Holarctic
Guides
Satilatlas marxi
Satilatlas marxi is a species of sheet-web weaving spider in the family Linyphiidae, described by Keyserling in 1886. It is a Holarctic species with documented occurrences in Alaska, Canada (Alberta, British Columbia, Manitoba), and South Siberia, Russia. The genus Satilatlas belongs to the diverse dwarf spider family, whose members construct horizontal sheet webs to capture prey. Very little is known about the specific biology of this species.
Satyrium
Satyrid Hairstreaks
Satyrium is a genus of butterflies in the family Lycaenidae, commonly known as satyrid hairstreaks. Species in this genus are distributed across the Holarctic ecozone. Many species exhibit specialized ecological associations, including larval dependencies on particular oak species and mutualistic relationships with ants. Several species have been the focus of conservation concern due to habitat specificity and perceived rarity.
Scathophaginae
dung flies, yellow dung flies
Scathophaginae is a subfamily of predatory flies within the family Scathophagidae, commonly known as dung flies. The subfamily contains at least 30 genera and approximately 130 described species. Adults are frequently associated with dung and decaying organic matter, where they occur in large numbers. The group is notable for being predatory rather than coprophagous, with both adults and larvae feeding on other insects.
Scatophila
shore fly
Scatophila is a genus of shore flies (Diptera: Ephydridae) in the tribe Scatellini. The genus contains at least 26 Nearctic species, with additional species distributed across the Palearctic. Three new species were described from the Nearctic in 2021: S. angusta, S. bolwigi, and S. mystacina. Five species (S. contaminata, S. cribrata, S. iowana, S. mesogramma, and S. unicornis) have Holarctic distributions.
Schizotus fuscicollis
A small beetle in the family Pyrochroidae, known from the Holarctic region with confirmed records from Alaska. The species is placed in the genus Schizotus, which is characterized by soft-bodied adults and larvae typically associated with decaying organic matter. Specific biological details for this species remain poorly documented in published literature.
Sciodrepoides
Sciodrepoides is a genus of small carrion beetles in the family Leiodidae, subfamily Cholevinae, containing approximately five described species. The genus includes notable necrophagous species such as Sciodrepoides watsoni, which has been extensively studied for forensic entomology applications. Members are small-bodied, brown beetles with Holarctic distribution patterns.
Sciodrepoides watsoni
Sciodrepoides watsoni is a small (~3 mm) brown necrophagous beetle in the family Leiodidae with Holarctic distribution. It is notable for its utility in forensic entomology, where thermal summation models for its development have been established to estimate post-mortem intervals. The species completes development through egg, three larval instars, and pupa to adult, with head capsule width serving as the most reliable character for instar determination. It has been successfully reared in laboratory conditions at temperatures between 15°C and 25°C.
Scoliocentra tincta
Scoliocentra tincta is a species of fly in the family Heleomyzidae, first described by Francis Walker in 1849. Members of this family are commonly known as heleomyzid flies and are generally associated with decaying organic matter. The genus Scoliocentra is distributed across the Holarctic region. Specific ecological details for S. tincta remain poorly documented.
Scoliopteryx libatrix
Herald Moth, Herald
Scoliopteryx libatrix, commonly known as the herald moth, is a noctuid moth distributed across the Holarctic region. Adults are notable for their distinctive wing patterning and behavior of overwintering in caves, mines, and similar sheltered structures. The species has been documented as a host for entomopathogenic fungi and shares hibernacula with insectivorous bats. Its acoustic sensitivity to bat echolocation frequencies, combined with an absence of evasive flight responses during hibernation, represents an unusual behavioral adaptation.
Scolobates auriculatus
Scolobates auriculatus is a species of ichneumon wasp in the family Ichneumonidae, first described by Fabricius in 1804. The species is recorded from Belgium and Canada (Alberta), suggesting a Holarctic distribution. Like other ichneumonids, it is presumed to be a parasitoid, though specific host associations remain undocumented. The genus Scolobates contains relatively few described species, and S. auriculatus appears to be infrequently encountered based on available collection records.
