California-endemic
Guides
Scaphinotus bullatus
Inflated Snail-eating Beetle
Scaphinotus bullatus, commonly known as the inflated snail-eating beetle, is a species of ground beetle in the family Carabidae. It is endemic to California, where it inhabits coniferous and mixed forests. Adults are brachypterous (short-winged), a trait associated with its forest floor habitat. The species belongs to the tribe Cychrini, whose members are specialized predators of snails and slugs.
Scaphinotus cordatus
Heart-shaped Thorax Snail-eating Beetle
Scaphinotus cordatus is a species of ground beetle in the family Carabidae, commonly known as the Heart-shaped Thorax Snail-eating Beetle. It is found in North America, specifically in California, where it inhabits coastal mixed forests. Adults are brachypterous (short-winged), a trait common in the genus Scaphinotus. The species belongs to the tribe Cychrini, a group of large ground beetles often referred to as "snail hunters" due to their specialized diet.
Scaphinotus crenatus
Notched Snail-eating Beetle
Scaphinotus crenatus, commonly known as the notched snail-eating beetle, is a species of ground beetle in the family Carabidae. It is a member of the subfamily Carabinae, which includes the so-called "caterpillar hunters" and "snail hunters." This species is endemic to California, where it inhabits forested environments. Adults are brachypterous (short-winged) and nocturnal in their activity patterns.
Scaphinotus longiceps
Long-headed Snail-eating Beetle, Humboldt ground beetle
Scaphinotus longiceps is a ground beetle in the family Carabidae, commonly known as the Long-headed Snail-eating Beetle or Humboldt ground beetle. Adults are brachypterous (short-winged) and nocturnal. The species inhabits coastal temperate coniferous rainforests and mixed forests in California.
Scaphinotus riversi
Rivers' snail-eating beetle
Scaphinotus riversi, commonly known as Rivers' snail-eating beetle, is a flightless ground beetle in the family Carabidae. The species is endemic to California, where it inhabits forested environments. Adults are brachypterous (short-winged) and exhibit nocturnal activity patterns. As a member of the genus Scaphinotus, it is presumed to be a molluscivore, feeding on snails and slugs, though direct dietary observations for this specific species are not documented.
Scaphinotus striatopunctatus
Pore-winged Snail-eating Beetle
A species of ground beetle in the family Carabidae, commonly known as the pore-winged snail-eating beetle. It is native to California in western North America, where it inhabits deciduous forests, canyons, and grassy knolls. Adults are distinctive for being brachypterous (short-winged), gregarious, and nocturnal in their activity patterns.
Scaphinotus subtilis
Slender Snail-eating Beetle
Scaphinotus subtilis, commonly known as the slender snail-eating beetle, is a species of ground beetle in the family Carabidae. It is endemic to California in North America. Adults are brachypterous (short-winged) and nocturnal, and the species is typically found near bodies of water.
Schinia carrizoensis
Carrizo flower moth
Schinia carrizoensis is a species of flower moth in the family Noctuidae, described by Osbourne in 2010. It is known only from central California. The wingspan is approximately 31 mm. As a member of the genus Schinia, it likely shares the characteristic behavior of resting on host plant flowers during the day, though specific details for this species remain limited.
Schinia suetus californica
Schinia suetus californica is a subspecies of flower moth in the family Noctuidae, endemic to California. It belongs to the genus Schinia, which contains at least 123 species in North America north of Mexico, many of which are diurnal and exhibit striking coloration that camouflages them on their host flowers. The subspecific epithet 'californica' indicates a restricted geographic distribution within the state. Like other Schinia species, it likely has a close ecological association with specific host plants for larval development.
Schizopus sallei
Schizopus sallei is a species of false jewel beetle in the family Schizopodidae, a small family within the superfamily Buprestoidea. The species was described by George Henry Horn in 1885. Two subspecies are recognized: the nominate S. s. sallei and S. s. nigricans, described by Nelson in 1991. It is one of the few species in this distinctive family, which was historically classified within Buprestidae but is now recognized as a separate lineage.
Scrobipalpula lycii
Scrobipalpula lycii is a species of gelechiid moth described in 2001. It is known only from California, where it appears to be associated with Lycium californicum. The species is poorly documented, with no confirmed observations in citizen science databases.
Scrobipalpuloides spinosa
Scrobipalpuloides spinosa is a moth in the family Gelechiidae, described by Povolný in 2000. It is known from California in North America. No observations of this species have been recorded on iNaturalist. Information regarding its biology, host plants, and ecology remains undocumented in available sources.
