Western-north-america
Guides
Pelegrina aeneola
Coppered White-cheeked Jumping Spider
Pelegrina aeneola is a small jumping spider in the family Salticidae, found in western North America. Females measure approximately 5.5 mm and males 5 mm, with pronounced sexual dimorphism in coloration. The species occupies diverse vegetation types and has been documented feeding on insect eggs. Despite being relatively well-observed, detailed natural history information remains limited.
Pelochrista bolanderana
Pelochrista bolanderana is a species of tortricid moth in the family Tortricidae, subfamily Olethreutinae, and tribe Eucosmini. It was first described by Walsingham in 1879. The species belongs to a large genus of small moths, many of which are associated with coniferous hosts. Specific biological details for this species remain poorly documented in available literature.
Pelochrista dilatana
Pelochrista dilatana is a species of tortricid moth in the tribe Eucosmini, first described by Walsingham in 1895. The genus Pelochrista comprises numerous small moth species, many of which are poorly documented in terms of biology and ecology. This species belongs to a diverse group of tortricids commonly referred to as shoot borers or fruit borers, though specific life history details for P. dilatana remain limited in published literature.
Pelochrista olivacea
Pelochrista olivacea is a species of tortricid moth described by Wright and Gilligan in 2017. It belongs to the genus Pelochrista, a diverse group of small moths within the family Tortricidae. The species is part of the subfamily Olethreutinae and tribe Eucosmini. As a recently described species, detailed biological information remains limited.
Pelochrista pulveratana
Pelochrista pulveratana is a species of tortricid moth described by Walsingham in 1879. It belongs to the large genus Pelochrista within the subfamily Olethreutinae. As with many Pelochrista species, specific biological details remain poorly documented in accessible literature.
Pentagramma
goldback ferns
Pentagramma is a small genus of North American ferns in the family Pteridaceae, segregated from Pityrogramma in 1990. The genus comprises six recognized diploid species, primarily distributed in California and Baja California, with P. triangularis ranging more broadly across western North America. Members produce a distinctive powdery-waxy secretion called farina on their lower leaf surfaces.
Peritaxia
Peritaxia is a genus of broad-nosed weevils (Curculionidae: Entiminae) established by Horn in 1876. The genus contains approximately seven described species distributed in western North America. Species are characterized by their relatively small size and distinctive sculpturing of the elytra and pronotum. The genus is classified in the tribe Byrsopagini, a group of flightless weevils associated with particular soil and vegetation conditions.
Perlinodes
Perlinodes is a genus of stoneflies in the family Perlodidae. It was established by Needham and Claassen in 1925 and is classified within the tribe Arcynopterygini. The genus is found in western North America, with records from Alberta and several western U.S. states. Like other perlodid stoneflies, members of this genus are aquatic as nymphs and terrestrial as adults.
Pero meskaria
Meske's Pero Moth
Pero meskaria is a geometrid moth species described by Alpheus Spring Packard in 1876. It is native to western North America, with records spanning from southern Texas west to California and east through Nevada, Utah, and western Colorado. The species belongs to the genus Pero, a group of moths commonly known as 'pero moths' within the family Geometridae.
Petrophila jaliscalis
Jalisco Petrophila
Petrophila jaliscalis is a small aquatic moth in the family Crambidae, described by Schaus in 1906. The species has a broad North American distribution spanning from Alberta, Canada through the western United States to Mexico. Adults are active nearly year-round and have forewings measuring 7–11 mm. The larvae are aquatic and feed on algae.
Pexopsylla cercocarpi
Pexopsylla cercocarpi is a species of jumping plant louse (family Psyllidae) described by Jensen in 1957. The specific epithet "cercocarpi" indicates an association with Cercocarpus (mountain mahogany), a genus of flowering plants in the family Rosaceae. Like other psyllids, this species is likely a phloem-feeding specialist on its host plant. The genus Pexopsylla is part of the diverse psyllid fauna of western North America.
