Endemic
Guides
Abagrotis rubricundis
Abagrotis rubricundis is a noctuid moth described by Buckett in 1968. It is restricted to mountainous regions of California and southwestern Oregon. The species has a wingspan of approximately 38 mm. It is a rarely recorded species with limited ecological data available.
Abedus immaculatus
Abedus immaculatus is a species of giant water bug in the family Belostomatidae. It is the only Abedus species found in the eastern United States, with a range extending throughout Florida north into Georgia and west along the Gulf Coast to Mississippi. Adults measure 13–14 mm in length, making them the smallest species in the genus Abedus and the smallest belostomatid in the United States. The species is the sole member of the subgenus Microabedus. It is locally common in parts of the Everglades, where it occurs in shorter hydroperiod sites.
giant-water-bugaquatic-insectfreshwaterwetlandEvergladesendemiceastern-United-Statessmallest-belostomatid-USAmale-parental-careBelostomatidaeHemipteraMicroabedushydroperiodFloridaGeorgiaMississippiGulf-CoastThomas-Say1832Abedus-cantrallisynonymywater-bugtrue-bugNepomorphaHeteropteraInsectaArthropodaAnimaliaAblautus schlingeri
Oso Flaco Robber Fly
Ablautus schlingeri, commonly known as the oso flaco robber fly, is a small predatory fly in the family Asilidae. The species is endemic to California and has been documented at Oso Flaco Lake and surrounding dune habitats. It faces potential threats from sand mining operations that degrade its specialized sandy habitat. The species was described by Wilcox in 1966 and remains relatively poorly known.
Acalyptris lotella
Acalyptris lotella is a minute moth in the family Nepticulidae, known for its highly specialized larval biology. The species is endemic to California and represents one of the few documented cases of stem-mining behavior in this genus. Its larvae create internal tunnels within the stems of Lotus scoparius, a chaparral shrub. The species was originally described as Microcalyptris lotella in 1987 and later transferred to Acalyptris.
Acantholyda floridana
Acantholyda floridana is a species of sawfly in the family Pamphiliidae. The genus Acantholyda comprises web-spinning sawflies whose larvae construct silken webs on host plants. This species is endemic to Florida, with records from the northern and central portions of the peninsula. Adults are active in spring and early summer. Larval biology and specific host associations for this species remain poorly documented.
Acneus beeri
Beer's false water penny beetle
Acneus beeri is a species of aquatic beetle in the family Psephenidae, known from a single female specimen collected east of Cascadia, Oregon in July 1940. The species belongs to the false water penny beetles, a group characterized by their flattened, oval body form adapted for clinging to submerged surfaces in flowing water. No additional specimens have been reported in the more than 80 years since its original description, making it one of the most poorly known North American beetle species.
Acrocercops arbutella
Acrocercops arbutella is a small moth in the family Gracillariidae, first described by Braun in 1925. The species is endemic to Arizona, United States, where it occurs on its host plant Arbutus arizonica. Larvae are leaf miners that create distinctive upper surface blotch mines on the leaves of their host.
Acrodectes philopagus
Alpine Shieldback
Acrodectes philopagus, commonly known as the Alpine Shieldback, is the sole described species in the monotypic genus Acrodectes. It is a shield-backed katydid in the family Tettigoniidae, first described by Rehn and Hebard in 1920. The species is known from high-elevation habitats in California. As with other tettigoniids, it possesses enlarged hind legs adapted for jumping and long antennae.
Acrolophitus pulchellus
Idaho point-headed grasshopper
Acrolophitus pulchellus is a species of grasshopper in the family Acrididae, endemic to Idaho in the United States. It occupies a highly restricted range in dry, sparsely vegetated shrubland habitats on foothills and floodplains. The species is characterized by its pointed head, soft hairy body covering, and distinctive green and white coloration. It is closely associated with stemless mock goldenweed (Stenotus acaulis) as an important host plant.
