Types of Butterflies in Connecticut
Around 120 butterfly species have been recorded in Connecticut, a strong list for the third-smallest state, because it packs a rocky coast on Long Island Sound, the Connecticut River valley, trap-rock ridges and the cool Litchfield Hills into 5,500 square miles. Connecticut has no official state butterfly; its best-known species are the Monarch that streams along the shoreline every September, the Eastern Tiger Swallowtail, the Mourning Cloak that wakes on the first warm day of March, and the Baltimore Checkerspot of wet meadows. Brush-footed butterflies and skippers make up most of the list, and about a dozen southern species turn up only as late-summer strays.
On this page
- Butterflies found in Connecticut
- Butterflies of Connecticut at a glance
- Signature Connecticut butterflies
- The Connecticut butterfly calendar
- Where to see butterflies in Connecticut
- Host plants and butterfly gardening in Connecticut
- Rare and threatened butterflies in Connecticut
- How to identify butterflies in Connecticut
- Frequently asked questions
Butterflies of Connecticut at a glance
Connecticut is small, but it is not poor in butterflies. The statewide atlas fieldwork of the late 1990s and the records gathered since put the total at around 120 species, of which roughly 100 breed here every year; the rest are strays from the south or species that have not been seen for decades. The variety comes from the landscape: a salt-marsh and beach coast along Long Island Sound, the broad Connecticut River valley with its floodplain meadows, the trap-rock ridges of the Metacomet range, sandy pine barrens in the north-east, and the cooler hardwood hills of Litchfield County in the north-west, where northern species such as the Atlantis Fritillary and Compton Tortoiseshell reach their southern limit.
The brush-footed butterflies are the largest family on the list, from the fritillaries and checkerspots of open meadows to the anglewings and tortoiseshells that hibernate as adults. The skippers come next, led by a long run of dusky-brown duskywings that are hard to separate in the field, followed by the hairstreaks and elfins of the gossamer-winged family, the whites and sulphurs, seven swallowtails and a single metalmark.
Signature Connecticut butterflies
The Monarch is the butterfly most people in Connecticut know by name. It breeds on milkweed across the state from June, and in September the migrating generation funnels along the Long Island Sound shoreline, where beach plums and seaside goldenrod at Hammonasset and Milford Point can hold hundreds of butterflies on a good afternoon.
The Eastern Tiger Swallowtail is the largest resident, a yellow-and-black giant of woodland edges and lilac bushes from May to September; the Spicebush and Black Swallowtails share its gardens, and the Giant Swallowtail, once a rare stray, has bred in the Connecticut River valley on prickly-ash in several recent summers as its range creeps north.
The Mourning Cloak is the first butterfly of the year, often on the wing over snow in March after wintering as an adult under loose bark. In wet meadows with turtlehead, the Baltimore Checkerspot flies in late June and early July, its black wings bordered with orange crescents and dotted with cream. The Great Spangled Fritillary is the big orange butterfly on milkweed and thistle in July, and the tiny Pearl Crescent is on almost every roadside aster patch from May to October.
The Connecticut butterfly calendar
The season opens with the hibernators. Mourning Cloaks, Eastern Commas and Question Marks appear on the first days above 15 °C in March, weeks before anything emerges from a chrysalis; our guide to where butterflies go in winter explains how they survive a New England January. April brings the first fresh adults, Spring Azures over dogwood and the Brown Elfin in the pine barrens, and by early May the West Virginia White is flying in rich, moist woods with toothwort, followed by the Juvenal's and Sleepy Duskywings around the oaks.
June and July are the peak. Fritillaries, hairstreaks, the Baltimore Checkerspot, the Silver-spotted Skipper and the first summer brood of swallowtails all overlap, and the Banded, Striped and Edwards' Hairstreaks can be found on milkweed flowers in the same week. August belongs to the second broods and to immigrants: Red Admirals, Painted and American Ladies, Common Buckeyes and the Cloudless Sulphur push up from the south. September is Monarch month on the coast, and the last Clouded and Orange Sulphurs can still be seen over clover in a warm early November.
Where to see butterflies in Connecticut
Any sunny meadow with milkweed, thistle and goldenrod will produce twenty species on a July afternoon, but a few places are worth a special trip.
