California
Guides
Ablautus 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.
Acmaeodera
Acmaeodera is a large genus of jewel beetles (family Buprestidae) with over 150 species in North America, reaching greatest diversity in the desert southwest and Mexico. Adults are metallic, often with distinctive color patterns, and are frequently observed visiting flowers to feed on pollen. The genus is distinguished by unique flight morphology: elytra are fused along the midline and remain closed during flight, functioning as a protective shield over the abdomen while only the hindwings provide propulsion. This trait, combined with abdominal banding in many species, creates a wasp-like appearance in flight and has led to recognition of several species as hymenopteran mimics. Larvae are wood-borers in twigs and branches of various woody plants.
Buprestidaejewel-beetlesmetallic-wood-boring-beetlesflower-visitorspollen-feederselytra-fusionflight-morphologyhymenopteran-mimicrywood-borersNorth-AmericaMexicoArizonaTexasCaliforniaNew-MexicoOklahomaAlbertaAsteraceaeCercocarpusspring-activemonsoon-activefall-activetaxonomically-difficultcollector's-itemdiurnalCerceris-preyAcmaeodera rubrocuprea
Acmaeodera rubrocuprea is a species of metallic wood-boring beetle in the family Buprestidae, described by Westcott & Nelson in 2000. The species is known from the southwestern United States and Mexico. It has been confirmed as breeding exclusively within dead branches of Cercocarpus ledifolius (curl-leaf mountain mahogany), making it one of five buprestid species associated exclusively with this host genus. The specific epithet 'rubrocuprea' refers to its reddish-copper coloration.
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.
Acrolophus furcatus
Acrolophus furcatus is a small moth in the family Acrolophidae, described by Lord Walsingham in 1887. The species is known from arid and semi-arid regions of southwestern North America, with records from Arizona, California, and Texas. Like other members of the genus, it is commonly referred to as a 'grass tubeworm moth' due to larval behavior. The family Acrolophidae was historically treated as a subfamily of Tineidae but is now recognized as distinct.
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 browni
Acronicta browni is a moth species in the family Noctuidae, described by Mustelin and Leuschner in 2000. It belongs to the genus Acronicta, commonly known as dagger moths, characterized by distinctive dark dagger-shaped markings on the forewings of many species. The species is known from North America, with confirmed records from California. Like other members of its genus, it is presumed to have a typical noctuid life cycle with nocturnal adult activity.
Acronicta othello
Acronicta othello is a noctuid moth described by Smith in 1908. It belongs to the dagger moth genus Acronicta, a group characterized by distinctive dark markings on the forewings that often resemble daggers or swords. The species occurs in western North America, with records from California and surrounding regions. Like other members of its genus, it is presumed to be nocturnal and attracted to light sources.
Adaleres
broad-nosed weevils
Adaleres is a genus of broad-nosed weevils in the family Curculionidae, containing at least three described species: A. flandersi, A. humeralis, and A. ovipennis. The genus was established by Casey in 1895 and is classified within the tribe Byrsopagini of the subfamily Entiminae. These weevils are distributed in western North America, with records from California and Mexico.
Adaleres ovipennis
Adaleres ovipennis is a broad-nosed weevil in the family Curculionidae, described by Casey in 1895. It belongs to the tribe Byrsopagini within the subfamily Entiminae. The species is recorded from North America, with specific distribution records from California, particularly Sonoma County. As a member of the broad-nosed weevils, it shares the characteristic short, broad rostrum typical of Entiminae.
Adelpha californica
California sister
Adelpha californica, the California sister, is a butterfly species in the family Nymphalidae found in western North America. Adults are active from March through November, with one to three generations per year depending on conditions. The species is unpalatable to predators and serves as the model for a large mimicry complex involving other butterflies. Larvae feed exclusively on oaks (Quercus), particularly canyon live oak and coast live oak.
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 convexa
Aegialia convexa is a species of aphodiine dung beetle in the family Scarabaeidae, described by Fall in 1932. It is a member of the tribe Aegialiini, a group of beetles associated with sandy coastal and dune habitats. The species is found in North America, with records from California.
