Western-united-states
Guides
Lytta rathvoni
Lytta rathvoni is a blister beetle in the family Meloidae, native to North America. The species was named in honor of Simon Rathvon, a 19th-century American entomologist. As a member of the genus Lytta, it shares the characteristic chemical defense of blister beetles, producing cantharidin. The species is placed in the subgenus Poreospasta within Lytta.
Macrosteles nielsoni
Macrosteles nielsoni is a leafhopper species in the family Cicadellidae, described by Kwon & Kwon in 2022. It belongs to the large genus Macrosteles, which includes numerous small leafhopper species. The species has been recorded from the western United States.
Marchena
Marchena is a monotypic genus of jumping spiders endemic to the western United States. Its sole described species, M. minuta, inhabits conifer bark habitats along the Pacific coast. The genus is the only North American representative of the subfamily Heliophaninae. Marchena forms a monophyletic group with the genera Afraflacilla, Pseudicius, and Festucula.
Martia
Martia is a monotypic genus of snout moths (Pyralidae: Phycitinae) established by Émile Louis Ragonot in 1887. The genus contains a single species, Martia arizonella, also described by Ragonot in the same publication. This North American moth is found in arid and semi-arid regions of the western United States.
Microtes
Microtes is a genus of band-winged grasshoppers (Acrididae) endemic to western North America. The genus contains at least three described species, including the little buzzer grasshopper (M. occidentalis). Members of this genus are placed in the tribe Sphingonotini within the subfamily Oedipodinae, a group characterized by enlarged hind wings with dark bands used in courtship displays.
Mimetus eutypus
pirate spider
Mimetus eutypus is a small araneomorph spider in the family Mimetidae, commonly known as pirate spiders or cannibal spiders. The species was described by Chamberlin & Ivie in 1935 and is known from the United States. Like other mimetids, it is an araneophagic predator that infiltrates the webs of other spiders rather than building its own. The species was formerly placed in the genus Reo.
Neocoelidia candida
Neocoelidia candida is a leafhopper species in the family Cicadellidae, subfamily Neocoelidiinae, first described by Ball in 1909. The species is recorded from several western and central U.S. states including Arizona, California, Colorado, Kansas, and Nevada. As a member of the leafhopper family, it belongs to a diverse group of sap-feeding insects. The genus Neocoelidia is part of the tribe Neocoelidiini, which contains species typically associated with woody vegetation.
Nevadasilus blantoni
Nevadasilus blantoni is a species of robber fly (family Asilidae) in the genus Nevadasilus. It is a predatory dipteran endemic to the western United States, specifically associated with Nevada and surrounding arid regions. The species is named in honor of entomologist John Blanton. As with other Asilidae, it is presumed to be an aerial predator of other insects, though detailed studies of its biology remain limited.
Nomia melanderi
alkali bee, Alkali Nomia
Nomia melanderi, commonly known as the alkali bee, is a solitary ground-nesting bee native to the western United States. It is the world's only intensively managed ground-nesting bee, commercially cultivated for alfalfa pollination. The species nests in dense aggregations in moist, alkaline soils and exhibits traits that preceded insect sociality, including defense of offspring against pathogens and predators.
Norvellina clarivida
Norvellina clarivida is a leafhopper species in the family Cicadellidae, first described by Van Duzee in 1894. The genus Norvellina belongs to the tribe Platymetopiini within the subfamily Deltocephalinae. Like other leafhoppers, it possesses piercing-sucking mouthparts used to extract plant sap. Available records indicate this species occurs in the western United States, specifically Colorado and Utah.
Ophiogomphus morrisoni
Great Basin Snaketail
Ophiogomphus morrisoni, commonly known as the Great Basin Snaketail, is a species of clubtail dragonfly in the family Gomphidae. The species was first described by Selys in 1879. It is endemic to western North America and has been recorded from Oregon, California, and Utah. The IUCN lists the species as Least Concern with a stable population.
