Hessel's Hairstreak
Hessel's Hairstreak is a small lycaenid butterfly endemic to Atlantic coastal wetlands of the eastern United States. The species exhibits complete ecological dependence on Atlantic white-cedar (Chamaecyparis thyoides), which serves as the exclusive larval host plant and provides adult camouflage habitat. Populations are patchily distributed and declining due to habitat loss, with state-level endangered status in Connecticut and G3 vulnerable ranking globally.
Frosted Elfin
Callophrys irus, the frosted elfin, is a rare Lycaenid butterfly endemic to fire-maintained habitats in eastern North America. Adults are small with brown forewings and frosted gray hindwings with a short tail. The species has declined across much of its range, with many populations now isolated and some presumed extirpated. It is listed as threatened or endangered in multiple eastern U.S. states.
Callophrys irus arsace is a historically reported subspecies of the frosted elfin butterfly, originally described from coastal regions of the southeastern United States (Carolinas and Virginia). Genetic analysis of preserved specimens found no evidence that this subspecies is genetically distinct from the nominate subspecies C. i. irus. Field surveys conducted in 2019 and 2021 failed to locate any extant populations within its historical range. The subspecies has not been observed in over two decades and may be extirpated.
Frosted Elfin
Callophrys irus hadros is a subspecies of Frosted Elfin butterfly in the family Lycaenidae. It has been studied in Arkansas where research has examined its distribution and habitat preferences. The subspecies is part of a complex of elfin butterflies that occur in North America. Limited observational data exists, with only 10 records documented on iNaturalist.
Johnson's Hairstreak
Callophrys johnsoni, commonly known as Johnson's Hairstreak, is a small butterfly in the family Lycaenidae. It occurs in coniferous forests of western North America from British Columbia to central California. The species has a highly specialized larval diet, feeding exclusively on dwarf mistletoes (Arceuthobium species). Adults are active in late spring and early summer, with a single generation per year.
Sandia Hairstreak
Callophrys mcfarlandi, the Sandia Hairstreak, is a small butterfly species native to North America with a restricted geographic range. It was discovered in 1958 in La Cueva Canyon, Albuquerque, New Mexico, by University of Kansas student Noel McFarland and formally described in 1960. The species was designated as one of New Mexico's state insects in 2003. It belongs to the hairstreak group within the family Lycaenidae.
Eastern Pine Elfin
Callophrys niphon, the eastern pine elfin, is a small butterfly in the family Lycaenidae native to North America. It is closely associated with pine habitats and has a single annual flight period that varies geographically. The species is distinguished from similar elfins by wing pattern characteristics.
Hoary Elfin
Callophrys polios, the hoary elfin, is a small butterfly in the family Lycaenidae with a wingspan of 22–29 mm. It is a northern specialist species associated primarily with pine-oak barrens and other open habitats. The species has a broad but patchy distribution across North America, from Alaska and Canada south through the Great Lakes, New England, Appalachians, Rocky Mountains, and Pacific Coast to northern California. Adults are active in spring, with a single generation from April to June. The species is listed as a species of special concern and believed extirpated in Connecticut.
Sheridan's Hairstreak, Sheridan's Green Hairstreak
A small, tail-less hairstreak butterfly with a wingspan of 20–24 mm, recognized by the characteristic straight white line crossing the underside of both wings. The species exhibits variable underside coloration from bright green to dark gray-green. It was designated the state butterfly of Wyoming in 2009. The species occupies a broad elevational range and shows significant geographic variation in wing pattern expression.
Thicket Hairstreak
Callophrys spinetorum, the thicket hairstreak, is a small butterfly in the family Lycaenidae described by William Chapman Hewitson in 1867. It is distributed across western North America from British Columbia through the Rocky Mountains to New Mexico and Mexico, and through California to Baja California. The species is a specialist herbivore whose larvae feed exclusively on dwarf mistletoes in the genus Arceuthobium, exhibiting remarkable mimicry of their host plants.
