California-endemic
Guides
Melanoliarus californicus
Melanoliarus californicus is a species of planthopper in the family Cixiidae, first described by Van Duzee in 1914. The species epithet indicates its association with California. Cixiidae are small to medium-sized planthoppers characterized by their brachypterous (short-winged) or macropterous (long-winged) forms and are commonly found in diverse terrestrial habitats.
Melanoplus bernardinae
Melanoplus bernardinae is a species of spur-throated grasshopper in the family Acrididae, described by Hebard in 1920. It belongs to the large genus Melanoplus, which contains many economically and ecologically significant grasshopper species in North America. The species is documented from California and is part of the western North American grasshopper fauna. Like other Melanoplus species, it is expected to exhibit typical grasshopper life history with egg diapause and nymphal development through multiple instars, though specific biological details remain poorly documented.
Melanoplus devastator
devastating grasshopper
Melanoplus devastator, the devastating grasshopper, is a medium-sized spur-throated grasshopper endemic to the far western United States, primarily California, with limited occurrence in Oregon and Washington. It is a major agricultural pest known for irruptive population outbreaks that can cause extensive damage to rangeland forage, orchards, and crops. The species exhibits a unique life history among rangeland grasshoppers, with females entering reproductive diapause during summer and resuming egg development in fall triggered by decreasing photoperiod. When populations explode, nymphal bands and adult swarms migrate from depleted foothill rangelands into valley agricultural areas, sometimes traveling 30 miles or more.
Melikaiella flora
Live Oak Petiole Gall Wasp
Melikaiella flora is a cynipid gall wasp that induces distinctive leaf galls on live oak trees (Quercus agrifolia, Q. wislizeni, and Q. chrysolepis) in California. The species exhibits a complex life cycle involving two generations, with second-generation females ovipositing into acorns rather than leaf tissue. The galls typically engulf the entire petiole and may extend into the leaf blade, representing one of the more dramatic gall morphologies among North American Cynipidae. Formerly classified as Callirhytis milleri, the species was reclassified to reflect improved understanding of cynipid phylogeny.
Mesamia diana
Mesamia diana is a species of leafhopper in the family Cicadellidae, subfamily Deltocephalinae, described by Van Duzee in 1925. It belongs to the tribe Platymetopiini, a group of leafhoppers within the large and diverse family Cicadellidae. The genus Mesamia is part of the leafhopper superfamily Membracoidea, which includes some of the most economically significant plant-feeding insects. Very little specific information is available about the biology or ecology of this particular species.
Metaphycus matteolus
Metaphycus matteolus is a species of parasitic wasp in the family Encyrtidae, described by Compere in 1947. The species belongs to a genus of primary parasitoids known for attacking scale insects (Coccoidea). Like other Metaphycus species, M. matteolus is likely associated with soft scale hosts, though specific host records for this species are not well documented in available literature. The genus Metaphycus contains numerous species used in classical biological control programs against scale insect pests.
Microbembex californica
Microbembex californica is a species of sand wasp in the family Crabronidae, first described by R. Bohart in 1970. It belongs to a genus of small to medium-sized predatory wasps that inhabit sandy environments. Like other members of the Bembicinae, this species likely excavates burrows in soil and provisions them with prey for their larvae. The specific epithet "californica" indicates a geographic association with California.
Microterys yolandae
Microterys yolandae is a species of parasitoid wasp in the family Encyrtidae, described by Compere in 1926. The species is represented in the UCR Entomology Research Museum collection, which holds one of the largest Encyrtidae collections worldwide. As with other Microterys species, it likely functions as a parasitoid of scale insects (Coccoidea), though specific host records for this species remain unpublished. The species has been documented in California.
Miloderes nelsoni
Nelson's Miloderes Weevil
Miloderes nelsoni is a species of broad-nosed weevil in the family Curculionidae, subfamily Entiminae. The species was described by David G. Kissinger in 1960. It belongs to the tribe Byrsopagini, a group of flightless weevils characterized by their fused elytra and reduced hind wings. The specific epithet honors an individual named Nelson, though the exact honoree has not been documented in available sources. Records indicate presence in California, specifically Inyo County.
Mohavacris
desert long-horned grasshopper
Mohavacris is a monotypic genus of grasshoppers in the family Tanaoceridae, containing a single described species, M. timberlakei. The genus is endemic to desert regions of California and belongs to a small family of long-horned grasshoppers adapted to arid environments. Members of this family are characterized by their elongated antennae and nocturnal habits, distinguishing them from typical short-horned grasshoppers.
Moriuss occidens
Moriuss occidens is a species of ant-loving beetle in the family Staphylinidae, subfamily Pselaphinae. It belongs to the tribe Trichonychini and is one of very few species in the genus Moriuss. The species was described by Casey in 1893 and is known from California. Pselaphine beetles are generally small, cryptic, and associated with leaf litter and soil habitats.
