Western-north-america
Guides
Caudatella
Caudatella is a genus of mayflies in the family Ephemerellidae, established by Edmunds in 1959. Species within this genus are primarily distributed in western North America, with documented occurrences in Montana and other regions. The genus has been subject to taxonomic revision, particularly regarding species complexes such as C. heterocaudata and C. hystrix. Larval stages are aquatic and associated with stream habitats.
Caudellia nigrella
snout moth
Caudellia nigrella is a species of snout moth in the family Pyralidae, described by George Duryea Hulst in 1890. It is one of approximately 1,500 species in the subfamily Phycitinae, a diverse group of small moths often associated with dried plant materials. The species occurs in western North America, with records from the southwestern United States and extending northward into Canada.
Ceanothia ceanothi
Ceanothia ceanothi is a species of jumping plant louse (psyllid) in the family Psyllidae, described by Crawford in 1914. The species is associated with Ceanothus host plants, as indicated by its specific epithet. It belongs to a group of sap-feeding insects that specialize on particular plant taxa. Distribution records indicate presence in western North America.
Cecrita lunata
Cecrita lunata is a moth species in the family Notodontidae, the prominents. It was first described by Henry Edwards in 1884 and is found in the western United States and Mexico. The species was transferred from the genus Heterocampa to Cecrita in 2021 based on published research. It has been assigned Hodges number 7993 in the North American moth numbering system.
Celastrina echo
Echo Azure, Western Azure
Celastrina echo is a small blue butterfly in the family Lycaenidae, native to western North America. Its taxonomic status was elevated from subspecies of C. ladon to full species in 2001. The species exhibits complex associations with ants throughout its larval development and displays considerable variation in brood number depending on local climate conditions.
Celastrina echo cinerea
Southwestern Azure
Celastrina echo cinerea, the Southwestern Azure, is a subspecies of the echo azure butterfly in the family Lycaenidae. It is one of several subspecies within the Celastrina echo species complex, which is found across western North America. The species is known generally as the echo azure or western azure. Host plant associations include Aesculus californica (California buckeye) in the Bay Area region.
Celastrina echo echo
Pacific Azure, Echo Azure, Western Azure
Celastrina echo echo, commonly known as the Pacific Azure, is a subspecies of small blue butterfly in the family Lycaenidae. It occurs in western North America, particularly in California and neighboring states. The subspecies is associated with specific host plants including California buckeye (Aesculus californica) and various Ceanothus species. Adults are active in spring, with flight timing varying by elevation and latitude.
Celastrina echo nigrescens
Northwestern Azure
Celastrina echo nigrescens, the Northwestern Azure, is a subspecies of the western azure butterfly in the family Lycaenidae. It is currently recognized as a synonym of Celastrina ladon. The subspecies was described by J. Fletcher in 1903. Like other azure butterflies, it is associated with specific host plants including California buckeye (Aesculus californica).
Cenocorixa wileyi
Cenocorixa wileyi is a species of water boatman in the family Corixidae. It was described by Hungerford in 1930. The genus Cenocorixa is endemic to western North America and contains several species adapted to lentic freshwater habitats. This species is part of a genus characterized by distinctive male genitalic structures and specific habitat preferences.
Cenopis vabroui
Cenopis vabroui is a species of tortricid moth described by Powell & Brown in 2012. It belongs to the genus Cenopis, a group of small moths commonly known as fruit-tree leafroller moths. As a recently described species, detailed biological information remains limited. The species is known from the western United States.
Centrodera spurca
yellow Douglas-fir borer
Centrodera spurca, commonly known as the yellow Douglas-fir borer, is a species of flower longhorn beetle in the family Cerambycidae. It is native to North America, with records from western Canada (British Columbia, Alberta) and the western United States. The species has been documented in coniferous forest habitats, particularly in association with Douglas-fir (Pseudotsuga menziesii). A notable disjunct population occurs in the Sacramento Mountains of New Mexico, separated from the main Pacific Coast distribution.
Cephalodynerus russipes
Cephalodynerus russipes is a species of potter wasp in the subfamily Eumeninae, first described by Bohart in 1942. The genus Cephalodynerus is characterized by distinctive head morphology with expanded genae (cheek regions), though species-specific traits for C. russipes remain poorly documented. This species belongs to a group of solitary wasps that construct mud nests provisioned with paralyzed caterpillars.
Cephenemyia apicata
nose bot fly
Cephenemyia apicata is a nose bot fly (family Oestridae) that parasitizes Columbian black-tailed deer (Odocoileus hemionus columbianus). First instar larvae develop in the deer's bronchi for 6–8 months before migrating to retropharyngeal pouches. Adult males aggregate at elevated stands of Castanopsis and Quercus in California, with activity occurring from April through July when air temperatures reach 20°C. Females exhibit a distinctive visible attack behavior, landing on or near deer and eliciting curiosity before larvipositing into nostrils.