Aeoloplides tenuipennis
narrow-winged saltbush grasshopper, narrow-winged bush grasshopper
A spur-throated grasshopper specialized on chenopod plants, particularly saltbushes (Atriplex species). It inhabits arid and semi-arid regions of the southwestern United States and northern Mexico, where it feeds on plants often considered noxious weeds, including Russian thistle (Salsola tragus). The species is generally regarded as beneficial or innocuous in rangeland settings rather than a crop pest.
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.
Aglossa acallalis
Aglossa acallalis is a species of snout moth in the family Pyralidae. It was described by Harrison Gray Dyar Jr. in 1908 based on specimens from the southwestern United States. The species is known from a limited geographic range in southern Arizona and California. It belongs to the genus Aglossa, which includes several species associated with stored products and organic debris.
Aglossa cacamica
Aglossa cacamica is a snout moth in the family Pyralidae, described by Harrison Gray Dyar Jr. in 1913–1914. It is native to North America, with confirmed records from California. The species has a wingspan of 22–34 mm. It belongs to a genus whose common name derives from the elongated labial palps that form a snout-like projection.
Agnostokasia
Agnostokasia is a genus of spur-throated grasshoppers in the family Acrididae, established by Gurney and Rentz in 1964. The genus contains at least one described species, A. sublima. These grasshoppers belong to the subfamily Melanoplinae, a diverse group of North American grasshoppers commonly known as spur-throated grasshoppers due to a distinctive ventral projection on the prosternum.
Agrilus auroguttatus
Goldspotted Oak Borer
Agrilus auroguttatus, the goldspotted oak borer, is a jewel beetle native to southeastern Arizona that became invasive in southern California around 2004. In California, it has caused extensive mortality in oak forests, killing an estimated 80,000 trees, primarily affecting red oaks. The species exhibits significantly higher population densities in its invasive range compared to its native range, where it coexists with a more diverse community of native borers. It was previously treated as a subspecies of Agrilus coxalis but is now recognized as a distinct species.
Agymnastus ingens
Lubberly Band-winged Grasshopper
Agymnastus ingens, known as the lubberly band-winged grasshopper, is a species of band-winged grasshopper in the family Acrididae. It is found in North America, with confirmed records from California. Females are flightless, a distinctive trait within this species. The specific epithet 'ingens' is Latin for 'huge' or 'enormous'.
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.
Alconeura tricolor
Alconeura tricolor is a species of leafhopper in the family Cicadellidae, subfamily Typhlocybinae, tribe Dikraneurini. It was described by Van Duzee in 1914. The species is known from the southwestern United States, with records from California and New Mexico. As a member of the Typhlocybinae, it belongs to a group commonly known as the 'sharpshooters' or 'leafhoppers,' though specific biological details for this species remain poorly documented.
Aleuroplatus coronata
Crown Whitefly
Aleuroplatus coronata, known as the crown whitefly, is a small sap-feeding insect in the family Aleyrodidae. Native to the southern United States and Mexico, it has established populations in California where it primarily infests oak and chestnut trees. The species derives its common name from the distinctive crown of waxy filaments surrounding the puparium. Heavy infestations can cause leaf drop, though the species generally causes limited harm to healthy host trees.
Aleuroplatus gelatinosus
Aleuroplatus gelatinosus is a species of whitefly (family Aleyrodidae) described by Cockerell in 1898. It belongs to a genus characterized by distinctive puparial morphology. The species has been documented in California and the northwestern region of Mexico. Like other whiteflies, it is presumed to feed on plant phloem, though specific host associations remain poorly documented.
Almita portalia
Almita portalia is a small moth in the family Crambidae, first described by Bernard Landry in 1995. The species is known from a very limited geographic range in the southwestern United States, with records only from Arizona and California. It belongs to the genus Almita, a group of crambid moths about which little biological information has been published.
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.
Amerizus spectabilis
spectacular riverbank ground beetle
Amerizus spectabilis is a species of ground beetle in the family Carabidae. It occurs along the Pacific coast of North America from Alaska to California. The species is commonly known as the spectacular riverbank ground beetle.
Amycle saxatilis
Amycle saxatilis is a fulgorid planthopper species described by Van Duzee in 1914. It belongs to the family Fulgoridae, a group of large, often strikingly patterned planthoppers sometimes called lanternflies. The specific epithet "saxatilis" (meaning "of rocks" or "rock-dwelling") suggests an association with rocky habitats. The genus Amycle is part of the subfamily Amyclinae, a primarily New World group. Very little specific biological information is available for this particular species.