Scopula frigidaria
Frigid Wave
Scopula frigidaria is a small geometrid moth distributed across boreal regions of northern Eurasia and North America. Adults have a wingspan of 21–23 mm and are active from late May through June. The species exhibits a univoltine life cycle with larvae feeding exclusively on bilberry (Vaccinium myrtillus). Larvae overwinter in the larval stage, with development spanning from July through May of the following year. Two subspecies are recognized: the nominate form and S. f. schoyeni restricted to the Kola Peninsula and Fennoscandia.
Scythris immaculatella
Scythris immaculatella is a minute moth species in the family Scythrididae, first described from North America in 1875. The species belongs to a group commonly known as flower moths, characterized by their extremely small size and association with flowering plants. Records indicate a Holarctic distribution spanning North America and Eurasia. Like many scythridids, its biology remains poorly documented.
Scythris inspersella
Norfolk owlet
Scythris inspersella, commonly known as the Norfolk owlet, is a small moth in the family Scythrididae first described by Jacob Hübner in 1817. It has a Holarctic distribution spanning Asia, Europe, and North America. The species is diurnal and has been observed visiting flowers during its July–August flight period. Its larvae feed gregariously on willowherbs (Onagraceae), spinning together the terminal shoots of their host plants.
Sepsis neocynipsea
black scavenger fly
Sepsis neocynipsea is a black scavenger fly in the family Sepsidae, widespread across the Holarctic region including North American grasslands. The species is obligate on cow dung for reproduction, with females depositing eggs on fresh dung and larvae completing development within or near the dung pat. Research has documented severe sensitivity to ivermectin residues in livestock dung, with females showing approximately three times higher mortality than males when exposed. The species exhibits complex interactions between chemical stress and environmental conditions, including potential hormetic effects where combined heat and ivermectin exposure can improve survival relative to ivermectin alone.
Sericoda
Sericoda is a genus of harpaline ground beetles native to the Holarctic region, with apparent North American origin. These beetles are pyrophilous, meaning they are strongly attracted to burned areas following forest fires. They are generally smaller than related genera such as Agonum. Two species, Sericoda quadripunctata and S. bembidioides, have been extensively studied in boreal forests of Alberta, Canada, where they serve as hosts for phoretic mites of the genus Antennoseius.
Sericoda quadripunctata
Four-spotted Sericoda
Sericoda quadripunctata is a pyrophilous ground beetle strongly associated with recently burned forests in boreal regions. Its abundance peaks in the first year after wildfire and declines sharply by the third post-fire year. The species serves as a phoretic host for specialized mites (Antennoseius perseus and A. pyrophilus) that inhabit the space beneath its elytra. It occurs across the Holarctic region, including Europe, Northern Asia, and North America.
Sericomyia
Pond Flies
Sericomyia is a genus of large hoverflies in the family Syrphidae, commonly known as pond flies. Species within this genus are notable bee mimics, displaying both short-pile and long-pile coloration patterns. The genus is widespread across boreal forests of the Holarctic region, extending southward at higher elevations into the Oriental and Neotropical regions. Larvae are of the rat-tailed maggot type, specialized for aquatic life in oxygen-poor environments.
Sialis
Holarctic Alderflies
Sialis is a genus of alderflies in the family Sialidae, characterized by small, brown, heavy-bodied insects with forewings 10–20 mm long. The genus is distinguished from other Megaloptera by having fewer than fifteen square cells along the upper edge of the front wings. Adults are diurnal and active in late spring. Larvae are aquatic predators that develop over two years before pupating in shoreline soil.
Simplocaria
pill beetles
Simplocaria is a genus of pill beetles (family Byrrhidae) established by Stephens in 1829. The genus contains more than 30 described species. Members of this genus are associated with forest habitats in northern regions. Simplocaria metallica has been specifically studied in northern Alberta, Canada, in relation to forest habitat characteristics.
Simplocariini
pill beetles
Simplocariini is a tribe of pill beetles (family Byrrhidae) comprising approximately 9 genera and more than 40 described species. The tribe was established by Mulsant & Rey in 1869 and is classified within the subfamily Byrrhinae. Members of this tribe share the family characteristic of conglobation—the ability to roll into a ball when disturbed. The tribe includes genera distributed across the Holarctic region, with some genera showing more restricted geographic ranges.