Serica ligulata
Serica ligulata is a small scarab beetle in the family Scarabaeidae, described by Dawson in 1932. Adults measure approximately 9.5 mm in length and are characterized by their chocolate brown, glabrous, sub-shining appearance. The species is endemic to California, with two recognized subspecies: S. l. ligulata and S. l. praetermissa. Subspecies praetermissa has been documented feeding on specific host plants including Arctostaphylos glandulosa, Arctostaphylos pungens, and the flowers of Adenostoma fasciculatum.
Serica serotina
Serica serotina is a scarab beetle species in the family Scarabaeidae. Adults measure approximately 8–11 mm in length. The species is known from California, where it has been documented in multiple localities.
Sigmocheirini
Sigmocheirini is a tribe of flat-backed millipedes (Order Polydesmida) in the family Xystodesmidae, established by Causey in 1955. The tribe contains the genus Sigmocheir, whose species are endemic to California's Sierra Nevada foothills. Members of this tribe exhibit the characteristic flattened body form typical of xystodesmid millipedes.
Sonoma isabellae
Sonoma isabellae is a small rove beetle in the family Staphylinidae, specifically within the subfamily Pselaphinae. It is classified as an "ant-loving beetle," indicating a myrmecophilous lifestyle. The species was described by J. L. LeConte in 1852 and is known from California and broader North America. As a member of the tribe Faronitae, it belongs to a group of beetles that are typically small, compact, and associated with ant colonies.
Sorhoanus lenis
Sorhoanus lenis is a species of leafhopper in the family Cicadellidae, first described by Van Duzee in 1925. It belongs to the subfamily Deltocephalinae and tribe Paralimnini, a group of small to medium-sized leafhoppers often associated with grasses and sedges. The species is known from California, though detailed biological information remains limited. Like other members of its genus, it likely inhabits open, grassy environments where its host plants occur.
Speyeria adiaste
unsilvered fritillary, adiaste fritillary
Speyeria adiaste is a California-endemic fritillary butterfly in the family Nymphalidae, distinguished from congeners by the unsilvered hindwing spots that give it its common name. The species occurs in two disjunct populations in coastal California mountains. Adults feed on flower nectar and larvae feed on Viola species. Mark-recapture studies of the subspecies S. a. clemencei have revealed extremely limited adult dispersal and declining population trends, highlighting conservation concerns for this isolated endemic.
Speyeria adiaste atossa
Atossa fritillary
Speyeria adiaste atossa, the Atossa fritillary, is an extinct subspecies of the unsilvered fritillary butterfly. It was last observed around 1960 in the mountain ranges of southern California. The precise cause of extinction remains unknown, though drought conditions in the late 1950s may have contributed to population decline. The subspecies was first described by William Henry Edwards in 1864. Speyeria is now treated as a subgenus of Argynnis.
Sphaerobothris platti
Sphaerobothris platti is a species of metallic wood-boring beetle in the family Buprestidae. It was described by Cazier in 1938. The species is known from southern California, with records from San Diego County, and is part of the genus Sphaerobothris, which belongs to the tribe Coraebini within the subfamily Agrilinae.
Spharagemon bunites
Spharagemon bunites is a species of band-winged grasshopper in the family Acrididae, described by Otte in 1984. It belongs to the subfamily Oedipodinae, tribe Trimerotropini, a group characterized by banded or colored hind wings that are often concealed at rest. The species is known from California and is considered present in North America, though detailed biological information remains limited.
Sternidocinus
Sternidocinus is a monotypic genus of longhorn beetles (Cerambycidae) in the subfamily Lamiinae. The genus contains a single species, Sternidocinus barbarus, described by Van Dyke in 1920. The genus itself was established by Dillon in 1956. The sole species is endemic to California.
Stictostix californicus
Stictostix californicus is a species of parasitoid wasp in the family Encyrtidae. The genus Stictostix belongs to the diverse chalcidoid wasp superfamily, a group of minute parasitoids widely used in biological control. The specific epithet 'californicus' indicates a geographic association with California. Encyrtid wasps are generally known as parasitoids of scale insects, mealybugs, and other homopteran pests, though specific host records for this species remain undocumented in the provided sources.
Stonemyia velutina
velvety stonian horsefly, Volutine Stoneyian Tabanid Fly
Stonemyia velutina is a rare horsefly endemic to California, first described in 1892. The species was not observed between 1942 and 2023, leading to a premature declaration of extinction in 1996. Its 2023 rediscovery confirmed continued survival, though knowledge of its biology remains limited. The species belongs to the family Tabanidae, a group of biting flies whose females typically require blood meals for egg development.
Stropenron californica
Stropenron californica is a species of click beetle in the family Elateridae, endemic to California. The genus Stropenron is a small, poorly documented group within the diverse click beetle family. Very little biological information has been published for this species.