Xami Hairstreak, Green Hairstreak, Elfin
Callophrys xami is a small lycaenid butterfly with a wingspan of 2.38–2.86 cm, recognized by the distinctive W-shaped postmedian white line on its yellowish-green hindwing underside. Males defend territories for mating, and the species exhibits complex sexual behavior involving a 'false head' wing pattern that deflects predator attacks. The butterfly is associated with Crassulaceae host plants, particularly Echeveria and Sedum species.
Calpodini is a tribe of satyrine butterflies distributed primarily in the Neotropical region. The group includes medium-sized species with relatively plain wing patterns compared to other satyrines. Members are associated with forested and semi-open habitats in Central and South America. The tribe has received less taxonomic attention than related groups such as the Euptychiina, and its internal phylogenetic relationships remain partially unresolved.
Red-banded Hairstreak
Calycopis cecrops, commonly known as the red-banded hairstreak, is a small butterfly native to the southeastern United States. Adults have a wingspan of 23–32 mm and are characterized by grayish underwings with a distinctive red band. The species has been observed feeding on fallen leaves of sumac species and other trees. It is typically found in coastal areas and open habitats.
dusky-blue groundstreak
Calycopis isobeon, the dusky-blue groundstreak, is a small hairstreak butterfly in the family Lycaenidae. It ranges from Venezuela northward through Central America and Mexico to central Texas. The species is extremely similar in appearance to the red-banded hairstreak (Calycopis cecrops), and the two are sometimes treated as conspecific due to their close morphological resemblance.
Jonah crab
Cancer borealis, commonly known as the Jonah crab, is a marine brachyuran crab native to the western Atlantic Ocean. It inhabits waters from Newfoundland to Florida, primarily in rocky marine environments. The species possesses a rounded, rough-edged carapace with small light spots and robust claws with dark brown-black tips. Males reach larger sizes than females, with maximum carapace widths of 222 mm versus approximately 150 mm. The Jonah crab has been extensively studied as a model organism for neurophysiology, particularly for its stomatogastric nervous system, which has contributed to understanding neural circuit function and neuromuscular control.
Red-bordered Metalmark
Caria ino, commonly known as the red-bordered metalmark, is a butterfly species in the family Riodinidae. It occurs in North America and has been documented in at least 2,113 iNaturalist observations. Two subspecies are recognized: Caria ino ino and Caria ino melicerta. The species was first described by Godman and Salvin in 1886.
Arctic Skipper
Carterocephalus mandan, commonly known as the Arctic Skipper, is a butterfly species in the family Hesperiidae. It is found in North America, with records from the Canadian provinces of Alberta, Manitoba, and Saskatchewan, as well as the U.S. state of Vermont. The species is closely related to Carterocephalus palaemon, the Chequered Skipper, which has been the subject of conservation translocation efforts in Britain.
Western Arctic Skipper
Carterocephalus skada, commonly known as the Western Arctic Skipper, is a species of butterfly in the family Hesperiidae. It belongs to the genus Carterocephalus, which includes several Arctic and subarctic skipper species. The species is part of a group of butterflies adapted to cooler climates and northern latitudes.
Fritzgaertner's Flat
Celaenorrhinus fritzgaertneri is a spread-wing skipper butterfly in the family Hesperiidae, originally described from Texas in 1880. The species occurs in Central America and North America, with two recognized subspecies: the nominate form and C. f. variegatus. It belongs to a genus of approximately 90 species distributed primarily in the Old World tropics, with this species representing one of the few New World members.
Holarctic Azures
Celastrina is a genus of small butterflies in the family Lycaenidae, commonly known as the Holarctic Azures. The genus is distributed across the Palearctic, Nearctic, Indomalayan, and Australasian realms. Species within this genus are typically associated with specific host plants, with larvae showing varying degrees of dietary specialization. Several species have been studied in detail for their ecological relationships, including facultative mutualisms with ants.
