Western-north-america
Guides
Scaphinotus interruptus
Ménétriés' snail-eating beetle, Menetries' Snail-eating Beetle
Scaphinotus interruptus is a species of ground beetle in the tribe Cychrini, commonly known as Ménétriés' snail-eating beetle. Adults are flightless due to reduced wings (brachyptery) and are specialized predators of terrestrial snails. The species is endemic to mountainous regions of the western United States, specifically California and Oregon.
Scaphinotus marginatus
Margined Snail-eating Beetle
Scaphinotus marginatus is a large, flightless ground beetle in the family Carabidae, commonly known as the margined snail-eating beetle. Adults are brachypterous (short-winged) and nocturnal, preying exclusively on snails and slugs. The species inhabits coniferous, mixed, and deciduous forests across western North America, typically near streams and lakes. It is distinguished from similar Scaphinotus species by subtle elytral margin characteristics and geographic distribution.
Scaphinotus oreophilus
mountain loving snail-eating beetle
Scaphinotus oreophilus is a large ground beetle in the subfamily Carabinae, commonly known as the mountain loving snail-eating beetle. Adults are brachypterous (short-winged), rendering them flightless. The species belongs to a group of "snail hunters" characterized by robust bodies and prominent, sculptured mandibles adapted for crushing mollusk shells. It occurs in montane regions of the western United States.
Scaphinotus relictus
Relic Snail-eating Beetle, rilictual snail-eating beetle
Scaphinotus relictus is a species of ground beetle in the family Carabidae, commonly known as the Relic Snail-eating Beetle. This species is found in western North America, with records from Alberta and British Columbia in Canada southward through Idaho, Montana, Washington, and California in the United States. It inhabits deciduous, mixed, and coniferous forest habitats. Adults are brachypterous (short-winged) and nocturnal in their activity patterns.
Scaphinotus velutinus
Velvet Snail-eating Beetle
Scaphinotus velutinus, commonly known as the velvet snail-eating beetle, is a flightless ground beetle species in the family Carabidae. It is endemic to western North America, with confirmed records from California and Oregon. The species inhabits coniferous forest ecosystems and is characterized by reduced wings (brachyptery). As a member of the genus Scaphinotus, it is specialized for predation on terrestrial snails.
Scaphinotus ventricosus
potbellied snail-eating beetle, pot-bellied snail-eating beetle
Scaphinotus ventricosus is a species of ground beetle in the family Carabidae, commonly known as the potbellied snail-eating beetle. It is native to western North America, with documented occurrence in California and Oregon. Adults are distinctive among ground beetles for their brachypterous (short-winged) condition, which renders them flightless. The species exhibits gregarious and nocturnal behavior. It inhabits deciduous forests and poison-oak thickets, where it presumably feeds on snails as suggested by its common name and the feeding habits of related species in the genus.
Schinia acutilinea
Acute-lined Flower Moth, Angled Gem
Schinia acutilinea is a small noctuid moth found in arid western North America. Adults have a wingspan of 25–27 mm and are active in August. The species was described by Augustus Radcliffe Grote in 1878 and was synonymized with Schinia accessa by David F. Hardwick in 1996, though subsequent research by Michael G. Pogue suggests this lumped multiple distinct species.
Schinia albafascia
Schinia albafascia is a noctuid moth in the genus Schinia, a diverse group of flower-associated moths known for their colorful appearance and specialized host plant relationships. The species occurs in western North America from the Rocky Mountains to the Pacific Coast. Adults are active from mid-summer through early autumn. The larvae feed specifically on Ericameria nauseosa, a shrubby member of the sunflower family.
Schinia aurantiaca
Schinia aurantiaca is a small noctuid moth native to western North America. The species exhibits bright orange coloration and has a wingspan of approximately 17 mm. Larvae are specialized feeders on flowers of Eriastrum sapphirinum and Gilia species. Two subspecies are recognized: S. a. aurantiaca and S. a. tenuimargo.
