30 Butterfly Species in Montana

In this illustrative guide, you’ll explore the mesmerising world of 30 butterfly species calling Montana home.

This journey will lead you from the Eastern Tiger Swallowtail to the Regal Fritillary, unveiling their distinct traits and characteristics.

Brace yourself to be engulfed in the vibrant colors, hidden nuances, and beautiful patterns found throughout Montana’s butterfly population.

Eastern Tiger Swallowtail (Papilio glaucus)

The Eastern Tiger Swallowtail is a striking species native to Montana.

eastern tiger swallowtail butterfly

  • Habitat: It thrives in a variety of landscapes, from forests to suburban gardens.
  • Appearance: Displaying large black stripes on a yellow background, it’s easy to spot. Males have a clear yellow coloring, while females exhibit a touch of blue on their hind wings.
  • Size: These butterflies range from 3 to 5.5 inches (7.6 to 14 cm) in wingspan.
  • Diet: As adults, they are generalist feeders, sipping nectar from a vast array of flowers.
  • Reproduction: Females lay spherical, greenish eggs on leaves of various trees and flowers.
  • Lifespan: These butterflies live for about a month in their adult form.
  • Host Plants: Willow, Cherry, Ash, Birch, and Maple trees serve as host plants for their larvae.

Black Swallowtail (Papilio polyxenes)

The Black Swallowtail, scientifically known as Papilio polyxenes, is a stunning specimen to behold. You will find this butterfly species abundant in different environments.

Black Swallowtail butterfly

Let’s delve deeper into its characteristics:

  • Habitat: It thrives in open fields, farmlands, suburbs, and even gardens.
  • Appearance: It boasts a striking color palette of black, blue, yellow, and red spots, with a unique ‘tail’ on each hindwing.
  • Size: This species averages a wingspan of about 3.5 inches (8.9 cm).
  • Diet: Adult Black Swallowtails feed primarily on nectar from a variety of flowers.
  • Reproduction: Females lay spherical, pale green eggs, mostly on the new growth of host plants.
  • Lifespan: An adult’s life usually spans 10 to 12 days.
  • Host Plants: Their caterpillars prefer the taste of plants in the carrot family, including dill and parsley.

Keep an eye out for Black Swallowtails next time you’re outside. They surely add a touch of beauty to Montana’s scenery.

Western Tailed-Blue (Cupido amyntula)

The Western Tailed-Blue butterfly, scientifically known as ‘Cupido amyntula’, is a real gem in Montana’s varied species of butterflies.

Western Tailed-Blue butterfly

Below are some key details about these captivating creatures:

  • Habitat: This butterfly is found in open wooded areas and meadows, fields and along roadsides.
  • Appearance: The Western Tailed-Blue is small and grayish blue, having a tail on each hindwing.
  • Size: They are petite, with a wing span of approximately 1 to 1.25 inches (2.54 to 3.18 cm) wide.
  • Diet: Adults feed on nectar from small flowers, while larvae feed on leaves of host plants.
  • Reproduction: Females lay eggs on the flower buds of host plants. The deceptor larvae or caterpillars appear green with white stripes.
  • Lifespan: Adult Western Tailed-Blue butterflies live about 7 to 10 days.
  • Host Plants: Mainly legumes, such as clover and vetch, are preferred host plants.

Don’t be fooled by their size, these creatures are resilient and hold an important place in our ecosystem.

American Copper (Lycaena phlaeas)

The American Copper, also known as Lycaena phlaeas, is a small butterfly native to Montana, recognized for its striking colors and arresting patterns.

American Copper butterfly

  • Habitat: This species thrives in grassy and open, sunny areas, including meadows and fields.
  • Appearance: American Coppers are identified by their copper-colored wings, adorned with black spots on the top side and distinguished by a grayish, patterned underside.
  • Size: They are petite, with a wingspan measuring about 1 to 1.5 inches (2.5 to 3.8 cm).
  • Diet: These butterflies usually feed on nectar from flowers such as clover and buckwheat.
  • Reproduction: Females lay eggs individually on the underside of host plants. The larvae feed on the leaves.
  • Lifespan: The American Copper usually lives for about two to three weeks as an adult.
  • Host Plants: Common Sorrel (Rumex acetosa) and Sheep’s Sorrel (Rumex acetosella) are primary host plants for the larval stage.

