimnini. Distribution records indicate occurrence across northern and central Eurasia, including Alaska and regions of Kazakhstan, Russia, and Mongolia.
Diplolepis
gall wasps, rose gall wasps
Diplolepis is a genus of gall-inducing wasps in the family Diplolepididae, most commonly associated with roses (Rosa spp.). These small wasps are notable for inducing complex, often conspicuous galls on their host plants through chemical manipulation of plant tissues. The genus includes both sexual and parthenogenetic species, with some like D. rosae reproducing primarily by thelytokous parthenogenesis. Diplolepis species exhibit intricate life cycles involving alternation between sexual and agamic generations, and their galls support diverse communities of parasitoids and inquilines.
Dismodicus
dwarf spiders
Dismodicus is a genus of dwarf spiders in the family Linyphiidae, first described by Eugène Louis Simon in 1884. The genus contains six species distributed across the Northern Hemisphere, with centers of diversity in Europe and North America. These spiders are part of the sheet-web weaving guild, constructing horizontal webs close to the ground.
Dolichocephala
dagger flies
Dolichocephala is a genus of empidid flies (dagger flies) in the subfamily Clinocerinae, established by Macquart in 1823. The genus contains at least 50 described species distributed across the Holarctic and Oriental regions. Recent taxonomic revisions have significantly expanded the known species diversity in North America and Southeast Asia.
Dolichomitus pterelas
A parasitoid wasp in the family Ichneumonidae, characterized by an exceptionally long ovipositor used to reach host larvae concealed deep within wood. The species exhibits aposematic coloration with metallic blue-black body and golden-yellow wings. It is a solitary parasitoid of wood-boring insect larvae.
Donaciinae
Aquatic Leaf Beetles, Reed Beetles
Donaciinae is a subfamily of leaf beetles (Chrysomelidae) comprising approximately 100 species across six genera, including Donacia, Macroplea, and Plateumaris. Members are strongly associated with aquatic and semi-aquatic habitats, with larvae developing underwater attached to plant roots. The subfamily is characterized by distinctive morphological adaptations and an obligate symbiosis with bacteria that produce the silk-like material used to construct waterproof pupal cocoons. Donaciinae are primarily distributed in the Northern Hemisphere with extensions into Africa, Madagascar, and Australasia.
Drapetisca
sheetweb weavers
Drapetisca is a genus of dwarf sheetweb spiders in the family Linyphiidae, first described by Anton Menge in 1866. Members are exceptionally small, with females measuring 4–5 mm and males 3–4 mm in body length. These spiders are highly specialized tree trunk dwellers that construct minimal, nearly invisible sheet webs. The genus currently comprises approximately 7 species distributed across the Holarctic region, including North America, Europe, Asia, and Japan.
Drepanosiphinae
Drepanosiphinae is a Holarctic subfamily of aphids within Aphididae, comprising approximately 13 genera (8 extinct) and over 60 described species. The six extant genera—Drepanaphis, Drepanosiphoniella, Drepanosiphum, Megalosiphonaphis, Shenahweum, and Yamatocallis—exhibit strict host associations primarily with maple trees (Acer spp.). The subfamily is characterized by enlarged fore or mid femora and rastral spines on hind tibiae. Molecular phylogenetic studies confirm its monophyly and reveal complex endosymbiotic relationships with both Buchnera aphidicola and Sodalis-like bacteria in most species.
Dryudella
Dryudella is a genus of solitary digger wasps in the family Crabronidae, subfamily Astatinae, containing over 50 described species distributed across the Holarctic region. These small wasps (typically under 10 mm) are specialized predators of true bugs (Hemiptera), with females constructing nest burrows in sandy soils to provision their offspring. Males exhibit distinctive holoptic eyes that meet at the top of the head and possess broad hind wings that enable rapid flight from perches on twigs and stems. The genus shows sexual habitat segregation, with females typically in shaded nesting areas and males in sunny locations.
Dyschirius politus
Dyschirius politus is a small ground beetle species in the subfamily Scaritinae, first described by Pierre François Marie Auguste Dejean in 1825. The species belongs to the genus Dyschirius, a diverse group of ground beetles characterized by their compact body form and fossorial (burrowing) habits. Records indicate a Holarctic distribution spanning North America and Eurasia.
Dysstroma citrata
Dark Marbled Carpet, Northern Marbled Carpet
A Holarctic geometrid moth with highly variable forewing coloration ranging from whitish to dark brown or black. Adults are active in mid-summer. The species occupies mountainous and wetland habitats across a broad latitudinal range from the Arctic to temperate zones.
Dytiscus
predaceous diving beetles
Dytiscus is a Holarctic genus of large predaceous diving beetles comprising 26 species. Adults range 2.2–4.4 cm in length and are fully aquatic, breathing air collected under their elytra. Both adults and larvae are active predators. The genus has been observed to reduce mosquito larva populations in wetland habitats.
Ebaeina
Ebaeina is a subtribe of soft-bodied plant beetles within the family Melyridae (order Coleoptera). Members of this subtribe are characterized by their soft, flexible elytra and generally small to medium body size. The subtribe is primarily distributed in the Holarctic region, with greatest diversity in western North America. Ebaeina beetles are often found in association with flowers and vegetation where they feed on pollen and small arthropods.