Asher's Blue
Celastrina asheri is a recently described butterfly species in the family Lycaenidae, formally recognized in 2022. It belongs to the taxonomically complex Celastrina genus, which has undergone significant revision. The species is known from observations primarily in western North America. As a newly described taxon, detailed natural history information remains limited.
Pacific Azure, Echo Azure, Western Azure
Celastrina echo echo, commonly known as the Pacific Azure, is a subspecies of small blue butterfly in the family Lycaenidae. It occurs in western North America, particularly in California and neighboring states. The subspecies is associated with specific host plants including California buckeye (Aesculus californica) and various Ceanothus species. Adults are active in spring, with flight timing varying by elevation and latitude.
Northwestern Azure
Celastrina echo nigrescens, the Northwestern Azure, is a subspecies of the western azure butterfly in the family Lycaenidae. It is currently recognized as a synonym of Celastrina ladon. The subspecies was described by J. Fletcher in 1903. Like other azure butterflies, it is associated with specific host plants including California buckeye (Aesculus californica).
lucia azure, northern azure, eastern spring azure, northern spring azure
Celastrina lucia is a small butterfly in the family Lycaenidae, commonly known as the northern azure or eastern spring azure. It was historically treated as a subspecies of C. ladon until taxonomic research in the 1990s established it as a distinct species. The butterfly occurs in eastern North America from the Maritimes south through the Appalachian Mountains to West Virginia. Adults are sexually dimorphic and active from April to July.
Common Streaky-Skipper
Celotes nessus, commonly known as the common streaky-skipper, is a small skipper butterfly in the family Hesperiidae. It occurs in the southwestern United States and northern Mexico, with occasional strays reaching farther north. The species is multivoltine, with adults active from spring through late summer. Larvae feed on mallow species, while adults visit flowers for nectar.
Mead's Wood-Nymph, Mead's Wood Nymph
Cercyonis meadii is a brush-footed butterfly in the family Nymphalidae, found in North America. First described by William Henry Edwards in 1872, it is one of several wood-nymph species in the genus Cercyonis. The species is distinguished from congeners by subtle morphological differences in wing pattern and size. Four subspecies are currently recognized, with the nominate subspecies C. m. meadii occurring across the core range.
Small Wood-Nymph, Dark Wood-Nymph
Cercyonis oetus is a brush-footed butterfly of western North America, commonly known as the Small Wood-Nymph or Dark Wood-Nymph. It is a medium-sized satyrine with a wingspan of 32–45 mm. Adults fly in a single generation from June to August. The species has four recognized subspecies distributed across its range.
Common Wood-Nymph, Wood-Nymph, Grayling, Blue-Eyed Grayling, Goggle Eye
Cercyonis pegala is a widespread North American satyrine butterfly commonly known as the Common Wood-Nymph. It occupies diverse open habitats including grasslands, meadows, and woodland edges across much of the continent. The species exhibits notable variation in wing pattern across its range, with coastal and interior populations showing consistent differences in eyespot size and number. Unlike some congeners, it remains common and broadly distributed, though habitat loss affects local populations.
leafwings, leafwing butterflies
Charaxinae is a subfamily of approximately 400 species of nymphalid butterflies commonly known as leafwings. They are primarily tropical in distribution, with some species extending into temperate regions of North America, Europe, China, and southern Australia. Adults are robust, fast-flying butterflies that frequently feed on non-floral liquid sources including carrion, dung, and rotting fruit. The subfamily exhibits substantial morphological diversity across its constituent tribes.
Chiomara is a genus of skipper butterflies (family Hesperiidae) established by Godman and Salvin in 1899. The genus belongs to the subfamily Pyrginae, commonly known as the spread-winged skippers. Species in this genus are found in the Neotropical region.
Amethyst Hairstreak, Maesites Hairstreak, Verde Azul Hairstreak
Chlorostrymon maesites, commonly known as the Amethyst Hairstreak, is a species of hairstreak butterfly in the family Lycaenidae. It is found in the Caribbean and North America. The species was originally described as Thecla maesites by Herrich-Schäffer in 1864 and is now classified under the genus Chlorostrymon.