Ceraleptus pacificus
Ceraleptus pacificus is a leaf-footed bug in the family Coreidae, first described by Barber in 1914. The species is distributed across western North America and Central America. As a member of the true bugs (Hemiptera), it possesses piercing-sucking mouthparts typical of the order.
Ceranemota fasciata
Ceranemota fasciata is a moth in the family Drepanidae (hook-tip moths) described by William Barnes and James Halliday McDunnough in 1910. It occurs in western North America from coastal southern Alaska through British Columbia to northern California. The species inhabits coastal rainforests, mixed hardwood forests, and montane riparian areas. Larvae feed on Amelanchier alnifolia and various Prunus species including P. ilicifolia and P. virginiana.
Ceranemota tearlei
Ceranemota tearlei is a moth in the family Drepanidae, first described by Henry Edwards in 1888. It occurs in western North America from British Columbia and Alberta south to California, Utah, and Colorado. Adults are active from late August to October, with one generation per year. The larvae feed on specific woody plants including serviceberry, mountain-ash, and willow species.
Ceratagallia artemisia
Ceratagallia artemisia is a species of leafhopper in the family Cicadellidae, described by Oman in 1939. The specific epithet 'artemisia' suggests an association with plants in the genus Artemisia (sagebrush and related species). As a member of the tribe Agalliini, this species belongs to a group of leafhoppers known for their small size and often cryptic habits on host plants.
Ceratagallia californica
Ceratagallia californica is a species of leafhopper in the family Cicadellidae, first described by Baker in 1898. The species has undergone taxonomic revision, with some authorities placing it in the genus Aceratagallia. Distribution records indicate occurrence in western North America from British Columbia to California and eastward to Colorado and Utah. Like other leafhoppers, it is a phloem-feeding insect associated with vascular plants.
Ceratagallia lophia
Ceratagallia lophia is a species of leafhopper in the family Cicadellidae. Members of this genus are characterized by distinctive head and pronotal structures. The species is part of a group of leafhoppers associated with specific host plants in western North America.
Ceratagallia obscura
Ceratagallia obscura is a leafhopper species in the family Cicadellidae. It is currently recognized as a synonym of Aceratagallia obscura. The species has been recorded from western North America including Arizona, California, Oregon, and Ontario, Canada. Very little specific biological information is available for this taxon.
Ceratodalia gueneata
Guenée's Carpet Moth
Ceratodalia gueneata is a moth species in the family Geometridae and the sole member of its genus. It is found in western North America, from British Columbia and Alberta south to Colorado and California. The species is commonly known as Guenée's Carpet Moth.
Cercyonis oetus
Small Wood-Nymph, Dark Wood-Nymph
Cercyonis oetus is a brush-footed butterfly of western North America, commonly known as the Small Wood-Nymph or Dark Wood-Nymph. It is a medium-sized satyrine with a wingspan of 32–45 mm. Adults fly in a single generation from June to August. The species has four recognized subspecies distributed across its range.
Ceriana tridens
Western Wasp Fly
Ceriana tridens is a syrphid fly species native to western North America, commonly known as the Western Wasp Fly. It exhibits striking wasp mimicry, with coloration resembling yellowjackets or paper wasps. The species has been documented ovipositing in tree fissures, where larvae feed on sap.
Ceroxys latiusculus
narrow-banded picture-winged fly, picture-winged fly
Ceroxys latiusculus, commonly known as the narrow-banded picture-winged fly, is a species of ulidiid fly native to western North America. Adults measure 9–12 mm and are recognized by their grayish-brown bodies, black abdomen with gray bands, and distinctively patterned wings. The species is frequently encountered as a nuisance pest when adults enter buildings in autumn to seek winter shelter. Larvae develop within the seed heads of Senecio plants.
Ceuthophilus agassizii
Ceuthophilus agassizii is a camel cricket species in the family Rhaphidophoridae, described by Scudder in 1861. As a member of the genus Ceuthophilus, it shares the characteristic humpbacked profile, elongated antennae, and powerful jumping legs typical of camel crickets. The species is native to western North America, with confirmed records from British Columbia and Washington. Like other Ceuthophilus species, it inhabits cool, damp, dark environments.
Ceuthophilus utahensis
Utah camel cricket
Ceuthophilus utahensis, the Utah camel cricket, is a wingless orthopteran in the family Rhaphidophoridae. The species is native to western North America, with documented occurrences in Colorado, New Mexico, and Utah. Like other camel crickets, it is adapted to dark, moist microhabitats. The species was described by Thomas in 1876.
