Lycaenidae
Guides
Chlorostrymon
hairstreaks
Chlorostrymon is a genus of hairstreak butterflies in the family Lycaenidae, established by Clench in 1961. The genus comprises six recognized species distributed across the Nearctic and Neotropical realms, including the well-known silver-banded hairstreak (C. simaethis). Species within this genus are characterized by their association with the hairstreak tribe Eumaeini.
Chlorostrymon maesites
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.
Chlorostrymon simaethis
silver-banded hairstreak, St. Christopher's hairstreak, Key lime hairstreak
Chlorostrymon simaethis is a small lycaenid butterfly distributed across the southern United States, Mexico, Central America, and South America. The species exhibits strong sexual dimorphism in wing coloration, with males displaying iridescent purple uppersides and females appearing grayish brown. The common name refers to the distinctive bright silvery-white postmedian band on the lime green underside of both wings. The butterfly is closely associated with its host plants in the genus Cardiospermum, where larvae develop inside seed pods.
Chlorostrymon simaethis sarita
Sarita Hairstreak
Chlorostrymon simaethis sarita is a subspecies of hairstreak butterfly in the family Lycaenidae, historically described from Baja California. It is currently treated as a synonym under Chlorostrymon simaethis, though some sources maintain it as a valid subspecies. The name honors its type locality and has been subject to taxonomic revision.
Cupido
Tailed-Blues
Cupido is a genus of small butterflies in the family Lycaenidae, commonly known as Tailed-Blues. The genus is confined to the Palearctic region and includes species characterized by short tail-like projections on the hindwings. Members of this genus are typically associated with grassland and open habitats, with larvae feeding on various leguminous plants. The genus has been subject to taxonomic revision, with the subgenus Everes sometimes included within Cupido.
Cupido amyntula
Western Tailed-Blue
Cupido amyntula, commonly known as the Western Tailed-Blue, is a small butterfly in the family Lycaenidae found across western North America. Males display blue upperside wing coloration while females are darker brown with a brown band on the outer wing. The species has a wingspan of 2.2 to 2.9 cm and is distinguished from similar species by the presence of tail-like projections on the hindwings.
Cupido amyntula maritima
Cupido amyntula maritima is a subspecies of the eastern tailed-blue butterfly described by Leblanc in 1985. The taxon is currently recognized as a synonym of Elkalyce amyntula, with records from Vermont and the United States. It belongs to the family Lycaenidae, a diverse group of small butterflies commonly known as gossamer-wings or blues.
Cupido comyntas
Eastern Tailed-Blue, Eastern Tailed Blue
Cupido comyntas, commonly known as the eastern tailed-blue, is a medium-sized butterfly native to eastern North America. It is distinguished from other blue butterflies in its range by the presence of a small thin tail on each hindwing. The species has been observed in laboratory settings by researchers studying butterfly ecology and pesticide toxicology, and is considered a favorite among some entomologists due to its accessibility for study.
Cyanophrys miserabilis
Clench's greenstreak, miserabilis hairstreak
Cyanophrys miserabilis is a species of hairstreak butterfly in the family Lycaenidae. It was originally described as Thecla miserabilis by Clench in 1946. The species is known from North America, where it is one of several greenstreak butterflies in the genus Cyanophrys. It is assigned MONA/Hodges number 4308.
Cyclargus
A genus of lycaenid butterflies established by Vladimir Nabokov in 1945, split from the genus Hemiargus. The genus contains several species distributed across the Caribbean and southern Florida, including the critically endangered Miami blue butterfly (C. thomasi bethunebakeri). Taxonomic validity remains debated among lepidopterists.
Cyclargus ammon
Nickerbean Blue, Lucas' Blue
Cyclargus ammon is a species of blue butterfly in the family Lycaenidae. Commonly known as the Nickerbean Blue or Lucas' Blue, it occurs in the Caribbean and North America. The species was originally described by Lucas in 1856 as Lycaena ammon and later transferred to the genus Cyclargus. It is one of approximately 74 observed species in the genus on iNaturalist.
