Pacific-coast
Guides
Grapholita edwardsiana
San Francisco Tree Lupine Moth
Grapholita edwardsiana, known as the San Francisco Tree Lupine Moth, is a species of tortricid moth in the family Tortricidae, subfamily Olethreutinae. The species was described by Kearfott in 1907 and is placed in the genus Grapholita, a diverse group of small moths commonly referred to as fruitworms or bud moths. Many Grapholita species are associated with leguminous plants, and the specific epithet "edwardsiana" suggests a possible association with lupines (Lupinus), particularly tree lupine. The species is part of the tribe Grapholitini, which includes numerous economically important pests of fruits and seeds.
Grapsus grapsus
Sally Lightfoot Crab, Red Rock Crab, Abuete Negro
Grapsus grapsus is a common intertidal crab native to the Pacific and Atlantic coasts of the Americas. Adults display highly variable coloration ranging from brownish-red to mottled yellow and pink, while juveniles are darkly colored for camouflage on volcanic substrates. The species is renowned for its agility and rapid escape response, making it difficult to capture. It occupies rocky shorelines just above the spray zone and has been documented engaging in cleaning symbiosis with marine iguanas in the Galápagos.
Hemigrapsus nudus
Purple Shore Crab
The purple shore crab (Hemigrapsus nudus) is a small intertidal crab native to the Pacific coast of North America. It shelters under rocks in the mid to high intertidal zone and feeds primarily on green algae, particularly sea lettuce. The species is distinguished from similar shore crabs by its purple coloration and smooth carapace lacking prominent teeth or spines between the eyes.
Henricus umbrabasana
Brown-shouldered Henricus
Henricus umbrabasana is a small tortricid moth known from the Pacific Coast of the United States. The species was described by Kearfott in 1908 and is characterized by its modest forewing size of 7.5–9 mm. It is one of approximately 40 described species in the genus Henricus, a group of small tortricine moths predominantly distributed in the Nearctic region.
Hesperonemastoma modestum
Hesperonemastoma modestum is a species of harvestman (Opiliones) in the family Taracidae. It was described by Nathan Banks in 1894 and occurs in western North America. The species has been recorded from British Columbia and several locations in California and Oregon. Like other taracids, it belongs to the suborder Dyspnoi.
Heteroecus sanctaeclarae
Mushroom Gall Wasp, Steeple Gall Wasp
Heteroecus sanctaeclarae is a cynipid gall wasp that induces distinctive bud galls on oaks. The galls are bilobed, with the larval chamber located at the seam between the two sections. This species was first described by David T. Fullaway in 1911 under the name Callirhytis sanctae-clarae. It is primarily known from the Pacific coast of North America.
Lasiopagon pacificus
Pacific Sandpirate
Lasiopogon pacificus is a species of robber fly in the family Asilidae, commonly known as the Pacific Sandpirate. It was described by Cole and Wilcox in 1938. The species belongs to a genus of predatory flies that inhabit sandy environments. As with other Asilidae, it is presumed to be an active aerial predator of other insects. Available records indicate limited observation data, with approximately 20 documented sightings on iNaturalist.
Ligia pallasii
Sleepy Seaslater, Rock Louse, Sleepy Sea Slater
Ligia pallasii is a large, semiterrestrial isopod in the family Ligiidae, commonly known as the sleepy seaslater or rock louse. It is among the largest sea slaters, reaching 25–30 mm in body length. This species inhabits the high intertidal zone along the Pacific coast of North America, from the Aleutian Islands to northern California. It exhibits nocturnal scavenging behavior, feeding primarily on algae and organic matter, and seeks shelter in moist microhabitats during daylight hours to avoid desiccation.
Limonius canus
Pacific Coast Wireworm
Limonius canus, commonly known as the Pacific Coast wireworm, is a click beetle species in the family Elateridae. The larval stage is a significant agricultural pest, particularly damaging to potatoes, wheat, and other crops in the Pacific Coast region of North America. Research has documented its behavioral responses to insecticides, including repellence and contact-induced morbidity from certain compounds. The species harbors diverse gut bacteria that have been investigated for potential biocontrol applications.
Lophopanopeus bellus
black-clawed crab, Blackclaw Crestleg Crab
Lophopanopeus bellus is a small crab native to the Pacific coast of North America, ranging from Alaska to California. The species is characterized by its rounded carapace with low tubercles, black claws, and highly variable coloration. Two subspecies are recognized: L. b. bellus in the northern portion of the range and L. b. diegensis in the southern portion. The species is notable for being parasitized by the barnacle Loxothylacus panopaei.
