Lycaenidae
Guides
Allosmaitia strophius
Strophius Hairstreak
Allosmaitia strophius, the Strophius Hairstreak, is a small Neotropical hairstreak butterfly in the family Lycaenidae. It ranges from southern Brazil northward through Central America to Sinaloa, Mexico, with occasional strays reaching Texas. Adults are active year-round in Central America, with Texas records limited to November. The species has a wingspan of 22–32 mm.
Arawacus
stripe-streaks, stripestreaks
Arawacus is a genus of gossamer-wing butterflies in the family Lycaenidae, commonly known as stripe-streaks. The genus contains approximately 17 described species distributed throughout the Neotropical realm, from Mexico south through Central America to Brazil, Peru, and Argentina. Members of this genus are notable for their distinctive false-head defensive morphology on the hindwings, which helps misdirect predator attacks away from vital body parts.
Atlides
Great Purple Hairstreak (for A. halesus)
Atlides is a genus of gossamer-winged butterflies in the family Lycaenidae, subfamily Theclinae, tribe Eumaeini. The genus contains approximately 18 named species plus 5 or more undescribed species distributed across the Americas from the southern United States to Argentina. The most well-known species, Atlides halesus (great purple hairstreak), is notable for its iridescent blue coloration—despite its common name containing "purple"—and its exclusive larval association with mistletoe species (Phoradendron). Males of at least some species possess androconial scales producing distinctive volatile compounds; A. polybe males emit a grape-like aroma from methyl anthranilate, the first such compound reported in Papilionoidea.
Atlides halesus
Great Purple Hairstreak, Great Blue Hairstreak
Atlides halesus is a striking gossamer-winged butterfly in the family Lycaenidae, notable for its misnomer of a common name—despite being called the "Great Purple Hairstreak," it displays iridescent blue coloration rather than purple. This Neotropical species ranges from warm-temperate and subtropical North America southward nearly to the Isthmus of Panama. The larvae feed exclusively on mistletoe species (Phoradendron spp.), making this butterfly dependent on the presence of these parasitic plants. Adults are known for hilltopping behavior, where males defend perches on elevated terrain to intercept females.
Brephidium
pygmy blues
Brephidium is a genus of butterflies in the family Lycaenidae, commonly known as pygmy blues. The genus contains three species with a striking disjunct distribution: two species occur in the Americas (Brephidium exilis and Brephidium pseudofea), while the third (Brephidium metophis) is found in southern Africa. These are among the smallest butterflies in the world, with Brephidium exilis being the smallest butterfly in North America.
Brephidium exilis
Western Pygmy Blue, Pygmy Blue
Brephidium exilis, commonly known as the Western Pygmy Blue, is the smallest butterfly species in North America. Despite its diminutive size, it is widespread and relatively common across its range, though often overlooked due to its minute stature. The species belongs to the family Lycaenidae (gossamer-winged butterflies) and is recognized as a synonym of Brephidium exile.
Brephidium pseudofea
Eastern Pygmy-Blue
Brephidium pseudofea, commonly known as the Eastern Pygmy-Blue, is one of the smallest butterflies in North America. It belongs to the family Lycaenidae and is closely related to the Western Pygmy-Blue (Brephidium exilis), from which it can be distinguished by distribution and subtle morphological differences. The species is associated with coastal and salt marsh habitats in the eastern United States.
Callophrys affinis
Western Green Hairstreak, Immaculate Green Hairstreak
Callophrys affinis is a small butterfly in the family Lycaenidae, commonly known as the western green hairstreak or immaculate green hairstreak. It is found in western North America from western Canada through the western United States. Adults fly in a single generation from early spring to mid-summer. The larvae feed specifically on Eriogonum umbellatum.
Callophrys affinis affinis
Western Green Hairstreak, Immaculate Green Hairstreak
Callophrys affinis affinis, the western green hairstreak, is a subspecies of butterfly in the family Lycaenidae. It occurs in western North America, where adults have been observed in early summer. The subspecies is distinguished by its greenish wing coloration, typical of the green hairstreak group. Limited specific information exists for this subspecies separate from the broader species Callophrys affinis.
