Western-north-america
Guides
Hirudisomatidae
Hirudisomatidae is a family of colobognathan millipedes in the order Polyzoniida, comprising approximately 20 species across seven genera. The family exhibits a disjunct distribution spanning Eurasia from Spain to the Himalayas, Japan, and western North America from southwest Canada to central Mexico. Members of this family possess characteristic colobognathan features including reduced mouthparts and a simplified head structure. The family contains two genera in the Western Hemisphere (Octoglena and Mexiconium) with seven species, while the remaining five genera occur in the Eastern Hemisphere.
Hister militaris
clown beetle
Hister militaris is a species of clown beetle (family Histeridae) described by Horn in 1870. It belongs to the genus Hister, one of the most species-rich genera in the family. The species occurs in western North America, with records from British Columbia south through the western United States to California and Arizona. Like other hister beetles, it is likely predaceous, though specific ecological details remain poorly documented.
Hololena
funnel-web weavers
Hololena is a genus of funnel-web spiders (family Agelenidae) endemic to western North America. The genus contains approximately 30 recognized species, though taxonomic revision is needed. These spiders construct flat, sheet-like webs with a funnel retreat and are abundant in human-altered environments. Males exhibit specialized courtship behaviors including vibrational signals that induce female catalepsy, reducing sexual cannibalism risk. Bites to humans have been documented but result in mild, self-limiting symptoms.
Hololena santana
Hololena santana is a funnel-web weaver spider in the family Agelenidae, described by Chamberlin & Ivie in 1942. The species is found in the United States and belongs to a genus of approximately 30 recognized species restricted to the western third of North America. Like other Hololena, it constructs flat, sheet-like webs with a funnel-shaped retreat and is known to occasionally enter human dwellings.
Hololena tentativa
Hololena tentativa is a funnel-web weaver spider in the family Agelenidae, found in the United States. Like other Hololena species, it constructs flat, sheet-like webs with a funnel-shaped retreat. The genus is restricted to the western third of the U.S. and contains approximately thirty recognized species in need of taxonomic revision.
Holopleurini
Holopleurini is a monotypic tribe of longhorn beetles (Cerambycidae) containing a single genus, Holopleura, and a single species, Holopleura marginata. The tribe is classified within the subfamily Cerambycinae. Information on this group is extremely limited due to its rarity and restricted distribution. The species appears to be endemic to a narrow geographic range in western North America.
Homoeosoma albescentella
Homoeosoma albescentella is a species of snout moth in the family Pyralidae, described by Émile Louis Ragonot in 1887. It is found in western North America, with records from California, Nevada, and Washington. The species belongs to a genus containing several sunflower-associated moths, though specific ecological details for this species remain limited.
Homoeosoma impressalis
Homoeosoma impressalis is a species of snout moth in the family Pyralidae, described by George Duryea Hulst in 1886. It belongs to the genus Homoeosoma, which contains several species associated with sunflower and other composite plants. The species is found in western North America, specifically in Arizona and California. Like other members of its genus, it is likely associated with plants in the Asteraceae family, though specific ecological details remain poorly documented.
Honora montinatatella
snout moth
Honora montinatatella is a species of snout moth in the family Pyralidae, first described by George Duryea Hulst in 1887. It is endemic to western North America, with documented occurrences in Arizona, California, and Washington. The species has a wingspan of approximately 23 mm. It is classified within the subfamily Phycitinae, a diverse group of small moths often associated with dried plant materials.
Honora subsciurella
Honora subsciurella is a species of snout moth in the genus Honora, first described by Émile Louis Ragonot in 1887. It belongs to the family Pyralidae, subfamily Phycitinae. The species is known from western North America, with records from Colorado and California. Very little detailed information about its biology, appearance, or ecology has been published.
Hoplia callipyge
Grapevine Hoplia
Hoplia callipyge is a small scarab beetle in the family Scarabaeidae, commonly known as the Grapevine Hoplia. Adults are active in spring and are recognized as minor agricultural and garden pests due to their feeding on rose petals and other flowers. The species occurs in western North America from British Columbia to Baja California. Larvae develop in soil, feeding on roots and decaying organic matter.
