Western-north-america
Guides
Bolshecapnia
small winter stoneflies
Bolshecapnia is a genus of small winter stoneflies in the family Capniidae, first described by Ricker in 1965 as a subgenus of Capnia and later elevated to genus rank. The genus currently comprises four species distributed in western North America. Members of this genus are adapted to cold-water environments and exhibit the characteristic winter-emergence pattern typical of Capniidae.
Bombus appositus
White-shouldered Bumble Bee
Bombus appositus, the white-shouldered bumblebee, is a western North American bumble bee species found in open habitats from southwestern Canada through the Cascade Mountains and Sierra Nevada to central California. It nests underground or on the surface and has been documented feeding on diverse floral resources including giant hyssops, thistles, gentians, and clovers. The species is known to be a host for the cuckoo bumblebee Bombus insularis.
Bombus flavifrons
yellow-fronted bumble bee, yellowhead bumblebee
Bombus flavifrons is a robust bumble bee native to North America, distributed across much of Canada, Alaska, and the western contiguous United States. The species exhibits intraspecific color pattern variation across its range due to Müllerian mimicry. It inhabits high-altitude and high-latitude environments including tundra, taiga, and mountain forests and meadows. The species is host to the parasitic cuckoo bumble bee Bombus insularis.
Bombus huntii
Hunt's Bumble Bee, Hunt Bumblebee
Bombus huntii is a native western North American bumble bee with a broad range spanning western Canada to the Trans-Mexican Volcanic Belt. The species occupies diverse habitats from desert scrub to high-elevation pine ecosystems and has been documented foraging on at least eight plant genera. While populations have declined, it remains among the more common bumble bees in western North America. Its genome was sequenced as part of the Beenome100 project.
Bombus mckayi
McKay's Western Bumble Bee
Bombus mckayi is a North American bumble bee species originally described as a subspecies of Bombus occidentalis. It is now recognized as a distinct species within the subgenus Bombus sensu stricto. The species occurs in western North America, though detailed ecological information remains limited compared to better-studied congeners.
Bombus mixtus
Fuzzy-Horned Bumble Bee, Tricoloured Bumblebee, Orange-Belted Bumblebee, Mixed Bumblebee
Bombus mixtus is a bumble bee species native to western North America, with a disjunct population in the Great Lakes region. It occupies diverse habitats including mountain meadows, taiga, tundra, chaparral, and open grassy areas. The species has been documented feeding on multiple flowering plant genera and nests both underground and on the surface. It is one of several Bombus species surveyed during 2016 conservation efforts for rare bumble bees in the Mt. Ashland area of Oregon.
Bombus nevadensis
Nevada bumble bee, Nevada bumblebee
Bombus nevadensis, the Nevada bumble bee, is a North American bumble bee species distinguished by its long proboscis and distinctive coloration. Queens and workers have entirely black heads, while males display yellow on the face and top of the head. The species inhabits open habitats from Alaska to California and east to Wisconsin, with populations extending into Arizona, New Mexico, and Mexico. It nests underground and forages on a variety of flowering plants.
Bombus occidentalis
Western bumble bee, white-bottomed bee
Bombus occidentalis, the western bumble bee, is a medium to large bumble bee species native to western North America. Once among the most common bumble bees in its range, it has experienced severe population declines since the late 1990s, with losses exceeding 40% in some areas and near-disappearance from parts of California, Oregon, and Washington. The species was listed as endangered under the California Endangered Species Act in 2019. It is a generalist forager and effective pollinator of crops including tomatoes, peppers, and berries through buzz pollination.
Bombus sitkensis
Sitka bumble bee, Sitka bumblebee
Bombus sitkensis, the Sitka bumble bee, is a medium-sized bumble bee species native to western North America. It is distinguished by its distinctive color pattern featuring yellow and black on the thorax with a black central patch, yellow on the first two abdominal segments, black on segments three and four with yellow posterior rims, and brownish-red terminal segments. The species exhibits an exceptionally long flight period for queens, spanning nearly the entire year in some populations. It has experienced mild population declines in parts of California due to competition with Bombus vosnesenskii for nesting sites.