Schinia crotchii
Schinia crotchii is a small noctuid moth in the subfamily Heliothinae. It was formerly treated as a synonym of Schinia cupes but has been restored to full species status based on systematic revision. The species has a restricted distribution in western North America, with larvae that feed specifically on Castilleja exserta.
Schinia cumatilis
silver-banded gem, Silver-banded Gem Moth
Schinia cumatilis is a small noctuid moth known as the silver-banded gem, first described by Grote in 1865. The species occurs across western North America from the southwestern United States into southern Canada. Adults have a wingspan of approximately 24–27 mm. The larvae are specialist feeders on Artemisia frigida.
Schinia deserticola
A small noctuid moth of western North American deserts, formerly treated as a subspecies of Schinia cupes. Adults have a wingspan of 22–28 mm. The species is closely tied to its larval host plant Camissonia claviformis, with adults typically found resting on or near the flowers.
Schinia intermontana
Schinia intermontana is a noctuid moth described by Hardwick in 1958. It was formerly considered a subspecies of Schinia villosa but has since been elevated to full species status. The species is distributed across the interior western United States and southwestern Canada. Larvae feed on Erigeron species.
Schinia meadi
Mead's Flower Moth
Schinia meadi is a small noctuid moth of western North America, described by Augustus Radcliffe Grote in 1873. Adults have a wingspan of approximately 24 mm and are active from June to July. The species belongs to the flower moth genus Schinia, whose larvae typically feed on flowers and seed pods of their host plants.
Schinia mortua
Schinia mortua is a small noctuid moth found across the western half of North America. Adults have a wingspan of 23–27 mm. The species is associated with host plants in the Asteraceae family, specifically Grindelia and Haplopappus, on which the larvae feed. Like many Schinia species, adults are likely flower-visiting and may be active during daylight hours.
Schinia obliqua
Schinia obliqua is a small noctuid moth in the subfamily Heliothinae, first described by Smith in 1883. The species is native to western North America, with confirmed records from California to Colorado and western Texas. Adults are active from July through September. The wingspan measures approximately 23 mm. Schinia unimacula was synonymized with this species in 1996 but later resurrected as a separate species in 2003, though some taxonomic uncertainty may persist.
Schinia oleagina
Schinia oleagina is a noctuid moth described by Morrison in 1875. It occurs across much of western North America and has a wingspan of approximately 27 mm. The species is notable for its specialized larval association with Brickellia, a genus of flowering plants in the aster family. Like other members of the genus Schinia, adults are often found resting on or near their host plants.
Schinia suetus
Schinia suetus is a noctuid moth first described by Augustus Radcliffe Grote in 1873. It occurs in mountainous regions of western North America, with adults active during summer months. The species has four recognized subspecies distributed across its range. Larvae feed on Lupinus species.
Schinia tertia
Third Flower Moth
Schinia tertia is a small noctuid moth native to western North America. Adults have a wingspan of approximately 25 mm and are active from April to October in two generations per year. The species is notable for its specialized larval diet on flowering plants in three genera: Ericameria, Isocoma pluriflora, and Liatris.
Schinia unimacula
Rabbitbush Flower Moth
A small flower moth in the family Noctuidae with a wingspan of approximately 25 mm. Adults are active from July to October across the western United States. The species is closely associated with rabbitbrush (Ericameria) as its larval host plant.
Schinia vacciniae
Schinia vacciniae is a small noctuid moth with a wingspan of approximately 19 mm. It belongs to the genus Schinia, a diverse group of flower moths known for their often colorful appearance and specialized associations with particular host plants. The species is documented from western North America, with records from Arizona, California, Idaho, Oregon, and Washington.