Patches and Allies, checkerspots, patches, crescentspots
Chlosyne is a genus of brush-footed butterflies (family Nymphalidae) distributed across North and South America. The genus includes approximately 25-30 species commonly known as patches, checkerspots, and crescentspots based on their wing patterns. Species in this genus exhibit diverse ecological strategies, with larvae of many species feeding gregariously in early instars—a trait that has been shown to enhance growth rates and survival in studied species such as C. lacinia and C. janais. Adults typically display orange, black, and white checkered wing patterns that vary considerably among species and geographic regions.
Sagebrush Checkerspot
Chlosyne acastus, the sagebrush checkerspot, is a butterfly in the family Nymphalidae native to western North America. Adults have a wingspan of 33–44 mm and display the characteristic orange and black checkered pattern typical of the genus. The species has one flight period annually, with adults active from May through early September. Larvae feed on specific Asteraceae host plants, with documented utilization of rabbit-brush, desert-aster, woolly sunflower, arrowleaf balsamroot, and common sunflower.
Rockslide Checkerspot
Chlosyne damoetas, commonly known as the Rockslide Checkerspot, is a butterfly species in the family Nymphalidae. It is native to western North America, where it inhabits rocky and montane environments. The species was originally described by Skinner in 1902 under the basionym Melitaea damoetas.
Definite Patch, Definite Checkerspot
Chlosyne definita, commonly known as the Definite Patch or Definite Checkerspot, is a butterfly species in the family Nymphalidae. It is native to North America and belongs to the checkerspot group within the genus Chlosyne. The species was first described by Aaron in 1885, originally placed in the genus Melitaea. Two subspecies are recognized: C. d. definita and C. d. anastasia.
Banded Checkerspot, Banded Patch
Chlosyne endeis, commonly known as the banded checkerspot or banded patch, is a species of butterfly in the family Nymphalidae. It belongs to the tribe Melitaeini, which includes crescents, checkerspots, and anglewings. The species was first described by Godman and Salvin in 1894. Two subspecies are recognized: Chlosyne endeis endeis and Chlosyne endeis pardelina.
Eumeda Checkerspot
Chlosyne eumeda is a checkerspot butterfly in the family Nymphalidae, described by Godman and Salvin in 1894. It is primarily found in Mexico, with rare strays occasionally reaching southern Arizona and southern Texas. The species belongs to a genus of brush-footed butterflies known for their distinctive checkered wing patterns.
Fulvia checkerspot
Chlosyne fulvia, the Fulvia checkerspot, is a butterfly in the family Nymphalidae. The species ranges from the southwestern United States (Kansas, Colorado, southern Utah, Arizona) south to central Mexico. Adults have a wingspan of 32–50 mm and feed on flower nectar. The larvae are specialized feeders on Castilleja species, particularly Castillega integra and Castilleja lanata.
Gabb's Checkerspot
Chlosyne gabbii is a rare checkerspot butterfly endemic to California. Adults have a wingspan of 32–45 mm with bright orange-brown and black checkered uppersides; females are lighter than males. The species is threatened throughout its range and is known from only a small geographic area in the western United States.
Harris's checkerspot
Chlosyne harrisii, or Harris's checkerspot, is a North American butterfly in the family Nymphalidae. It is a Batesian mimic of the unpalatable Baltimore checkerspot (Euphydryas phaeton), sharing similar orange and black checkered wing patterns. The species has a single flight period in early summer and is closely associated with wet meadow habitats where its host plant, flat-topped white aster (Aster umbellatus), grows. It is listed as a species of special concern and believed extirpated in Connecticut.
crimson patch, janais patch
Chlosyne janais is a common New World butterfly in the family Nymphalidae, known as the crimson patch or janais patch. It ranges from Colombia north through Central America and Mexico to southern Texas, with occasional sightings extending into northern Texas and southeastern Mexico. The species inhabits lowland tropical to subtropical forest edges, fields, and riparian areas. Adults feed on flower nectar, while larvae feed gregariously on acanthus shrubs, particularly Anisacanthus wrightii and Odontonema callistachyus. Reproduction is continuous in the tropics; in temperate areas, multiple broods occur from July to November.
