27 Butterflies in Maine: From Common Monarchs to Rare Hairstreaks
September 29, 2026
Short summers, cold winters, and boggy northern terrain don’t sound like ideal butterfly territory, yet butterflies in Maine make up one of the most surprising insect communities in New England. With over 120 species, butterflies contribute a colorful component to Maine’s biological diversity, playing important ecological roles as pollinators of wildflowers and as prey to larger animals. Some of these species are city-lot regulars; others survive only in a single cedar swamp or coastal heath.
What makes Maine’s butterfly list so interesting is the mix. Common garden visitors like the Cabbage White fly right alongside some of the rarest insects in the country, and roughly 20% of Maine’s butterflies are currently considered Extinct, Endangered, or of Special Concern. Maine is also home to plenty of other distinctive native wildlife, from the tufted Maine Coon cat to a surprising range of pollinating insects. Below are 27 species worth learning to recognize on sight.
Pro Tip: Most Maine butterflies are active from May through September, though a few overwintering species can appear on the first warm afternoon in March.
1. Pink-edged Sulphur
The Pink-edged Sulphur (Colias interior) is a soft yellow-orange butterfly named for the faint pink fringe along its wing edges. It sticks close to blueberry barrens and boreal bogs, where its caterpillars feed almost exclusively on low-growing blueberry plants (Vaccinium species).
Look for this species from late June through August in Maine’s Downeast blueberry country. It flies low and fast over open ground, rarely straying far from its host shrubs, which makes barren habitat conservation directly tied to its survival.
2. Monarch
The Monarch (Danaus plexippus) is Maine’s best-known long-distance flier, instantly recognizable by its bold orange-and-black wings. Migratory Monarchs arrive and lay eggs during Maine’s summer months, and the larvae emerge in late spring to begin feeding on milkweed before metamorphosis.
Adult Monarchs that hatch in late summer make the multi-generational trip to central Mexico for winter, a journey no single butterfly completes twice. Milkweed loss along the migration corridor is the species’ biggest threat, and gardeners can help simply by planting native milkweed. Like many Maine caterpillars, Monarch larvae face constant pressure from birds and other animals that eat butterflies at every life stage.
3. Spicebush Swallowtail
The Spicebush Swallowtail (Papilio troilus) is a dark, blue-green-tinged swallowtail that reaches Maine at the northern edge of its range. Its caterpillars are famous for the false eyespots on their thorax, which make a small green larva look startlingly like a tiny snake head to would-be predators.
Host plants are spicebush and sassafras, both scarce this far north, so sightings tend to cluster in the state’s warmer southern counties. Adults are strong fliers and often mistaken for the more common Black Swallowtail at a glance.
4. White Admiral
The White Admiral (Limenitis arthemis arthemis) shows off broad white bands cutting across otherwise deep black wings, a pattern that makes it one of the easiest large butterflies to identify in flight. Maine’s roughly 120 butterfly species include the White Admiral, Baltimore Checkerspot, and Crowberry Blue, three names that come up often in conversations about the state’s native fauna.
This subspecies favors northern hardwood and mixed forests, where caterpillars feed on birch, willow, aspen, and poplar leaves. It hybridizes readily with the Red-spotted Purple where their ranges overlap in central Maine.
5. Baltimore Checkerspot
Few Maine butterflies show off a bolder pattern than the Baltimore Checkerspot (Euphydryas phaeton), whose orange, black, and cream checkerboard wings put it among the most colorful animals found in northeastern wetlands. Caterpillars feed almost exclusively on turtlehead (Chelone glabra), a wildflower of wet meadows and stream edges.
Young larvae overwinter communally in a silk web at the base of their host plant, then disperse the following spring to finish feeding. Because turtlehead is a fairly specific wetland plant, this species’ populations rise and fall with wetland health.