Phaenops gentilis
Phaenops gentilis is a metallic wood-boring beetle in the family Buprestidae, known for its bright metallic green coloration. Adults are approximately 8 mm in length and are associated with pine forests, particularly ponderosa pine. The species has been documented exhibiting erratic running behavior when disturbed and is known to pause for grooming and egg-laying activities. It occurs in western North America including Colorado, Arizona, and British Columbia.
Phanogomphus kurilis
Pacific clubtail
Phanogomphus kurilis, known as the Pacific clubtail, is a dragonfly species in the family Gomphidae. It occurs in the western United States. The IUCN assessed this species as Least Concern in 2016, indicating no immediate conservation threats. It is one of approximately 50 species in the genus Phanogomphus, a group of clubtail dragonflies characterized by expanded terminal abdominal segments.
Pheidole californica
California Big-headed Ant
Pheidole californica is a species of big-headed ant in the genus Pheidole, characterized by the presence of dimorphic worker castes including small workers and large-headed soldiers. The species belongs to the diverse myrmicine ant fauna of western North America. Like other Pheidole species, it exhibits the classic soldier-worker caste system where soldiers possess disproportionately enlarged heads and mandibles used for defense and food processing. The species was described by Mayr in 1870 and includes two recognized subspecies: P. c. californica and P. c. oregonica.
Phidippus ardens
Desert Red Jumping Spider
Phidippus ardens is a species of jumping spider in the family Salticidae. It is found in the western United States and Mexico. Like other members of the genus Phidippus, it possesses enlarged anterior median eyes characteristic of salticids and is an active visual predator.
Phidippus johnsoni
red-backed jumping spider, Johnson jumping spider
Phidippus johnsoni is a large jumping spider native to western North America and one of the most commonly encountered species in the genus. Adults reach approximately 10 mm in body length. Both sexes display a bright red abdomen and distinctive iridescent teal chelicerae, with females additionally bearing a black central stripe on the abdomen. The species is known to be a mimic of velvet ants (Dasymutilla), which are wasps with painful stings.
Philanthus gloriosus
Bee-wolf
Philanthus gloriosus is a bee-hunting wasp in the family Crabronidae, occurring west of the 100th meridian in North America. As a member of the beewolf genus Philanthus, females hunt bees to provision underground nests for their larvae. The species ranges from the Canadian prairies through the western United States to central Mexico.
Philanthus multimaculatus
beewolf, bee-hunting wasp
Philanthus multimaculatus is a common North American beewolf wasp in the family Crabronidae. Females are solitary nesters that excavate burrows in sandy soil, often in aggregations with conspecifics. They provision nest cells with paralyzed bees, primarily sweat bees (Halictidae), and lay a single egg on each prey item. Males exhibit territorial behavior, perching on grass stems near nesting areas to intercept females and chase rival males. Adults visit flowers for nectar and serve as pollinators while also functioning as predators that regulate bee populations.
Philanthus pacificus
Pacific beewolf
Philanthus pacificus is a solitary wasp species in the beewolf genus Philanthus, native to western North America. As a member of the Crabronidae family, females are known to provision underground nests with paralyzed bees as food for their developing larvae. The species occurs from southwestern British Columbia through California to Baja California and Sonora, Mexico. Two subspecies are recognized: P. p. arizonae and the nominate P. p. pacificus.
Philocasca
Philocasca is a genus of caddisflies (Trichoptera: Limnephilidae) established by Ross in 1941, containing species native to western North America. The genus has undergone taxonomic revision, with three species (P. alba, P. thor, and P. antennata) transferred to the new genus Montiphylax based on morphological distinctions in wing patterns, genitalia structure, and larval setae. Remaining Philocasca species include P. banksi, P. demita, P. oron, and P. rivularis. The genus exhibits notable ecological diversity, including both aquatic and terrestrial larval habits.
Philodromus infuscatus utus
Philodromus infuscatus utus is a subspecies of running crab spider in the family Philodromidae, described by Chamberlin in 1921. It belongs to the infuscatus species group, which comprises 20 species and 2 subspecies distributed across North and Central America and the West Indies. This subspecies is distinguished from the nominate P. i. infuscatus by its occurrence in the western United States, whereas the nominate form occurs in the eastern United States. The infuscatus group as a whole is endemic to the Americas with primary habitats in arid regions of the United States and Mexico.