Cyclargus thomasi
Miami blue, Caribbean blue, Thomas's blue
Cyclargus thomasi is a small blue butterfly in the family Lycaenidae with a disjunct distribution across the Caribbean, Florida, and parts of North America. The subspecies C. t. bethunebakeri, known as the Miami blue, is endemic to Florida and was federally listed as endangered in 2012. This subspecies has declined dramatically due to habitat loss and now persists primarily in the Florida Keys. The species exhibits myrmecophilous relationships with ants, particularly Florida carpenter ants, which protect caterpillars in exchange for sugary secretions.
Echinargus
Reakirt's blue
Echinargus is a monotypic butterfly genus in the family Lycaenidae, containing the single species Echinargus isola (Reakirt's blue). The genus was described by Vladimir Nabokov in 1945. The species is notable for its extensive migratory behavior, regularly moving northward from its core range in Central America and the southern United States into northern regions.
Electrostrymon guzanta
Electrostrymon guzanta is a neotropical hairstreak butterfly in the family Lycaenidae. The species occurs in Central and northern South America, where adults inhabit forested environments. Like other members of the genus, it exhibits the characteristic tail-like hindwing extensions typical of hairstreaks. The species was originally described by William Chapman Hewitson in 1877 under the genus Thecla.
Electrostrymon hugon
Ruddy Hairstreak
Electrostrymon hugon, commonly known as the Ruddy Hairstreak, is a species of butterfly in the family Lycaenidae. The species was described by Godart in 1824 based on a specimen from Haiti. It is currently treated as a synonym of Electrostrymon endymion by GBIF, though it remains recognized as a distinct species by other sources including NCBI and iNaturalist. The species is part of the hairstreak group within the Lycaenidae, characterized by small size and often intricate wing patterns.
Erora laeta
Early Hairstreak
Erora laeta, commonly known as the early hairstreak, is a small butterfly in the family Lycaenidae. It occurs in deciduous and mixed woodlands of eastern North America. The species is notable for its early spring emergence and specialized association with American beech as a larval host. Adults have a wingspan of 21–24 mm.
Erora quaderna
Arizona hairstreak
Erora quaderna, commonly known as the Arizona hairstreak, is a butterfly species in the family Lycaenidae. It is native to North America. The species was first described by William Chapman Hewitson in 1868 under the basionym Thecla quaderna. Two subspecies are recognized: E. q. quaderna and E. q. sanfordi.
Eumaeini
hairstreaks, elfin butterflies
Eumaeini is a diverse tribe of gossamer-winged butterflies (family Lycaenidae), typically placed in the subfamily Theclinae but sometimes treated as a separate subfamily Eumaeinae. The tribe contains over 1,000 described species, predominantly distributed in the Neotropical realm, with some representatives extending into the Nearctic region and isolated occurrences in the Palearctic. Members are commonly known as hairstreaks or elfin butterflies, characterized by often intricate wing patterns and, in many species, thin tail-like projections on the hindwings. The group has been subject to extensive taxonomic revision due to high species diversity and morphological complexity.
Eumaeus
Cycadians
Eumaeus is a genus of lycaenid butterflies commonly known as cycadians, characterized by their striking coloration and obligate association with cycad host plants. Members of this genus are specialist herbivores that sequester neurotoxic compounds from their hosts, rendering them chemically defended against predators. Several species have experienced severe population declines due to overharvesting and habitat destruction of their cycad hosts, followed by remarkable recoveries linked to urban ornamental plantings. The genus represents a notable example of reconciliation ecology, where conservation success has been achieved through human-modified landscapes.
Eumaeus atala
Atala, Atala butterfly, Atala hairstreak, coontie hairstreak
The Atala butterfly is a small, colorful lycaenid butterfly unique within its range for its aposematic coloration and exclusive association with cycad host plants. Once considered the most conspicuous insect in South Florida in 1888, it was believed extinct by the 1950s due to overharvesting of its sole native host plant, coontie (Zamia integrifolia), for starch production. Rediscovered in 1979 on a Miami barrier island, the species has recovered dramatically through conservation efforts and the popularity of coontie as an ornamental landscape plant, becoming common enough in southeast Florida to occasionally be regarded as a pest. The butterfly sequesters toxic cycasin compounds from its host, rendering all life stages unpalatable to predators.