Easily spotted due to its vibrant colors, the American Copper is a small but significant part of Montana’s biodiversity.

Gray Hairstreak (Strymon melinus)

As you venture out into Montana’s ecosystems, you are likely to encounter the Gray Hairstreak. Majestic yet diminutive, this butterfly is prevalent across the United States.

Gray Hairstreak butterfly

  • Habitat: This wide-ranging species is comfortable in various habitats, including fields, gardens, and meadows.
  • Appearance: Displaying an understated elegance, it sports gray wings stitched with thin black lines. Bright orange spots cap its lower wings, while its tail-like projections fool predators.
  • Size: Like a feather freed from a bird, it spans only about 1.25 inches (3.2 cm) in width.
  • Diet: Nectar from a variety of flowers fuels the adult Gray Hairstreak, while larvae munch on leaves.
  • Reproduction: Females meticulously choose plants on which to deposit their eggs, landing with exquisite delicacy.
  • Lifespan: Usually living just a few weeks, some adults wintering in the south can survive several months.
  • Host Plants: Broad in taste, caterpillars of this species feed on a vast range of plants – exceeding 40 families!

Northern Azure (Celastrina lucia)

The Northern Azure butterfly is a frequent sight in Montana’s diverse landscapes.

Northern Azure (Celastrina lucia)

Let’s delve into the specifics of this little creature:

  • Habitat: Commonly found in woodlands, fields, and gardens.
  • Appearance: They radiate in shades of blue to gray, with wide black borders on the upper side of their wings.
  • Size: The butterfly is small-sized, with a wingspan ranging from 1 to 1.25 inches (2.54cm to 3.175cm).
  • Diet: The adult Northern Azure feeds mainly on flower nectar.
  • Reproduction: These butterflies exhibit a one-year life cycle, laying eggs in the spring which hatch into caterpillars.
  • Lifespan: Not definitively known, but believed to be a few weeks to a month for the adult stage.
  • Host Plants: Larvae feed on different species of flowering plants like dogwoods, spiraea, and blueberries.

It’s interesting to note that these creatures display variations in color and patterns across their range, making them a joy to spot and identify.

Painted Lady (Vanessa cardui)

The Painted Lady is a captivating butterfly species that adorns Montana’s landscapes.

painted lady butterfly

  • Habitat: This butterfly thrives in various settings, including meadows, fields, gardens, and even roadsides.
  • Appearance: The Painted Lady boasts an exquisite pattern of bright orange, black, and white on its wings, with eye-catching ‘eye spots’ on the undersides.
  • Size: Adults range between 2 to 2.9 inches (5.1 cm to 7.3 cm) in wingspan.
  • Diet: Nectar from various plants, including thistles, asters, and cosmos, serves as their principal food source.
  • Reproduction: The female lays her greenish-yellow eggs on a host plant’s leaves, as the caterpillars feed on the host plants on hatching.
  • Lifespan: Adults have a short lifespan of two to four weeks on average.
  • Host Plants: The preferred host plants include thistles, mallows, and plants from the sunflower family.

This brilliant butterfly is known for its impressive migration, covering thousands of miles.

Anise Swallowtail (Papilio zelicaon)

The Anise Swallowtail is a marvelous creature that thrives in several environments in Montana. This butterfly breed is truly fascinating.

anise swallowtail butterfly

  • Habitat: This butterfly species prefers open, sunny areas including hillsides, gardens, and fields.
  • Appearance: The Anise Swallowtail features yellow and black stripes, with blue and orange spots near its tail.
  • Size: The wingspan of this butterfly is typically 2.75-3.5 inches (~7-9cm), quite impressive.
  • Diet: The Anise Swallowtail caterpillar loves munching on different plants, especially those from the carrot family. The adult butterflies feed on nectar from a range of flowers.
  • Reproduction: These butterflies usually lay their eggs on host plants. The larvae then eat leaves to grow and once mature, they transform into butterflies.
  • Lifespan: The life expectancy of an Anise Swallowtail rests around 3 weeks to a month.
  • Host Plants: This species utilizes a variety of host plants but its favorites include parsley, dill, and anise plants.

Western Tiger Swallowtail (Papilio rutulus)

The Western Tiger Swallowtail is a vibrant inhabitant of Montana.