Siphlonurus alternatus
Northern Summer Mayfly
Siphlonurus alternatus is a primitive minnow mayfly with a Holarctic distribution spanning North America and Europe. The species is univoltine, overwintering as eggs and emerging as adults between May and August. Larvae inhabit deep pools in rivers, streams, and calcareous lakes, where they feed on fine particulate organic detritus. Adults emerge during daylight hours, with males forming swarms at dawn and dusk.
Sitonini
Sitonini is a tribe of broad-nosed weevils (Curculionidae: Entiminae) with a Holarctic distribution. Members are specialized feeders on Fabaceae, with adults consuming leaves and larvae feeding on root nodules. The tribe includes economically significant pests, particularly in the genera Sitona and Charagmus, which damage lupin and other legume crops in Europe.
Smerinthus
Eyed Hawkmoths
Smerinthus is a Holarctic genus of hawkmoths in the family Sphingidae, containing approximately 12 recognized species. Adults are characterized by prominent eyespots on the hindwings and forewing patterns that resemble dried leaves. Adults possess reduced or absent mouthparts and do not feed. Larvae feed on a variety of host plants in the families Salicaceae and possibly others.
Somotrichus
Somotrichus is a monotypic genus of ground beetles in the family Carabidae, established by Seidlitz in 1887. It contains a single species, Somotrichus unifasciatus, distributed across the Holarctic region. The genus belongs to the subtribe Somotrichina within the tribe Lebiini.
Spallanzania hebes
Spallanzania hebes is a species of tachinid fly described by Fallén in 1820. It belongs to the subfamily Exoristinae and tribe Goniini within the parasitoid fly family Tachinidae. The species has a broad Holarctic distribution spanning North America, Europe, and Asia.
Spargania luctuata
White-banded Carpet, White-banded Carpet Moth
Spargania luctuata, commonly known as the white-banded carpet, is a geometrid moth with a Holarctic distribution spanning northern and central Europe, North Asia, and North America. Adults are bivoltine in at least parts of their range, flying from late April through September. The species is recognized by its characteristic wing pattern featuring a prominent white transverse band. Larvae feed specifically on rosebay willowherb (Chamaenerion angustifolium and related species).
Sphecomyia cryptica
Sphecomyia cryptica is a species of hoverfly (Diptera: Syrphidae) described in 2019 from the genus Sphecomyia, a group of large wasp-mimicking flies in the subtribe Criorhinina. It belongs to the S. pattonii species group, characterized by the absence of pruinose scutellar vittae. The species exhibits distinctive abdominal patterning with pruinose sternites and yellow-banded tergites. As a member of this Holarctic genus, it likely functions as a pollinator in its adult stage. Biological data remain limited due to its recent description.
Sphecomyia vittata
Long-horned Yellowjacket Fly
Sphecomyia vittata is a large, striking syrphid fly known for its exceptional mimicry of yellowjacket wasps. It possesses unusually long, thick antennae for a fly—longer than the head depth in lateral view—which enhances its resemblance to vespid wasps. The species belongs to the S. vittata species group within subtribe Criorhinina, characterized by pruinose scutellar vittae and specific thoracic pruinosity patterns. Adults are flower visitors, though detailed natural history remains poorly documented. The species has a Holarctic distribution with concentration in eastern North America.
Spilichneumon
Spilichneumon is a genus of ichneumon wasps containing at least 30 described species. These wasps are notable for being among the first wasps active in early spring, having overwintered as adults in protected locations such as rotten logs. The genus has a holarctic and Oriental distribution, with North American species concentrated in northern regions, Canada, Alaska, and mountainous areas extending south to Arizona. Females are internal parasitoids of noctuid moth caterpillars, with larvae developing inside hosts and emerging from the pupal stage.