- Hammonasset Beach State Park, Madison — the state's best-known Monarch staging site in September, with Common Buckeyes, sulphurs and the occasional southern stray on the seaside goldenrod.
- Milford Point and the Stratford marshes — Broad-winged and Salt Marsh Skippers along the tidal creeks in summer, Monarchs in autumn.
- Talcott Mountain and the trap-rock ridges — Juniper Hairstreaks around red cedar on the dry summits, Falcate Orangetips and elfins in spring.
- Pachaug State Forest and the north-eastern pine barrens — Brown and Hoary Elfins, duskywings and the Edwards' Hairstreak on scrub oak.
- The Litchfield Hills — northern species such as the Atlantis Fritillary, Compton Tortoiseshell and Harris' Checkerspot in the wet meadows and beaver ponds.
Connecticut shares almost all of its butterflies with neighbouring Massachusetts and New York, and the coastal species with Rhode Island and Long Island.
Host plants and butterfly gardening in Connecticut
A Connecticut garden earns its butterflies with native host plants for the caterpillars rather than with nectar alone. Common milkweed and swamp milkweed feed Monarchs; dill, parsley and fennel bring the Black Swallowtail; spicebush and sassafras are the only foods of the Spicebush Swallowtail; black cherry and tulip tree raise Eastern Tiger Swallowtails; and a patch of stinging nettle in a sunny corner supports Red Admirals, Eastern Commas and Question Marks. Violets left in the lawn feed the fritillaries, turtlehead in a damp spot brings the Baltimore Checkerspot, and asters are used by Pearl Crescents in summer and by every migrant for nectar in September.
For nectar, plant in sequence: wild lupine and dame's rocket in May, milkweed and bee balm in July, Joe-Pye weed and ironweed in August, and goldenrod and New England aster for the Monarch flight in the autumn. Mow less often; the Clouded Sulphur, Little Wood-Satyr and most skippers breed in grass and clover that is cut only once a year.
Rare and threatened butterflies in Connecticut
The biggest loss is the Regal Fritillary. It once flew in coastal and river-valley grasslands across southern New England, but the last Connecticut records date from the early 1990s and the species is now considered extirpated from the state, as it is from the rest of New England. The Hessel's Hairstreak, tied to Atlantic white cedar swamps, and the Northern Metalmark, confined to a few limestone glades in the north-west, are both listed by the Connecticut Department of Energy and Environmental Protection, together with the Frosted Elfin of the pine barrens and several skippers of the shrinking sandplain grasslands.
Loss of open habitat is the common thread. Old fields that once held fritillaries and skippers have grown back to forest or been built over, and wet meadows have been drained. The Monarch is watched closely too: the eastern population that passes through Connecticut has fallen sharply since the 1990s, and the state's milkweed plantings along highways and in schoolyards are part of the response.
Butterflies found in Connecticut
72 species listed for Connecticut, grouped by family. Linked names have a full profile on this site with pictures of every life stage.
Brush-Footed (Nymphalidae)
Limenitis arthemisRed Spotted Purple (Limenitis arthemis)The red-spotted purple is a large, tailless North American brush-footed butterfly whose upperside shines iridescent blue-black, a pattern copied from 
Limenitis archippusViceroy (Limenitis archippus)The viceroy (Limenitis archippus) is an orange-and-black North American butterfly that looks like a small monarch but carries one extra black line cur
Asterocampa celtisHackberry Emperor (Asterocampa celtis)The hackberry emperor is a medium-sized tan and brown butterfly of eastern and central North America that never strays far from a hackberry tree, and 