Western Tiger Swallowtail butterfly

  • Habitat: This species is found in a variety of landscapes including forests, rivers, and urban parks.
  • Appearance: It spots yellow wings, with black stripes and blue and orange details on the bottom wing. It’s a delightful sight.
  • Size: It’s one of the larger species, ranging from 2.9 to 4.1 inches (7.2 to 10.4 centimeters).
  • Diet: The adults enjoy nectaring from various flowers, while caterpillars prefer green leaves.
  • Reproduction: After mating, females lay eggs singly on host plant leaves.
  • Lifespan: From egg to butterfly, it spans a few months. But as adult, it lives only around a week.
  • Host Plants: For the caterpillars, the willows and cottonwoods are common picks.

The Western Tiger Swallowtail contributes greatly to the splendor of Montana’s biodiversity.

Monarch (Danaus plexippus)

The Monarch Butterfly is one of the most well-known butterfly species in Montana. Noted for its striking beauty, it has become a symbol of the butterfly world.


  • Habitat: They are migratory butterflies, found in a variety of habitats including fields, meadows, and suburban areas.
  • Appearance: These butterflies have a deep orange and black pattern, with white spots on the edge of the wings.
  • Size: Monarchs are quite large, they can have a wingspan of up to 4 inches (about 10 centimeters).
  • Diet: The adults drink nectar from a vast array of flowers, while caterpillars feed exclusively on Milkweed.
  • Reproduction: After mating, females lay their eggs on the underside of Milkweed leaves.
  • Lifespan: Monarchs can live for up to two months, undergoing a unique migratory pattern before they die.
  • Host Plants: Milkweed is the single host plant for Monarch caterpillars, making the conservation of this plant vital for the butterfly’s survival.

Greenish Blue (Icaricia saepiolus)

The Greenish Blue butterfly is one of the spectacular species dotting Montana’s lush landscape.

Greenish Blue (Pseudophilotes vicrama)

  • Habitat: This butterfly thrives in sunny, open spaces with rich vegetation, such as meadows or foothills.
  • Appearance: They present a delightful sight with upper wings of vibrant blue in males, while the females boast brownish-gray upper wings.
  • Size: Greenish Blue butterflies are delicate, modestly sized, measuring about 1 inch (2.5 cm) in wing span.
  • Diet: It’s mainly nectar they seek, favoring flowering plants like alfalfa and clovers.
  • Reproduction: In a single year, female lays eggs multiple times, depositing them on host plants’ leaves.
  • Lifespan: Adult butterflies enjoy brief lives of about one week during the summer.
  • Host Plants: The larval host plants typically include various legumes such as lupines and vetches.

A closer look at the Greenish Blue butterfly reveals its unique contribution to Montana’s butterfly biodiversity, feeding on flowers that other butterflies often overlook.

American Lady (Vanessa virginiensis)

The American Lady is a show-stopper butterfly that you may encounter in Montana. I’ll be introducing you to some quick facts about this beautiful creature.

American Lady butterfly

  • Habitat: Prefers open meadows and gardens.
  • Appearance: Displays a stunning orange and black upperwing, with eye-catching white spots. The underwing has a subtle two-eye pattern.
  • Size: Averages roughly 2 to 2.5 inches (5 to 6.35 cm) in wingspan.
  • Diet: Adults feed on nectar, whereas caterpillars prefer plants from the Aster family.
  • Reproduction: Females lay green eggs on host plants. The caterpillars are molted and turn to chrysalis before emerging as adult butterflies.
  • Lifespan: Its life cycle spans about a month from egg to adult.
  • Host Plants: Utilizes cudweeds, everlastings and pussytoes.

Remember, the survival of butterfly species like the American Lady lies substantially in preserving these habitats and plant species.

Spring Azure (Celastrina ladon)

The Spring Azure (Celastrina ladon) is a fascinating butterfly species to observe.

Spring Azure butterfly

  • Habitat: Can be found in multiple habitats ranging from open woodlands to meadows.
  • Appearance: Mainly recognized by their light blue wings contrasted by a dark border.
  • Size: Small-sized, spanning about 1-1.5 inches (2.5-3.8 centimeters).
  • Diet: Prefers the nectar of diverse flowers, like viburnum and dogwood. Caterpillars feed on the buds of various shrubs.
  • Reproduction: Females lay their eggs on flower buds. Caterpillars emerge and feed on the plants.
  • Lifespan: On average, their life span is about one year, from egg to mature butterfly.
  • Host Plants: Their larvae use various shrubs and flowers, including dogwood, viburnum, and blueberry, as host plants.

