Baltimore Checkerspot (Euphydryas phaeton)
The Baltimore Checkerspot is a species of very brightly colored butterflies that were once widely spread throughout its range and is now experiencing significant declines in recent years. Conservation measures have been adopted in places like Maryland, where the species has become extremely rare.
Scientific Classification
- Family: Nymphalidae
- Genus: Euphydryas
- Scientific Name: Euphydryas phaeton
Description and Identification
Caterpillar
Mature larvae have a black head, with alternating bands of black and bright yellow lines and marks all over, while the entire body is covered with spine-like protrusions arranged along the alternating bands. The newborn caterpillars move to the plant tip, consuming the leaves of the host plant in a web-like pattern. They spend the entire winter as half-grown caterpillars, hibernating under dead grass and leaves.
Pupa
The chrysalis is pure white with spots and markings in bright orange-yellow and black. The stage lasts for around two weeks before the adult emerges.
Adult Butterfly
Sexual Dimorphism: Not present
Color and Appearance: When the wings are open, the four wings show a black base with two broad, banded borders, with the inner one showing checkers in white and the outer one in orange to yellowish-orange. Also, there are orange spots on the black base. When the wings are closed, it shows a similar view, except that, the white patterns are more intense, and hence looks brighter.
Average wingspan: 1.5 to 2.5 inches
Flight pattern: Fast and erratic; looks rather dull and black while in flight
Quick Facts |
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Distribution | West of Nova Scotia, throughout the Great Lakes region to SE Manitoba; almost the entire southern parts of the eastern US to the north in Georgia, Mississippi, and Oklahoma |
Habitat | Open and sunny wet meadows, but also in upland fields |
Lifespan of adults | Believed to be about 6 to 9 months |
Host plants | Turtlehead (Chelone glabra) before winter; ash (Fraxinus), viburnums, penstemon, plantains (Plantago), and honeysuckle (Lonicera) during spring |
Adult diet | Nectar from flowers (especially milkweed, viburnum, and wild rose) |
Did You Know?
- The butterfly gets its name after the early American colonist and politician George Calvert, the first Baron of Baltimore whose crest was orange and black.
- These arthropods are poisonous to birds.
- As a behavioral adaptation, they advertise their bad taste spreading their brightly-colored wings while feeding on nectar.
- The species is very rarely seen in gardens.
- Since 1973, it is the state insect of the U.S. State of Maryland.

