Home / Brush-Footed (Nymphalidae) / Bay Checkerspot (Euphydryas editha bayensis)

Bay Checkerspot (Euphydryas editha bayensis)

Bay Checkerspot Butterfly

The Bay Checkerspot is a threatened subspecies of Edith’s checkerspot butterfly found in a very small region of the United States. It is the black banding of this butterfly that gives it its unique appearance and its name.

Scientific Classification

  • Family: Nymphalidae
  • Genus: Euphydryas
  • Scientific Name: Euphydryas editha bayensis


Description and Identification


Bay Checkerspot Butterfly Caterpillar

The mature larva of the bay checkerspot is black in color with numerous hairy growths all over the body in small tufts. There is also a dotted line in bright yellow or orange, running vertically through the middle of the dorsal side.


The chrysalis is white in color with uneven markings in orange and black that gives the pupa an almost similar look like the adult stage.

Adult Butterfly

Sexual Dimorphism: Not present

Color and Appearance: When the wings are open, the dorsal side of the forewings show markings with black bands along the veins of the wing’s upper part contrasting sharply with bright red, yellow and white spots. When the wings are closed, the ventral part displays a mirror image of the upper side.

Euphydryas Editha Bayensis

Average wingspan: Little more than 2 inches (51 mm)

Flight pattern: Medium to fast


Females can lay up to five masses of eggs, with each containing 2 to 250, deposited at the base of the host plant

Quick Facts

Distribution San Francisco Bay region of the U.S. state of California
Habitat Ridge tops, open woodlands, alpine tundra, grasslands and rocky outcrops of the mountains
Host plants Plantago erecta, Castilleja exserta, Castilleja densiflora
Adult diet Flower nectar

Did You Know?

  • The male butterflies typically emerge four to eight days before the female.

Bay Checkerspot Butterfly Habitat


Bay Checkerspot Butterfly Images

Bay Checkerspot Butterfly Photos

Pictures Of Bay Checkerspot Butterfly

Bay Checkerspot Butterfly Pictures

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