Spiriverpa
Spiriverpa is a genus of stiletto flies (Diptera: Therevidae: Therevinae) containing six recognized species distributed across the Holarctic Region. The genus was established by Irwin and Lyneborg in 1981 and has undergone recent taxonomic revision to clarify species boundaries and synonymize several previously misplaced taxa. Species within this genus are distinguished primarily by male genitalia morphology.
Spiriverpa bella
A stiletto fly species in the family Therevidae, occurring in the Holarctic region. Originally described as Thereva bella by Kröber in 1914, the species was later transferred to Spiriverpa. The subspecies Thereva bella nigrimana Kröber was synonymized with the nominate form in a 2005 taxonomic revision.
Stenamma
cryptic leaf-litter ants
Stenamma is a genus of cryptic ants in the family Formicidae, subfamily Myrmicinae. The genus was long thought to be restricted to temperate regions, but extensive Neotropical collections have revealed a major radiation in Middle America with 40 recognized species, 33 of them newly described. Species are notably adapted to cool, wet environments at mid to high elevations, where they can become the dominant ant genus in leaf-litter samples—contrary to the typical ant pattern of decreasing diversity with elevation.
Stenamma chiricahua
Stenamma chiricahua is a species of ant in the family Formicidae, first described by Snelling in 1973. The species epithet refers to the Chiricahua Mountains of southeastern Arizona, indicating its type locality and geographic association with this Madrean Sky Island range. As a member of the genus Stenamma, it belongs to a cryptic ant group known for occurring in cool, wet forest habitats at mid to high elevations. The Middle American clade of Stenamma, which includes this species, underwent a major taxonomic revision in 2013 that recognized 40 species, 33 of which were newly described, revealing a previously overlooked radiation of Neotropical ants.
Stenamma schmittii
Stenamma schmittii is a species of ant in the genus Stenamma, described by Wheeler in 1903. The genus Stenamma comprises cryptic "leaf-litter" ants found in moderately humid to wet forest habitats across the Holarctic region, Central America, and northwestern South America. Species in this genus are adapted to cool, wet environments at mid to high elevations, often becoming the most common ant genus in cloud forest leaf-litter samples. Stenamma species exhibit diverse life history strategies and nesting behaviors, including the use of clay "door-pebbles" for nest protection in some species.
Stenodemini
Stenodemini is a tribe of plant bugs (family Miridae) comprising approximately 18 genera and over 60 described species. Members are primarily associated with grasses and grassland habitats. The tribe includes economically and ecologically significant genera such as Stenodema, Leptopterna, Notostira, and Trigonotylus. Species within this tribe show complex feeding relationships with multiple grass host plants, with ecological separation often achieved through temporal partitioning and microhabitat specialization.
Stenus juno
Stenus juno is a species of predatory rove beetle in the family Staphylinidae, subfamily Steninae. It was first described by Paykull in 1789. The species has a broad Holarctic distribution, occurring across Europe, northern Asia, and North America. Like other members of the genus Stenus, it possesses specialized adaptations for capturing prey.
Stenus latissimus hatchi
Stenus latissimus hatchi is a subspecies of rove beetle in the family Staphylinidae, subfamily Steninae. Like other members of the genus Stenus, it possesses the specialized labial apparatus that allows some species to capture prey using adhesive secretions. The subspecies occurs across a broad transcontinental range spanning northern Eurasia and western North America. As a member of the Steninae, it is associated with moist habitats near water bodies where the water-gliding behavior characteristic of many congeners may be expressed.
Stenus morio
Stenus morio is a species of rove beetle in the subfamily Steninae, first described by Gravenhorst in 1806. It belongs to a genus noted for specialized predatory adaptations, including the ability to use blood pressure to eject mouthparts for capturing prey. The species has a broad Holarctic distribution spanning Europe, Asia, and North America.
Stenus plicipennis
Stenus plicipennis is a species of rove beetle in the subfamily Steninae, described by Casey in 1884. Like other members of the genus Stenus, it possesses the characteristic labial apparatus used for prey capture, though the specific ecology of this species remains poorly documented. The species has a Holarctic distribution, occurring across northern North America and eastern Russia. It represents one of numerous Stenus species adapted to moist microhabitats where predatory specialization on small invertebrates occurs.
