Regal Fritillary

Regal Fritillary

Regal fritillaries (Speyeria idalia) are colorful prairie butterflies that once ranged more than a million square miles. Today the species range is less than half that size and has almost disappeared east of the Mississippi.

These butterflies can be confused with a Monarch butterfly with their bright red-orange with black forewings. Regal fritillaries have black hind wings with a row of white spots on the lower edge of the hind wing.

Wing Span:
Somewhat smaller than a Monarch, its wingspans is 2- 5/8 to 4- 1/8 inches (6.7 - 10.5 cm).

Life History:
Males patrol for females with a low, steady flight. Females walk through vegetation to lay single eggs on various plants, even if the host violets are not present. Most eggs are laid in August. The caterpillars hatch and overwinter unfed; in spring they eat leaves of violets.

One brood from mid-June to mid-August.

Caterpillar Food/Host:
Violets including bird's foot violet, prairie violet, and Nuttal’s violet.

Adult Food:
Adults use variable sources of nectar including from flowers of milkweeds, thistles, blazing stars, and purple coneflower.
Tall-grass prairie and other open sites including damp meadows, marshes, wet fields, and mountain pastures. Regal fritillaries are found on existing native prairie sites on Tewaukon National Wildlife Refuge.

Tall-grass prairie remnants in Montana and eastern North Dakota south to Colorado, Nebraska, and Oklahoma; rare or absent from former range east of the Mississippi River.

Rapidly vanishing or declining in much of its range this is a species of concern for the US Fish & Wildlife Service. Staff at Tewaukon National Wildlife Refuge are reconstructing prairie communities on former cropland and areas that have exotic, single species plant communities. We are also keeping our existing native prairie areas healthy by using burning and grazing to favor the native plant community.