Despite their small size, they add a delightful touch of color to Montana’s landscapes.

Red Admiral (Vanessa atalanta)

The Red Admiral or Vanessa atalanta, is a striking butterfly species that you might have spotted in Montana.

red-admiral butterfly

  • Habitat: This adaptable creature thrives in a variety of environments including parks, yards, edges of forests, and even mountainous regions.
  • Appearance: It displays a notable contrast of deep red bands set against a black or very dark brown background.
  • Size: A medium-sized beauty, it typically measures 2 to 2.75 inches (5.1 to 6.9 cm) in wingspan.
  • Diet: The Red Admiral prefers to feast on nectar from flowers, and has a fondness for rotting fruit.
  • Reproduction: This species reproduces multiple times a year, with females laying their green eggs on plants individually.
  • Lifespan: Although their lifespan is fairly short, spanning just a few weeks, the Red Admiral can produce several generations in a single year.
  • Host Plants: You’ll often find their caterpillars on nettle plants, which serve as their primary food source.

California Tortoiseshell (Nymphalis californica)

Meet the California Tortoiseshell. Found in conifer and mixed forests, it’s a common sight in Montana.

California Tortoiseshell butterfly

  • Habitat: You’ll spot it in conifer and mixed forests. It also thrives in alpine regions.
  • Appearance: Distinct with orange-brown coloration on its upper wings set off by black markings. The underwings, however, mimic dead leaves.
  • Size: Adult wingspans range between 2 to 2.8 inches (~5.1 to 7.1 cm).
  • Diet: Adults enjoy flower nectar, while larvae prefer California lilac.
  • Reproduction: Females lay eggs on the undersides of host plant leaves. Caterpillars experience 5 stages before pupating.
  • Lifespan: Adults live for around a week to a month, but in the pupae stage, they can hibernate for several months.
  • Host Plants: California Tortoiseshells typically use Ceanothus (wild lilac) as their host plants.

This butterfly is a witness to change, hibernating over winter and emerging in spectacular swarms as the temperatures rise.

Cloudless Sulphur (Phoebis sennae)

The Cloudless Sulphur is a unique butterfly that adds color to the blue skies of Montana.

cloudless sulphur butterfly

  • Habitat: Naturally, they thrive in open areas, gardens, and roadside fields.
  • Appearance: Cloudless Sulphurs sport a vibrant yellow color. They sometimes have small red spots on their wings.
  • Size: This butterfly generally measures anywhere between 2.3 to 3.1 inches (5.8 to 7.8 centimeters).
  • Diet: They feed on nectar from a variety of different flowers, showing a preference for red and pink flowers.
  • Reproduction: Females lay white, round eggs on host plant leaves.
  • Lifespan: Their average lifespan ranges from 6 to 14 days. This small window is generally divided into 4 phases- egg, larva, pupa, and adult.
  • Host Plants: Partridge peas and other types of pea plants are typically the most desirable plants for egg-laying.

Their vibrant streak in the sky serves as a beautiful backdrop for the serene landscape of Montana.

Eastern Comma (Polygonia comma)

The Eastern Comma is an intriguing butterfly species that can be found in Montana.

Eastern Comma butterfly

Here’s a more detailed glimpse at this butterfly:

  • Habitat: Typically, they are found in woodland and forested areas.
  • Appearance: They’re identified by their orange and brown wings and distinct silver comma-shaped marking on the underwings.
  • Size: They have a wingspan ranging between 1.75 to 2.25 inches (4.5-5.7 cm).
  • Diet: They feed on tree sap, decaying fruit, and nectar from flowers.
  • Reproduction: Their egg-laying process begins in late spring and early summer.
  • Lifespan: These butterflies live for about a year.
  • Host Plants: They lay their eggs on plants like the American Elm and Hop Vine.

These particulars make the Eastern Comma an exciting find for butterfly watchers in Montana.

Variable Checkerspot (Euphydryas chalcedona)

The Variable Checkerspot is a fascinating species that you may encounter in Montana. This butterfly showcases a vibrant symphony of colors, combining patterns of orange, black, white, and yellow to charm observers.