6. Crowberry Blue
Hessel’s Hairstreak, Purple Lesser Fritillary, and Crowberry Blue are some of Maine’s rarest butterflies, and the Crowberry Blue (Plebejus idas) may be the hardest of the three to actually find. This subspecies survives only on a handful of coastal heathlands near Mount Desert Island and the Schoodic Peninsula, where its caterpillars feed on mountain crowberry.
One Maine blogger who tracked the species down described the underside as ivory and spotted, but noted that when it opens its wings, “you are dazzled by a vibrant, iridescent blue that shimmers” across the upper surface. Habitat this specific leaves almost no margin for error if coastal heath is disturbed.
7. Hessel’s Hairstreak
The Hessel’s Hairstreak (Callophrys hesseli) is tied to one plant and almost nowhere else. This rare and endangered species feeds only on Atlantic white cedar growing in a few swamps in York County, and it shows olive green and rusty brown wing colors that help it camouflage against the Atlantic white-cedar in both its caterpillar and adult form.
Habitat loss, urban development, and pesticides have pushed this butterfly onto Maine’s list of Species of Greatest Conservation Need. It shares that distinction with several other insects tracked on the state’s roster of endangered animals in Maine, underscoring how narrow habitat requirements can put a species at risk even where development pressure is relatively light.
8. Purple Lesser Fritillary
The Purple Lesser Fritillary (Boloria titania) rounds out Maine’s trio of rarest butterflies alongside the Crowberry Blue and Hessel’s Hairstreak. These butterflies are often described as graceful and elegant, seen fluttering in the air or basking in the sun across the cool, boggy habitats they prefer.
Caterpillars feed on violets growing in wet, mossy openings, and adults tend to stay close to intact peatland. Because these bogs recover slowly from disturbance, the species is treated as a conservation priority under Maine’s ongoing butterfly monitoring efforts.
9. Red Admiral
The Red Admiral (Vanessa atalanta) is a fast, territorial flier with dark wings crossed by bold orange-red bands. Numbers swing wildly from year to year; some seasons bring only scattered sightings, while others produce sudden mass emergences across the entire state.
Caterpillars feed on nettles, rolling a leaf into a protective tube as they grow. Adults are famously curious about people, often landing on clothing or skin, likely drawn to salt and moisture rather than any real interest in humans.
10. Cabbage White
Cabbage White butterflies (Pieris rapae) are the most common of the white butterflies, flying around residential gardens from spring through summer. This introduced European species has become one of Maine’s most familiar backyard insects, in no small part because its caterpillars feed on cabbage, broccoli, and other garden brassicas.
Telling males from females is simple once you know the trick: females have two black spots on an otherwise white wing, while males have only one black spot. Gardeners often consider the caterpillars a nuisance, though the adults are valuable early-season pollinators.
11. Mustard White
The Mustard White (Pieris oleracea) is a native look-alike to the Cabbage White, distinguished by cleaner white wings with faint gray veining on the underside, especially in its early spring brood. Unlike its introduced cousin, this species relies on native mustards and toothwort growing along woodland edges.
Populations have declined in parts of its range as garlic mustard, an invasive plant, replaces the native host plants caterpillars need. Spring-brood adults look noticeably different from the plainer summer generation, a seasonal shift called polyphenism.
12. Checkered White
The Checkered White (Pontia protodice) is an uncommon stray in Maine, more typical of open, dry habitats farther south and west. Its checkered black-and-white wing pattern distinguishes it from both the Cabbage White and Mustard White at a glance.
Sightings tend to cluster in disturbed, sunny fields and roadsides rather than the forests and wetlands favored by many native Maine species. Because it isn’t a reliable breeding resident this far north, most Maine records represent individuals that wandered in from warmer regions.
13. Clouded Sulphur
The Clouded Sulphur (Colias philodice) is a common, clear-yellow butterfly of clover fields, roadsides, and lawns across the state. If a yellow butterfly is fluttering around flowers in a Maine field, there’s a good chance it’s a Colias species such as the Clouded Sulphur rather than one of the region’s rarer yellows.