Lotisma trigonana
Lotisma trigonana is a small moth in the family Copromorphidae, ranging along the Pacific coast of North America from Alaska to Costa Rica. Adults have a wingspan of 14–22 mm. The species has two recognized subspecies: the nominate form and L. t. durangoensis from Durango, Mexico. Larvae are known to feed on salal (Gaultheria shallon) and cranberry.
Lucifotychus cognatus
Lucifotychus cognatus is a small rove beetle (Staphylinidae: Pselaphinae) described by John Lawrence LeConte in 1874. Originally described under the genus Tychus, it was later transferred to Lucifotychus, a genus within the tribe Tychini. The species occurs in western North America from Alaska through British Columbia and along the Pacific coast to California. Like other pselaphine rove beetles, it is likely associated with forest floor habitats and decaying organic matter, though specific ecological details remain poorly documented.
Megalorchestia
sand-hoppers
Megalorchestia is a genus of sand-hoppers in the family Talitridae, erected by Johann Friedrich von Brandt in 1851. The genus contains seven recognized species distributed along the Pacific coast of North America. Members are commonly found in coastal beach environments where they exhibit characteristic jumping locomotion.
Megalorchestia corniculata
beach hopper
Megalorchestia corniculata is a beach-dwelling amphipod in the family Talitridae, commonly known as a beach hopper. It inhabits sandy intertidal zones along the Pacific coast of North America. The species plays a significant ecological role as a consumer of marine wrack, contributing to nutrient cycling in coastal ecosystems.
Microhelia angelica
Microhelia angelica is a small noctuid moth species described by Smith in 1900. It occurs along the Pacific coast of North America from California to Washington. The species has a wingspan of 9–13 mm, making it one of the smaller members of the subfamily Heliothinae. Little is known of its biology beyond basic collection records.
Neoalcis
Neoalcis is a monotypic genus of geometrid moths established by James Halliday McDunnough in 1920. It contains a single species, Neoalcis californiaria (brown-lined looper), described by Packard in 1871. The genus is endemic to western North America, where its sole species occurs along the Pacific coast from California to British Columbia.
Omus laevis
Night-stalking Tiger Beetle
Omus laevis is a synonym of Omus californicus californicus, a nocturnal tiger beetle species in the genus Omus. Members of this genus are restricted to the Pacific region of North America and are characterized by their nocturnal activity pattern, which distinguishes them from most other tiger beetles. The species is part of a taxonomically complex group historically treated as variable subspecies of O. californicus.
Pagurus samuelis
blueband hermit crab
A small intertidal hermit crab native to the eastern Pacific coast, distinguished by bright blue bands on the legs of adults. It is the most common hermit crab in California. The species exhibits strong shell fidelity, preferentially occupying shells of the black turban snail (Tegula funebralis). Behavioral studies demonstrate that shell acquisition takes priority over feeding when both resources are scarce, and that social isolation heightens aggressive behavior and dominance in shell competition.
Parabagrotis insularis
Parabagrotis insularis is a small noctuid moth native to the Pacific Coast of North America. Adults are active from spring through fall, with forewings measuring 13–16 mm. The species was described by Augustus Radcliffe Grote in 1876 and is assigned Hodges number 11047.2.
Paraphrosylus
Paraphrosylus is a genus of long-legged flies in the family Dolichopodidae. Originally described as a subgenus of Aphrosylus, it was later elevated to full genus rank. Members of this genus are restricted to rocky coastlines of the Eastern Pacific, where they inhabit the intertidal zone. Six species are currently recognized, ranging from Alaska to southern California.
Pentidotea montereyensis
Pentidotea montereyensis is a marine isopod in the family Idoteidae, first described by Maloney in 1933. The species is found in the temperate northern Pacific Ocean and is associated with kelp and algal habitats. Like other idoteid isopods, it is dorsoventrally flattened and adapted for clinging to macroalgae. The species has been documented through 254 iNaturalist observations, indicating moderate contemporary recording effort.
Pentidotea resecata
Eelgrass Isopod
Pentidotea resecata, commonly known as the eelgrass isopod, is a marine isopod in the family Idoteidae. It inhabits shallow intertidal zones along the Pacific coast of North America, where it is closely associated with eelgrass (Zostera) beds. The species plays a documented role in eelgrass ecology through grazing activities.
Pimoa haden
Large Hammockweb Spider
Pimoa haden is a species of large hammockweb spider in the family Pimoidae, found in the western United States. It was described by Chamberlin & Ivie in 1943. The species is notable for its relatively large size compared to other members of the family, with females reaching up to 12 mm in body length. Like other Pimoa species, it constructs fine, net-like horizontal webs that can span considerable distances.