Sympistis mut
Sympistis mut is a moth species in the family Noctuidae, first described by James T. Troubridge in 2008. It is endemic to California. The species has a wingspan of 36–39 mm. Little is known about its biology beyond basic taxonomic description.
Synecdoche albicosta
Synecdoche albicosta is a species of planthopper in the family Achilidae, first described by Van Duzee in 1917. It belongs to the subfamily Myconinae and tribe Plectoderini. The species is recorded from California. Like other achilid planthoppers, it is a member of the infraorder Fulgoromorpha within the order Hemiptera.
Synecdoche autumnalis
Synecdoche autumnalis is a species of planthopper in the family Achilidae, described by O'Brien in 1971. It belongs to the tribe Plectoderini within the subfamily Myconinae. The species epithet "autumnalis" suggests seasonal activity in autumn. Like other achilid planthoppers, it is a member of the infraorder Fulgoromorpha, a group known for diverse and often elaborate head structures, though specific morphological features of this species remain poorly documented in accessible literature.
Synecdoche cara
Synecdoche cara is a species of planthopper in the family Achilidae, first described by Van Duzee in 1910. It belongs to the tribe Plectoderini within the subfamily Myconinae. The species has been recorded in California, with 29 observations documented on iNaturalist. As a member of the Fulgoromorpha, it is part of a diverse group of hemipterans commonly known as planthoppers.
Synecdoche fusca
Synecdoche fusca is a species of planthopper in the family Achilidae, described by Van Duzee in 1908. It belongs to the order Hemiptera, suborder Auchenorrhyncha, and infraorder Fulgoromorpha. The species has been documented in California based on distribution records. Very little is known about its biology or ecology.
Synecdoche nervata
Synecdoche nervata is a species of planthopper in the family Achilidae, described by Van Duzee in 1910. It belongs to a genus of New World achilids characterized by distinctive wing venation patterns. The species is known from California and represents one of the few documented members of this genus in western North America.
Synetocephalus diegensis
A small leaf beetle in the family Chrysomelidae, described from California. The species epithet refers to San Diego, indicating its type locality. Very few observations exist in biodiversity databases, suggesting it is either rare, undercollected, or restricted to specific habitats. It belongs to a genus of flea beetles characterized by enlarged hind femora adapted for jumping.
Taracus ubicki
A small harvestman species in the family Taracidae, described from California in 2016 as part of a major revision of the genus Taracus. The species is one of eight new Taracus species described in that work, expanding known diversity in western North American ischyropsalidoid harvestmen.
Tegrodera erosa inornata
Tegrodera erosa inornata is a subspecies of blister beetle endemic to cismontane southern California and Baja California. It is one of three subspecies within the T. erosa species complex, distinguished from the nominate subspecies by reduced or absent elytral markings. Like all Tegrodera species, it contains cantharidin in its hemolymph and has been associated with livestock toxicity concerns when present in alfalfa hay. The subspecies is currently considered to be undergoing range retrenchment due to urban development.
Tegrodera latecincta
Soldier Blister Beetle, Iron Cross Blister Beetle
Tegrodera latecincta is a large, colorful blister beetle endemic to the Owens and Antelope valleys of eastern California. As the northernmost species in the genus Tegrodera, it is geographically isolated from its closest relative T. erosa by the San Gabriel and San Bernardino mountains, and from T. aloga by the Mojave Desert. Adults are active in late spring and early summer, often forming conspicuous feeding and mating aggregations. Like other meloid beetles, it possesses cantharidin in its hemolymph for chemical defense.
Telamona californica
Telamona californica is a species of treehopper in the family Membracidae, described by Flynn in 2023. As a member of the tribe Telamonini within subfamily Smiliinae, it belongs to a group known for pronounced pronotal modifications. The specific epithet 'californica' indicates a geographic association with California. Like other Telamona species, it possesses the enlarged pronotum characteristic of treehoppers, though specific morphological details for this species remain limited in available sources.
Teleiopsis baldiana
Teleiopsis baldiana is a small gelechiid moth described in 1920 by William Barnes and August Busck. It is restricted to California in western North America. The species is associated with poison oak (Toxicodendron diversilobum), on which its larvae feed and roll leaves.
Telonaca ramona pasadena
Telonaca ramona pasadena is a subspecies of treehopper in the family Membracidae, first described by Ball in 1931. It belongs to the tribe Telamonini within the subfamily Smiliinae. Treehoppers in this genus are characterized by their enlarged pronotum, which forms distinctive helmet-like or thorn-like structures. The subspecies epithet "pasadena" suggests a geographic association with the Pasadena area of California.