Orectoderus montanus
Orectoderus montanus is a species of plant bug in the family Miridae, described by Knight in 1968. It belongs to the true bugs (Heteroptera), a group characterized by piercing-sucking mouthparts. The species is found in western North America, with records from the Great Plains and Rocky Mountain regions.
Orthonevra flukei
Fluke's Mucksucker
Orthonevra flukei is an uncommon syrphid fly species known from the Western United States. Males measure approximately 4.5 mm and females 5.5 mm. The species exhibits distinctive metallic coloration on the head and thorax, with complex wing venation patterns that include clouded areas and brown spots. Like other members of its genus, it possesses rat-tailed larvae, though specific larval habitat preferences for this species remain undocumented.
Orus ferrugineus
Orus ferrugineus is a species of rove beetle (family Staphylinidae) in the subfamily Paederinae, described by Casey in 1905. The species is known from the western United States, with records from Arizona, California, Colorado, New Mexico, and Utah. As a member of the large rove beetle family, it likely inhabits soil and leaf litter environments typical of the group, though specific ecological details remain poorly documented.
Paropomala wyomingensis
Wyoming toothpick grasshopper
Paropomala wyomingensis, the Wyoming toothpick grasshopper, is a slant-faced grasshopper in the family Acrididae. It is common in the shortgrass prairies of eastern Wyoming, with populations diminishing in mixedgrass prairie and desert regions. Adults are active from mid-July to early September. The species feeds on multiple grass species and has been recorded from the western United States south to Central America.
Phidippus concinnus
Phidippus concinnus is a species of jumping spider in the family Salticidae, known from the western United States. The species exhibits distinctive coloration with a reddish brown carapace featuring white lateral stripes and a red abdomen with a broad black band. It inhabits coniferous forests at higher elevations and matures during summer months. Like other members of the genus Phidippus, it possesses enlarged anterior median eyes characteristic of active-hunting jumping spiders.
Phobetus palpalis
Phobetus palpalis is a species of scarab beetle in the family Scarabaeidae, subfamily Melolonthinae, and tribe Phobetusini. Described by Saylor in 1936, this species is known from California in the western United States. The genus Phobetus belongs to a group of scarab beetles commonly referred to as May beetles or June beetles, though specific biological details for this species remain poorly documented in published literature.
Phytocoris maricopae
Phytocoris maricopae is a species of plant bug in the family Miridae, first described by Stonedahl in 1988. It belongs to a large genus of mirid bugs that are primarily associated with vegetation. The species is recorded from several western U.S. states. Like other members of Phytocoris, it is likely a plant-feeding insect with occasional predatory behavior.
Phytocoris squamosus
Phytocoris squamosus is a species of plant bug in the family Miridae, first described by Knight in 1934. It is recorded from the western United States including Arizona, Nevada, Utah, Texas, and Oregon. As a member of the genus Phytocoris, it shares the general characteristics of being mostly plant-feeding with occasional predation on smaller insects. The species is documented in 46 iNaturalist observations.
Plagiostira gillettei gillettei
A subspecies of katydid in the family Tettigoniidae, recorded from arid and semi-arid regions of the western United States. The type subspecies of Plagiostira gillettei. One observation from a 2018 collecting trip in New Mexico/Texas documented a large individual with brachypterous (short-winged) adults.
Plagiostira gillettei utahensis
Plagiostira gillettei utahensis is a subspecies of katydid in the family Tettigoniidae, described by Tinkham in 1962. It belongs to a genus characterized by large body size and brachypterous (short-winged) adults. The subspecies is distributed across the western United States including California, Colorado, Nevada, and Utah. Like other members of its genus, it is associated with arid and semi-arid habitats.
