Butterflies in Pennsylvania: A Guide to the Most Common Species

Pennsylvania is home to over 140 species of butterflies due to its diverse habitats and location at the intersection of northern and southern butterfly ranges. From the Appalachian Mountains to the forests and farmlands of the Piedmont region, the Keystone State provides plentiful food and habitat for butterflies.

In this article, we’ll highlight the 15 most common butterflies you’re likely to encounter in Pennsylvania.

1. Monarch

The iconic monarch butterfly (Danaus plexippus) is arguably the most recognizable butterfly in the northeastern United States. Its bright orange wings with black veins and white spots make it unmistakable. Monarchs migrate through Pennsylvania each fall on their way to Mexico for the winter. Look for them feeding on milkweed, the only food their caterpillars will eat.

2. Eastern Tiger Swallowtail

With a wingspan up to 5.5 inches, the eastern tiger swallowtail (Papilio glaucus) is Pennsylvania’s largest butterfly. It glides gracefully through open fields and meadows. Males are always yellow and black, while females may be yellow or nearly all black Caterpillars feed on wild cherry and other trees.

3. Cabbage White

The small cabbage white butterfly (Pieris rapae) flutters erratically around gardens and fields. Males have one black spot on each wing while females have two. Originally from Europe, they earned their name from the damage their green caterpillars inflict on cabbage and other brassica crops.

4. Red Admiral

Red admirals (Vanessa atalanta) are a common sight in Pennsylvania, especially near woodlands and thickets. Their wings feature striking bands of orange, white, and dark brown. These butterflies often feed on rotting fruit. They migrate south for winter but recolonize the state each spring.

5. Painted Lady

Painted ladies (Vanessa cardui) are orange and black like monarchs but lack the thick black veins They migrate long distances and turn up in Pennsylvania intermittently in large numbers during years with favorable conditions farther south These butterflies can mate year-round due to their constant movement,

6. Pearl Crescent

Pearl crescents (Phyciodes tharos) inhabit fields and meadows statewide. Ranging from bright orange to pale yellow, their wings are dotted with black along the edges. Caterpillars feed solely on asters, so adult butterflies are drawn to these and related flowers.

7. Great Spangled Fritillary

Pennsylvania’s state butterfly, the great spangled fritillary (Speyeria cybele), is a frequent sight in fields of black-eyed susans and other flowers. It has orange wings decorated with black lines and white spots. Caterpillars feed on violets.

8. Common Buckeye

The common buckeye (Junonia coenia) gets its name from the prominent eyespots on its wings, which serve to startle predators. These medium-sized, brown butterflies are migrants, returning to Pennsylvania each summer from the south and as far away as Mexico.

9. Clouded Sulphur

Living up to its name, the clouded sulphur butterfly (Colias philodice) comes in either a pale yellow or white color form. Look for them fluttering over alfalfa fields and meadows. They breed readily in the Pennsylvania climate, fueling their abundance.

10. Eastern Comma

The eastern comma (Polygonia comma) is aptly named for the silvery comma markings on its underside. The rough, bark-like wings provide excellent camouflage when the butterfly is at rest. It overwinters as an adult and emerges early in spring.

11. Question Mark

Question marks (Polygonia interrogationis) flap slowly through woodland openings and edges. Their irregular orange and brown markings resemble fallen leaves when wings are folded. Look for the faint silvery question mark on their underwings.

12. Mourning Cloak

Mourning cloaks (Nymphalis antiopa) are among the first butterflies seen each spring. Their velvety, chocolate-brown wings lined in yellow make them unmistakable. They may even survive cold snaps as adults over the winter by hiding out in tree hollows and other shelters.

13. Cabbage White

The imported cabbage worm (Pieris rapae) earned its name from the damage its green, velvety caterpillars inflict on cabbage and other brassicas. These small white butterflies lay their eggs on the undersides of brassica leaves in late spring.

14. Eastern Tailed Blue

Males of this tiny species (Cupido comyntas) stake out territories in fields waiting for females. Their wings are vivid powder blue above with a thin black border. Females are mostly brown. Look for these butterflies perched on clover and other low plants.

15. Silver-Spotted Skipper

Silver-spotted skippers (Epargyreus clarus) are some of the most common butterflies in Pennsylvania. They have fast, darting flight and feed on a wide variety of nectar sources. Watch for them on purple coneflowers, Joe Pye weed, and other meadow flowers.

With over 140 butterfly species calling Pennsylvania home, there’s a good chance you’ll cross paths with one of these beautiful insects on your next hike or stroll around the backyard. Keep an eye out for flashes of color dancing through the air!