Callophrys affinis apama
Western Green Hairstreak
Callophrys affinis apama is a subspecies of the western green hairstreak butterfly, a small lycaenid found in western North America. It is one of several subspecies within the C. affinis complex, which shows geographic variation across its range. The species is associated with open habitats where its larval host plants grow. Adults are active in spring and early summer, with a rapid, low flight pattern typical of hairstreak butterflies.
Callophrys affinis homoperplexa
Western Green Hairstreak
Callophrys affinis homoperplexa is a subspecies of the western green hairstreak butterfly, a member of the gossamer-winged family Lycaenidae. It occurs in western North America, where adults are active during spring and early summer. The subspecies is distinguished from related populations by subtle differences in wing pattern and coloration.
Callophrys dumetorum
Lotus Hairstreak, Bramble Hairstreak, Coastal Green Hairstreak, Bluish Green Hairstreak, Oregon Green Hairstreak (subspecies C. d. oregonensis)
Callophrys dumetorum is a small lycaenid butterfly found primarily in coastal California. The species exhibits striking sexual dimorphism in wing coloration, with vivid green ventral surfaces and subdued brown dorsal surfaces. Taxonomic history of this species has been complex, involving lectotype disputes and temporary replacement of the name C. dumetorum with C. perplexa before ICZN Opinion 2291 reverted the changes in 2012.
Callophrys dumetorum dumetorum
A subspecies of hairstreak butterfly in the family Lycaenidae, endemic to coastal California. It is one of at least two recognized subspecies within Callophrys dumetorum, with the nominate subspecies restricted to a narrower range than the species as a whole. The species is known by the common names bramble hairstreak or lotus hairstreak.
Callophrys gryneus castalis
Texas Hairstreak
Callophrys gryneus castalis is a subspecies of juniper hairstreak butterfly in the family Lycaenidae. It has been a subject of taxonomic debate regarding whether it warrants elevation to full species status based on mitochondrial DNA barcode divergence. The subspecies is associated with juniper and cedar habitats in parts of its range. Observations are relatively sparse, with limited documentation of its biology and ecology.
Callophrys gryneus gryneus
Olive Hairstreak, Juniper Hairstreak
Callophrys gryneus gryneus is a subspecies of the juniper hairstreak butterfly found in eastern North America. This small lycaenid butterfly is closely associated with juniper host plants, particularly species of Juniperus. The subspecific designation reflects geographic and phenotypic variation within the broader C. gryneus complex, which has been the subject of taxonomic debate regarding species boundaries. Adults are typically observed in spring and early summer.
Callophrys gryneus juniperaria
Cedar Hairstreak, Juniper Hairstreak, Olive Hairstreak
A subspecies of juniper hairstreak butterfly in the family Lycaenidae. The name 'juniperaria' reflects its close association with juniper host plants. This subspecies is part of the broader Callophrys gryneus species complex, which shows regional variation across North America. Based on source materials, it has been observed in Oklahoma and Kansas, typically in habitats where juniper or cedar species occur.
Callophrys gryneus loki
Juniper Hairstreak, Olive Hairstreak
Callophrys gryneus loki is a subspecies of juniper hairstreak butterfly historically recognized from parts of the central and southern United States. The name is currently treated as a synonym in GBIF, with specimens reclassified under the nominate form Callophrys gryneus. These butterflies are associated with juniper and cedar host plants. Adults have been observed nectaring on milkweeds and other flowering plants in prairie and open woodland habitats. The taxon represents part of a complex of similar hairstreaks whose taxonomy remains under revision.
Callophrys gryneus muiri
Muir's Hairstreak, Muir Juniper Hairstreak
A western North American subspecies of Juniper Hairstreak, historically treated as a distinct species (Callophrys muiri) based on phenotypic differences and geographic isolation. DNA barcoding studies indicate it is genetically divergent from other C. gryneus populations, though its taxonomic status remains debated. Associated with coniferous habitats in California.