Hoplinus echinatus
Hoplinus echinatus is a stilt bug species in the family Berytidae, characterized by its elongated, slender body and long legs typical of the group. It has been documented as a predator associated with sticky plants in western North America, where it navigates resinous or hooked trichomes to feed on trapped insect carrion. The species occurs across a broad range of arid and semi-arid habitats from southwestern Canada through the western United States to northern Mexico. Its ecology links it to plant-based food webs where dead insects serve as a resource for predatory arthropods.
Hoplisoides nebulosus spilopterus
Hoplisoides nebulosus spilopterus is a subspecies of sand wasp in the family Crabronidae. Females construct short burrows in sandy soil to provision with paralyzed treehoppers (Membracidae) as food for their larvae. The subspecies is distinguished by spotted wings and is found in western North America, including Colorado and Alberta. Adults are approximately 8-10 mm in length and are rarely observed on flowers, though they may visit aphid colonies to feed on honeydew.
Hoplisoides splendidulus
Hoplisoides splendidulus is a solitary sand wasp in the family Crabronidae, originally described by Bradley in 1920. Like other members of the genus Hoplisoides, it is a predator of treehoppers (Membracidae), provisioning underground burrows with paralyzed prey for its larval offspring. The species is part of a diverse genus containing approximately 18 species in North America, with most species distributed in western regions.
Hoplitis albifrons maura
Pacific Black Small-Mason
Hoplitis albifrons maura is a subspecies of mason bee in the family Megachilidae, native to western North America. It belongs to a group of solitary bees known for nesting in pre-existing cavities and constructing brood cells from collected materials. As a member of the osmiine bees, it contributes to pollination services in its native range. The subspecies designation indicates geographic variation within the broader H. albifrons species complex.
Hoplitis fulgida platyura
Pacific Green Small-Mason
Hoplitis fulgida platyura is a subspecies of mason bee in the family Megachilidae. It is native to western North America, where it occurs from British Columbia to California. The subspecies is distinguished from the nominate form by structural differences in the male antennae and subtle coloration differences. Like other members of the genus Hoplitis, females construct nests in pre-existing cavities and line brood cells with collected materials.
Hoplomachidea consors
Hoplomachidea consors is a species of plant bug in the family Miridae, first described by Uhler in 1893. It is a small true bug in the order Hemiptera, suborder Heteroptera. The species has been recorded from California and Nevada in the western United States. Like other mirids, it possesses piercing-sucking mouthparts typical of the family.
Hyalophora euryalus
Ceanothus silkmoth, Ceanothus silk moth
Hyalophora euryalus, the ceanothus silkmoth, is a large saturniid moth native to western North America. Adults lack functional mouthparts and do not feed, living solely to reproduce. The species is notable for its broad host plant range spanning multiple plant families. Larvae possess urticating hairs and scoli that can cause skin irritation. The moth has a single generation per year, with adults active from January through July depending on latitude and elevation.
Hyalophora euryalus euryalus
Ceanothus silk moth, Western cecropia moth
Hyalophora euryalus euryalus is a subspecies of giant silk moth in the family Saturniidae, native to western North America. Adults are among the largest moths in the region, with wingspans reaching up to 15 centimeters. The subspecies is distinguished by its reddish-brown wing coloration with prominent eyespots and white crescent markings. Like other Hyalophora species, adults lack functional mouthparts and do not feed, living only long enough to mate and reproduce. Larvae are notable for their large size, colorful tubercles, and urticating spines.
Hyalophora gloveri
Glover's silkmoth
Hyalophora gloveri is a large silkmoth in the family Saturniidae, first described by Strecker in 1872. The species occurs across western North America from the Rocky Mountains through the northern Great Plains and Canadian prairie provinces. Its taxonomic status remains debated; several authorities treat it as a subspecies of Hyalophora columbia. The species exhibits two recognized subspecies: H. g. gloveri and H. g. nokomis. Adults have a wingspan of approximately 100 mm.