Acroncosa minima
Acroncosa minima is a species of snout moth described by Herbert H. Neunzig in 2003. It is endemic to California, United States. The species belongs to the family Pyralidae, a large group of small moths commonly known as snout moths due to their projecting labial palps.
Acronicta heitzmani
Heitzman's Dagger, Heitzman's dagger moth
Acronicta heitzmani is a species of dagger moth in the family Noctuidae, first described by Charles V. Covell and Eric H. Metzler in 1992. The species is endemic to the central United States, with documented occurrence in Missouri, Arkansas, Illinois, and Ohio. It is a relatively small noctuid moth with forewing lengths of 12–14.5 mm in males and 12.5–15 mm in females. Like other members of the genus Acronicta, it is a nocturnal species attracted to artificial light sources.
Acronicta valliscola
Acronicta valliscola is a small noctuid moth described by André Blanchard in 1968. It is known exclusively from Big Bend National Park in western Texas, making it one of the most geographically restricted species in the genus. The species has a wingspan of 30–35 mm. Very little is known about its biology or ecology due to its limited known distribution and few documented observations.
Acylophorina
Acylophorina is a subtribe of rove beetles (Staphylinidae) within the tribe Staphylinini. The subtribe contains the genus Acylophorus, which includes species distributed in Madagascar and the Mascarene Islands. Members of this subtribe are characterized by specific morphological traits that distinguish them from related staphylinine beetles.
Adelphagrotis stellaris
Adelphagrotis stellaris is a noctuid moth described by Augustus Radcliffe Grote in 1880. It is a West Coast endemic with a range extending from southern British Columbia through the Cascade Range to the central California Coast Range. The species belongs to the subfamily Noctuinae, a diverse group of owlet moths.
Aegialia concinna
Ciervo Aegilian Scarab Beetle
Aegialia concinna is a small scarab beetle in the subfamily Aegialiinae. The species was described in 1977 and is known only from the western United States. Members of the genus Aegialia are commonly associated with sandy coastal or dune habitats.
Aegialia crescenta
Crescent Dunes scarab beetle
Aegialia crescenta is a species of scarab beetle in the subfamily Aegialiinae, first described by Gordon and Cartwright in 1977. It is endemic to the United States and appears to have a restricted distribution centered on Nevada. The species belongs to a genus of beetles typically associated with sandy habitats.
Aethecerinus hornii
Horn's Aethecerinus Long-Horned Beetle
Aethecerinus hornii is a rare longhorned beetle (family Cerambycidae) endemic to Florida scrub habitat in Highlands and Lee counties. Described by Lacordaire in 1869, this species belongs to the tribe Trachyderini, a group known for bright coloration, flower-feeding behavior, and diurnal activity. The species is extremely restricted in range and poorly represented in collections, with only five observations documented.
Aglaothorax longipennis
Santa Monica shieldback katydid, Santa Monica Mountains Shieldback
Aglaothorax longipennis is a shieldback katydid endemic to the United States, specifically known from the Santa Monica Mountains region of California. It belongs to the family Tettigoniidae, which includes katydids, crickets, and bush-crickets. The species was originally described as Neduba longipennis before being transferred to the genus Aglaothorax. It has been studied at Topanga State Park, indicating a restricted range within coastal southern California.
Agoliinus incommunis
Agoliinus incommunis is a species of small scarab beetle in the subfamily Aphodiinae, originally described by Fall in 1932. The species is documented from mountainous regions of western North America, with records spanning from British Columbia south to New Mexico. As a member of the Aphodiini tribe, it belongs to a group commonly known as small dung beetles, though specific ecological details for this species remain poorly documented. The species name "incommunis" (Latin for "uncommon" or "not shared") may allude to its rarity or restricted distribution.
Agonum crenistriatum
Agonum crenistriatum is a ground beetle in the subfamily Platyninae, described by John Lawrence LeConte in 1863. The species is endemic to North America, with records from the United States and Canada. It belongs to a genus of small to medium-sized predatory beetles commonly found in moist habitats. Very little specific biological information has been published for this particular species.