butterflyhairstreakLycaenidaecycadcoontieZamiaaposematic-colorationchemical-defenseconservationendangered-species-recoveryFlorida-endemicpine-rocklandhost-plant-specialistsequestrationurban-wildlifeornamental-pestfreeze-dried-dietex-situ-conservationreintroductionfire-dependent-ecosystemnative-plant-landscapingcycasin-toxicitymultivoltineterritorial-malescorematasound-producing-pupaeEuphilotes ancilla
Rocky Mountain dotted blue, Ancilla Blue
Euphilotes ancilla, commonly known as the Rocky Mountain dotted blue or Ancilla Blue, is a small butterfly in the family Lycaenidae. First described by Barnes and McDunnough in 1918, it inhabits sun-exposed rocky slopes and flats in western North America. The species has a documented wingspan of 17–23 mm and exhibits a close ecological relationship with Eriogonum host plants.
Euphilotes battoides
square-spotted blue, buckwheat blue
Euphilotes battoides is a small butterfly in the family Lycaenidae, commonly known as the square-spotted blue or buckwheat blue. It is native to western North America and exhibits strong ecological dependence on Eriogonum (buckwheat) species. The species comprises multiple recognized subspecies with restricted geographic ranges. Adults are active from spring through summer and feed primarily on buckwheat flower nectar.
Euphilotes battoides allyni
El Segundo Blue Butterfly
Euphilotes battoides allyni is a federally endangered subspecies of blue butterfly endemic to coastal sand dunes in southwestern Los Angeles County, California. The subspecies has an extremely restricted range, historically occurring only between El Segundo and San Pedro. It is one of the most geographically localized butterfly taxa in North America, with all known populations confined to areas supporting its obligate larval host plant, Eriogonum parvifolium (coastal buckwheat).
Euphilotes bernardino
Bernardino blue
Euphilotes bernardino, the Bernardino blue, is a small lycaenid butterfly native to western North America. The species was first described by Barnes and McDunnough in 1916. It occurs in montane habitats, particularly in the San Bernardino Mountains of southern California, though the full extent of its range extends more broadly across North America. The species comprises four recognized subspecies with varying geographic distributions.
Euphilotes columbiae
Columbian Blue
Euphilotes columbiae is a butterfly species in the family Lycaenidae, commonly known as the Columbian Blue. It is currently treated as a synonym of Euphilotes enoptes. The species was described by Mattoni in 1954. Like other members of the genus Euphilotes, it belongs to a group of small butterflies commonly referred to as 'blue' butterflies due to their characteristic wing coloration.
Euphilotes enoptes
dotted blue
Euphilotes enoptes, commonly known as the dotted blue, is a North American lycaenid butterfly in the subfamily Polyommatinae. The species comprises multiple described subspecies, including the federally endangered E. e. smithi, which has been the focus of conservation efforts in California. Subspecies vary in distribution and habitat associations across western North America.
Euphilotes enoptes enoptes
dotted blue
Euphilotes enoptes enoptes is the nominate subspecies of the dotted blue butterfly, a small lycaenid found in western North America. It belongs to a species complex with localized, patchy distributions tied to specific host plant communities. The subspecies is less studied than its federally endangered relative E. e. smithi, with most ecological research focusing on that coastal California population.
Euphilotes glaucon
Glaucon Blue
Euphilotes glaucon is a species of butterfly in the family Lycaenidae, commonly known as the Glaucon Blue. It is currently treated as a synonym of Euphilotes battoides (square-spotted blue or buckwheat blue) by some authorities. The species occurs in western North America and is associated with buckwheat plants as larval hosts.
Euphilotes mojave mojave
Mojave Blue
Euphilotes mojave mojave, commonly known as the Mojave Blue, is a subspecies of blue butterfly in the family Lycaenidae. It is native to North America and is part of the Euphilotes genus, which includes several species of dotted blue butterflies. The subspecies is associated with arid habitats in the Mojave Desert region.