Caterpillars feed on clover and alfalfa, making this species a familiar sight in agricultural areas throughout summer. It commonly forms mixed flight groups with the closely related Orange Sulphur, and the two occasionally hybridize.
14. Orange Sulphur
The Orange Sulphur (Colias eurytheme) looks nearly identical to the Clouded Sulphur at rest but shows a warm orange flush across the upper wings in flight. Like its relative, it feeds on clover and alfalfa as a caterpillar, which keeps it common in hayfields and farm edges.
Because Clouded and Orange Sulphurs share habitat and host plants, mixed-species pairs and hybrid offspring aren’t unusual where their populations overlap. Wing color intensity can vary enough between individuals that field identification sometimes requires a close look at wing-margin markings.
15. Cloudless Sulphur
The Cloudless Sulphur (Phoebis sennae) is a large, unmarked lemon-yellow butterfly that breeds mainly in the southern United States but occasionally strays as far north as Maine in late summer. Its size alone sets it apart from the smaller, more common sulphurs found statewide.
Sightings usually increase during years with strong southerly wind patterns that carry wandering adults northward. Maine records are almost always single individuals rather than established breeding populations, since the species can’t survive the state’s winters.
16. Large Orange Sulphur
The Large Orange Sulphur (Phoebis agarithe) is a genuinely rare find in Maine, a tropical and subtropical species whose deep orange wings set it apart from every other sulphur on this list. Its usual range runs from the Gulf Coast south into Mexico and Central America.
Any Maine sighting represents a long-distance wanderer rather than a resident population, and records this far north are noteworthy enough to be reported to regional butterfly recorders. Its host plants are tropical legumes unrelated to anything growing naturally in the state.
17. Little Sulphur
Also known as the Little Yellow, the Little Sulphur (Pyrisitia lisa) is a small, bright yellow butterfly that occasionally strays north from its core range in the southeastern United States. Its diminutive size and quick, low flight separate it from the larger Clouded and Orange Sulphurs.
Like several other southern sulphurs on this list, it cannot overwinter in Maine’s climate, so sightings depend entirely on seasonal dispersal from populations farther south. Caterpillars in its home range feed on partridge pea and other legumes.
18. American Copper
The American Copper (Lycaena phlaeas) is a small, fiery orange-and-black butterfly common in old fields, vacant lots, and roadside edges across Maine. It represents the state’s smaller Gossamer-Winged butterflies, standing in contrast to larger Brush-Footed species like the Monarch.
Caterpillars feed on sheep sorrel and curly dock, weedy plants tolerant of poor, disturbed soil, which is part of why this species thrives in spots other butterflies avoid. Adults are territorial and often perch on bare ground or low vegetation, darting out at passing insects.
19. Spring Azure
The Spring Azure (Celastrina ladon) is typically one of the very first butterflies Mainers see each year, appearing as a pale blue flicker along woodland edges while snow can still linger in shaded spots. It ranks among the most commonly spotted species in the state, alongside the Mourning Cloak and Cabbage White.
Caterpillars feed on flower buds of dogwood, viburnum, and blueberry rather than leaves, an unusual habit among Maine butterflies. This species appears on Maine’s official butterfly checklist as one of the state’s most frequently recorded Lycaenids.
20. Mourning Cloak
The Mourning Cloak (Nymphalis antiopa) has deep maroon wings edged in cream yellow with a row of blue spots, a pattern unmistakable once seen. This species overwinters as an adult and can appear on the first warm day in March, weeks before most other Maine butterflies emerge.
Adults shelter in tree bark crevices, woodpiles, and old sheds through the coldest months, then emerge to feed on tree sap and rotting fruit before flowers bloom. Caterpillars feed communally on willow, elm, and poplar, often stripping entire branches.