Morophagoides berkeleyella
Morophagoides berkeleyella is a species of clothes moth in the family Tineidae, described by Powell in 1968. It belongs to a genus of small moths associated with detritivorous or fungivorous feeding habits. The species is known from California, USA. Like other tineids, it likely occupies habitats rich in decaying organic matter.
Morsea catalinae
Catalina monkey grasshopper
Morsea catalinae, described by Rentz and Weissman in 1981, is a species of monkey grasshopper endemic to the family Eumastacidae. The common name "Catalina monkey grasshopper" references its association with Santa Catalina Island, California. Like other eumastacids, it possesses a distinctive body plan with elongated hind legs adapted for jumping and a pronotum that extends backward over the abdomen. The species has been documented from California and is considered present in North America, though specific habitat details and ecological data remain limited in published literature.
Morsea tamalpaisensis
tamalpais monkey grasshopper
Morsea tamalpaisensis, described by Rehn & Hebard in 1909, is a species of monkey grasshopper endemic to the family Eumastacidae. The common name references Mount Tamalpais in California, indicating a restricted geographic distribution. Like other eumastacids, this species exhibits the characteristic morphology of monkey grasshoppers, including a compact body form and specialized hind legs adapted for jumping. The species has been documented through limited observations, with 20 records in iNaturalist suggesting it is not frequently encountered.
Myzocallis agrifolicola
California Oak Aphid
Myzocallis agrifolicola is a species of oak-feeding aphid described by Richards in 1966. It is the type species for the subgenus Californicallis within the genus Myzocallis (Aphididae: Calaphidinae). The species is associated with oak trees (Quercus) in western North America, particularly California.
Nanularia monoensis
Nanularia monoensis is a species of metallic wood-boring beetle in the family Buprestidae. Described by Charles L. Bellamy in 1987, it is known from a restricted area in the Benton Range of Mono County, California. The species is considered rare, with few documented observations.
Neduba carinata
shield-backed katydid
Neduba carinata is a shield-backed katydid endemic to Fremont Peak in San Benito County, California. Formerly applied broadly to katydids across the western United States, this name now applies only to a restricted population following elevation of most subspecies to full species status. It is distinguished from the similar N. diabloica by a pronotum that is slightly longer and narrower.
Nemomydas tenuipes
Nemomydas tenuipes is a species of mydas fly in the family Mydidae, first described by Hermann Loew in 1872. Mydas flies are among the largest flies in North America and are characterized by their wasp-mimicking appearance. The genus Nemomydas contains relatively small species within this family. Very little is known about the specific biology of N. tenuipes.
Neocrania bifasciata
Neocrania bifasciata is a small moth species and the sole member of the genus Neocrania. It belongs to the family Eriocraniidae, a primitive group of Lepidoptera. The species is endemic to the Coast Ranges of southern California and was described by Davis in 1978. It is one of the few eriocraniid species found in western North America.
Neodiplocampta mirella
Neodiplocampta mirella is a species of bee fly in the family Bombyliidae, described by Hull and Martin in 1974. The species is known only from California. As a member of the subfamily Anthracinae and tribe Villini, it belongs to a group of bee flies characterized by particular wing venation patterns. No observations of this species have been recorded in iNaturalist.
Neomochtherus californicus
Neomochtherus californicus is a species of robber fly (family Asilidae) described by Hine in 1909. The species belongs to the tribe Neomochtherini within the subfamily Asilinae. Robber flies in this genus are predatory insects known for their agile flight and ambush hunting behavior. The specific epithet "californicus" indicates the species was originally described from California.
Neomymar
Neomymar is a genus of fairyflies (Mymaridae), among the smallest known insects. The genus was established by Crawford in 1913. Species within this genus are egg parasitoids, though specific host associations remain poorly documented compared to related genera such as Anagrus and Gonatocerus. The Nearctic species were revised by Triapitsyn, Berezovskiy and Huber in 2006, with three species described: N. komar, N. korsar, and N. zuparkoi. These species are known from California and Mexico.
Neophyllura pruinosa
Neophyllura pruinosa is a species of jumping plant louse (psyllid) in the family Liviidae, first described by Martin in 1931. As a member of the Hemiptera order, it is a sap-feeding insect that likely specializes on particular host plants. The genus Neophyllura is part of a group of psyllids associated with various plant families, though specific ecological details for this species remain poorly documented in available literature. The species has been recorded in California, USA based on distribution data.
Neurobathra bohartiella
Neurobathra bohartiella is a small moth in the family Gracillariidae, described by Opler in 1971. The species is endemic to California and is known only from a limited number of observations. Its larvae are leaf miners on coast live oak (Quercus agrifolia).