Euphilotes pallescens
Pallid Blue, Pale Blue, Pallid Dotted Blue
Euphilotes pallescens is a small lycaenid butterfly endemic to the Great Basin region of western North America. Populations exhibit significant genetic and morphological differentiation among isolated mountain ranges, reflecting long-term isolation in sky-island habitats. The species has a complex evolutionary history involving periods of divergence and potential reticulation. Its restricted distribution and habitat specificity make it a valuable model for studying phylogeography in arid mountain systems.
Euphilotes pallescens calneva
Honey Lake Blue
Euphilotes pallescens calneva is a subspecies of butterfly in the family Lycaenidae, commonly known as the Honey Lake Blue. It was described by John and Thomas Emmel in 1998. As a member of the genus Euphilotes, it belongs to a group of small butterflies commonly called 'blue' butterflies, though specific details about this particular subspecies remain limited in available sources.
Euphilotes rita
Rita's Blue, rita blue, desert buckwheat blue
Euphilotes rita is a small lycaenid butterfly native to the southwestern United States and northern Mexico. Adults are active from July through late September, with a single generation per year. The species exhibits strong ecological specialization on wild buckwheat (Eriogonum species) throughout its life cycle. Larvae are tended by ants, a characteristic mutualism within the Polyommatinae.
Glaucopsyche lygdamus
silvery blue
Glaucopsyche lygdamus, the silvery blue, is a small butterfly native to North America. It exhibits sexual dimorphism in wing coloration, with males displaying light blue uppersides and females showing dull grayish blue. The species occupies diverse habitats across western North America and Canada, and has demonstrated significant range expansion in some regions. Multiple subspecies have been described, reflecting geographic variation in morphology and ecology.
Habrodais
Habrodais is a genus of small butterflies in the family Lycaenidae, containing two species restricted to western North America. The genus was established by Scudder in 1876. Both species are associated with oak woodlands and have specialized ecological relationships with their host plants.
Habrodais grunus
Golden Hairstreak
The golden hairstreak is a small North American butterfly in the family Lycaenidae. It is strongly associated with oak habitats and displays unusual crepuscular activity patterns, being most active during dawn and dusk rather than midday. The species has a single annual generation and shows high fidelity to specific oak host plants for larval development.
Hemiargus
blues, blue butterflies
Hemiargus is a genus of small butterflies in the family Lycaenidae, commonly known as blues, found in North and South America. The genus contains approximately five recognized species, including the widespread Ceraunus blue (Hemiargus ceraunus) and Reakirt's blue (Hemiargus isola). These butterflies inhabit open, sunny environments and are characterized by their blue or grayish upper wing surfaces with variable spotting patterns. Some species engage in facultative mutualistic associations with ants during their larval stage, where caterpillars produce secretions that attract ant attendants who provide protection against predators.
Hemiargus ceraunus antibubastus
Florida Blue
Hemiargus ceraunus antibubastus, commonly known as the Florida Blue, is a butterfly subspecies in the family Lycaenidae. It is one of several subspecies of the Ceraunus blue, found primarily in Florida and the Florida Keys. The subspecies occurs in open habitats including coastal areas, scrub, and disturbed sites. Adults are active during warmer months and are associated with various legume host plants.
Hypaurotis
Hypaurotis is a monotypic genus of hairstreak butterflies in the family Lycaenidae. The sole species, Hypaurotis crysalus (Colorado Hairstreak), is endemic to montane oak scrublands of the southwestern United States and adjacent northern Mexico. The genus was erected by Scudder in 1876 based on specimens from Colorado.
Kisutam
Kisutam is a genus of butterflies in the family Lycaenidae, established by Johnson & Kroenlein in 1993. The genus is part of the diverse hairstreak butterfly lineage. Species in this genus are found in the Neotropical region.
Leptotes
Zebra Blues
Leptotes is a genus of small butterflies in the family Lycaenidae, commonly known as zebra blues due to their distinctive zebra-striped undersides. The genus contains multiple species distributed across tropical and subtropical regions including the Americas, Africa, Europe, the Middle East, southern and eastern Asia, and eastern Australia. Several endemic species occur on oceanic islands including the Galapagos, Canary Islands, Mauritius, Príncipe, and São Tomé. Leptotes species are myrmecophilous, meaning they have associations with ants, though research suggests ant partners play a minor role in their occurrence on host plants.