Philolithus carinatus
Philolithus carinatus is a species of darkling beetle in the family Tenebrionidae. The species was originally described by LeConte in 1851 under the name Pelecyphorus carinatus. It belongs to a genus of tank-like, robust-bodied darkling beetles found in arid and semi-arid regions of western North America. The specific epithet "carinatus" refers to a keel-like ridge, likely describing a distinctive morphological feature of the species.
Philonthus aurulentus
Philonthus aurulentus is a species of rove beetle in the family Staphylinidae, first described by Horn in 1884. The specific epithet 'aurulentus' suggests a golden or gold-colored appearance. The species occurs in western North America, with records from the Canadian provinces of Alberta, British Columbia, Manitoba, Northwest Territories, and Saskatchewan, and from the western United States including Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, North Dakota, Nebraska, Oregon, Utah, Washington, and Wyoming. Like other members of the genus Philonthus, it is likely a predatory beetle associated with decaying organic matter, though specific ecological details remain poorly documented.
Philonthus triangulum
Philonthus triangulum is a rove beetle in the family Staphylinidae, described by Horn in 1884. It belongs to a large genus of predatory beetles commonly found in decomposing organic matter and other habitats where small invertebrate prey is abundant. Like other members of Philonthus, it exhibits the characteristic shortened elytra and exposed abdominal segments typical of rove beetles. The species is recorded from western North America including the Pacific Northwest and southwestern United States, extending into Mexico.
Philotiella
Philotiella is a genus of small 'blue' butterflies in the family Lycaenidae, subfamily Polyommatinae, native to western North America. The genus contains two recognized species: Philotiella leona (Leona's Blue), described in 2000 and considered imperiled, and Philotiella speciosa (small blue), described in 1877. Research on P. speciosa indicates that diapause intensity varies with elevation and correlates with host plant bloom periods. Philotiella leona has been the subject of population biology and life history studies in south-central Oregon due to its conservation concern.
Phlaeopterus cavicollis
Phlaeopterus cavicollis is a rove beetle in the subfamily Omaliinae, first described from the Pacific Northwest region. The species is associated with cool, moist montane and coastal environments across western North America. It belongs to a genus characterized by compact body forms and association with forest floor habitats. Available records suggest it occupies a relatively narrow geographic range compared to some congeners.
Phlepsanus vanduzeei
Phlepsanus vanduzeei is a species of jewel beetle in the family Buprestidae. It was originally described as Acmaeodera vanduzeei by Van Dyke and later transferred to the genus Phlepsanus. The species is associated with Cercocarpus (mountain mahogany) host plants in western North America. Like other members of the genus, it is a wood-boring beetle whose larvae develop within dead branches of its host plant.
Phloeodes
diabolical ironclad beetle
Phloeodes is a genus of ironclad beetles in the family Zopheridae, native to western North America. The genus includes the well-known species Phloeodes diabolicus, commonly called the diabolical ironclad beetle, which has attracted scientific attention for its exceptional mechanical durability. Members of this genus are flightless, have heavily sclerotized exoskeletons, and feed on fungi growing under tree bark. The genus has been synonymized with Nosoderma in some taxonomic treatments, though Phloeodes remains in widespread use.
Phobetus
May beetles, junebugs
Phobetus is a genus of scarab beetles in the family Scarabaeidae, subfamily Melolonthinae, commonly known as May beetles or junebugs. The genus was established by LeConte in 1856 and contains approximately 11 described species. Species in this genus are distributed in arid and semi-arid regions of western North America, with several species endemic to specific desert mountain ranges. The genus is classified in the tribe Phobetusini, which is endemic to the Nearctic region.