Hybomitra sonomensis
horse fly
Hybomitra sonomensis is a species of horse fly in the family Tabanidae. It belongs to a species group that has been subject to taxonomic revision, with Hybomitra philipi now synonymized with it. The species occurs in western North America. It has been historically confused with related species, particularly Hybomitra enigmatica, which was described as a new species based on immature stages and adult morphology.
Hydraecia medialis
Hydraecia medialis is a noctuid moth native to western North America. Adults are active from mid-August through September and are characterized by pale gray-tan forewings with a darker, often reddish median area and distinctive red-brown or brown and white postmedial line. The species inhabits open ponderosa pine forests, drier sagebrush steppe, and juniper woodlands across a range extending from British Columbia to northern New Mexico.
Hydraena pacifica
Hydraena pacifica is a species of minute aquatic beetle in the family Hydraenidae, first described by Perkins in 1980. The species belongs to the genus Hydraena, commonly known as long-palped water beetles, characterized by their enlarged maxillary palps. It is distributed across western North America from Canada through the western United States. The species epithet 'pacifica' refers to its occurrence in the Pacific region of North America.
Hydriomena macdunnoughi
Hydriomena macdunnoughi is a small geometrid moth described by Louis W. Swett in 1918. It occurs in western North America from Yukon Territory through western Alberta to Colorado. The species has a wingspan of 14–16 mm and exhibits distinctive grey forewings with a dark central band and pale hindwings with brown wavy lines. Adults are active from spring through mid-summer, and larvae feed on willow species.
Hydrocolus paugus
Hydrocolus paugus is a predaceous diving beetle in the family Dytiscidae, first described by Fall in 1923. Originally described as Hydroporus paugus, it was later transferred to the genus Hydrocolus. It is a member of the subfamily Hydroporinae, which contains small to medium-sized diving beetles. The species is known from limited collection records in western North America.
Hylaeus episcopalis coquilletti
Hylaeus episcopalis coquilletti is a subspecies of yellow-faced bee in the family Colletidae. As with other members of the genus Hylaeus, this bee is nearly hairless and wasp-like in appearance, lacking the dense hair typical of most bees. Females have distinctive yellow or white markings on the inner margin of each eye, while males have the entire face colored yellow or white. These solitary bees nest in pre-existing cavities such as hollow stems or twigs, lining cells with a natural polymer secretion. The subspecies epithet "coquilletti" honors the entomologist James Charles Coquillett.
Hymenaphorura cocklei
Golden Snow Flea
Hymenaphorura cocklei is a species of springtail in the family Onychiuridae, commonly known as the Golden Snow Flea. It is an eyeless, soil-dwelling collembolan with a characteristic golden-yellow coloration. The species is primarily recorded from western North America, particularly in forested mountainous regions. It belongs to a genus distinguished by specialized mouthpart structures and reduced pigmentation.
Hymenomima umbellularia
Hymenomima umbellularia is a species of geometrid moth in the family Geometridae. The species name references its association with California bay laurel (Umbellularia californica), indicating a specialized ecological relationship with this host plant. It is primarily known from western North America, particularly California. Adults are active during spring and early summer. The species has been documented through 191 iNaturalist observations, suggesting moderate but localized abundance within its range.
Hyperaspidius hercules
Hyperaspidius hercules is a small lady beetle (Coccinellidae) found in western North America. Adults measure 2.10–4.00 mm in length. The species exhibits sexual dimorphism in pronotal coloration: males have yellow pronota with black basal spots, while females have black pronota with faint yellow lateral margins. The elytra are black with yellow markings on the anterior, lateral, and discal areas. It has been recorded from Alberta, Colorado, Idaho, Montana, Nevada, Utah, and Wyoming.
