silvery checkerspot

not listed

N5 - Secure

S4S5 - Apparently Secure to Secure

not listed

Silvery checkerspot is a medium-sized brush-foot butterfly. It has a wingspan of 1½″ to 2″.

The upperside of both wings is orange with a broad black margin, a black and white fringe, and other black markings. The amount of black markings is highly variable. The basal and discal areas are sometimes mostly black with a few irregular orange spots, sometimes mostly orange with irregular black spots and jagged lines.

The upperside of the forewing has four irregular black patches: a subapical patch that merges with the black border; a submarginal patch near the inner margin that merges with the black border; a median patch on the leading (costal) margin; and a median patch on the inner margin. The median area in the first two cells is tawny or pale orange. In the discal area there are 5 or 6 irregular black-bordered orange spots toward the costal margin and one elongated black-bordered orange spot toward the inner margin. The subapical area has a row of 5 tawny or pale orange spots. The three nearest the apex are very small.

The upperside of the hindwing no spots or faint chevron-shaped spots within the black border. There is a jagged, uninterrupted, postmedian line and a postmedian row of black spots. The spots are surrounded by orange, they do not touch the black border. At least one spots on each hindwing has a white center. The discal area is mostly black with a few orange spots.

The underside of the wings are very distinctive and are the best identifying feature. The underside of the forewing is orange with a medial row of four black spots; a black apical area; a postmedian row of 5 pale orange or white spots; a submarginal band of black-rimmed pale orange or white crescent-shaped spots; an orange marginal band; and a thin black line on the outer margin. The underside of the hindwing is orange with many black-rimmed white or pale orange spots. There are several spots in the basal area; three bands of connected spots in the median area; a band of tiny postmedial spots; and an uninterrupted band of crescent-shaped submarginal spots. The marginal band is orange and there is a thin black line on the outer margin.

The underside of the hindwing is tawny and pale orange with brown markings. There are three distinct bands of brown-bordered white spot; a discal band, a median band, and a submarginal band. The submarginal band is interrupted with a dark patch and a large silvery crescent.

The caterpillar is up to 13 ⁄16″ long and black with a dusting of numerous tiny white spots. The spots are the expanded base of the hairs (seta). On the thorax and each abdominal segment there is a short, black, branched spine (scolus) in the middorsal, subdorsal, supraspiracular, spiracular, and subspiracular regions. There is often, but not always, one broad or two narrow, yellow to orange, subspiracular stripes. The head is shiny black. Mature caterpillars are found in late May and June.

1½″ to 2″ wingspan

Woodland openings and edges, meadows, marshes, streamsides, roadsides.

One brood: Late May to early September, but mostly early June to late July

If disturbed, the caterpillar will curl up and fall to the ground.

Adults fly slowly and usually no more than one foot off the ground.

After mating in the spring the female lays rafts of up to 100 eggs on on the underside of a leaf. The young caterpillars feed and move together, skeletonizing the leaves. The third stage instar caterpillar overwinters in a “special brown skin” at the base of a host plant in a reduced metabolic state (diapause). In the spring the caterpillar resumes feeding.

Plants in the Asteraceae family, including coneflower (Rudbeckia), sunflower (Helianthus), aster (Symphyotrichum), and wingstem (Actinomeris alternifolia).

Flower nectar of red clover, dogbane, common milkweed, staghorn sumac, vetches, and fleabane.

Sources

7, 20, 21, 24, 29, 71.

Common, locally abundant

Upperside

Underside

Location:Llindstrom, MN

Location: Woodbury, Minnesota

Location: Wild River State Park