Agonum texanum
Agonum texanum is a ground beetle in the family Carabidae, subfamily Platyninae. The species was originally described by LeConte in 1878 as Platynus texanus. It is endemic to Texas, United States, and has been recorded in the GBIF database from both the USA and Mexico. As a member of the genus Agonum, it belongs to a diverse group of ground beetles commonly found in moist habitats.
Agraphini
Agraphini is a small weevil tribe in the subfamily Entiminae, established by Horn in 1876. It contains only two genera—Agraphus and Paragraphus—each represented by a single species. The tribe is endemic to the Atlantic coastal region of the eastern United States.
Agrotis arenarius
Sable Island Cutworm Moth
Agrotis arenarius is a noctuid moth endemic to Sable Island, Nova Scotia, Canada. First described by Neil in 1983, this species is known from only a handful of observations. Its restricted distribution to a single small island makes it one of the most geographically limited Agrotis species. The specific epithet "arenarius" refers to the sandy habitat of its island home.
Aguayomiris
Aguayomiris is a genus of plant bugs in the family Miridae, established by Maldonado Caprilles in 1987. As a member of the subfamily Bryocorinae (tribe Dicyphini or related group), it belongs to a lineage of mirids often associated with mosses, liverworts, or other cryptogamic vegetation. The genus is endemic to Puerto Rico, reflecting the island's distinctive Caribbean fauna. Very few species have been described, and the group remains poorly known biologically.
Alberada californiensis
Alberada californiensis is a species of snout moth described by Herbert H. Neunzig in 1997. It belongs to the family Pyralidae and is currently documented only from California. The species is represented by a small number of observations, reflecting limited survey effort rather than necessarily restricted abundance.
Aleptina arenaria
Aleptina arenaria is a small noctuid moth described in 2011. The species is known exclusively from White Sands National Park in New Mexico, where it inhabits the gypsum sand dune field. Its specific epithet references this specialized sandy habitat. The species is known from only two observations, making it one of the most geographically restricted moths in North America.
Allenius
Allenius is a genus of lady beetles (family Coccinellidae) containing a single described species, Allenius iviei. The genus was established in 2012 and is notable for its extreme rarity and distinctive morphology. The sole species is known from only a few specimens collected in the northwestern United States.
Alloblackburneus
Alloblackburneus is a genus of scarab beetles (family Scarabaeidae, subfamily Aphodiinae) described by Bordat in 2009. It belongs to the tribe Aphodiini, a group commonly known as small dung beetles. The genus is endemic to the Afrotropical region. Species in this genus are part of the diverse Aphodiinae fauna associated with decomposition and nutrient cycling in African ecosystems.
Alpheias oculiferalis
Alpheias oculiferalis is a species of snout moth in the family Pyralidae, first described by Émile Louis Ragonot in 1891. It belongs to the genus Alpheias within the subfamily Galleriinae. The species is endemic to the US state of Texas, with 54 iNaturalist observations supporting its continued presence in the region.
Alypia mariposa
Mariposa Forester
Alypia mariposa, the Mariposa Forester, is a day-flying moth in the family Noctuidae, first described in 1868. It is endemic to California's Coast Ranges and Sierra foothills, with a distribution spanning from Kern County northward to Placer County. Adults are active in spring, flying during April through June. The species is distinguished from its congener Alypia ridingsii by wing pattern differences.
Alypia wittfeldii
Wittfeld's Forester
Alypia wittfeldii, commonly known as Wittfeld's Forester, is a small noctuid moth endemic to the southeastern Atlantic coastal plain of the United States. First described by Henry Edwards in 1883, this species is notable for its restricted distribution, occurring almost exclusively in Florida (excluding the western panhandle), coastal Georgia, and South Carolina. Adults are active during the winter and early spring months, with forewings measuring 13–14 mm in length. The species belongs to the forester moths (genus Alypia), a group characterized by bright coloration and diurnal activity patterns that contrast with the typically nocturnal habits of most noctuids.