Speyeria aphroditeAphrodite Fritillary (Speyeria aphrodite)The Aphrodite fritillary (Speyeria aphrodite) is a large orange-and-black butterfly of prairies, dry fields and open woodland across southern Canada a
Speyeria cybeleGreat Spangled Fritillary (Speyeria cybele)A big orange butterfly of summer meadows, the great spangled fritillary is named for the sheet of silver spangles on the underside of its hindwings.Speyeria idaliaRegal Fritillary (Speyeria idalia)Big, fast and unmistakable, the regal fritillary is the butterfly of the North American tallgrass prairie: orange forewings, near-black hindwings stud
Boloria bellonaMeadow Fritillary (Boloria bellona)The meadow fritillary is a small orange-and-black butterfly of damp meadows and pastures across southern Canada and the northern United States, and th
Euptoieta claudiaVariegated Fritillary (Euptoieta claudia)Half fritillary and half longwing, the variegated fritillary is the orange butterfly of American roadsides, pastures and vacant lots.Danaus plexippusMonarch (Danaus plexippus)The monarch is a large orange butterfly with black-outlined wing veins and a black, white-spotted border, found across North America and now on severa
Vanessa atalantaRed Admiral (Vanessa atalanta)The red admiral (Vanessa atalanta) is a medium-sized blackish butterfly marked with one bright orange-red band across each forewing and a scatter of w
Vanessa carduiPainted Lady (Vanessa cardui)No other butterfly lives on so much of the planet.Nymphalis antiopaMourning Cloak (Nymphalis antiopa)The mourning cloak (Nymphalis antiopa) is a large dark butterfly of woodland, riverbank and suburb across North America and temperate Eurasia, and not
Polygonia commaEastern Comma (Polygonia comma)The eastern comma is an orange-and-black woodland butterfly of eastern North America with deeply ragged wing edges and a silvery comma-shaped mark on 
Polygonia interrogationisQuestion Mark (Polygonia interrogationis)The question mark is the largest of the North American anglewings, an orange-and-black woodland butterfly of the eastern United States, southeastern C
Chlosyne nycteisSilvery Checkerspot (Chlosyne nycteis)A medium-sized orange-and-black brush-foot of damp meadows and stream banks across eastern North America, the silvery checkerspot is named for the pal
Aglais milbertiMilbert’s Tortoiseshell (Aglais milberti)Milbert’s tortoiseshell (Aglais milberti) is a medium-sized brush-footed butterfly of northern North America, from Alaska and Canada south through the
Euphydryas phaetonBaltimore Checkerspot (Euphydryas phaeton)Black wings tiled with cream squares and rimmed in brick orange, the Baltimore checkerspot is the state insect of Maryland and one of the most tightly
Junonia coeniaCommon Buckeye (Junonia coenia)Six large eyespots on a brown ground make the common buckeye one of the easiest North American butterflies to name and one of the hardest to approach.
Phyciodes tharosPearl Crescent (Phyciodes tharos)Small, orange and endlessly busy, the pearl crescent is one of the butterflies most people in North America see without ever naming.Show all 10 other brush-footed species names
- White Admiral (Limenitis arthemis arthemis)
- Astyanax' Red-spotted Purple (Limenitis arthemis astyanax)
- Tawny Emperor (Asterocampa clyton)
- Atlantis Fritillary (Speyeria atlantis)
- Silver-bordered Fritillary (Boloria selene)
- American Snout (Libytheana carinenta)
- American Lady (Vanessa virginiensis)
- Compton Tortoiseshell (Nymphalis vaualbum)
- Gray Comma (Polygonia progne)
- Harris' Checkerspot (Chlosyne harrisii)
White and Sulphurs (Pieridae)
Colias philodiceClouded Sulphur (Colias philodice)The clouded sulphur is the plain yellow butterfly of North American roadsides, clover lawns and alfalfa fields, common from Alaska to the Gulf.