21. Harris’s Checkerspot
Harris’s Checkerspot (Chlosyne harrisii) shows a bold orange-and-black checkered pattern similar to the Baltimore Checkerspot, though slightly smaller and paler overall. It favors damp meadows and stream edges where its host plant, flat-topped white aster, grows in abundance.
Caterpillars feed communally when young, spinning a loose web over the host plant before dispersing to feed independently as they mature. Populations tend to be localized but stable where wet meadow habitat remains intact.
22. Pearl Crescent
The Pearl Crescent (Phyciodes tharos) is a small orange-and-brown butterfly marked with dark crescent shapes near the wing margins, common in open fields and along roadsides throughout the growing season. It produces multiple broods each summer, making it one of the more frequently seen small butterflies in southern Maine.
Caterpillars feed on various native aster species, and adults are frequent visitors to garden flowers as well as wild blooms. Its close resemblance to the Northern Pearl Crescent makes precise identification tricky without a close look at wing pattern details.
23. Northern Pearl Crescent
The Northern Pearl Crescent (Phyciodes cocyta) looks nearly identical to the Pearl Crescent but tends to favor cooler, more northern habitats and produces fewer broods per year. Some researchers treat it as a distinct species, while others classify it as a close relative within the same species complex.
Distinguishing the two crescents in the field usually requires examining subtle differences in the underside wing markings, and even experienced observers sometimes rely on range and habitat clues rather than pattern alone. Both species share similar aster host plants.
24. Eastern Comma
The Eastern Comma (Polygonia comma) gets its name from the small, silvery comma-shaped mark on the underside of its hindwing, visible when the butterfly rests with wings closed against tree bark. Like the Mourning Cloak, it overwinters as an adult and can be spotted on the first mild day of late winter.
Caterpillars feed on hops, elm, and nettles, and the species produces a summer form with brighter orange wings alongside a duller winter form built for camouflage. Adults are drawn to rotting fruit and tree sap far more than to flower nectar.
25. Inornate Ringlet
The Inornate Ringlet (Coenonympha inornata) is a plain buff-tan butterfly with a weak, low, bouncing flight typical of grassland satyrids. Despite its unassuming looks, it’s a common sight in Maine’s hayfields, meadows, and roadside grasses through the summer months.
Caterpillars feed on various grasses, which keeps this species tied closely to open, unmowed field habitat. Because it rarely strays far or flies fast, it’s one of the easier butterflies to observe up close without much effort.
26. Common Wood Nymph
The Common Wood Nymph (Cercyonis pegala) is a chunky brown butterfly best known for the large, dark eyespots on its forewings, a defense pattern that ranks among nature’s cleverer bluffs and echoes the startle effect seen in other animals with big eyes. It prefers grassy woodland edges, damp meadows, and shaded field margins.
Caterpillars feed on various grasses and are active mainly at night, sheltering during the day to avoid the same predators, including birds and even some snakes found in Maine, that hunt along grassy edges. Adults fly with a distinctive, erratic bounce low over vegetation.
27. Red-spotted Purple (Astyanax)
The Red-spotted Purple (Limenitis arthemis astyanax) is a striking, iridescent blue-black butterfly that mimics the toxic Pipevine Swallowtail, even though the two aren’t closely related. This subspecies of the same species as the White Admiral lacks the white wing band, and the two forms hybridize where their ranges meet in central Maine.
Caterpillars feed on wild cherry, willow, and poplar, and their odd, lumpy shape helps them blend in as bird droppings or twig damage rather than food. Adults favor deciduous woodland edges in the warmer, southern half of the state, rarely ranging as far north as true boreal habitat.
Twenty-seven species barely scratch the surface of what flies over Maine’s fields, bogs, and forest edges each summer. Peak butterfly-watching season runs from May through September, though a few hardy overwinterers show up the moment temperatures climb in early spring. Grabbing a field guide, learning a handful of host plants, and spending an afternoon near a sunny meadow is usually enough to turn up several species from this list in a single outing.