Polites sonora
Sonoran skipper, western long dash
Polites sonora is a small skipper butterfly in the family Hesperiidae found along the Pacific coast of North America. It has a wingspan of 25–27 mm and exhibits one generation annually in Canada, flying from mid-July to mid-August. Research indicates this species overwinters as eggs, with snowpack providing insulating protection that positively influences adult emergence success. Climate change poses significant threats through warming winters and reduced snow cover.
Pontomalota opaca
Pontomalota opaca is a species of rove beetle in the family Staphylinidae, first described by John Lawrence LeConte in 1863. The genus Pontomalota is characterized as a "sea shore genus," suggesting ecological affinity for coastal environments. This small beetle occurs in western North America, with records from Pacific coastal regions extending from Alaska through British Columbia to California, Oregon, and Washington, plus inland records from the northwestern United States. The species is among the least documented members of its genus, with limited observational records despite its relatively broad geographic range.
Promecognathus
Promecognathus is a genus of ground beetles comprising two described species, P. laevissimus and P. crassus. These beetles are specialist predators of cyanide-producing flat-backed millipedes in the family Xystodesmidae. They possess exceptional physiological tolerance to hydrogen cyanide, surviving doses 7–15 times greater than those lethal to other carabid beetles. This tolerance allows them to attack millipedes directly without behavioral avoidance of chemical defenses, representing the first documented case of cyanide tolerance in predatory insects.
Proserpinus lucidus
Pacific green sphinx, bear sphinx
Proserpinus lucidus is a small sphinx moth native to the Pacific coast of North America. Adults are active in winter from December to April, during which they do not feed. The species exhibits unusual seasonal timing among North American sphinx moths, with adults emerging and mating during the coldest months. Larvae feed on specific evening primrose relatives in the genera Clarkia and Camissonia, and possess a distinctive "bullseye" spot in place of the typical horn found in most sphinx moth caterpillars.
Protorthodes rufula
rufous Quaker moth
Protorthodes rufula is a small noctuid moth found along the Pacific Coast of western North America. The species exhibits highly variable forewing coloration ranging from pale buff to deep brown, with rufous shading present in most individuals. It has two distinct flight periods in northern populations and an extended season in southern California. The larvae develop on hardwoods in the rose family.
Psammopolia arietis
Psammopolia arietis is a noctuid moth restricted to Pacific Coast sand beaches from Mendocino, California to south-western Alaska. Adults fly from late July to early September. The larvae inhabit sand dunes and feed on specific coastal plants including beach pea, seashore knotweed, and yellow sand-verbena. The species is absent from the inland Strait of Georgia, indicating a strict dependence on outer coastal habitats.
Pterotaea albescens
Pterotaea albescens is a geometrid moth described by James Halliday McDunnough in 1941. The species is endemic to the Pacific Coast of North America, with confirmed records from California and Oregon. It belongs to the subfamily Ennominae, a diverse group of geometer moths commonly known as inchworms or loopers due to their characteristic larval locomotion.
Pugettia producta
Northern Kelp Crab, Shield-backed Kelp Crab
Pugettia producta is a spider crab found along the Pacific coast of North America, recognized by its shield-shaped carapace and long, multi-jointed legs adapted for climbing kelp. The species exhibits pronounced sexual dimorphism, with males reaching larger sizes and possessing more robust chelipeds. It demonstrates remarkable dietary flexibility, shifting from herbivory in summer to carnivory in winter.
Randallia ornata
globose sand crab, purple globe crab
Randallia ornata is a true crab in the family Leucosiidae, commonly known as the globose sand crab or purple globe crab. It inhabits sandy beaches along the eastern Pacific coast from Northern California to Baja California, Mexico. The species is notable as a host for an undescribed nemertean worm in the genus Carcinonemertes, which acts as an egg predator with infection rates reaching 70% in crab populations.
Spilosoma vestalis
Vestal tiger-moth, Vestal Tiger Moth
Spilosoma vestalis, the Vestal tiger-moth, is a species of tiger moth in the family Erebidae. Described by Alpheus Spring Packard in 1864, it occurs along the Pacific coast of western North America. Adults are active from May to June, with forewing lengths of 19–26 mm. The larvae feed on various woody and herbaceous plants.
Subhaida ingrata
Subhaida ingrata is a species of rove beetle in the family Staphylinidae, originally described as Pseudohaida ingrata by Hatch in 1957. The species belongs to the subfamily Omaliinae and tribe Coryphiini. It has been documented from western North America, including the Pacific coast and adjacent interior regions.