Amaurorhinus bewickianus
Amaurorhinus bewickianus is a weevil species in the family Curculionidae, endemic to the Madeira archipelago. It was first described by Wollaston in 1860 and has been recorded from Madeira Island and the nearby Desertas Islands. The species belongs to a small genus of flightless weevils with restricted distributions in the Macaronesian region. Its island endemism and apparent absence from mainland Europe suggest limited dispersal capability.
Amblycheila hoversoni
South Texas giant tiger beetle
Amblycheila hoversoni is a flightless, nocturnal tiger beetle first described in 1990 (published 1991). It holds the distinction of being the largest tiger beetle species in the Western Hemisphere. The species is endemic to south and west-central Texas, where it inhabits grassland and prairie habitats. Like other members of the genus Amblycheila, it exhibits a lumbering, deliberate gait rather than the rapid, jerky movement typical of most tiger beetles.
Amblycheila katzi
Trans-Pecos Giant Tiger Beetle
Amblycheila katzi is a small-sized tiger beetle (23–28 mm) endemic to the Trans-Pecos region of western Texas. It is distinguished from all other Amblycheila by its strongly petrophilous ecology, occupying vertical rock walls rather than ground habitats. Adults are nocturnal predators active on limestone surfaces 1–5 m above ground. The species has been successfully bred in captivity, with 59 adults reared from eggs.
Amblyomma tuberculatum
gopher tortoise tick
Amblyomma tuberculatum is a hard tick species endemic to the United States, commonly known as the gopher tortoise tick due to its intimate association with the gopher tortoise (Gopherus polyphemus). Unlike many tick species, its distribution appears more restricted than that of its primary host, with environmental factors such as sand depth and soil composition playing significant roles in habitat suitability. Laboratory studies have documented its complete life cycle, which requires a minimum of 207 days under controlled conditions.
Amiana
Amiana is a monotypic moth genus in the family Noctuidae, containing a single species, Amiana niama. The genus was established by Harrison Gray Dyar Jr. in 1904. It is endemic to the southwestern United States, specifically the state of Arizona. As a member of the subfamily Acronictinae, it belongs to a group of noctuid moths commonly known as dagger moths.
Ammopelmatus kelsoensis
Kelso Dunes Jerusalem Cricket, Kelso Jerusalem cricket
Ammopelmatus kelsoensis is a large, flightless orthopteran insect endemic to the Kelso Dunes of California. It belongs to the family Stenopelmatidae, commonly known as Jerusalem crickets. The species is distinguished from congeners by specific leg spine and spur characteristics, including short, spatulate apical tibial spurs and reduced ventral spines on the fore and hind tibiae. Adults are active in midsummer. The species has been collected exclusively from burrows of Rhachocnemis colonies, where it has been observed preying on nymphs of that genus.
Ammopelmatus mescaleroensis
Mescalero Jerusalem Cricket
Ammopelmatus mescaleroensis is a species of Jerusalem cricket endemic to the sand dunes of southeastern New Mexico. First described by Tinkham in 1979, it was later found to be conspecific with A. monahansensis, which was synonymized under A. mescaleroensis in a 2024 phylogenomic revision. A neotype has been designated for this species. The species is nocturnal and has been observed in sand dune habitats at night.
Ammopelmatus muwu
Point Conception Jerusalem Cricket
Ammopelmatus muwu is a Jerusalem cricket species in the family Stenopelmatidae. It is endemic to a restricted coastal region of central California, specifically parts of San Luis Obispo and Santa Barbara counties. The species was described in 1981 and is one of several sand dune-associated Ammopelmatus species in western North America. Like other members of its genus, it is nocturnal and fossorial.
Ammopelmatus nigrocapitatus
Black-headed Jerusalem Cricket
Ammopelmatus nigrocapitatus is a species of Jerusalem cricket in the family Stenopelmatidae, originally described by Tinkham & Rentz in 1969. It is one of 12 previously named taxa recognized as valid in a comprehensive 2025 revision of the genus. The species is endemic to parts of Southern California and is characterized by its distinctive black head. Like other Ammopelmatus species, it is a large, flightless orthopteran adapted to arid and semi-arid environments.