Amyelois
navel orangeworm
Amyelois is a monotypic genus of snout moths (Pyralidae) containing a single species, Amyelois transitella, commonly known as the navel orangeworm. The species is endemic to the tropical Western Hemisphere, including the southern United States, and has become a major agricultural pest in California nut orchards. Its abundance increased substantially during the first half of the 20th century.
Amyelois transitella
Navel Orangeworm, Navel Orangeworm Moth
The navel orangeworm moth (Amyelois transitella) is a pyralid moth native to the tropical western Hemisphere and southwestern United States. First described from Arizona in 1899, its abundance in California increased dramatically during the first half of the 20th century. It is now the most serious insect pest of almonds and pistachios in California, with larvae feeding directly on nuts and adults capable of introducing fungi that produce aflatoxins. The species has been extensively studied for its chemical ecology, particularly its sex pheromone system, which has enabled practical mating disruption programs in agricultural fields.
Anarsia lineatella
Peach twig borer, Almond fruit moth
Anarsia lineatella, commonly known as the peach twig borer, is a gelechiid moth native to Europe that was introduced to California in the 1880s and has since spread to other regions. It is a significant agricultural pest of stone fruits, particularly peach, almond, plum, and apricot. The species exhibits multivoltine life cycles with two to three generations per year in most regions, with development rates varying by climate. Adults are small moths with a wingspan of 11–14 mm. The species overwinters as second or third instar larvae within buds and bark cracks, with diapause termination synchronized by winter chilling.
Anchigarypus californicus
Anchigarypus californicus is a pseudoscorpion species originally described by Nathan Banks in 1909 as Garypus californicus. The species has since been reclassified from Garypus to Anchigarypus based on morphological and taxonomic revisions. It belongs to the family Garypidae, a group of pseudoscorpions commonly found in coastal and intertidal habitats. The species is known from North America, with records primarily from California and surrounding regions.
Andricus chrysolepidicola
Irregular Spindle Gall Wasp, irregular-spindle gall wasp
Andricus chrysolepidicola is a cynipid gall wasp that induces distinctive stem galls on several oak species in western North America. The species exhibits a complex heteroecious life cycle with alternating generations: first-year unisexual wasps produce irregular spindle-shaped stem galls, while second-year bisexual wasps induce bud galls. The species is primarily documented from California but has been recorded elsewhere along the Pacific coast and eastward to Nevada.
Anemosella nevalis
Anemosella nevalis is a species of snout moth in the family Pyralidae. It was described by William Barnes and Foster Hendrickson Benjamin in 1925. The species is known from arid regions of the southwestern United States.
Anomala carlsoni
Anomala carlsoni is a species of scarab beetle described by Hardy in 1976. It is currently recognized as a synonym of Leptohoplia carlsoni in some taxonomic databases, reflecting ongoing taxonomic uncertainty in the Rutelinae subfamily. The species is known from California, USA, placing it within the Nearctic realm. Like other members of the genus Anomala, it belongs to the chafer group of scarab beetles, though specific ecological and biological details remain undocumented in the available literature.
Anomala hardyorum
Hardy's Dune Beetle, Hardys' dune beetle
Anomala hardyorum, commonly known as Hardy's Dune Beetle, is a species of shining leaf chafer in the family Scarabaeidae. The species was described by Potts in 1976 and is endemic to the Algodones Dunes of North America. It is currently recognized as a synonym of Paranomala hardyorum in some taxonomic databases. As a member of the genus Anomala, it belongs to a group of scarab beetles commonly referred to as chafers or shining leaf chafers.
Anoncia sphacelina
Anoncia sphacelina is a small moth in the family Cosmopterigidae, first described by Keifer in 1935. It is known only from California in western North America. Adults are active in spring, and the larvae are documented feeding on Lepechinia calycina, a member of the mint family.
Anoncia venis
Anoncia venis is a small moth species in the family Cosmopterigidae, described by Ronald Hodges in 1978. The species is known from a limited geographic range in the southwestern United States, with records from Arizona and California. Like other members of the genus Anoncia, it likely has narrow, elongated forewings and a relatively plain appearance typical of many cosmet moths.