Schinia villosa
Little Dark Gem
Schinia villosa, commonly known as the Little Dark Gem, is a small noctuid moth first described by Augustus Radcliffe Grote in 1864. It is primarily a western North American species associated with montane habitats, though its range extends eastward across the Canadian prairies. The species exhibits the typical Schinia trait of flower-visiting behavior, with adults active in mid-summer and larvae feeding on Asteraceae hosts.
Schinia walsinghami
Schinia walsinghami is a small noctuid moth species with a wingspan of approximately 24 mm. Adults are active in late summer. The species belongs to the flower moth genus Schinia, whose members are typically associated with specific host plants and often rest on or near their host flowers during daylight hours. Larvae feed on species of Chrysothamnus and Ericameria (rabbitbrushes), both in the Asteraceae family.
Schizocosa mccooki
McCook's Split Wolf Spider
Schizocosa mccooki is a large wolf spider in the family Lycosidae, distributed across western North America from the Pacific coast to western Lake Erie. This species inhabits diverse open habitats including grasslands, chaparral, desert, and pinyon pine forests. Males produce complex vibratory courtship signals consisting of thumps and raps, with female mate choice influenced by male body mass and signal characteristics. Some populations have been observed digging burrows.
Schizomyia macrofila
Fiddleneck Midge Gall
Schizomyia macrofila is a gall midge species in the family Cecidomyiidae, known for inducing galls on fiddleneck plants (Amsinckia spp.). The species was described by Felt in 1907. As a member of the genus Schizomyia, it belongs to a group of gall midges specialized in forming distinct plant growths. The common name "Fiddleneck Midge Gall" reflects its association with this host plant group.
Schizopus
Schizopus is a genus of small beetles in the family Schizopodidae, established by LeConte in 1858. The genus contains two described species: Schizopus laetus LeConte, 1858 and Schizopus sallei Horn, 1885, with the latter including a recognized subspecies S. sallei nigricans Nelson, 1991. These beetles are rarely encountered and poorly known, with limited published information on their biology.
Schlingeria
Schlingeria is a genus of stiletto flies (family Therevidae) established by Irwin in 1977. It belongs to the subfamily Phycusinae, a group characterized by specialized morphological features including reduced wing venation and particular arrangements of thoracic bristles. The genus is poorly known, with only two observations recorded on iNaturalist and minimal published biological data available. Schlingeria species are presumably predatory as larvae, as is characteristic of the family Therevidae, though direct observations of life history remain undocumented.
Sclerobunus
harvestman
Sclerobunus is a genus of harvestmen (Opiliones: Laniatores) endemic to western North America. The genus was revised in 2014, which elevated several former subspecies to species rank, described five new species, and synonymized Cyptobunus under Sclerobunus. Species in this genus are primarily montane and show strong phylogeographic structure consistent with persistence in isolated mountain refugia during glacial cycles.
Scolopendra polymorpha
Common Desert Centipede, Tiger Centipede, Banded Desert Centipede, Sonoran Desert Centipede, Multicolored Centipede
Scolopendra polymorpha is a large centipede species native to arid regions of western North America. Adults typically measure 10–18 cm in body length. The species exhibits highly variable coloration, with common forms showing a dark brown to black body with yellow legs and orange to red head, though some populations display entirely blue coloration with indigo stripes. It is primarily nocturnal and has been documented to exhibit cannibalistic behavior. The venom contains bioactive peptides with demonstrated antimicrobial properties against human pathogens.
Scolopocryptops gracilis
Western Fire Centipede
Scolopocryptops gracilis is a centipede species in the family Scolopocryptopidae, commonly known as the Western Fire Centipede. It occurs in western North America from Mexico through the United States. The species has been documented in at least 1,200 observations on iNaturalist, indicating it is relatively frequently encountered in its range. It belongs to an order of large, predatory centipedes but is distinguished from the more widely known Scolopendridae by family-level characteristics.
Scolops grossus
Scolops grossus is a species of planthopper in the family Dictyopharidae, characterized by a distinctive elongated head projection. The species was described by Uhler in 1876. Like other members of the genus, it inhabits arid and semi-arid environments in western North America. It feeds on plant sap, primarily from host plants in the families Asteraceae and Chenopodiaceae.