Leanira Checkerspot
Chlosyne leanira, commonly known as the Leanira Checkerspot, is a butterfly in the family Nymphalidae, tribe Melitaeini. It occurs in western North America from Oregon through California, Nevada, Utah, western Colorado, and south to Baja California. The species exhibits sexual dimorphism in size and coloration, with females larger but males displaying more prominent red wing markings. Larvae are specialized feeders on Castilleja species (Orobanchaceae) and overwinter in the third instar.
Red-spotted Patch
Chlosyne melitaeoides, commonly known as the red-spotted patch, is a butterfly species in the family Nymphalidae. It belongs to a group that includes crescents, checkerspots, and anglewings. The species was originally described by Felder & Felder in 1867 under the basionym Synchloe melitaeoides. It carries the MONA/Hodges number 4501.1.
Silvery Checkerspot
Chlosyne nycteis, the silvery checkerspot, is a North American brush-footed butterfly in the family Nymphalidae. Adults display pale yellow-orange wings with dark borders and distinctive white-centered submarginal spots on the hindwings. The species inhabits moist areas including streamsides, meadows, and forest openings across a broad range from southern Canada to Georgia, Florida, and Texas. It has declined in parts of its northeastern range and is listed as a species of special concern in Connecticut and Maine, believed extirpated from Connecticut, Massachusetts, and New Hampshire.
Northern Checkerspot
Chlosyne palla, the northern checkerspot, is a North American butterfly in the family Nymphalidae. Adults have a wingspan of 30–48 mm and display a distinctive checkered pattern of dark brown, light orange, and tan on the upperside, with alternating red and yellow cells on the underside. The species has one flight period annually, occurring from April to July depending on elevation and latitude. Caterpillars feed on goldenrod, rabbitbrush, and asters.
High Sierra Checkerspot
Chlosyne palla altasierra is a subspecies of checkerspot butterfly in the family Nymphalidae, described by Emmel, Emmel & Mattoon in 1998. It is known by the common name High Sierra Checkerspot. The subspecies is recognized as valid and accepted in taxonomic databases. As a member of the genus Chlosyne, it belongs to a group of butterflies commonly known as crescents and checkerspots, which are characterized by their orange and black patterned wings.
Calydon Checkerspot
Chlosyne palla calydon is a subspecies of checkerspot butterfly in the family Nymphalidae, commonly known as the Calydon Checkerspot. It belongs to a group of brush-footed butterflies characterized by orange and black checkered wing patterns. The subspecies was described by W. Holland in 1931. Records indicate its presence in North America.
Rosita Patch
Chlosyne rosita is a butterfly species in the family Nymphalidae, characterized by distinctive orange-red patches on the wings. It occurs throughout Central America and Mexico, with occasional records in the southwestern United States. The species is similar in appearance to the more widespread crimson patch (Chlosyne janais).
Theona Checkerspot
Chlosyne theona, commonly known as the Theona Checkerspot, is a species of brush-footed butterfly in the family Nymphalidae. It is native to North America and has been recorded in Hawaii. The species is part of the checkerspot group within the genus Chlosyne, which includes several similar-looking species with patterned orange and black wing markings. The MONA or Hodges number for this species is 4508.
Arizona skipper
Codatractus arizonensis, commonly known as the Arizona skipper, is a species of dicot skipper butterfly in the family Hesperiidae. The species was first described by Skinner in 1905, originally as a subspecies of Heteropia melon. It is distributed across North America and Central America. As a member of the Pyrginae subfamily, it belongs to a group of skippers characterized by their rapid, darting flight patterns and association with dicotyledonous host plants.