Stenus pubescens
Stenus pubescens is a species of rove beetle in the family Staphylinidae, subfamily Steninae. It is one of numerous species in the large genus Stenus, which is characterized by distinctive adaptations including the ability to glide on water surfaces using specialized gland secretions. The species has a Holarctic distribution, occurring across much of Europe, northern Asia, and North America. Like other members of the genus, it is a predator of small invertebrates.
Stephanopachys substriatus
powder-post beetle, Pine Powderpost Beetle
Stephanopachys substriatus is a species of horned powder-post beetle in the family Bostrichidae. It has a Holarctic distribution, occurring in Europe, Northern Asia (excluding China), and North America. The species is commonly known as the powder-post beetle or Pine Powderpost Beetle, reflecting its association with coniferous wood degradation.
Stereocerus rubripes
Stereocerus rubripes is a species of ground beetle in the family Carabidae, characterized by its holarctic distribution spanning Europe, northern Asia, and North America. It inhabits woodland environments and belongs to the subfamily Pterostichinae, a diverse group of predominantly ground-dwelling predatory beetles. The species was first described by Motschulsky in 1860.
Sterictiphora
Sterictiphora is a Holarctic genus of sawflies in the family Argidae. The genus contains approximately 20 described species distributed across the northern temperate regions of North America, Europe, and Asia. Larvae of at least some species produce distinctive zigzag feeding patterns on host leaves. The genus is distinguished from the superficially similar Aproceros (which feeds on Ulmus) by host association with Prunus species.
Stictoleptura
Stictoleptura is a genus of longhorn beetles (Cerambycidae) distributed across the Holarctic region, with species in Europe, Asia, and North America. The genus includes medium-sized beetles typically associated with broadleaved woodland habitats. The first genome sequence for the genus was published for Stictoleptura scutellata, a scarce species in Britain associated with ancient woodland and wood pasture.
Stigmella lapponica
Stigmella lapponica is a minute moth in the family Nepticulidae, described by Maximilian Ferdinand Wocke in 1862 from northern Norway. The species is notable for its leaf-mining larvae that feed exclusively on birch leaves, creating distinctive slender galleries. Adults are active in May with a single generation per year, though partial second broods have been suggested. The moth occurs across the Holarctic region, including Europe, Asia, and North America.
Stiphrosoma
Stiphrosoma is a genus of small flies in the family Anthomyzidae, established by Czerny in 1928. The genus contains at least 14 recognized species, including the type species S. sabulosum and 13 species described from the New World. A revised generic diagnosis was established in 2005 to accommodate all known species. The genus exhibits holarctic distribution, with some species showing wing polymorphism.
Stroggylocephalus
Stroggylocephalus is a genus of leafhoppers in the family Cicadellidae, subfamily Aphrodinae. The genus was established by Flor in 1861 and contains at least six described species distributed across the Holarctic region. Species have been recorded from Europe, Asia, and North America.
Strophopteryx
mottled willowfly (for S. fasciata)
Strophopteryx is a genus of winter stoneflies comprising seven described species. Members are found in the Holarctic region, with records from North America and the Russian Far East. The genus belongs to the family Taeniopterygidae, a group characterized by adult emergence during cold months. Strophopteryx fasciata, the mottled willowfly, is the most well-known species and has been the subject of mitochondrial genome sequencing.
Stygnocoris sabulosus
hairy groundbug
Stygnocoris sabulosus is a small dirt-colored seed bug in the family Rhyparochromidae. The species was described by Schilling in 1829 and has been widely recorded across the Holarctic region. A taxonomic revision established S. sabulosus as the senior synonym of S. pygmaeus (R.F. Sahlberg, 1848). It is commonly known as the hairy groundbug.
Sulcacis
tree-fungus beetles
Sulcacis is a genus of minute tree-fungus beetles in the family Ciidae, established by Dury in 1917. The genus comprises eight described species distributed across the Holarctic region, including Europe, Asia, and North America. Species in this genus are associated with wood-decaying fungi and are documented hosts of entomopathogenic fungi and pseudoscorpion predators.