Baltimore Checkerspot

Euphydryas phaeton

Quick Facts

  • Species

    Native

  • Habitat

    The Baltimore checkerspot lives in wet, weedy meadows. Breeding habitat depends on presence of their host plants, including white turtlehead before winter and ash, viburnums, penstemon, plantains and honeysuckle during spring. They often live in colonies. 

  • Range

    The range of the Baltimore checkerspot extends from southern Canada and the eastern United States to the mountains of Virginia and North Carolina and west across the Great Lakes region. 

  • Diet

    White turtlehead leaves and nectar

  • Lifespan

    1 year

  • Status

    Threatened

The Baltimore checkerspot is a black, orange and white butterfly that feeds on white turtlehead leaves and nectar. It can be found in the entire Chesapeake Bay region.

Appearance

The Baltimore checkerspot has three distinct life stages, each with their own appearance. As a caterpillar, the Baltimore checkerspot has a black head and a body covered in alternating bands of black and bright yellow lines, with spine-like protrusions arranged along the alternating bands. As a pupa, the Baltimore checkerspot has a white chrysalis with bright orange-yellow and black markings. The adult Baltimore checkerspot butterfly has four wings with a black base with orange spots and two broad, banded borders, with the inner one showing checkers in white and the outer one in orange to yellowish-orange. Their wingspan is about 2.5 inches.

Feeding

Baltimore checkerspot caterpillars start feeding on white turtlehead (Chelone glabra L.) in the summer when the caterpillars are small. As they grow, Baltimore checkerspot caterpillars use a variety of host plants in addition to turtlehead, including arrowwood viburnum, narrow-leaved plantain, penstemon and honeysuckle. Adult Baltimore checkerspots feed on nectar from flowering plants that bloom during their flight period, such as milkweeds, dogbane, several species of mountain mint, wild rose and wild blackberry. 

Predators

As caterpillars, the Baltimore checkerspot suffers high mortality from falling off host plants and from parasitism by wasps. To combat these predators, newly-hatched caterpillars build a communal web at the end of their host plants’ leaves where they’re more protected from parasitic wasps. Once a butterfly, however, the Baltimore checkerspot is poisonous and bad tasting. They advertise these adaptations to predators like birds by spreading their brightly-colored wings while feeding on nectar. 

Flight

The flight pattern on Baltimore checkerspots is fast and erratic. While in flight, it’s bright wings can dull and black. 

Reproduction and Life Cycle

The life cycle of Baltimore checkerspots begin in early summer when male adults perch near the ground to find females. After mating, female butterflies lay one brood of 100 to 700 eggs under the leaves of white turtlehead, the Baltimore checkerspot’s larval host plant. Eggs start out yellow and change to red over a period of about 20 days, when they hatch into tiny caterpillars. Newly-hatched caterpillars move to the tip of the plant and feed together in a web which is enlarged downward as the caterpillars consume more of the plant. The caterpillars will continue to eat, grow and molt throughout the summer. Once it starts to get colder, they hibernate in dead leaves and grass on the ground until the weather warms in mid-April and the caterpillars become active and resume feeding. Baltimore checkerspot caterpillars then form a chrysalis and start their two-week transformation into butterflies. Once the adult butterflies emerges, the cycle repeats. 

Did You Know?

  • The Baltimore checkerspot is named for George Calvert, the first Lord Baltimore, because its orange and black colors match those on his heraldic shield. 
  • The Baltimore checkerspot has been the official insect of Maryland since 1973. 
  • The Baltimore Checkerspot has contributed to the spread of English plantain across the U.S. 
  • The Baltimore checkerspot is in the family Nymphalidae, also called the brush-footed butterflies due to their reduced front legs. This trait makes them appear to have four legs instead of six.
  • Maryland used to house multiple breeding colonies spanning 15 counties, but these numbers have decreased to 11 sites in seven counties. These colonies occur in the western and central portions of Maryland including the Appalachian Plateau, the Blue Ridge, the Ridge and Valley Region and in the Piedmont.

Sources and Additional Information

Protecting Maryland's State Insect: Introducing the Baltimore Checkerspot Recovery Team — Maryland Department of Natural Resources
Baltimore Checkerspot — Mass Audubon 
Baltimore Checkerspot Euphydryas phaeton — Butterflies and Moths of North America
Rare, Threatened and Endangered Animal Fact Sheet: Baltimore Checkerspot — Maryland Department of Natural Resources
Baltimore Checkerspot — Butterfly Identification
Conservation and Management of the Baltimore Checkerspot (Euphydryas phaeton Drury) in Maryland: Strategies for Statewide Monitoring and for Wetland Restoration, Captive Breeding and Release in the Piedmont Region — Maryland Department of Natural Resources 

Quick Facts

  • Species

    Native

  • Habitat

    The Baltimore checkerspot lives in wet, weedy meadows. Breeding habitat depends on presence of their host plants, including white turtlehead before winter and ash, viburnums, penstemon, plantains and honeysuckle during spring. They often live in colonies. 

  • Range

    The range of the Baltimore checkerspot extends from southern Canada and the eastern United States to the mountains of Virginia and North Carolina and west across the Great Lakes region. 

  • Diet

    White turtlehead leaves and nectar

  • Lifespan

    1 year

  • Status

    Threatened