Callophrys gryneus nelsoni
Nelson's Hairstreak, Nelson's Juniper Hairstreak
Callophrys gryneus nelsoni is a western North American subspecies of juniper hairstreak butterfly. Its taxonomic status has been debated, with some authorities treating it as a distinct subspecies while others have elevated it to full species rank as Mitoura nelsoni. DNA barcode studies indicate it is genetically divergent from other C. gryneus populations, though the magnitude of divergence is comparable to that seen between other recognized species in the genus. Adults are associated with juniper woodlands.
Callophrys gryneus plicataria
Cedar Hairstreak
Callophrys gryneus plicataria is a subspecies of juniper hairstreak butterfly in the family Lycaenidae. It is treated as a synonym of Mitoura gryneus in some taxonomic systems, reflecting ongoing debate about generic placement within the Eumaeini. The subspecies is associated with cedar and juniper habitats. Observations are concentrated in the northeastern United States, particularly Vermont.
Callophrys gryneus rosneri
Rosner's Hairstreak, Juniper Hairstreak
Callophrys gryneus rosneri is a subspecies of juniper hairstreak butterfly in the family Lycaenidae. It is currently recognized as a synonym of Mitoura gryneus in GBIF taxonomy, though iNaturalist maintains it as a distinct subspecies under Callophrys. The taxon was described by K. Johnson in 1976. Like other juniper hairstreaks, it is associated with juniper host plants.
Callophrys gryneus siva
Siva Juniper Hairstreak
Callophrys gryneus siva is a subspecies of juniper hairstreak butterfly in the family Lycaenidae, native to western North America. It is one of multiple named subspecies within the polytypic species C. gryneus, a group whose taxonomic boundaries have been debated based on mitochondrial DNA barcode analysis. The subspecies is associated with juniper host plants in arid and semi-arid habitats.
Callophrys gryneus smilacis
juniper hairstreak, olive hairstreak
Callophrys gryneus smilacis is a subspecies of juniper hairstreak butterfly in the family Lycaenidae. The subspecies is currently treated as a synonym of Mitoura gryneus in some taxonomic databases. Adults are associated with juniper and hackberry-bumelia-juniper woodland habitats. The species has been documented in Oklahoma and Vermont, with observations in late August. The taxonomic status of this subspecies remains unsettled, with conflicting treatments across sources.
Callophrys gryneus sweadneri
Sweadner's Juniper Hairstreak, juniper hairstreak, olive hairstreak
Callophrys gryneus sweadneri is a subspecies of juniper hairstreak butterfly in the family Lycaenidae. It occurs in North America and has been documented in Oklahoma and Kansas. Adults have been observed in late April and late August, suggesting a spring and late summer flight period. The subspecies is associated with juniper habitats, consistent with the species-level ecology of C. gryneus.
Callophrys gryneus thornei
Juniper Hairstreak, Thorne's Juniper Hairstreak
Callophrys gryneus thornei is a subspecies of juniper hairstreak butterfly in the family Lycaenidae. It is currently considered a synonym of Callophrys thornei. The species is associated with juniper habitats and has been documented in North America. Like other members of the gryneus complex, adults likely feed on nectar from various flowers and larvae feed on juniper species.
Callophrys henrici
Henry's elfin, woodland elfin
Callophrys henrici, commonly known as Henry's elfin or woodland elfin, is a small North American butterfly in the family Lycaenidae. The species exhibits distinct population groups with different host plant associations: Atlantic Coast populations feed on various hollies (Ilex species), while northern and Appalachian populations use redbud (Cercis canadensis). The species has shown recent range expansion in New England due to adoption of introduced common buckthorn (Rhamnus cathartica) as a host plant. It is listed as a species of special concern in Connecticut.
Callophrys irus
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
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.