Amphipoea erepta
cutworm, dart moth
Amphipoea erepta is a noctuid moth species found in North America. A subspecies, A. e. ryensis, has a highly restricted range, occurring only in a single 25-acre meadow in Pelham Bay Park, The Bronx, New York City. The species is assigned MONA/Hodges number 9461.
Amphipogon
greybeard grasses
Amphipogon, commonly known as greybeard grasses, is a genus of perennial grasses endemic to Australia. The genus belongs to the grass family Poaceae and is characterized by its distinctive inflorescences with hairy or bearded spikelets. Species within this genus are adapted to Australian temperate and Mediterranean climates, often occurring in woodland and forest understories.
Ampumixis
Ampumixis is a monotypic genus of riffle beetles in the family Elmidae, containing the single species Ampumixis dispar. The genus was described by Sanderson in 1954 and is endemic to the Western United States, specifically the region between California and Oregon. Adults are small, measuring approximately 2.1–2.5 mm in length.
Anacochylidia maderana
Anacochylidia maderana is a species of tortricid moth described from southern Arizona in 2019. It is known from two localities in the Madrean sky island region: Palmerlee in Cochise County and Madera Canyon in Santa Cruz County. The species name references Madera Canyon, one of its collection sites. Available specimens indicate adult activity in September. The early stages and larval host plants remain unknown.
Anaea troglodyta floridalis
Florida Leafwing
Anaea troglodyta floridalis is a federally endangered subspecies of butterfly endemic to southern Florida. It is one of the most imperiled butterflies in North America, with populations restricted to pine rockland and tropical hardwood hammock habitats in Miami-Dade County and Everglades National Park. The subspecies is highly dependent on its host plant Croton linearis for larval development. Habitat loss, fragmentation, and fire suppression have contributed to its decline, with remaining populations concentrated in protected areas.
Anillinus davidsoni
Anillinus davidsoni is a species of small ground beetle in the family Carabidae, described by Sokolov in 2012. It belongs to the tribe Bembidiini and subtribe Anillina, a group of minute, often eyeless or reduced-eyed beetles adapted to subterranean or cryptic habitats. The genus Anillinus is endemic to North America, with species distributed primarily in the eastern and central United States.
Anillinus folkertsioides
Anillinus folkertsioides is a small ground beetle species described in 2020 from Jackson County, Alabama. It is a litter-dwelling species, distinguishing it from the sympatric cave-dwelling Anillinus clinei found in the same county. The species belongs to the tribe Anillini, a group of minute carabid beetles often associated with subterranean or forest floor habitats. Its discovery brought the known Anillinus fauna of Alabama to twelve species.
Anillinus fortis
Anillinus fortis is a species of small ground beetle in the family Carabidae, endemic to the Eastern United States. It belongs to the tribe Anillina within the subfamily Trechinae, a group characterized by reduced eyes and adaptations to subterranean or soil-dwelling habits. The species was described by George Henry Horn in 1869. Like other members of its genus, it likely inhabits forest floor litter and soil microhabitats.
Anillinus jancae
Anillinus jancae is a small, eyeless ground beetle in the tribe Bembidiini. It was described by Thomas C. Barr in 1995 based on specimens from Kentucky. The species belongs to a genus of minute carabids adapted to subterranean or deep soil habitats. Like other Anillinus species, it exhibits troglomorphic traits including reduced pigmentation and vestigial eyes.
Anillinus langdoni
Anillinus langdoni is a small ground beetle in the tribe Bembidiini, described in 2004. It belongs to the A. langdoni species group, which includes four species with three endemic to the Great Smoky Mountains region. The species is distinguished from congeners primarily by male genitalia morphology and female spermathecal shape. Phylogeographic studies suggest its distribution reflects historical altitudinal shifts of habitat corridors and watershed-mediated isolation.