Variable Checkerspot butterfly

Here are some quick facts about this butterfly:

  • Habitat: Primarily resides in open woodland areas, fields, and hilltops.
  • Appearance: Orange wings with black, white, and yellow spots and lines.
  • Size: Boasts a wingspan of about 2 to 2.5 inches (5–6.4 cm).
  • Diet: Adult butterflies consume nectar from flowers. As for the caterpillars, they have a voracious appetite for the leaves of various plants.
  • Reproduction: These butterflies mate in the spring, with females then laying eggs on the underside of leaves.
  • Lifespan: As adults, they typically live up to one month.
  • Host Plants: Prefer plants from the Plantaginaceae family, such as sticky monkey flowers and Indian paintbrushes.

Silver-spotted Skipper (Epargyreus clarus)

The Silver-spotted Skipper is a noticeable species with its unique features.

Silver-spotted Skipper butterfly

Let’s delve into its finer details:

  • Habitat: These creatures thrive in a broad range of environments – from sunny meadows to woodland edges.
  • Appearance: Sporting a wing pattern with a silvery spot on the hindwings, these butterflies are quite striking. The body shows a fur-like appearance.
  • Size: They measure around 1.75 to 2.30 inches (4.4 to 5.8 cm) in wingspan, which gives them a medium stature.
  • Diet: They particularly enjoy nectar from wildflowers and sip water from moist spots.
  • Reproduction: Females lay eggs on the host plant leaves, which later hatch into larvae.
  • Lifespan: Short-lived, these butterflies usually survive 1-2 weeks in the summer.
  • Host Plants: Commonly seen on locusts, wisteria, and false indigo plants where they lay their eggs.

White Admiral (Limenitis arthemis arthemis)

The White Admiral is a captivating butterfly species found in Montana. It bursts into sight with a mixture of neat black striping on a canvas of white.

This elegant pattern, coupled with a majestic flight, makes it a captivating sight.

White Admiral butterfly

Here’s some additional intriguing information about the species:

  • Habitat: Prefers deciduous woodlands and mixed forests.
  • Appearance: Black stripes on a white base color. They have an elegant flight pattern and are a joy to watch.
  • Size: Wing span can range between 2.5-4 inches (6.35-10 cm).
  • Diet: Nectars of various flowers and sap from trees.
  • Reproduction: Females lay eggs on the leaf tops of host plants.
  • Lifespan: The adult butterflies live for a few weeks.
  • Host Plants: They utilize various species of willows, poplars, and birches.

Isn’t it fascinating that such an elegant and majestic creature rests in the quiet woodlands of Montana?

The White Admiral’s beauty, grace, and striking pattern make it a captivating butterfly species.

Viceroy (Limenitis archippus)

The Viceroy is a captivating butterfly species you can encounter in Montana.


  • Habitat: Viceroys adore wet, marshy areas such as swamps and meadows. They won’t stray far from water sources.
  • Appearance: The Viceroy’s resemblance to the Monarch can deceive predators. They boast an orange and black pattern with a distinguishing black line across the hindwings.
  • Size: Usually, they span from 2.5 to 3 inches (6.3 to 7.6 cm) across.
  • Diet: As caterpillars, they feed on willow and poplar leaves. Adult Viceroys enjoy nectar from flowers and also dine on dung and rotten fruit.
  • Reproduction: Females lay their eggs singularly on the tops of host plant leaves. Their hatchlings then feed upon those leaves.
  • Lifespan: Viceroys maintain an adult lifespan of approximately two weeks.
  • Host Plants: Willow and poplar trees are the preferred locations for Viceroy eggs.

Upon your next stroll through a Montana meadow or gallery forest, keep an eye peeled for the deceptive Viceroy butterfly. This delightful creature is sure to amaze you!

‘Astyanax’ Red-spotted Purple (Limenitis arthemis astyanax)

The ‘Astyanax’ Red-spotted Purple is a truly intriguing butterfly species found in Montana.

‘Astyanax’ Red-spotted Purple (Limenitis arthemis astyanax)

  • Habitat: These butterflies are known to reside along forest edges, fields, and stream banks.
  • Appearance: Mottled blue with sharp red spots, these beautiful creatures have white bands on their forewings.
  • Size: A healthy adult usually sports a wingspan circling 3.2 to 4 inches (8.1 to 10.2 cm).
  • Diet: Adult Red-spotted Purples enjoy a diverse diet including dung, fungi, rotting fruit, and tree sap.
  • Reproduction: Typically, females lay eggs on the host plant’s leaves, which hatch into caterpillars.
  • Lifespan: The lifespan of this species tends to be approximately 2 months.
  • Host Plants: Willows, poplar, and black cherry trees serve as the primary host plants. This is where they lay their eggs and the caterpillars feed off the leaves.