Plinthocoelium suaveolens plicatum
Bumelia Borer
Plinthocoelium suaveolens plicatum is the western subspecies of a striking longhorned beetle distributed from Texas west to New Mexico, Arizona, and northern Mexico. Distinguished from the nominate eastern subspecies by bronze or cupreous tints and weak transverse rugae on the pronotum, this beetle exhibits brilliant iridescent green coloration with contrasting orange and black legs. Larvae develop in the roots of living Sideroxylon lanuginosum (gum bumelia), with adults active during summer months. The subspecies intergrades with P. s. suaveolens in northeastern Texas.
Poecilanthrax monticola
Poecilanthrax monticola is a species of bee fly in the family Bombyliidae, described by Johnson & Johnson in 1957. The species is distributed in western North America, ranging from British Columbia and Alberta southward to Nebraska, Utah, and Colorado. As a member of the genus Poecilanthrax, it likely shares the parasitic larval lifestyle typical of the genus, developing inside caterpillars of noctuid moths, though specific life history details for this species remain undocumented.
Pogonomyrmex subdentatus
Pogonomyrmex subdentatus is a species of harvester ant in the genus Pogonomyrmex, described by Mayr in 1870. It is native to the western United States, with records from California and Nevada, and possibly Oregon and Colorado. As a harvester ant, it belongs to a group known for seed collection, nest construction, and potent defensive stings. The species is one of at least six native ant species documented in the vicinity of the Häagen-Dazs Honey Bee Haven at UC Davis, California.
Polyergus mexicanus
Western Amazon Ant
Polyergus mexicanus is an obligate social parasite known as the Western Amazon Ant, widely distributed across western North America. This species is incapable of performing basic colony tasks including foraging, nest excavation, and brood care, and depends entirely on enslaved workers of Formica host species. The species performs dramatic, coordinated raids on Formica colonies to capture larvae and pupae, which are then integrated into the parasite colony. Recent genetic studies have revealed substantial population structure associated with different host species, suggesting incipient speciation into host-specific lineages.
Prorella insipidata
Prorella insipidata is a small moth in the family Geometridae, first described in 1910. It is known from the western and southwestern United States. Adults are active from mid-summer through autumn.
Prorella mellisa
Prorella mellisa is a Geometridae moth species described by John Arthur Grossbeck in 1908. It occurs in the western United States, with records from California, Arizona, Colorado, and Montana. Adult flight activity has been documented in May and from July through October.
Protolophus tuberculatus
Protolophus tuberculatus is a species of harvestman (order Opiliones) in the family Protolophidae, first described by Banks in 1893. It is found in the western United States and broader North America. As a member of the Protolophidae, it represents one of the relatively small families within the suborder Eupnoi. The specific epithet "tuberculatus" refers to tuberculate (bumpy or knobby) features, likely on the body surface.
Pseudopsallus puberus
Pseudopsallus puberus is a species of plant bug in the family Miridae. It was described by Uhler in 1894. The species is distributed across western North America and parts of Central America.
Pseudoxylosteus ornatus
Pseudoxylosteus ornatus is a small flower longhorn beetle in the family Cerambycidae, subfamily Lepturinae. It is the sole species in its genus, described by LeConte in 1873. Adults are approximately 10 mm in length and occur in the western United States.
Pyrgus scriptura
Small Checkered-Skipper, small checkered skipper
Pyrgus scriptura is a small skipper butterfly in the family Hesperiidae, commonly known as the small checkered skipper. It occurs across the western and central United States and southern Canada. The species has two generations per year and is associated with open, dry habitats. Larvae feed on plants in the mallow family (Malvaceae), particularly Sida hederacea.
Scaphytopius irroratus
Scaphytopius irroratus is a leafhopper species in the family Cicadellidae, first described by Van Duzee in 1910. It belongs to the genus Scaphytopius, a group of small to medium-sized leafhoppers commonly found in North America. The species has been documented in the western United States and northwestern Mexico. Like other members of its tribe Scaphytopiini, it is likely associated with herbaceous vegetation.