Chaetarthria nigrella
Chaetarthria nigrella is a minute water scavenger beetle in the family Hydrophilidae. It is one of the smallest members of its family, typically measuring only 1-2 millimeters in length. The species belongs to the subfamily Chaetarthriinae, a group of tiny beetles often associated with moist or aquatic microhabitats. Very few observations exist for this species, with only three records documented on iNaturalist, suggesting it is either genuinely rare, undercollected, or difficult to detect due to its minute size.
Chalcophora angulicollis
western sculptured pine borer, sculptured pine borer
Chalcophora angulicollis is a large metallic wood-boring beetle in the family Buprestidae, commonly known as the western sculptured pine borer. It is one of the largest jewel beetles in western North America, measuring 20–33 mm in length. The species is strictly associated with pine trees (Pinus spp.), where larvae develop in dead or dying wood. Adults are active during daylight hours and are frequently observed running on or flying to recently fallen or injured pine trunks and branches. The species was historically confused with the eastern Chalcophora virginiensis but was reinstated as valid based on distinct morphological differences in mouthparts, male genitalia, and elytral margins.
Chauliognathus deceptus
Chauliognathus deceptus is a species of soldier beetle in the family Cantharidae. It occurs in the foothills and mountains of western North America, where it replaces its close relative C. basalis. Adults display black and orange coloration and possess chemical defenses secreted from abdominal glands. The species participates in Müllerian mimicry with other toxic beetles sharing similar warning coloration.
Chauliognathus lewisi vittatus
Lewis' soldier beetle (striped subspecies)
Chauliognathus lewisi vittatus is a subspecies of soldier beetle in the family Cantharidae. The nominate species C. lewisi is distributed in western North America, and the subspecies vittatus appears to represent a striped or banded color morph. Soldier beetles in this genus are commonly found on flowers where they feed on pollen and nectar, and adults are known predators of soft-bodied insects such as aphids. The subspecific epithet "vittatus" refers to the presence of longitudinal stripes or bands on the elytra, distinguishing it from other populations of C. lewisi.
Chelis brucei
Bruce's tiger moth
Chelis brucei, commonly known as Bruce's tiger moth, is a species of tiger moth in the family Erebidae. Described by Henry Edwards in 1888, this moth is restricted to mountainous regions of western North America. Adults are active during a brief flight period in mid-summer, while larvae have been documented feeding on a limited set of host plants. The species was transferred from the genus Neoarctia to Chelis as part of a broader taxonomic reorganization of tiger moth genera.
Chilocorus orbus
twice-stabbed lady beetle, two-stabbed lady beetle
Chilocorus orbus is a small predatory lady beetle native to western North America. Adults are readily identified by their shiny black, dome-shaped bodies with two prominent oval red patches positioned near the head on the elytra. The species is an important biological control agent, feeding voraciously on scale insects in forests, orchards, and gardens. Both adults and larvae are predatory, with larvae described as resembling miniature alligators with branching spines.
Chionea albertensis
snow fly
Chionea albertensis is a wingless crane fly in the family Limoniidae, first described by Charles Paul Alexander in 1941. As a member of the 'snow fly' genus Chionea, it is adapted to cold environments and has been observed active on snow surfaces during winter months. The species is known from western North America, with records from Alberta, British Columbia, and southward to Oregon, Idaho, and Montana. Like other Chionea species, it lacks wings and has modified life history traits associated with subnivean habitats.
Chionodes abitus
Chionodes abitus is a small moth in the family Gelechiidae, described by Hodges in 1999. It occurs in western North America from California north to British Columbia and Saskatchewan. The species is associated with willow (Salix) hosts.
Chionodes braunella
Chionodes braunella is a small moth in the family Gelechiidae, first described by Keifer in 1931. The species is notable for its specialized larval diet on lupines and other leguminous plants across western North America. Its distribution spans from western Canada through the western United States to the northeastern part of the continent.
Chionodes chrysopyla
Chionodes chrysopyla is a small gelechiid moth with a wingspan of 11–13 mm, found in western North America. The species is distinguished by its patterned forewings featuring blackish markings on a whitish-ochreous ground color. Larvae are specialized feeders on several oak species (Quercus), particularly in California and adjacent regions.
Chionodes figurella
Chionodes figurella is a small gelechiid moth with a wingspan of 15–21 mm, distributed along the Pacific coast of North America from Washington to California and Nevada. The species is recognized by its distinctive wing pattern featuring ochreous forewings obscured by stone-grey and dark ochreous scaling, with pale veins appearing as thin whitish lines. The larvae are known to feed on Elymus grasses, including blue wildrye (Elymus glaucus).