Bombus vancouverensis
Vancouver Bumble Bee, Vancouver Island Bumblebee
Bombus vancouverensis is a eusocial bumblebee of subgenus Pyrobombus, widespread across mountainous regions of western North America. The species was long treated as synonymous with Bombus bifarius, with most historical literature on bifarius actually referring to vancouverensis. Genetic studies completed in 2020 confirmed their distinct status, with true B. bifarius being exclusively red-tailed and geographically restricted, while B. vancouverensis is polymorphic and broadly distributed. It is one of only two bumblebee species known to use pheromones for kin recognition.
Bombus vancouverensis nearcticus
Nearctic Bumble Bee
Bombus vancouverensis nearcticus is a subspecies of bumble bee native to western North America. It belongs to a species complex that has undergone taxonomic revision, with some authorities previously treating it as a distinct species (Bombus nearcticus) or synonymizing it with related taxa. The subspecies occurs in montane and coastal regions where it participates in pollination networks. Like other bumble bees in the subgenus Pyrobombus, it exhibits social colony structure with a single queen founding nests in spring.
Bombus vandykei
Van Dyke's bumble bee, Van Dyke's bumblebee
Bombus vandykei, commonly known as Van Dyke's bumble bee, is a species of bumble bee native to western North America. The species was first described by Frison in 1927 and is named in honor of entomologist Henry Van Dyke. It is a medium-sized bumble bee with distinctive coloration that distinguishes it from closely related species. The IUCN lists the species as Least Concern with a stable population.
Bombylius albicapillus
White-headed Bee Fly
Bombylius albicapillus is a species of bee fly in the family Bombyliidae, occurring in western North America. As a member of the tribe Bombyliini, it shares the characteristic bee-mimicking appearance common to this group. The species name "albicapillus" (white-headed) refers to a distinctive pale coloration on the head. Like other Bombylius species, adults are likely active in spring and associated with flowers, though specific biological details remain poorly documented.
Bombylius lancifer
Bombylius lancifer is a species of bee fly (family Bombyliidae) found in western North America. Bee flies in this genus are typically active in spring and are known for their bee-like appearance, hovering flight behavior, and parasitic larval life history. Adults visit flowers for nectar, while larvae develop as parasites in the nests of solitary bees.
Bondia shastana
Bondia shastana is a small moth in the family Carposinidae, described by Donald R. Davis in 1969. The species name references Mount Shasta, California, the type locality. Adults are active during multiple periods throughout the year, with flight records spanning spring, summer, and early autumn.
Booneacris
Wingless Mountain Grasshoppers
Booneacris is a genus of spur-throated grasshoppers in the family Acrididae, established by Rehn & Randell in 1962. The genus contains four described species, all characterized by reduced or absent wings. These grasshoppers are restricted to mountainous regions of western North America, with species found at high elevations. The common name "Wingless Mountain Grasshoppers" reflects their most distinctive trait and habitat preference.
Boopedon
boopies, ebony grasshopper (B. nubilum), yellow-belly boopie (B. flaviventris), prairie boopie (B. gracile), short-winged boopie (B. auriventris)
Boopedon is a genus of grasshoppers in the family Acrididae, commonly known as boopies. The genus contains at least eight described species distributed across western North American grasslands. Species in this genus are notable for pronounced sexual dimorphism, with males typically winged and darkly colored while females are often larger, flightless, and paler. Several species, particularly B. nubilum (the ebony grasshopper), are significant rangeland pests capable of reaching outbreak densities.
Boopedon nubilum
ebony grasshopper, black-males grasshopper, plains boopie
Boopedon nubilum is a large slant-faced grasshopper inhabiting western North American grasslands. Males are strikingly black with functional wings, while females are large, pale brown, and typically flightless. The species is a specialized grass feeder with documented food preferences that vary geographically. At high densities, it becomes a significant pest of rangeland forage, particularly in the southern mixedgrass and desert prairies of Arizona, New Mexico, and western Texas.