Neuroterus fragilis
succulent gall wasp
Neuroterus fragilis, commonly known as the succulent gall wasp, is a species of oak gall wasp in the family Cynipidae. It induces distinctive galls on California oak species, with only the spring bisexual generation currently documented. The species is notable for its relatively large galls compared to its tiny adult body size.
Nidicola jaegeri
minute pirate bug
Nidicola jaegeri is a minute pirate bug (family Anthocoridae) described from southern California in 1979. The species is specifically associated with bird nests, having been collected from the nests of the cactus wren (Campylorhynchus brunneicapillus) and the house finch (Carpodacus mexicanus). As a member of the genus Nidicola, it belongs to a group of anthocorids that have evolved close associations with vertebrate nesting environments.
Nippononebria altisierrae
high sierra false gazelle beetle
Nippononebria altisierrae, commonly known as the high sierra false gazelle beetle, is a black-colored ground beetle in the family Carabidae. It was originally described as Nebria altisierrae by Kavanaugh in 1984 and later transferred to the genus Nippononebria. The species belongs to the subgenus Vancouveria and is endemic to California's mountainous regions.
Norvellina rostrata
Norvellina rostrata is a leafhopper species in the family Cicadellidae, described by Lindsay in 1938. It belongs to the tribe Platymetopiini within the subfamily Deltocephalinae. Leafhoppers in this genus are true bugs with piercing-sucking mouthparts used to feed on plant sap. The species has been recorded from California based on available distribution data.
Nothembius aberrans
Nothembius aberrans is a species of stone centipede in the family Lithobiidae, first described by Chamberlin in 1916. It is a small, soil-dwelling centipede belonging to the order Lithobiomorpha, which contains the common stone centipedes. The species is known from California, USA, with limited published information available on its biology and ecology.
Nothembius insulae
Nothembius insulae is a species of lithobiomorph centipede described by Chamberlin in 1916. It belongs to the family Lithobiidae, a group commonly known as stone centipedes. The species is known only from California, USA. Like other lithobiids, it is presumed to be a predatory soil-dwelling arthropod, though specific biological details remain undocumented.
Oecleus netrion
Oecleus netrion is a species of planthopper in the family Cixiidae, described by Kramer in 1977. It belongs to the tribe Oecleini, a group of small to medium-sized cixiids characterized by specific wing venation patterns. Records indicate occurrence in California, though detailed biological information remains limited. As with other members of Cixiidae, it likely feeds on plant vascular fluids using piercing-sucking mouthparts.
Oedaleonotus borckii
Oedaleonotus borckii is a species of spur-throated grasshopper in the family Acrididae. It is found in North America, with records from California. As a member of the genus Oedaleonotus, it shares the characteristic short tegmina (forewings) that are shorter than the pronotum, distinguishing it from the related valley grasshopper (O. enigma) which has variable wing length including long-winged forms.
Oedaleonotus pinctus
Oedaleonotus pinctus is a species of spur-throated grasshopper in the family Acrididae, subfamily Melanoplinae. It is one of approximately nine species in the genus Oedaleonotus, a group primarily distributed in California and the western United States. The genus is characterized by short tegmina that are typically shorter than the pronotum and often narrow and widely separated. O. pinctus was described by Scudder in 1899 and is currently accepted as a valid species.
Okanagana arctostaphylae
Okanagana arctostaphylae is a small cicada species described by Van Duzee in 1915. It is native to California and belongs to the genus Okanagana, which contains numerous western North American cicada species. Like other Okanagana species, it is an annual cicada with a life cycle completed within a single year rather than the multi-year periodical cycles seen in Magicicada. The specific epithet arctostaphylae suggests an association with manzanita (Arctostaphylos), though the nature of this relationship requires confirmation.
Okanagana salicicola
Okanagana salicicola is a small North American cicada species described by Bliven in 1964. As a member of the genus Okanagana, it belongs to a group of annual cicadas found primarily in western North America. The specific epithet 'salicicola' suggests an association with willow (Salix) habitats. Like other Okanagana species, it is likely a habitat specialist with specific host plant relationships, though detailed ecological studies remain limited.
Okanagana villosa
Okanagana villosa is a species of annual cicada in the family Cicadidae, described by Davis in 1941. It is native to California and belongs to a genus of approximately 65 species found in western North America. Like other Okanagana species, it is not a periodical cicada and does not exhibit the synchronized mass emergences characteristic of Magicicada broods. The species name 'villosa' refers to hairy or shaggy appearance.
