Baltimore checkerspot

not listed

N4 - Apparently Secure

S4 - Apparently Secure

not listed

Baltimore checkerspot is a geographically variable, medium-sized butterfly. It is the official state insect of Maryland.

Adults have a wingspan of 1¾″ to 2¾″.

The upper side of both wings is black with orange marginal spots, 2 or 3 rows of white submarginal spots, and a few to several median orange spots and white spots. In flight it looks mostly black.

The underside of both wings is black with orange marginal spots, four rows of submarginal white spots, then four alternating median rows of orange and white spots.

The club at the tip of the antenna is bright orange.

The caterpillar is up to 1¾″ long, orange-and-black striped, and spiny. The head and the first and second thoracic segments are black. The first eight abdominal segments each have a broad orange band and two narrow sets of alternating black and orange bands. Each broad orange abdominal band has several black, branched spines (scoli). The branches of the scoli are hair-like and nearly as long as the scolus is tall. The ninth and tenth abdominal segments are black.

Wingspan: 1¾″ to 2¾″

Marshes, wet meadows, bogs, and swamps

One brood from mid-June to early August

In the spring the female lays a group of 100 to 700 eggs on a leaf of a host plant. The hatched larvae move to the tip of the plant and create a silky web. They feed within the web, expanding it downward as the season progresses and more of the plant is consumed. In August they spin a compact, pre-hibernation web and stop eating. In October they leave this nest and descend to the ground as a group. On the ground they split into smaller groups. Each small group constructs a hibernating web from dead grass, leaves, and other debris in which they will spend the winter.

First-stage larvae: White turtlehead (Chelone glabra) and English plantain (Plantago lanceolata).

Fourth-stage larvae: A wider variety of plants including ash (Fraxinus spp.), viburnum (Viburnum spp.), honeysuckle (Lonicera spp.), and those species listed above.

Flower nectar of shrubby cinquefoil (Dasiphora fruticosa ssp. floribunda), spreading dogbane (Apocynum androsaemifolium), black-eyed Susan (Rudbeckia hirta), milkweed (Asclepias spp.), viburnum (Viburnum spp.), and rose (Rosa spp.).

Sources

7, 20, 21, 29, 30, 71.

Uncommon and local

Adult Dorsal View

Adult Ventral View

Caterpillar