Scolops hesperius
Scolops hesperius is a small planthopper in the family Dictyopharidae, characterized by a distinctive elongated rostrum that gives the genus its common nickname "rhinoceros planthoppers." The species occurs in western North America and shares the genus-wide traits of squat body form, straw to brown or gray coloration, and enlarged hind legs adapted for jumping. Like other Scolops species, it inhabits arid environments including dry fields, prairies, and grasslands. The biology of this species specifically remains poorly documented, as most research has addressed the genus collectively.
Scolytus unispinosus
Douglas-fir engraver
Scolytus unispinosus, the Douglas-fir engraver, is a bark beetle native to western North America. It acts primarily as a secondary insect, colonizing the tops, limbs, and branches of Douglas-fir trees that have been killed or weakened by other factors. While it occasionally kills young trees, it is generally of minor economic importance and commonly attacks logging slash. In British Columbia's interior, it frequently occurs in association with the Douglas-fir beetle (Dendroctonus pseudotsugae).
Scoparia palloralis
Scoparia palloralis is a small moth in the family Crambidae, described by Harrison Gray Dyar Jr. in 1906. It occurs in western North America from British Columbia to southern California, with inland records from Colorado and western Texas. The species exhibits seasonal flight activity in spring and summer, with timing varying by latitude and elevation.
Scopula fuscata
Scopula fuscata is a moth in the family Geometridae, first described by George Duryea Hulst in 1887. It is distributed across western North America from southwestern Saskatchewan through British Columbia and southward to California and Arizona. The species inhabits montane environments including foothill regions. Adults have a wingspan of 24–28 mm.
Scopula luteolata
Scopula luteolata is a small moth in the family Geometridae, subfamily Sterrhinae. It is restricted to western North America, occurring in montane habitats from southwestern Canada through the western United States. The species is associated with forest edge and opening habitats in mountainous regions. Adults have a wingspan of 23–26 mm. Like other geometrid moths, its larvae are likely 'inchworm' type caterpillars, though specific host plant associations remain poorly documented.
Scopula siccata
Scopula siccata is a species of geometrid moth first described by James Halliday McDunnough in 1939. It occurs in mountainous regions of western North America, inhabiting dry slopes at moderate to high elevations. The species has a relatively restricted distribution spanning from northern Colorado northward through Wyoming, western Montana, and Idaho to southern British Columbia and southwestern Alberta. Adults have a wingspan of 23–24 mm. Like other members of the genus Scopula, the larvae are likely inchworm-type caterpillars, though specific host plant associations remain undocumented.
Scymnus coniferarum
conifer lady beetle
Scymnus coniferarum is a small predatory lady beetle native to western North America. It has been studied as a potential biological control agent for the hemlock woolly adelgid (Adelges tsugae), an invasive pest of eastern hemlock in eastern North America. Field studies in Washington State indicate it feeds on multiple adelgid species across different conifer hosts, with higher abundance observed on pine adelgids than on hemlock woolly adelgid.
Scymnus pacificus
Scymnus pacificus is a small lady beetle (Coccinellidae) described by Crotch in 1874. Adults measure approximately 2.0–2.8 mm in length. The species occurs in western North America, with records from California extending eastward to western Texas, Colorado, and Utah. As a member of the genus Scymnus, it belongs to a group of minute lady beetles often associated with scale insect and mealybug predation, though specific ecological data for this species remain limited.
Segestria pacifica
tube web spider
Segestria pacifica is a species of tube web spider in the family Segestriidae, first described by Nathan Banks in 1891. It is found in the western United States and British Columbia, Canada. The species is characterized by its brown coloration, medium-large body size, and notably large, black, shiny chelicerae. Like other segestriids, it constructs silken tubes in crevices for shelter and prey capture.
