Speyeria idalia

Regal Fritillary (Speyeria idalia) Life History: The regal fritillary population size seems to fluctuate. In some years individuals will be abundant and will scatter more widely while in other years, they are scarce. There is a single annual generation in this species. In South Dakota the first males appear in mid-June and fly until August, while the females flight period is early July to mid-September. The light brown eggs are laid near violets. After hatching, the unfed caterpillars over-winter beneath leaves on the ground. In spring, as temperatures rise, the larvae begin feeding on the leaves of violets. They are nocturnal feeders, staying hidden during the day. Mature larvae are velvety black with dull yellow to reddish orange stripes and six rows of tapering, fleshy spines. When full grown, the caterpillars shed their skin and form a light brown chrysalis with black spots. About two weeks later, the chrysalis splits open and the adult emerges.