Phyciodes mylitta
Mylitta Crescent, Mylitta Crescentspot
Phyciodes mylitta, commonly known as the Mylitta Crescent or Mylitta Crescentspot, is a small brush-footed butterfly native to western North America. It is an abundant, weedy species that has expanded its range following the introduction of European thistle species. The butterfly is strongly associated with thistles (Cirsium, Carduus, and Silybum) as larval host plants, and adults visit diverse flowers for nectar. It is notable for its variable wing patterns, with males showing especially variable upperside markings, and for its ability to breed continuously in warm conditions.
Phyciodes orseis
California Crescent, Orseis crescentspot
Phyciodes orseis is a small nymphalid butterfly endemic to western North America, with its core range in northern California and Oregon. It inhabits mountain valleys, meadows, and stream canyons, where it has been documented as part of ecosystem monitoring efforts on the Fremont-Winema National Forests. The species has experienced range contraction, with historical records from the San Francisco Bay Area now considered mislabeled or representing extirpated populations.
Phyciodes pallida
Pale Crescent, Pallid Crescentspot
Phyciodes pallida is a butterfly species in the family Nymphalidae, commonly known as the pale crescent or pallid crescentspot. It occurs in western North America. Adults have a wingspan of 33–44 mm. The species has at least two recognized subspecies: P. p. pallida and P. p. barnesi.
Phyllodesma occidentis
Phyllodesma occidentis is a lappet moth species in the family Lasiocampidae, first described by Walker in 1855. The species belongs to a genus of moths whose larvae typically feed on woody plants. As a member of the Lasiocampidae, it shares characteristics with other tent caterpillars and lappet moths, including hairy bodies and larvae that often feed gregariously. The specific biology and ecology of this species remain poorly documented in available literature.
Phyllonorycter holodisci
Phyllonorycter holodisci is a small moth in the family Gracillariidae, described by Annette Braun in 1939. The species is endemic to western North America, with confirmed records from California, Oregon, Washington, Idaho, and British Columbia. Its larvae are specialized leaf miners that feed exclusively on Holodiscus discolor, a shrub commonly known as ocean spray or creambush. The mine is constructed on the upper surface of the host leaf.
Phyllonorycter leucothorax
Phyllonorycter leucothorax is a micro-moth species in the family Gracillariidae, commonly known as leaf blotch miner moths. The genus is characterized by extremely small adult size and larval stages that mine within leaves. This species was described by Walsingham in 1907 and is known from the western United States.
Phyllophaga errans
Phyllophaga errans is a species of scarab beetle in the genus Phyllophaga, commonly known as May beetles or June beetles. The genus contains over 400 species in North America, making it one of the most speciose beetle genera in the region. Species-level identification within Phyllophaga is notoriously difficult and typically requires examination of male and female genitalia. P. errans occurs in the western United States.
Phyllopidea picta
painted plant bug
Phyllopidea picta is a species of plant bug in the family Miridae, first described by Uhler in 1893 under the basionym Bolteria picta. It is a member of the true bugs (Heteroptera) within the order Hemiptera. The species has been documented in western North America, with confirmed records from California, Nevada, and Utah.
Phylloteras cupella
urn gall wasp, banded urn gall wasp
Phylloteras cupella is a cynipid wasp that induces distinctive leaf galls on multiple oak species in western North America. The wasp measures 1.3–2 mm in length. Its galls display a characteristic ombré color gradient, transitioning from lighter tones at the top to darker shades below, with new galls appearing yellow, red, or mauve, aging to purple, and ultimately turning brown. The species was originally described as Trigonaspis cupella by Weld in 1926 and later transferred to Phylloteras.
Phyllotreta pusilla
Western Black Flea Beetle
Phyllotreta pusilla, commonly known as the western black flea beetle, is a flea beetle species in the family Chrysomelidae. It is distributed across Central America and North America, with documented presence in regions including Alberta, Canada and Colorado, USA. The species is recognized as an agricultural pest of canola and mustard crops, where it causes plant injury through feeding damage. Research has identified significant variation in host plant susceptibility among different canola and mustard varieties.