Ectemnius continuus
Common Ectemnius
Ectemnius continuus is a small to medium-sized digger wasp in the family Crabronidae, widespread throughout the Holarctic region. It is black with yellow markings on the scapes, pronotum, tibiae and tergites, and has a clypeus covered with shining silver hairs. The species is notable for having 12 antennal segments in both sexes, unlike most aculeates where males typically have 13 segments. Males possess unique small spines on the first and second tarsomeres of the mid tarsus.
Ectoedemia argyropeza
Virgin Pigmy
A Holarctic microlepidopteran in the family Nepticulidae, characterized by parthenogenetic reproduction with extremely rare males. Adults are active in late spring. Larvae are leaf miners on aspen species, producing distinctive mines that persist on host leaves. The species exhibits clonal population structure with limited dispersal capacity.
Eidophasia
A Holarctic genus of plutellid moths comprising 12 species with heterogeneous morphologies. The genus currently lacks established synapomorphies, making species-level taxonomy challenging. E. syenitella, a European representative, was recently redescribed with first documentation of genitalia for both sexes. Larval biology is documented for at least one species, indicating specialization on Brassicaceae hosts.
Elachiptera
frit flies
Elachiptera is a genus of small frit flies in the family Chloropidae, subfamily Oscinellinae. The genus contains approximately 81 valid species distributed across North America, Europe, and Asia, with some species extending into the Oriental Region. Several species are known agricultural pests of cereal crops, with larvae feeding internally within stems of wheat and maize. The genus includes both fully winged and wingless (brachypterous) species.
Elaphrus lapponicus
Northern Peacock Beetle
Elaphrus lapponicus is a ground beetle species in the subfamily Elaphrinae, described by Gyllenhal in 1810. It belongs to a genus known for species that closely resemble tiger beetles (Cicindelinae), often leading to misidentification by collectors. The species has a Holarctic distribution, occurring across northern regions of North America and Eurasia. Like other members of Elaphrus, it likely inhabits moist, open habitats near water.
Elaphrus lapponicus lapponicus
Elaphrus lapponicus lapponicus is a subspecies of ground beetle in the family Carabidae. It belongs to a genus frequently mistaken for tiger beetles due to convergent morphology. The species is part of a holarctic complex with distribution across northern regions.
Elasmostethus
Birch shieldbug
Elasmostethus is a genus of shield bugs in the family Acanthosomatidae, comprising approximately 15 described species distributed across the Holarctic region. The genus is notable for exhibiting asocial behavior—specifically, the absence of maternal care of eggs—contrasting with subsocial species found elsewhere in the family. Species within this genus show significant interspecific variation in life history traits including egg size, developmental periods, and female body size, though clutch size remains relatively consistent across species.
Elasmostethus interstinctus
Birch Shield Bug
Elasmostethus interstinctus, commonly known as the birch shield bug, is a shield bug in the family Acanthosomatidae with a Holarctic distribution across Europe, Northern Asia, and North America. Adults measure 8–11.5 mm and display distinctive bright yellow-green and red coloration. The species is univoltine, with adults overwintering in leaf litter and emerging in spring to reproduce on birch and other host plants.
Ellescus
Ellescus is a genus of true weevils in the family Curculionidae, tribe Ellescini. The genus contains approximately 16 described species globally. In North America, four valid species are recognized: the widespread and morphologically variable E. ephippiatus, the Holarctic E. bipunctatus, the west coast endemic E. californicus, and the temperate E. michaeli. Species identification relies on morphological examination and molecular markers, particularly ITS2, which has proven more reliable than CO1 for delineating closely related species.
Ellescus bipunctatus
Ellescus bipunctatus is a Holarctic weevil species in the tribe Ellescini. A recent taxonomic revision designated a neotype for this species and established E. borealis as its junior synonym. It is one of four valid Ellescus species in North America, where it occurs alongside the widespread E. ephippiatus, the west coast endemic E. californicus, and the newly described E. michaeli. The species has been distinguished from congeners using integrative taxonomy combining morphological and molecular data.
Elliptera
Elliptera is a genus of crane flies in the family Limoniidae, established by Schiner in 1863. The genus comprises ten described species distributed across the Holarctic region, including North America, Europe, and East Asia. Immature stages have been described for only a few species, with larvae inhabiting aquatic, hygropetric environments on wet rocks in mountainous areas.
Emblyna
Emblyna is a genus of cribellate araneomorph spiders in the family Dictynidae, first described by R. V. Chamberlin in 1948. The genus contains approximately 76 species with a broad geographic distribution spanning North America, Europe, and Asia. Emblyna species are small to medium-sized spiders that construct irregular, tangled webs. Two species, E. francisca and E. reticulata, have been documented to exhibit behavioral niche partitioning, allowing coexistence in sympatric populations.
Empicoris culiciformis
thread-legged assassin bug
Empicoris culiciformis is a predatory true bug in the family Reduviidae, characterized by its delicate build and raptorial forelegs. The species has a Holarctic distribution spanning Europe, the Palearctic, North Africa, and North America. It is rarely encountered due to its cryptic lifestyle in concealed habitats.
Enargia
Enargia is a genus of moths in the family Noctuidae, first described by Hübner in 1821. The genus contains approximately twelve recognized species distributed across the Holarctic region. Members are classified within the subfamily Noctuinae, tribe Xylenini, subtribe Cosmiina.
Enoplognatha marmorata
marbled cobweb spider
A species of cobweb spider in the family Theridiidae, native to the Holarctic region. It constructs tangled, irregular webs in outdoor vegetation rather than in buildings. The species shows considerable color variation, with individuals ranging from pale to dark with marbled or striped abdominal patterns.