Temnothorax caguatan
Temnothorax caguatan is a species of small myrmicine ant described in 2014 from California, USA. It belongs to a genus of cavity-nesting ants known for nesting in pre-existing cavities such as hollow acorns, twigs, and rock crevices. The species was one of ten new Temnothorax species described from California in a single study, effectively doubling the known species diversity of this genus in the state. Like other members of Temnothorax, it is likely a generalist scavenger with colonies of moderate size.
Tetracanthella californica
Tetracanthella californica is a species of springtail described by Deharveng in 1978. It belongs to the family Isotomidae, a diverse group of small, wingless hexapods found in soil and leaf litter ecosystems. The species epithet indicates its occurrence in California. Like other Collembola, it contributes to decomposition processes in terrestrial habitats.
Tetracis australis
Tetracis australis is a geometrid moth described by Ferris in 2010. It is restricted to a narrow coastal and montane range in southern California and northern Baja California, Mexico. The species exhibits spring seasonality, with adult flight from March through late June. Larval host associations remain provisional, with Quercus and Populus species suggested as probable food plants.
Tetrix sierrana
Sierra Pygmy Grasshopper
Tetrix sierrana is a species of pygmy grasshopper in the family Tetrigidae, endemic to California in the western United States. Like other members of the genus Tetrix, it is a minute jumping insect with a highly modified pronotum that extends backward over the abdomen. The species was described in 1956 and remains poorly known, with very few documented observations.
Thyridanthrax luminis
Thyridanthrax luminis is a species of bee fly in the family Bombyliidae, described by Hall in 1970. The species is known from California. Bee flies in this genus are parasitoids, with females laying eggs in the nests of solitary wasps. A related species, Thyridanthrax sp., has been observed parasitizing nests of the thread-waisted wasp Ammophila aberti in Arizona.
Timema boharti
Bohart's timema
Timema boharti is a small walkingstick species in the family Timematidae, endemic to California. It inhabits xeric pinyon-juniper woodland with chaparral intrusions at elevations around 915 m. The species exhibits two distinct colour morphs—greyish and green—with assortative mating by colour phase. It is nocturnal and has been collected in late April, with both mating pairs and late-instar nymphs observed. Like other Timema species, it is wingless and feeds on host plants within its specialized habitat.
Timema californicum
California timema
Timema californicum is a sexually dimorphic walkingstick insect endemic to California. Males are smaller than females and possess conspicuous cerci used to grasp females during copulation. The species exhibits hemimetabolous development with gradual morphological changes: hatchlings are phenotypically identical between sexes, juveniles show minor differences, and adults display pronounced sexual dimorphism. Males complete development with one fewer moult than females.
Timonidia solitaria
Timonidia solitaria is a species of planthopper in the family Dictyopharidae, described from California in 1922. The genus Timonidia is placed in the subfamily Orgeriinae, a group of dictyopharid planthoppers often associated with arid and semi-arid habitats. Like other members of this family, it likely possesses an enlarged, often elaborately modified head structure characteristic of many fulgoromorphs. The specific epithet 'solitaria' suggests this species may occur singly or in low densities relative to congeners.
Tipula jacintoensis
Tipula jacintoensis is a species of large crane fly in the family Tipulidae. It was described by Charles Paul Alexander in 1946. The species is known only from California, where it has been recorded in the San Jacinto Mountains. As a member of the genus Tipula, it shares the characteristic elongated body and extremely long legs typical of crane flies, though specific details of its biology remain poorly documented.
Tipula simplex
range crane fly
Tipula simplex, commonly known as the range crane fly, is a crane fly species in the family Tipulidae found in California and potentially Oregon. It is notable for pronounced sexual dimorphism in wing development: males possess fully developed wings, while females are essentially wingless with reduced wings subequal to the halteres. The species inhabits unirrigated pastures and has been documented to reach larval densities capable of causing significant pasture damage.
Trachusa perdita
California leafcutting bee, California Resin-Leafcutter
Trachusa perdita is a solitary leafcutting bee native to California, belonging to the family Megachilidae. Females construct underground nests in hillsides, lining brood cells with leaves collected from Buckthorn shrubs. The species is notable for its distinctive nesting behavior and specific host-plant relationship for nest construction materials.
Trichinorhipis
Trichinorhipis is a monotypic genus of jewel beetles (Buprestidae) endemic to southern California. The sole species, Trichinorhipis knulli, measures under 4 mm and exhibits distinctive sexual dimorphism in antennae: males possess fan-like (flabellate) antennae adapted for detecting female sex pheromones, while females have unmodified serrate antennae. The genus is placed in its own subtribe (Trichinorphidina) within the tribe Xenorhipidini due to unique morphological characters distinguishing it from related genera Hesperorhipis and Xenorhipis.