Colias eurythemeOrange Sulphur (Colias eurytheme)The orange sulphur is a medium-sized orange-and-black butterfly of open fields, roadsides and alfalfa farms across almost the whole of North America, 
Phoebis sennaeCloudless Sulphur (Phoebis sennae)The cloudless sulphur is a large, fast-flying lemon-yellow butterfly of the Americas, resident from Argentina north through the tropics to the souther
Eurema lisaLittle Yellow (Eurema lisa)A thumbnail-sized sulphur that flutters low over roadsides and fallow fields, the little yellow is one of the most numerous butterflies in eastern Nor
Eurema nicippeSleepy Orange (Eurema nicippe)The sleepy orange is a small, deep-orange sulphur of the southern United States, Mexico and Central America, easily known by the ragged black border t
Pieris rapaeCabbage White (Pieris rapae)The cabbage white is probably the most-seen butterfly on the planet: a small, chalk-white insect with one or two black spots that drifts over allotmen
Pontia protodiceCheckered White (Pontia protodice)The checkered white is a medium-sized white butterfly of dry, open, disturbed ground across the United States and northern Mexico, recognised by the g- Southern Dogface (Colias cesonia)
- Orange-barred Sulphur (Phoebis philea)
- West Virginia White (Pieris virginiensis)
Gossamer-Winged (Lycaenidae)
Callophrys gryneusJuniper Hairstreak (Callophrys gryneus)The juniper hairstreak (Callophrys gryneus) is a small North American butterfly, barely over an inch across, whose underside is a clear leaf green cro
Calycopis cecropsRed-banded Hairstreak (Calycopis cecrops)The red-banded hairstreak is a small grey-brown butterfly of the southeastern United States, named for the broad white-and-red line that runs across t
Strymon melinusGray Hairstreak (Strymon melinus)Small, slate-grey and almost impossible to avoid, the gray hairstreak is the most widespread hairstreak in North America and probably the least fussy - Harvester (Feniseca tarquinius)
- Hessel's Hairstreak (Callophrys hesseli)
- Brown Elfin (Callophrys augustinus)
- Edwards' Hairstreak (Satyrium edwardsii)
- Banded Hairstreak (Satyrium calanus)
- Striped Hairstreak (Satyrium liparops)
Metalmark (Riodinidae)
- Northern Metalmark (Calephelis borealis)
Swallowtail (Papilionidae)
Papilio polyxenesBlack Swallowtail (Papilio polyxenes)The black swallowtail is a black, yellow-spotted butterfly of open country across most of North America, and its caterpillar is the familiar green-and
Papilio canadensisCanadian Tiger Swallowtail (Papilio canadensis)The tiger swallowtail of the north woods, built for a short summer: one brood a year, a winter spent frozen inside a bark-colored chrysalis, and caterPapilio glaucusEastern Tiger Swallowtail (Papilio glaucus)The eastern tiger swallowtail is a large yellow butterfly with four black tiger stripes on each forewing and a tail on each hindwing, and it is the co
Papilio cresphontesGiant Swallowtail (Papilio cresphontes)The largest butterfly in the United States and Canada, the giant swallowtail sails over citrus groves and woodland edges on dark wings crossed by a ba
Papilio troilusSpicebush Swallowtail (Papilio troilus)The spicebush swallowtail is a black swallowtail of eastern North American woodland edges and swamps, marked by a row of ivory spots along the forewin
Protographium marcellusZebra Swallowtail (Protographium marcellus)The zebra swallowtail is a white-and-black striped butterfly of the eastern United States with the longest tails of any North American swallowtail, an
Battus philenorPipevine Swallowtail (Battus philenor)The pipevine swallowtail is a large black North American swallowtail with an iridescent blue to blue-green hindwing and a single curved row of seven oSkipper (Hesperiidae)
Epargyreus clarusSilver-spotted Skipper (Epargyreus clarus)The silver-spotted skipper is a large, chocolate-brown butterfly of gardens, field edges and woodland clearings across almost the whole of North Ameri
Urbanus proteusLong-tailed Skipper (Urbanus proteus)A stocky brown skipper with a shimmer of blue-green over its body and wing bases and two long tails trailing from the hindwings, the long-tailed skippShow all 14 other skipper species names
- Columbine Duskywing (Erynnis lucilius)
- Dreamy Duskywing (Erynnis icelus)
- Horace's Duskywing (Erynnis horatius)
- Juvenal's Duskywing (Erynnis juvenalis)
- Persius Duskywing (Erynnis persius)
- Wild Indigo Duskywing (Erynnis baptisiae)
- Sleepy Duskywing (Erynnis brizo)
- Mottled Duskywing (Erynnis martialis)
- Zarucco Duskywing (Erynnis zarucco)
- Northern Cloudywing (Thorybes pylades)
- Southern Cloudywing (Thorybes bathyllus)
- Common Checkered-Skipper (Pyrgus communis)
- Common Sootywing (Pholisora catullus)
- Hoary Edge (Achalarus lyciades)
How to identify butterflies in Connecticut
Start with size and colour. A big yellow butterfly with black stripes is the Eastern Tiger Swallowtail; if it is black with blue on the hindwing it is a female tiger, a Spicebush, a Black or a Pipevine Swallowtail, and the underside spots decide which. The Red-spotted Purple has the same blue sheen but no tails, while the Viceroy is the Monarch look-alike with a black line across the hindwing. Orange butterflies on July milkweed are usually fritillaries; the Great Spangled is large with silver spots below, the Aphrodite very similar but with an extra black spot near the forewing base, and the Meadow Fritillary small with no silver at all.