Phymatodes
Phymatodes is a genus of longhorn beetles (Cerambycidae) in the tribe Callidiini, with more than 50 described species distributed across the northern hemisphere. The genus is most diverse in western North America, where 26 species are currently recognized. Species exhibit considerable taxonomic complexity, with recent nomenclatural revisions clarifying misapplied names and synonymies. Some species are associated with specific host plants, including grape vines (Vitis) and maple (Acer), while others have broader host associations.
Phymatodes hirtellus
Phymatodes hirtellus is a species of longhorn beetle (family Cerambycidae) in the subfamily Cerambycinae, tribe Callidiini. The species was described by LeConte in 1873 and occurs in western North America, with records from British Columbia, California, and Mexico (including Baja California). A previously recognized subspecies, Phymatodes hirtellus densipennis, has been synonymized under the nominate form based on nomenclatural revisions by Swift & Ray (2010). The genus Phymatodes is most diverse in western North America and includes species associated with various woody host plants.
Phymatodes lengi
Phymatodes lengi is a species of longhorn beetle in the family Cerambycidae, described by Joutel in 1911. It is a member of the genus Phymatodes, which is most diverse in the western United States and Canada. The species is found in the United States, though specific details about its biology and ecology remain poorly documented. It is one of 26 species currently recognized in the genus in North America.
Phymatodes maculicollis
Phymatodes maculicollis is a species of longhorn beetle in the family Cerambycidae, described by LeConte in 1878. The species belongs to the genus Phymatodes, which is most diverse in western North America and contains approximately 26 recognized species on the continent. Like other members of its genus, P. maculicollis is associated with woody host plants, though specific host associations for this species remain poorly documented. The species has been recorded across a broad geographic range in North America, from western Canada through the western United States.
Phymatodes nigrescens
Phymatodes nigrescens is a species of longhorn beetle in the family Cerambycidae, first described by Hardy & Preece in 1927. The species was previously known under the synonym Phymatodes oregonensis, which was synonymized under P. nigrescens by Swift & Ray in 2010 based on examination of type specimens. It is one of 26 currently recognized species in the genus Phymatodes in North America.
Phymatodes nitidus
sequoia cone borer
Phymatodes nitidus is a longhorn beetle (family Cerambycidae) native to western North America. The species is notable for its specialized reproductive association with conifers, specifically laying eggs on giant sequoia and coast redwood cones. Larvae burrow into these cones to develop. The species was described by LeConte in 1874. Phymatodes mojavensis was synonymized under P. nitidus in 2010.
Phymatodes obliquus
Phymatodes obliquus is a species of longhorn beetle in the family Cerambycidae. It was formerly confused with P. decussatus due to misapplication of that name by Linsley (1964), but was correctly identified as a distinct species by Swift & Ray (2010). The species is primarily associated with oak (Quercus) hosts in western North America.
Phymatopsallus
Phymatopsallus is a genus of plant bugs (family Miridae, subfamily Phylinae) endemic to western North America. The genus was established by Knight in 1964. A 2006 revision significantly expanded understanding of the group, describing 9 new genera and 15 new species within the Phymatopsallus group. These are small, soft-bodied true bugs with the typical mirid morphology of slender bodies and hemelytra with distinct membranous apices.
Phymatopus behrensii
Phymatopus behrensii is a hepialid moth described by Stretch in 1872. It is known from California and Washington in the western United States. The species has a wingspan of approximately 43 mm. Larvae have been recorded feeding on a diverse range of plants including Helenium, Lupinus, Malus, and various ferns.
Phymatopus hectoides
Orange-Lined Ghost Moth
Phymatopus hectoides is a small ghost moth in the family Hepialidae, described by Boisduval in 1868. It occurs in the western United States, where adults are active in late spring and summer. The larvae are known to feed on a diverse range of host plants, boring into shoots and roots.
Phytocoris becki
Phytocoris becki is a species of plant bug in the family Miridae, described by Knight in 1968. It belongs to a large genus of mostly plant-feeding true bugs. The species is known from arid and semi-arid regions of the western United States. Like other members of Phytocoris, it is likely attracted to lights at night.