Hyperaspis cincta
Corona Sigil Lady Beetle
Hyperaspis cincta is a small lady beetle species in the family Coccinellidae, measuring approximately 2.0–2.6 mm in length. It is native to western North America, with confirmed records from California and Utah. Adults are distinguished from the similar Hyperaspis inflexa by their wider marginal vitta on the elytra. The genus Hyperaspis includes species known as predatory biocontrol agents of scale insects.
Hyperaspis dissoluta
dissolute lady beetle
Hyperaspis dissoluta is a small lady beetle native to western North America. Adults measure 2.0–2.75 mm and are characterized by black elytra with yellow or red markings. The species is a specialized predator of scale insects, with larvae that produce a distinctive white waxy coating for protection. Two subspecies are recognized: H. d. dissoluta and H. d. nevadica, differing in size and elytral pattern.
Hyperaspis jovialis
Jovial Sigil Lady Beetle
Hyperaspis jovialis is a small lady beetle in the family Coccinellidae, known from western North America. Adults measure 2.40–2.80 mm and exhibit sexual dimorphism in pronotum coloration. The species belongs to a genus whose larvae are specialized predators of scale insects, often producing waxy coatings for camouflage and protection. Adults display variable elytral color patterns ranging from black with orange spots to orange with black markings.
Hyperaspis oculaticauda
eye-tailed lady beetle
Hyperaspis oculaticauda, the eye-tailed lady beetle, is a small predatory lady beetle in the family Coccinellidae. Adults measure 1.80–2.40 mm in length and are characterized by black elytra with a single apical spot. The species is native to western North America, with confirmed records from California, Nevada, and Oregon. Like other Hyperaspis species, it is a specialized predator of scale insects.
Hyperaspis pleuralis
Side-spotted Sigil Lady Beetle
Hyperaspis pleuralis is a small lady beetle native to western North America, measuring 1.95–2.85 mm in length. Males are distinguished by yellow coloration on the lateral and anterolateral areas of the pronotum. The species exhibits typical Hyperaspis biology: larvae produce a white waxy coating that camouflages them among scale insects while providing protection from predators and ants. Both larvae and adults are specialized predators of scale insects, making them valuable biological control agents in natural and ornamental ecosystems.
Hyperaspis quadrivittata
Four-streaked Lady Beetle
Hyperaspis quadrivittata is a small lady beetle (2.0-2.7 mm) native to western North America, found primarily west of the 100th meridian. It is a member of the Coccinellidae family and is distinguished by four red or yellowish streaks on its black elytra. Like other Hyperaspis species, it is a predator of scale insects, though specific prey associations for this species are not well documented in the literature.
Hyperaspis taeniata
Ribboned lady beetle, Ribboned Sigil Lady Beetle
Hyperaspis taeniata, known as the ribboned lady beetle, is a small predatory beetle in the family Coccinellidae. Adults measure 2.2–3 mm in length. Males are distinguished by a yellow lateral border on the pronotum. The species is native to western North America, with confirmed records from California, Arizona, and Utah. Like other Hyperaspis species, it is a specialist predator of scale insects and their eggs.
Hypercompe permaculata
many-spotted tiger moth
Hypercompe permaculata, commonly known as the many-spotted tiger moth, is a species of tiger moth in the family Erebidae. It was first described by Alpheus Spring Packard in 1872. The species is native to western North America, ranging across the western United States and into parts of northern Mexico and southern Canada.
Hypexilis
Hypexilis is a genus of longhorn beetles in the family Cerambycidae, subfamily Cerambycinae, and tribe Graciliini. The genus was established by Horn in 1885 and contains two described species: H. longipennis Linsley, 1935 and H. pallida Horn, 1885. Members of this genus are known from western North America, particularly in montane juniper-oak-pinyon woodland habitats.
Hypocaccus estriatus
clown beetle
Hypocaccus estriatus is a species of clown beetle in the family Histeridae, first described by John Lawrence LeConte in 1857. The species is native to western North America, with documented occurrences in Canada and the western United States. Like other histerid beetles, it is presumed to be associated with decomposing organic matter, though specific ecological details remain poorly documented.