Omus californicus angustocylindricus
Narrow Night-stalking Tiger Beetle
Omus californicus angustocylindricus is a subspecies of night-stalking tiger beetle endemic to California. It is one of several subspecies within the Omus californicus complex, characterized by its narrow, elongated body form. Adults are nocturnal and difficult to observe, with activity patterns tied to seasonal conditions. Larvae construct burrows in forested habitats, typically found along logging roads or under cover objects. The subspecies is considered rare and has been documented from limited localities in northern California, particularly in Plumas County.
Omus californicus californicus
California Night-stalking Tiger Beetle
Omus californicus californicus is the nominate subspecies of the California night-stalking tiger beetle, a flightless, nocturnal carabid beetle endemic to California. Adults are active primarily in spring and early summer, with larvae occupying permanent burrows in soil. The species exhibits strong habitat fidelity to specific substrates and moisture conditions. Unlike diurnal tiger beetles in the genus Cicindela, Omus species are crepuscular to nocturnal hunters that do not rely on vision for prey capture.
Orgerius bilobatus
Orgerius bilobatus is a species of planthopper in the family Dictyopharidae, described from California in 1943. The specific epithet "bilobatus" refers to a bilobed (two-lobed) structure, likely a diagnostic morphological feature. Like other members of Orgeriinae, it belongs to a group of fulgoroid planthoppers characterized by elongated head processes. The species is documented from California but remains poorly known, with no observations recorded on iNaturalist.
Orgerius glaucus
Orgerius glaucus is a species of planthopper in the family Dictyopharidae, described by Emeljanov in 2006. It belongs to the subfamily Orgeriinae, a group commonly known as dictyopharid planthoppers. The species is known from California, USA. As a member of Hemiptera, it possesses piercing-sucking mouthparts typical of true bugs. Little detailed information is available regarding its biology or ecology.
Oropodes chumash
Oropodes chumash is a species of ant-loving beetle in the family Staphylinidae, subfamily Pselaphinae. It was described in 2011 by Chandler & Caterino. The species epithet refers to the Chumash people, indigenous to coastal California. Like other pselaphines, it is likely associated with ant colonies, though specific biological details remain poorly documented. The species is known from California, USA.
Orus fraternus
Orus fraternus is a rove beetle (family Staphylinidae) described by Henry Clinton Fall in 1901. It belongs to the genus Orus within the tribe Lathrobiini. Very little is known about this species beyond its taxonomic placement and type locality in California.
Paeromopus
Paeromopus is a genus of large cylindrical millipedes endemic to California, United States. The genus contains four species, with body lengths ranging from 10 to 16.5 cm, making P. paniculus the longest millipede species in North America. Three species have restricted ranges in the Sierra Nevada mountains, while P. angusticeps has a broad distribution across Northern California and the Central Coast. The genus was established by Ferdinand Karsch in 1881 and belongs to the family Paeromopodidae.
Pagaronia furcata
Pagaronia furcata is a leafhopper species in the family Cicadellidae, first described by Oman in 1938. It belongs to the subfamily Evacanthinae, a group of leafhoppers characterized by distinctive head morphology. The species has been documented in California, with 25 observations recorded on iNaturalist. Limited information exists regarding its biology and ecology.
Paracapnia boris
Colusa Snowfly
Paracapnia boris is a species of winter stonefly in the family Capniidae, described by Stark & Baumann in 2004. It is known from California and is commonly referred to as the Colusa Snowfly. Like other capniids, it is likely active during cold months when few other insects are present. The species name honors someone named Boris, presumably a colleague or contributor to stonefly research.
Paracapnia humboldta
Redwood Snowfly
Paracapnia humboldta is a species of small winter stonefly in the family Capniidae, described from California in 2007. It belongs to a genus of snowflies that are active during cold months. The species epithet references Humboldt County, where the type specimen was collected. It is one of the more recently described members of this genus in western North America.
Paravilla fumosa
Paravilla fumosa is a species of bee fly in the family Bombyliidae, described by Hall in 1981. It is endemic to California. As a member of the bee fly family, it likely exhibits the characteristic parasitoid lifestyle of many bombyliids, though specific details remain unreported.
Pardalosus slevini
Pardalosus slevini is a species of scarab beetle in the subfamily Aphodiinae, described by Van Dyke in 1928. It is a dung beetle endemic to California. The genus Pardalosus contains species associated with burrowing owl nests and mammal burrows. Records for this species are sparse, with only two observations documented on iNaturalist.
Parochodaeus californicus
Parochodaeus californicus is a species of sand-loving scarab beetle in the family Ochodaeidae. First described by Horn in 1895, this beetle is endemic to California, USA. Members of the genus Parochodaeus are associated with sandy habitats, though specific ecological details for this species remain limited.
Penehuleria acuticephala
Penehuleria acuticephala is a species of leafhopper in the family Cicadellidae, first described by Beamer in 1934. It belongs to the subfamily Deltocephalinae and tribe Athysanini. The species is known from California, with very few documented observations.