Callophrys irus hadros
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.
Callophrys irus irus
Frosted Elfin
Callophrys irus irus is the nominate subspecies of the frosted elfin butterfly, a rare Lycaenid with a historical range spanning from Ontario to Florida and west to Texas and Wisconsin. Genetic studies have found no evidence that this subspecies is genetically distinct from other populations, including the historically recognized C. i. arsace. The species inhabits fire-maintained pine barren habitats and has experienced significant population declines due to habitat loss and fragmentation. Conservation efforts focus on managing habitat patch area and host plant abundance to improve occupancy probability.
Callophrys johnsoni
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.
Callophrys lanoraieensis
bog elfin
Callophrys lanoraieensis, the bog elfin, is a small North American butterfly in the family Lycaenidae. It is a habitat specialist restricted to peatland ecosystems dominated by black spruce and tamarack. The species has a limited distribution in the northeastern United States and eastern Canada, with isolated populations across its range. Its small size, dull brown coloration, and lack of hindwing tails distinguish it from related elfin species.
Callophrys mcfarlandi
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.
Callophrys niphon clarki
Callophrys niphon clarki is a subspecies of the eastern pine elfin butterfly, a member of the family Lycaenidae. The parent species, Callophrys niphon, is native to North America. This subspecies was described by T. Freeman in 1938. According to GBIF records, this name is currently treated as a synonym under the genus Incisalia as Incisalia niphon. Very few observations (4) of this subspecies have been recorded in iNaturalist, suggesting it is either rare, poorly surveyed, or taxonomically merged with related forms.
Callophrys polios
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.
Callophrys sheridanii
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.
Callophrys sheridanii lemberti
Lembert's Hairstreak
Lembert's Hairstreak is a subspecies of the Sheridan's Hairstreak butterfly, first described by Tilden in 1963. It is classified within the family Lycaenidae, commonly known as gossamer-winged butterflies. The subspecies is endemic to California and is associated with specific host plant relationships typical of hairstreak butterflies.
Callophrys spinetorum
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.
Callophrys xami
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.
Calycopis
groundstreaks, hairstreaks
Calycopis is a genus of small butterflies in the family Lycaenidae, commonly known as groundstreaks or hairstreaks. The genus contains numerous species distributed across the Neotropical and Nearctic realms. A controversial taxonomic revision by Kurt Johnson in 1991 proposed extensive splitting of the genus, but most modern authors reject these changes as unjustified. Species within Calycopis are typically associated with forest edges and disturbed habitats where their larval host plants occur.
Calycopis cecrops
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.
Calycopis isobeon
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.
Celastrina
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.
Celastrina asheri
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.
Celastrina echo cinerea
Southwestern Azure
Celastrina echo cinerea, the Southwestern Azure, is a subspecies of the echo azure butterfly in the family Lycaenidae. It is one of several subspecies within the Celastrina echo species complex, which is found across western North America. The species is known generally as the echo azure or western azure. Host plant associations include Aesculus californica (California buckeye) in the Bay Area region.
Celastrina echo echo
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.
Celastrina echo nigrescens
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).
Celastrina echo sidara
echo azure, western azure
Celastrina echo sidara is a subspecies of the echo azure butterfly, originally described by Clench in 1944. It belongs to the family Lycaenidae, commonly known as the gossamer-winged butterflies. The subspecies is currently treated as a synonym of Celastrina ladon in some taxonomic databases, reflecting ongoing taxonomic uncertainty within the Celastrina echo species complex. As a member of the Polyommatinae subfamily, it shares characteristics with other 'blue' butterflies.
Celastrina lucia
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.
Celastrina neglecta
Summer Azure
Celastrina neglecta, the summer azure, is a small North American butterfly in the family Lycaenidae. It is distinguished from similar Celastrina species by its late-season flight period, pale blue upper surface with extensive white scaling, and specific wing pattern details. The species has undergone taxonomic revision, previously treated as a synonym of C. argiolus lucia.