Boreocanthon simplex
Boreocanthon simplex is a dung beetle species in the family Scarabaeidae, native to western North America. It exhibits exceptional morphological and color variation compared to congeners, leading to speculation that it may represent multiple cryptic species. The species demonstrates remarkable ecological versatility, occurring across diverse habitats and elevations from below 300 m to above 3,000 m. Its remains have been recovered from the La Brea tar pits, indicating a long presence in the region.
Brachycoryna dolorosa
Brachycoryna dolorosa is a small leaf beetle in the family Chrysomelidae, subfamily Cassidinae. Adults measure 2.1–3.1 mm in length. The species is known from western North America, with records from California, Idaho, Montana, Utah, and Washington. Adults have been collected from several plant species including Media elegans, Media sativa, Holocarpha heermannii, Hemizona species, and Ceanothus cuneatus, though the actual foodplant remains unknown.
Brachycoryna hardyi
Brachycoryna hardyi is a small leaf beetle in the family Chrysomelidae, subfamily Cassidinae. It measures 2.5–3.7 mm as an adult and exhibits variable coloration with reddish-yellow and black patterning. The species has been recorded feeding on three Ceanothus species and occurs across western North America from Canada to Mexico.
Brachylampis blaisdelli
Blaisdell's firefly
Brachylampis blaisdelli is a species of firefly in the family Lampyridae, described by Van Dyke in 1939. It is placed in the subfamily Ototretinae, a group characterized by reduced or absent light-producing organs in adults. The species is known from western North America and is one of at least three North American species in a closely related group within the genus.
Brachylomia curvifascia
Brachylomia curvifascia is a noctuid moth first described by Smith in 1891. It is endemic to western North America, ranging from British Columbia to California. Adults are active in late summer, with flight records from August to September in California. The species belongs to the genus Brachylomia, a group of small to medium-sized moths within the subfamily Noctuinae.
Brachylomia populi
Brachylomia populi is a noctuid moth species first described by Strecker in 1898. It inhabits the inland mountain regions of western North America, with larvae that feed specifically on cottonwood, aspen (Populus), and oak (Quercus) leaves. The species has a wingspan of approximately 30 mm and is known from 133 iNaturalist observations.
Brachymelecta californica
California Digger-cuckoo Bee
Brachymelecta californica, the California digger-cuckoo bee, is a cleptoparasitic bee species in the family Apidae. As a cuckoo bee, it does not construct its own nests or collect pollen, but instead lays eggs in the nests of host bees, primarily species of Anthophora. The species is native to western North America and has been documented across a broad geographic range including California and adjacent regions.
Brachynemurus californicus
Brachynemurus californicus is a species of antlion (family Myrmeleontidae) first described by Banks in 1895. As a member of the order Neuroptera, it shares the characteristic net-veined wings and complete metamorphosis typical of this group. The genus Brachynemurus contains species known for their distinctive adult morphology and predatory larval behavior. This species occurs in western North America, with records from California and surrounding regions.
Brachypanorpa sacajawea
Brachypanorpa sacajawea is a species of short-faced scorpionfly in the family Panorpodidae, described by George Byers in 1990. It belongs to a genus characterized by reduced wing venation and abbreviated rostrums compared to other mecopterans. The species is known from a small number of observations in western North America. Like other Panorpodidae, adults are likely non-feeding or feed sparingly, with larvae presumed to be detritivores in soil or leaf litter.
Brachystoma occidentale
Brachystoma occidentale is a species of dance fly in the family Brachystomatidae, first described by Melander in 1902. The species name "occidentale" refers to its western distribution in North America. Dance flies in this family are predatory as adults and are commonly found in moist habitats near streams and wetlands. Limited observational data exists for this species, with 27 observations recorded on iNaturalist.
Bradynotes obesa
Slow Mountain Grasshopper, Mountain Lubber Grasshopper, Western Lubber Grasshopper
Bradynotes obesa is a large, flightless spur-throated grasshopper endemic to western North America. It is characterized by its robust, heavy-bodied morphology and slow, deliberate movement. The species inhabits transitional zones between pine savannah and sagebrush desert in mountainous regions, particularly at lower elevations in the Big Horn and Wind River Mountains of Wyoming. It is notable for its very early spring emergence, with adults present primarily in May and June, and its gregarious behavior in localized populations.