Anopheles franciscanus
Anopheles franciscanus is a mosquito species in the family Culicidae, first described by McCracken in 1904. The species has been documented in southern California and is part of the Anopheles genus, which includes mosquitoes capable of transmitting malaria parasites. Seven subspecies have been described, ranging across Middle America and North America.
Anthocharis sara gunderi
Santa Catalina Orangetip
A subspecies of the Sara Orangetip butterfly endemic to Santa Catalina Island, California. The Santa Catalina Orangetip is distinguished by its island-restricted distribution and subtle morphological differences from mainland populations. Like other orangetips, it displays the characteristic orange wing tips in males, though specific distinguishing features for this subspecies require careful examination.
Anthocharis sara sara
Sara Orangetip, Pacific Orangetip
Anthocharis sara sara is the nominate subspecies of the Sara orangetip butterfly, ranging along the Pacific coast of North America. Adults display distinctive orange wing tips on otherwise white forewings, with green marbling on the ventral hindwings. The subspecies is associated with coastal and montane habitats where its host plants in the mustard family occur.
Anthocharis sara sempervirens
Sara Orange-Tip
Anthocharis sara sempervirens is a subspecies of the Sara Orange-Tip butterfly, first described in 2008. It belongs to the family Pieridae, which includes the whites and sulphurs. The subspecies epithet "sempervirens" (meaning "evergreen") references the coastal redwood (Sequoia sempervirens) forests with which this butterfly is associated. Like other orange-tips, males display distinctive orange coloration on the forewing tips.
Anuroctonus
Swollenstinger Scorpions, California Swollen-stinger Scorpions
Anuroctonus is a genus of scorpions in the family Chactidae, commonly known as swollenstinger scorpions. The genus is characterized by a distinctive swollen region on the telson just before the stinger, particularly prominent in mature males. The best-known species, Anuroctonus pococki, occurs in the coastal ranges of Southern California and Baja California. These scorpions are nocturnal ambush predators that construct burrows and are noted for their relatively large size compared to regional congeners.
Anuroctonus pococki
California Swollenstinger Scorpion, California swollen-stinger scorpion
Anuroctonus pococki is a large scorpion species reaching 65 mm in length, distinguished by a swollen region on the telson just before the stinger—most prominent in mature males—and large black-tipped pedipalps. Native to the Coast Ranges of Southern California and Baja California, it is the only member of its genus found in Baja California. First described in 2004, this nocturnal ambush predator constructs burrows and exhibits mildly venomous stings that are typically painful but non-serious.
Apache californicum
Apache californicum is a small, red planthopper endemic to California. It belongs to the family Derbidae, a group of fulgoroid insects commonly known as planthoppers. Males can be distinguished from the similar Apache degeerii by the presence of two pairs of hooks at the base of the flagellum, whereas A. degeerii has only a single pair.
Apantesis bolanderi
Apantesis bolanderi is a small tiger moth in the family Erebidae, originally described from Mount Shasta, California in 1872. It was formerly classified in the genus Grammia but was transferred to Apantesis along with related genera. The species is known from a single locality and remains poorly documented, with no confirmed observations in major biodiversity databases.
Apantesis edwardsii
A tiger moth in the family Erebidae, Apantesis edwardsii was described by Stretch in 1872. It has a highly restricted distribution, known only from the San Francisco area of California and Klamath County in Oregon. The species was transferred from the genus Grammia to Apantesis in a taxonomic revision that consolidated several related genera.
Apantesis hewletti
Apantesis hewletti is a small tiger moth species in the family Erebidae, originally described from southwestern California in 1918. It was formerly classified under the genus Grammia but was reassigned to Apantesis following taxonomic revisions that consolidated several related genera. Adults are characterized by striking coloration with black forewings bearing pale bands and bright yellow to orange-red hindwings. The species has been documented in May, though comprehensive data on its biology and ecology remains limited.
Apantesis ornata
Ornate Tiger Moth, Achaia Moth
Apantesis ornata is a tiger moth in the family Erebidae, originally described by Packard in 1864 under the name Callarctia ornata. The species was long classified in the genus Grammia before being transferred to Apantesis in a 2016 revision that consolidated several related genera. It occurs across western North America from southern British Columbia to southern California and eastward to the Rocky Mountain states. Adults are active during summer months and are attracted to light. The species exhibits the bright warning coloration typical of tiger moths, though specific details of its biology remain incompletely documented.