Hypochilus kastoni
Hypochilus kastoni is a species of lampshade spider in the family Hypochilidae, described by Norman Platnick in 1987. It is one of several species in the genus Hypochilus, a group of spiders notable for their distinctive web architecture and relictual distribution in North America. The species is known from the western United States, where it inhabits rocky habitats. Like other Hypochilus species, it constructs characteristic flat, circular webs with a conical retreat, resembling a lampshade in appearance.
Hypocoena basistriga
White-veined Sedge Moth
Hypocoena basistriga is a small noctuid moth with a distinctive pattern of white-veined forewings against a dark brown background. It inhabits mesic environments across western North America, from Alaska to the western Great Lakes region. The species has a single annual generation with adults active in late summer and early fall. Larval biology remains undocumented, though related species are stem borers in monocots.
Hypsalonia rentzi
Hypsalonia rentzi is a species of spur-throated grasshopper in the family Acrididae, described by Gurney & Eades in 1961. It belongs to the tribe Podismini within the subfamily Melanoplinae. The species is known from limited occurrence records in western North America.
Hystricia abrupta
Spiny-butt fly
Hystricia abrupta is a species of bristle fly in the family Tachinidae, commonly recognized by its spiny abdomen. This large tachinid fly is frequently found in western North America, where adults visit late summer and fall wildflowers for nectar. Like other tachinid flies, it is a parasitoid, with larvae developing inside host insects. It is often mistaken for similar large tachinids such as Adejeania vexatrix and Paradejeania rutilioides due to its robust, spiny appearance.
Idia occidentalis
Western Idia
Idia occidentalis is a small litter moth in the family Erebidae, first described by Smith in 1884. It was formerly treated as a subspecies of Idia lubricalis but is now recognized as a distinct species. The species is found in western North America, with adults active primarily in late summer in northern parts of its range. It inhabits dry, open environments including arid grasslands and badlands.
Idiocerus distinctus
Idiocerus distinctus is a leafhopper species in the family Cicadellidae, subfamily Eurymelinae, first described by Gillette & Baker in 1895. It belongs to a genus of relatively large, robust leafhoppers often associated with woody host plants. The species has been recorded from several western North American states. Like other Idiocerus species, it likely feeds on plant sap using piercing-sucking mouthparts, though specific biological details remain poorly documented in available literature.
Idiocerus ensiger
Idiocerus ensiger is a species of leafhopper in the family Cicadellidae, first described by Ball in 1902. It belongs to the subfamily Eurymelinae and tribe Idiocerini. The species is known from western North America, with records from California, Colorado, Idaho, Oregon, and Utah. As with other members of the genus Idiocerus, it is associated with woody plants, though specific host associations for this species remain poorly documented.
Idiocerus maximus
Idiocerus maximus is a species of leafhopper in the family Cicadellidae, described by Freytag in 1965. The species is currently treated as a synonym of Populicerus formosus. It belongs to the subfamily Eurymelinae, a group of leafhoppers often associated with woody host plants. Records indicate a western North American distribution.
Idiocerus morosus
A leafhopper species in the family Cicadellidae, described by Ball in 1902. Records indicate occurrence in western North American states including Arizona, California, Colorado, New Mexico, and Oregon. Very little published biological information is available for this species.
Idiocerus musteus arsiniatus
Idiocerus musteus arsiniatus is a subspecies of leafhopper in the family Cicadellidae, described by Hamilton in 1985. It belongs to a genus of relatively large, robust leafhoppers often associated with woody plants. The subspecies designation indicates geographic or morphological differentiation from the nominate form I. musteus musteus. Records indicate presence in western North America.
Idiocerus pericallis
Idiocerus pericallis is a species of leafhopper in the family Cicadellidae, described by Hamilton in 1980. It belongs to the subfamily Idiocerinae, a group characterized by broad heads and often associated with woody plants. The species is documented from western North America, with records from British Columbia, Colorado, and Oregon. As with most Idiocerus species, it likely feeds on plant sap using piercing-sucking mouthparts typical of the family.