Braggia
Braggia is a genus of aphids (Aphididae: Aphidinae: Aphidini) described by Gillette & Palmer in 1929. Species in this genus are specialized feeders on buckwheat (Eriogonum spp., Polygonaceae) in western North America. The genus includes at least two recently described species: Braggia columbiana from Washington and Oregon, and Braggia longicauda from Washington, Oregon, and northern California. These aphids have been documented with associated parasitoid species, though specific taxa are not detailed in available sources.
Bruchomorpha beameri
A small planthopper in the family Caliscelidae, described by Doering in 1940. The species belongs to the genus Bruchomorpha, a group of diminutive fulgoroid planthoppers found in western North America. Records indicate occurrence in grassland and prairie habitats across the western United States and into Canada.
Bruchomorpha extensa
Bruchomorpha extensa is a planthopper species in the family Caliscelidae, first described by Ball in 1935. It belongs to a genus characterized by distinctive morphological features within the Fulgoroidea superfamily. The species has been documented in western North America, with occurrence records spanning from the southwestern United States to northwestern Mexico. Like other caliscelid planthoppers, it is presumed to feed on plant vascular fluids, though specific host associations remain poorly documented.
Brychius hornii
Horn's Crawling Water Beetle
Brychius hornii is a species of crawling water beetle in the family Haliplidae, first described by George Robert Crotch in 1873. It is native to western North America, where adults inhabit small streams and irrigation ditches, primarily on gravel substrates. The species belongs to a small genus of aquatic beetles adapted to life in running water environments.
Bryelmis
Bryelmis is a genus of riffle beetles in the family Elmidae, established by Barr in 2011. The genus contains three described species, all described in the same 2011 publication: Bryelmis idahoensis, Bryelmis rivularis, and Bryelmis siskiyou. As members of Elmidae, these beetles are aquatic and associated with flowing water habitats. The genus is relatively newly described and appears to be restricted to western North America based on species epithets.
Bryotropha hodgesi
Bryotropha hodgesi is a small gelechiid moth described in 2004. It is known from the western coast of North America, ranging from the United States into extreme southern Canada. The species was named in honor of R.W. Hodges.
Buckellacris
Buckellacris is a genus of spur-throated grasshoppers in the family Acrididae, established by Rehn & Rehn in 1945. The genus contains at least three described species distributed in western North America. Members belong to the tribe Podismini within the subfamily Melanoplinae. One species, Buckellacris nuda, is commonly known as Buckell's timberline grasshopper.
Buckellacris chilcotinae
Chilcotin Grasshopper
Buckellacris chilcotinae is a species of spur-throated grasshopper in the family Acrididae, commonly known as the Chilcotin Grasshopper. The species was originally described as Bradynotes chilcotinae by Hebard in 1922 and later transferred to the genus Buckellacris. It occurs in western North America with documented records from British Columbia and Washington. Two subspecies are recognized: the nominate B. c. chilcotinae and B. c. tacoma.
Buprestis lyrata
pink-faced jewel beetle
Buprestis lyrata is a species of metallic wood-boring beetle in the family Buprestidae, first described by Thomas L. Casey in 1909. It is found in the Nearctic region, primarily in western North America including Alberta and British Columbia in Canada. Adults are known to frequent freshly dead conifers, particularly Douglas-fir (Pseudotsuga menziesii), where they can be found on trunks and branches. The species is part of the diverse genus Buprestis, which contains many colorful and sought-after jewel beetles among collectors.
Cacama
Cactus Dodger Cicadas
Cacama is a genus of cicadas in the family Cicadidae, commonly known as "cactus dodger cicadas." The genus contains at least 12 recognized species distributed across western North America, from the southern Great Plains to California. These cicadas are notable for their association with cacti, particularly Opuntia and Cylindropuntia species, and their ability to navigate among spiny hosts without injury. The type species, Cacama valvata, has been studied for its thermal physiology and distinctive mating behaviors.