These butterflies bring their own unique color and charm to the wildlife of Montana.

Clodius Parnassian (Parnassius clodius)

The Clodius Parnassian is notable among Montana’s butterfly species.

Clodius Parnassian butterfly

  • Habitat: Uniquely, it thrives in high-altitude zones such as mountain meadows and rocky areas.
  • Appearance: Intriguingly, it sports white wings decorated with distinct black veins and red spots.
  • Size: It measures around 2 to 2.5 inches (5 to 6.4 cm), delivering striking visuals despite its compact size.
  • Diet: As caterpillars, they feast on various plant species. Once matured, they draw nutrients from flowers, especially stonecrop.
  • Reproduction: Remarkably, females lay eggs on the top of host plants, which hatch into caterpillars going into a two-year life cycle.
  • Lifespan: This species experiences a relatively brief adult lifespan, often lasting just a few weeks in the summer.
  • Host Plants: They have a preference for bleeding hearts and stonecrop, which the larvae utilize for nutrients and camouflage.

This butterfly embodies the rugged, unpredictable beauty of Montana’s landscape. Certainly, the Clodius Parnassian stands as a testament to nature’s ability to adapt and thrive in varying conditions.

Great Spangled Fritillary (Speyeria cybele)

The Great Spangled Fritillary, an exciting species to discover.

Great Spangled Fritillary

Let’s delve into their remarkable characteristics:

  • Habitat: Regularly spotted in mountainous regions, meadows, fields, and gardens.
  • Appearance: Bright orange with large black spots. The underside hindwing features silver spots, hence their name.
  • Size: They are considerable in size, spanning around 2.5 to 3.5 inches (6.3 to 8.9 cm).
  • Diet: Their preferred sustenance primarily consists of nectar, notably from milkweed and thistles.
  • Reproduction: Females lay eggs in late summer and the caterpillars hatch the following spring.
  • Lifespan: These butterflies typically have a lifespan of about one year.
  • Host Plants: Violets are key. They provide food and a place for the butterfly to lay eggs.

Exploring and understanding the intricate lives of these creatures heightens one’s respect for the vast diversity of butterfly species in Montana.

Edith’s Checkerspot (Euphydryas editha)

Edith’s Checkerspot, scientifically known as Euphydryas editha, is an engaging spectacle in Montana.

This butterfly has a unique overwintering process, namely as a chrysalis, that becomes distinct as you delve into its characteristics.

Edith’s Checkerspot (Euphydryas editha)

  • Habitat: Mostly slopes and meadows with a good supply of nectar and host plants
  • Appearance: Unique checkerboard pattern of white, red and black on the wings
  • Size: Generally spans from 3.1 cm to 4.4cm diagonally (1.2-1.7 inches)
  • Diet: Caterpillars feed on certain species of plantain, lousewort and owl’s clover. Adult butterflies consume flower nectar.
  • Reproduction: Females lay eggs in clusters on the underside of host plant leaves.
  • Lifespan: The adult stage lasts around 10 days whereas the caterpillar stage endures for up to 10 months.
  • Host Plants: Prefers plantains, lousewort, and owl’s clover.

Captivating in its visual complexity, Edith’s Checkerspot continues to embellish Montana’s rich biodiversity.

Mourning Cloak (Nymphalis antiopa)

The Mourning Cloak is an intriguing butterfly with a fascinating life cycle.

Mourning Cloak butterfly

  • Habitat: You’ll find this unique species living across temperate environments – from thick forests to suburban gardens.
  • Appearance: Distinguished by its dark brown wings edged in a band of bright blue spots, it showcases contrasting colors.
  • Size: Adult wingspans average between 2.25 to 4 inches (around 6 to 10 cm), making it a reasonably large butterfly.
  • Diet: Both adult butterflies and caterpillars feed on tree sap, insects, and rotting fruit, rather than nectar.
  • Reproduction: Females lay clusters of eggs on the underside of host plants in spring.
  • Lifespan: Interestingly, Mourning Cloaks have a lifespan of 11-12 months, one of the most extended butterfly lifespans.
  • Host Plants: Preferred host plants include willow, elm, aspen, and hackberry tree species.