Chionodes landryi
Chionodes landryi is a small moth in the family Gelechiidae, described by Hodges in 1999. It is known from a limited number of records in western North America, specifically from Alberta, New Mexico, and Wyoming. The species belongs to a large genus of gelechiid moths, many of which are poorly known biologically.
Chionodes petalumensis
Chionodes petalumensis is a gelechiid moth species distributed across western North America from southern British Columbia to California, Arizona, and Colorado. The species was first described from Petaluma, California, which is reflected in its specific epithet. Its caterpillars are specialized feeders on oak leaves, with documented associations to Garry oak and valley oak.
Chionodes pinguicula
Chionodes pinguicula is a small gelechiid moth described by Meyrick in 1929. It occurs in arid and semi-arid regions of western North America. The species has a wingspan of 13–15 mm. Larvae are known to feed on Atriplex canescens (fourwing saltbush), a common shrub in desert habitats.
Chionodes powelli
Chionodes powelli is a species of gelechiid moth described by Hodges in 1999. It is distributed across western and southern North America, with records from California, Oregon, and Washington in the west, and from Texas through Florida in the south. The species is notable for its larval association with oaks, specifically three species of western North American Quercus.
Chionodes trichostola
Chionodes trichostola is a gelechiid moth described by Meyrick in 1923. It occurs across western North America from southwestern British Columbia to Texas. The species exhibits sexual dimorphism in wingspan, with males measuring approximately 19 mm and females 16 mm. Larvae have been documented feeding on multiple oak species and related plants.
Chlamydatus obliquus
Chlamydatus obliquus is a species of plant bug in the family Miridae, first described by Uhler in 1893 as Agalliastes obliquus. It is native to North America, with records from western Canada and the western United States. As a member of the Miridae, it belongs to one of the largest families of true bugs, commonly known as plant bugs or leaf bugs.
Chloealtis
slant-faced grasshoppers
Chloealtis is a genus of slant-faced grasshoppers in the family Acrididae, containing approximately five described species. Species in this genus are associated with forested and mountainous habitats in western North America. The genus has been studied extensively for its unusual meiotic chromosome behavior, particularly regarding synaptonemal complex formation and nuclear envelope attachment during cell division.
Chloealtis abdominalis
Rocky Mountain Sprinkled Locust
Chloealtis abdominalis is a species of slant-faced grasshopper in the family Acrididae, commonly known as the Rocky Mountain Sprinkled Locust. It belongs to the subfamily Gomphocerinae, a group characterized by their slanted face profile and stridulatory pegs on the hind legs used for sound production. The species has been documented in the western United States, with records from Colorado, Montana, Nebraska, and Wyoming. It is one of two species in the genus Chloealtis known from Colorado, alongside the more widespread C. conspersa.
Chlorosea
Chlorosea is a genus of moths in the family Geometridae, subfamily Geometrinae. The genus contains four described species: C. banksaria, C. margaretaria, C. nevadaria, and C. roseitacta. These moths are found in western North America, with records primarily from the western United States. The genus was established by Packard in 1873.
Chlosyne acastus
Sagebrush Checkerspot
Chlosyne acastus, the sagebrush checkerspot, is a butterfly in the family Nymphalidae native to western North America. Adults have a wingspan of 33–44 mm and display the characteristic orange and black checkered pattern typical of the genus. The species has one flight period annually, with adults active from May through early September. Larvae feed on specific Asteraceae host plants, with documented utilization of rabbit-brush, desert-aster, woolly sunflower, arrowleaf balsamroot, and common sunflower.
Chlosyne damoetas
Rockslide Checkerspot
Chlosyne damoetas, commonly known as the Rockslide Checkerspot, is a butterfly species in the family Nymphalidae. It is native to western North America, where it inhabits rocky and montane environments. The species was originally described by Skinner in 1902 under the basionym Melitaea damoetas.
Chlosyne leanira
Leanira Checkerspot
Chlosyne leanira, commonly known as the Leanira Checkerspot, is a butterfly in the family Nymphalidae, tribe Melitaeini. It occurs in western North America from Oregon through California, Nevada, Utah, western Colorado, and south to Baja California. The species exhibits sexual dimorphism in size and coloration, with females larger but males displaying more prominent red wing markings. Larvae are specialized feeders on Castilleja species (Orobanchaceae) and overwinter in the third instar.
Chlosyne whitneyi
rockslide checkerspot, Sierra Nevada checkerspot
Chlosyne whitneyi is a small checkerspot butterfly native to mountainous regions of western North America. Adults are active from July to August in a single annual generation. The species is tightly associated with alpine rockslide and scree slope habitats. Larvae feed on Erigeron and Solidago species in the sunflower family.