Cacama dissimilis
Plateau Cactus-Dodger
Cacama dissimilis is a species of cicada in the family Cicadidae, commonly known as the Plateau Cactus-Dodger. It occurs in arid and semi-arid regions of western North America and Central America. Like other members of the genus Cacama, it is associated with cactus habitats. The species was originally described as Cicada dissimilis by Distant in 1881.
Cacopsylla alba
Cacopsylla alba is a species of psyllid, or jumping plant louse, in the family Psyllidae. Like other psyllids, it is a small, phloem-feeding insect that uses piercing-sucking mouthparts to extract sap from host plants. The species was originally described as Psylla alba by Crawford in 1914 before being transferred to the genus Cacopsylla. It belongs to a large genus of psyllids, many of which are associated with specific host plants and some of which are significant agricultural pests.
Cacopsylla curta
Cacopsylla curta is a species of jumping plant louse in the family Psyllidae, first described by Tuthill in 1943. Like other members of the genus Cacopsylla, it is a small sap-feeding insect associated with woody plants. The species has been documented in western North America, with records from California, Colorado, and Oregon. As with many psyllid species, detailed biological information remains limited in published sources.
Cacopsylla magnicauda
Cacopsylla magnicauda is a species of psyllid, commonly known as a jumping plant louse, within the family Psyllidae. First described by Crawford in 1914, this species belongs to a genus containing numerous plant-feeding insects that use piercing-sucking mouthparts to extract phloem sap. Like other psyllids, it is likely associated with specific host plants, though detailed ecological studies for this particular species appear limited. The species has been recorded in western North America including Alberta, British Columbia, California, Colorado, and Manitoba.
Caelius montanus
Caelius montanus is a species of scarab beetle in the family Scarabaeidae, subfamily Aegialiinae. It was originally described as Aegialia montana by Brown in 1931. The species is found in mountainous and northern regions of western North America, including Alaska, the western Canadian provinces, and the Rocky Mountain states of the United States. Like other members of the tribe Aegialiini, it is associated with sandy or loose soil habitats.
Caenurgina annexa
Banded Grass Moth
Caenurgina annexa, commonly known as the banded grass moth, is a species of moth in the family Erebidae. It was described by Henry Edwards in 1890. The species is endemic to western North America, with adults active during spring months. The wingspan measures 28–30 mm.
Californiulus chamberlini
Californiulus chamberlini is a species of millipede in the family Paeromopodidae, native to western North America. It is one of several species within the genus Californiulus, which is endemic to California and adjacent regions. Like other members of its family, it possesses the elongated, cylindrical body form typical of juliform millipedes. The species was described by Brölemann in 1922.
Californiulus yosemitensis
Yosemite Millipede
Californiulus yosemitensis is a large cylindrical millipede in the family Paeromopodidae, reaching up to 11 cm in length. It is distinguished by a broad yellow or orange dorsal band with a central black stripe running the length of the black body. The species is the most widespread member of its genus, occurring across the Sierra Nevada and adjacent ranges from southwestern Oregon to Kern County, California. It was described by Ralph Vary Chamberlin in 1941 from specimens collected in Yosemite National Park.
Callibaetis californicus
small minnow mayfly
Callibaetis californicus is a small minnow mayfly in the family Baetidae, first described by Banks in 1900. The species occurs across Central America and western North America, including all of Mexico and the western United States. As a member of the Baetidae, it belongs to one of the most diverse families of mayflies, commonly known as small minnow mayflies for their streamlined, fish-like nymphal form.
Callimoxys nigrinus
Callimoxys nigrinus is a longhorn beetle (Cerambycidae) described in 2011 from the western United States. The species is known from limited collections and remains poorly documented in the scientific literature. Its biology and ecology have not been formally studied.
Callimus ruficollis
Callimus ruficollis is a species of longhorn beetle in the family Cerambycidae, described by LeConte in 1873. It belongs to the tribe Stenopterini within the subfamily Cerambycinae. The species is distributed in western North America, with records from California, Mexico, and the United States. As a member of the genus Callimus, it is part of a group of beetles characterized by their slender, elongated bodies and relatively short antennae compared to many other cerambycids.