The hard groups are the duskywings, which need a close look at the forewing spots, and the hairstreaks, told by the pattern of lines and orange marks on the underside. Small yellow butterflies in late summer are the Little Yellow or the Sleepy Orange, both southern strays; sulphurs with a black border are residents. The state-by-state guides cover the species shared with the rest of the Northeast.
Frequently asked questions about Connecticut butterflies
How many types of butterflies are found in Connecticut?
Around 120 butterfly species have been recorded in Connecticut, and roughly 100 of them breed in the state every year. The remainder are southern strays such as the Cloudless Sulphur and Long-tailed Skipper, or species that have not been seen for decades, including the Regal Fritillary. Brush-footed butterflies and skippers are the two largest families.
Does Connecticut have an official state butterfly?
No. Connecticut has never designated a state butterfly; its official state insect is the European mantis, adopted in 1977. The Monarch, Eastern Tiger Swallowtail and Mourning Cloak are the species most often proposed by schoolchildren, but none has been written into law.
When do Monarch butterflies migrate through Connecticut?
Monarchs migrate through Connecticut from late August to early October, with the peak in the second half of September. The butterflies follow the Long Island Sound shoreline westward, and coastal parks such as Hammonasset Beach and Milford Point can hold hundreds feeding on seaside goldenrod before they cross to Long Island and continue south to Mexico.
What is the largest butterfly in Connecticut?
The Eastern Tiger Swallowtail is the largest resident butterfly in Connecticut, with females reaching a wingspan of about 140 mm. The Giant Swallowtail, which has bred in the Connecticut River valley in recent summers, can be slightly larger, but it is still a scarce northern outpost of a southern species.
Which butterflies are most common in Connecticut?
The Cabbage White is the most frequently seen butterfly in Connecticut towns and farmland, followed by the Clouded and Orange Sulphurs over clover, the Pearl Crescent on roadside asters, the Eastern Tiger Swallowtail, the Silver-spotted Skipper, the Red Admiral and, in late summer and September, the Monarch.
What is the first butterfly to appear in Connecticut each spring?
The Mourning Cloak is usually the first, sometimes flying over snow in early March. It spends the winter as an adult under bark or in woodpiles, so it needs only a warm afternoon to wake. The Eastern Comma and Question Mark, which hibernate the same way, follow within days, and the first freshly emerged Spring Azures appear in April.
Is the Baltimore Checkerspot found in Connecticut?
Yes. The Baltimore Checkerspot (Euphydryas phaeton) is a resident of Connecticut wet meadows and fens where its host plant, white turtlehead, grows. Adults fly in a single brood from mid-June to mid-July. The caterpillars feed communally in a silk web in late summer and hibernate half-grown before finishing on turtlehead or plantain in spring.
Are there sulphur butterflies in Connecticut?
Yes. The Clouded Sulphur and Orange Sulphur are among the commonest butterflies in Connecticut, flying over clover and alfalfa fields from May to November. The Cloudless Sulphur, Little Yellow, Sleepy Orange and Southern Dogface are southern species that reach the state only as late-summer immigrants and do not survive the winter.
Which Connecticut butterflies are endangered?
The Regal Fritillary is considered extirpated from Connecticut, with no records since the early 1990s. Species listed by the state as endangered, threatened or of special concern include Hessel's Hairstreak of Atlantic white cedar swamps, the Northern Metalmark of limestone glades, the Frosted Elfin and several skippers of sandplain grasslands.
What is the best time of year to see butterflies in Connecticut?
Late June to early August is the best time, when fritillaries, hairstreaks, checkerspots, swallowtails and skippers all overlap in flowering meadows. Late September is the second highlight, when Monarchs, Common Buckeyes and Painted Ladies gather on goldenrod along the coast. Very little flies between November and early March.
Published January 2, 2020 · Last updated September 21, 2026