Selenophorus chaparralus
Selenophorus chaparralus is a ground beetle species described by Purrington in 2000. It belongs to the genus Selenophorus, a group of nocturnal ground beetles within the family Carabidae. The species epithet 'chaparralus' suggests an association with chaparral vegetation, a type of Mediterranean scrubland found in parts of western North America. As a recently described species with limited observation records, much of its biology remains undocumented.
Semanotus amethystinus
Amethyst Cedar Borer
Semanotus amethystinus is a longhorned beetle in the family Cerambycidae, commonly known as the Amethyst Cedar Borer. The species is native to western North America and has been introduced to Hawaii. Adults are typically found on or near their coniferous host trees, particularly junipers and cedars. Larvae develop as wood-borers in the trunks and larger limbs of living or stressed trees, creating galleries packed with frass.
Semanotus amplus
Semanotus amplus is a species of longhorned beetle (family Cerambycidae) in the tribe Callidiini. It is a wood-boring beetle associated with coniferous hosts, particularly junipers. The species was described by Casey in 1912 and is known from western North America. Field observations indicate it infests living or recently dead wood, with larvae creating galleries in the sapwood. Adults have been encountered at night on host tree trunks.
Semanotus conformis
Semanotus conformis is a species of longhorned beetle (family Cerambycidae) in the tribe Callidiini, described by Casey in 1924. It belongs to a genus of wood-boring beetles that infest conifers, particularly junipers and related Cupressaceae. The species is poorly documented in the available literature, with minimal published information on its biology, distribution, and host associations. Available records suggest it occurs in the western United States.
Sergiolus angustus
Sergiolus angustus is a ground spider in the family Gnaphosidae, native to western North America. Like other members of its genus, it exhibits bold coloration that may represent mimicry of velvet ants (Mutillidae). The species is medium-sized, diurnal, and nomadic, actively hunting rather than building webs to capture prey. It constructs silk retreats for molting, egg guarding, and overwintering.
Sergiolus columbianus
Sergiolus columbianus is a ground spider in the family Gnaphosidae, native to western North America. It is one of approximately sixteen Sergiolus species found north of Mexico. Like other members of its genus, it displays bold coloration that may serve as mimicry of velvet ants (Mutillidae). It is a nomadic hunter that does not construct prey-capture webs.
Sergiolus montanus
Common Patterned Ant-mimic Ground Spider
Sergiolus montanus is a medium-sized ground spider in the family Gnaphosidae, distinguished by bold coloration that may serve as mimicry of velvet ants (Mutillidae). It is primarily active during daylight hours and does not construct webs for prey capture. The species is found in western North America, with records from Alberta and British Columbia in Canada southward through the western United States. Like other members of the genus, it is agile, nomadic, and capable of climbing vegetation and vertical surfaces.
Serica anthracina
Serica anthracina is a small scarab beetle in the family Scarabaeidae, described by LeConte in 1856. Adults measure 5–8.5 mm in length and exhibit variable coloration ranging from uniform testaceous to black. The species is distributed across western North America, from the Canadian prairies through the Rocky Mountain region to the Pacific coast.
Serica fimbriata
Serica fimbriata is a species of scarab beetle in the family Scarabaeidae, distributed in western North America and Central America. Adults are small, measuring approximately 10.5 mm in length, with distinctive chestnut-brown coloration and dense velvety pubescence. The species is notable for its fimbriate (fringed) pronotal and elytral margins bearing long, stiff, fulvous hairs. Adults feed on flowers of several plant species including Lotus scoparius, Eriogonum fasciculatum, and Adenostoma species.
Sialis rotunda
Alderfly
Sialis rotunda is a species of alderfly in the family Sialidae, order Megaloptera. It is a small to medium-sized aquatic insect whose larvae develop in freshwater habitats. Adults are short-lived and primarily focus on reproduction. The species was described by Nathan Banks in 1920 and is native to western North America.