Schinia illustra
Schinia illustra is a small moth in the family Noctuidae, described by Smith in 1906. It is found in the western United States, specifically in Colorado, Nevada, New Mexico, Utah, and Wyoming. The wingspan measures 24–26 mm. Like other members of the genus Schinia, adults are likely associated with flowers for nectar and resting.
Stenoptilia exclamationis
Exclamatory and Colorado Plume Moths
Stenoptilia exclamationis is a moth complex in the family Pterophoridae, commonly known as the Exclamatory and Colorado Plume Moths. It occurs in the western United States, with records from California and Oregon. The complex designation indicates this taxon may encompass multiple closely related species or subspecies that require further taxonomic clarification. As a plume moth, it belongs to a family characterized by distinctive wing morphology.
Tabanus punctifer
western horse fly, western black horse fly
Tabanus punctifer, commonly known as the western horse fly or western black horse fly, is a large biting fly in the family Tabanidae. It is distinguished from other North American horse flies by its creamy white thorax covered with long hairs and completely black abdomen. Females require blood meals for egg development and bite horses, livestock, and humans. The species is found throughout the southern and western United States.
Tetraopes basalis
western milkweed longhorn beetle
Tetraopes basalis is a longhorn beetle in the family Cerambycidae, commonly known as the western milkweed longhorn beetle. It was described by John Lawrence LeConte in 1852 and occurs in the United States. The species is closely associated with milkweed plants (Asclepias), on which adults feed and larvae develop. Adults are most active from April to August.
Tortistilus wickhami
A North American treehopper in the family Membracidae, recently documented for the first time in Mexico's Baja California peninsula. Previously known from the western and southwestern United States, this species was collected from grapevines in Valle de Guadalupe vineyards during 2023. Its presence in commercial vineyards raises concerns about potential economic impact, as it is suspected to be a candidate vector for grapevine red blotch virus.
treehopperMembracidaevineyard-pestgrapevine-red-blotch-virusagricultural-pestMexico-first-recordBaja-CaliforniaValle-de-GuadalupeVitis-viniferaDNA-barcoding-identification2023-detectioneconomic-entomologyplant-virus-vectorSmiliinaeCeresiniHemipteraCicadomorphaNorth-Americawestern-United-Statesinvasive-potentialviticulturewine-grape-pestTrogloderus kandai
Trogloderus kandai is a psammophilic darkling beetle described in 2019 from Owens Valley, California. It belongs to a genus of six newly described species restricted to dunes and sandy habitats in the western United States. The species is part of the tribe Amphidorini, associated with desert stink beetles.
Trogloderus nevadus
Trogloderus nevadus is a darkling beetle (Tenebrionidae) in the psammophilic genus Trogloderus. Originally described in 1943 from dunes around Pyramid Lake, Nevada. The species was briefly treated as a subspecies of T. costatus (1946) but restored to specific standing by Johnston in 2018. It is restricted to sandy dune habitats in the western United States.
Tropidolophus
great crested grasshopper
Tropidolophus is a monotypic genus of band-winged grasshoppers in the family Acrididae, containing the single species T. formosus. The genus is classified within the subfamily Oedipodinae and tribe Tropidolophini. It is native to North America, with records from the western United States and northeastern Mexico.
Yersiniops
Grasshopper Mantises
Yersiniops is a genus of ground-dwelling mantids native to the Americas, distinguished by their cursorial hunting strategy of actively running down prey rather than ambushing from vegetation. The genus is characterized by pointed, 'horned' eyes and predominantly gray coloration. Two species, Y. solitarius and Y. sophronicus, occur in the United States, where they inhabit arid western regions. These small mantids represent one of two ground mantid genera in North America, alongside Litaneutria.
Zosteropoda
Zosteropoda is a genus of owlet moths in the family Noctuidae, tribe Eriopygini. The genus was established by Augustus Radcliffe Grote in 1874 and currently contains three recognized species. Members are found in North America, with records concentrated in the western United States and adjacent regions.