Leptotes cassius
Cassius blue, tropical striped blue
Leptotes cassius is a small, strikingly blue butterfly in the family Lycaenidae, distributed across the southern United States, Caribbean, Mexico, Central America, and South America. The species exhibits facultative myrmecophily, with larvae tended by Camponotus ants, though ant presence does not significantly influence oviposition decisions. Caterpillars are florivorous, developing inside flower buds of leguminous host plants. Multiple subspecies are recognized, with L. c. theonus serving as the type species of the genus Leptotes.
Lycaena cupreus
Lustrous Copper
Lycaena cupreus, commonly known as the Lustrous Copper, is a butterfly species in the family Lycaenidae native to the western mountains of North America. The species was first described by Edwards in 1870 under the basionym Chrysophanus cupreus. It belongs to a genus of copper butterflies that are frequently used as indicators of environmental change and habitat quality. The Lustrous Copper is part of the diverse Lycaena genus, which includes species showing varying population trends in response to climate change and land use pressures.
Lycaena dorcas castro
A subspecies of copper butterfly in the family Lycaenidae. Originally described by Reakirt in 1866 under the name Lycaena dorcas castro, this taxon is now treated as a synonym of Epidemia dorcas. The name reflects 19th-century North American lepidopteran taxonomy.
Lycaena dorcas claytoni
Clayton's Copper
Lycaena dorcas claytoni is a subspecies of copper butterfly in the family Lycaenidae. It belongs to the dorcas copper complex, a group of closely related taxa distributed across North America. The subspecies was described by A.E. Brower in 1940. Like other members of the genus Epidemia (formerly placed in Lycaena), this taxon is associated with wetland habitats and larval host plants in the genus Polygonum.
Lycaena dorcas dorcas
Lycaena dorcas dorcas is a subspecies of copper butterfly in the family Lycaenidae. The species is currently classified under the genus Epidemia, though historically treated under Lycaena. The subspecies is part of a taxon with a complex taxonomic history involving multiple genus-level reassignments.
Lycaena heteronea
blue copper
Lycaena heteronea, the blue copper, is a North American butterfly in the family Lycaenidae. Males display bright sky-blue upper wing surfaces with dark veins, while females are copper-brown with black dots. The species is tightly associated with Eriogonum (buckwheat) host plants and occupies a range of open habitats in western North America from British Columbia to New Mexico. It is single-brooded with flight seasons varying geographically from April through August.
Lycaena nivalis
lilac-bordered copper, nivalis copper
Lycaena nivalis is a small butterfly in the family Lycaenidae, known as the lilac-bordered copper or nivalis copper. It inhabits the western mountains of North America. Adults are active during mid-summer, with a flight period from July to mid-August. The species has a wingspan of 25–29 mm. Two subspecies are recognized: L. n. nivalis and L. n. browni.
Lycaena phlaeas
small copper, American copper, common copper
Lycaena phlaeas is a holarctic butterfly in the family Lycaenidae, commonly known as the small copper or American copper. It is widespread across Europe, Asia, North America, and North Africa. The species is notable for its bright orange forewings with dark borders and black spots. It has been identified as a generalist species that shows resilience to habitat degradation, with populations in Germany demonstrating a positive trend in the Grassland Butterfly Index despite overall declines in grassland butterfly populations.
Lycaena rubida
Ruddy Copper
Lycaena rubida, the Ruddy Copper, is a North American butterfly species in the family Lycaenidae. It belongs to a genus whose members are commonly known as coppers, characterized by orange-copper coloration on the upper wing surfaces. The species inhabits western North America, where it is associated with grassland and open habitats. Like other Lycaena species, it has been affected by broader population declines documented across western North American butterfly faunas.
Lycaena rubida ferrisi
Ferris's Ruddy Copper
Lycaena rubida ferrisi is a subspecies of the Ruddy Copper butterfly, a member of the family Lycaenidae. As a subspecies of Lycaena rubida, it belongs to a group of copper butterflies characterized by orange-copper coloration on the upper wing surfaces. The subspecies epithet 'ferrisi' honors entomologist Gordon Ferris. Specific details distinguishing this subspecies from the nominate form are not well-documented in the provided sources.