Tanystoma
Tanystoma is a genus of ground beetles (Carabidae) in the subfamily Platyninae. It comprises five described species distributed along the Pacific Coast of North America. One species, Tanystoma maculicolle, is commonly known as the tule beetle. The genus was established by Motschulsky in 1845.
Telamona vestita carynotana
Telamona vestita carynotana is a subspecies of treehopper in the family Membracidae, described by Ball in 1931. It belongs to the diverse genus Telamona, which is part of the Nearctic tribe Telamonini within subfamily Smiliinae. Treehoppers in this genus are characterized by pronounced pronotal modifications that create distinctive silhouettes. This subspecies has been documented from California and Oregon.
Terralonus californicus
Intertidal Jumping Spider, Beach Jumping Spider
Terralonus californicus is a jumping spider in the family Salticidae, notable as one of the few spider species known to regularly inhabit coastal beach environments. It is found in the United States, primarily along the Pacific coast. The species has been documented through over 750 observations on iNaturalist, indicating it is relatively well-observed among coastal arachnids. Its intertidal habitat distinguishes it from most other jumping spiders, which typically occupy terrestrial vegetation and ground habitats.
Thalassotrechus
Thalassotrechus is a monotypic genus of ground beetles in the family Carabidae, containing only the species Thalassotrechus barbarae. The genus is notable for its specialized intertidal habitat, with the single species inhabiting crevices in rocky intertidal zones along the Pacific coast of North America. Members of this genus exhibit specialized habitat recognition behaviors mediated by chemical and physical cues in their sediment environment.
Thinopinus pictus
Pictured Rove Beetle
Thinopinus pictus is a wingless rove beetle (Coleoptera: Staphylinidae) endemic to sandy beaches along the Pacific coast of North America from southern Alaska to Baja California. Both larvae and adults are strictly nocturnal predators that emerge from temporary sand burrows at night to hunt beach hoppers (Orchestoidea). The species exhibits limited dispersal and predictable emergence patterns tied to tidal cycles, with populations forming a 15–30 meter wide band that shifts seaward during neap tides and landward during spring tides.
Thinusa fletcheri
Thinusa fletcheri is an intertidal rove beetle in the family Staphylinidae. It was described by Casey in 1906 and is one of several species in the genus Thinusa. The genus was revised taxonomically in 1997, with T. fletcheri redescribed and lectotype designated from Casey's syntype series.
Tipula pacifica
Pacific crane fly
Tipula pacifica is a species of large crane fly in the family Tipulidae. It occurs along the Pacific coast of North America, from British Columbia south to California. The species was described by Doane in 1912. As a member of the genus Tipula, it shares the characteristic elongated body and extremely long legs typical of crane flies.
Traskorchestia
beach hoppers
Traskorchestia is a genus of beach hoppers in the family Talitridae, established by Bousfield in 1982. The genus contains at least three described species: T. georgiana, T. ochotensis, and T. traskiana (the Pacific beach hopper). These amphipods inhabit coastal environments and are part of the supralittoral community.
Traskorchestia traskiana
Pacific beach hopper
Traskorchestia traskiana, the Pacific beach hopper, is a supralittoral amphipod inhabiting coastal beaches of the Pacific Northwest. Its activity patterns are directly influenced by tidal inundation cycles, with behavioral adaptations to periodic flooding in the zone above the high tide line. The species has been studied for its population biology and behavioral responses to environmental conditions in nearshore ecosystems.
Usofila pacifica
Usofila pacifica is a small true spider in the family Telemidae, described by Banks in 1894. It is found along the west coast of North America, from the United States into Canada. The species inhabits moist forest floor environments, where it constructs minute, delicate webs.
Viridiseptis
Viridiseptis is a monotypic moth genus in the family Noctuidae, erected in 2015. Its sole species, Viridiseptis marina, was originally described in 1874. The genus is endemic to the Pacific coast of North America, ranging from southwestern Oregon through California. Adults are characterized by distinctive green forewings with complex dark patterning.
Zootermopsis angusticollis
Pacific Dampwood Termite
Zootermopsis angusticollis is a dampwood termite species native to the Pacific coast of North America. It is among the largest termites in North America and is notable for its strict dependence on moist, decaying wood. The species is eusocial, living in colonies with distinct castes including workers, soldiers, nymphs, and reproductives. It has been extensively studied as a model organism for hindgut symbiont ecology and represents one of the best-studied lower termites in terms of gut microbial communities.