Equally captivating and elusive, this particular butterfly species adds a distinct charm to Montana’s broad-spectrum butterfly catalog.

Cabbage White (Pieris rapae)

Frequently seen flittering about, the Cabbage White is one of Montana’s most notable butterflies.

Cabbage White butterfly

  • Habitat: They occupy diverse habitats such as open grassy fields, woodlands, and especially gardens.
  • Appearance: Cabbage Whites have a pale or white color palette, with distinct dark spots on their wings.
  • Size: These visually pleasing creatures average about 4 to 7 cm (1.6 to 2.8 in) in wingspan.
  • Diet: As adults, they prefer nectar foods, selecting from a broad range of flowering plants.
  • Reproduction: Reproducing up to 3 times in a year, females can lay hundreds of tiny, yellow eggs.
  • Lifespan: Typically, they have a short lifespan of around two weeks.
  • Host Plants: The caterpillars are not picky eaters. Their preference includes a broad range of crops, especially brassicas, making them a foe to farmers and gardeners alike.

In Montana, they are pretty usual from spring to fall hence you might be familiar with them already.

Pale Swallowtail (Papilio eurymedon)

The Pale Swallowtail butterfly, scientifically known as Papilio eurymedon, is a remarkable species that further enriches Montana’s diverse butterfly ecosystem.

Pale Swallowtail butterfly

  • Habitat: They are typically found in the forests, meadows, and stream edges of Montana.
  • Appearance: Their wings are pale cream-colored with some black lines and spots.
  • Size: The average wingspan ranges from 3.5 to 4.5 inches (9 to 11.5 cm).
  • Diet: These butterflies feed mainly on flower nectar but also on rotting fruits and tree sap.
  • Reproduction: They lay their eggs singly on the leaves of the host plants.
  • Lifespan: They live up to 12 days as adults.
  • Host Plants: Their larva feeds on a variety of trees such as sycamore, cherry, and willow.

The Pale Swallowtail is an integral part of Montana’s beautiful and delicate ecological balance. Such creatures further add to the natural charm and wonder of the state.

Orange Sulphur (Colias eurytheme)

Orange Sulphur Butterflies, colloquially known as “Alfalfa Butterflies,” are a common sight in Montana. These creatures bring a vibrant splash of color to the state’s diverse habitats.

Orange Sulphur butterfly

  • Habitat: This butterfly species is ubiquitous across fields, near roadsides, and even in urban gardens.
  • Appearance: Their upper wing surface exhibits a bright orange with distinct black borders and spots that beautifully contrast with the warm hue.
  • Size: In general, the wingspan of these fluttery fellows ranges between 1.5 to 2.75 inches (38 to 70mm).
  • Diet: Nectar from a variety of flowers makes up their main diet.
  • Reproduction: Female Orange Sulphurs lay their pale green eggs on the host plants where the caterpillars will feed.
  • Lifespan: Although short-lived with a lifespan of just around a week, they multiply quickly due to multiple broods each year.
  • Host Plants: Alfalfa, clovers, and peas are some of their favorites among leguminous plants that serve as their primary hosts.

Regal Fritillary (Speyeria idalia)

The Regal Fritillary is a captivating species of butterfly that you can spot in Montana.


Here’s a rundown of this species:

  • Habitat: These species thrive in prairie grasslands and meadows.
  • Appearance: They flaunt visually striking orange-brown wings with black patterns. The females slightly differ from males with darker wing color.
  • Size: The wingspan is 2.5-4 inches (6.35-10.16 cm), making them one of the larger species to be found in Montana.
  • Diet: The Regal Fritillary primarily feeds on nectar from various flowers.
  • Reproduction: They typically lay their eggs near food plants during late summer.
  • Lifespan: Adult butterflies live around 2-3 weeks.
  • Host Plants: Violet plants serve as home for Regal Fritillary caterpillars, from which they derive their nourishment.

Getting the chance to observe the Regal Fritillary would be such a fascinating experience during your Montana visit.


As you can see, Montana is truly a haven for beautiful and diverse butterfly species.

Each characterizes its unique beauty and contributes to the balance of Montana’s ecosystem.

Feel free to leave a comment on your favorite butterfly from this list or any other species you might have encountered in the wild.

Butterflies   Updated: August 10, 2023
avatar Welcome to Insectic, a blog to learn about insects and bugs. I'm Richard, and I've created this website to share my experience, knowledge, and passion with others.

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