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North Dakota's

Federally Listed Endangered, Threatened, and Candidate Species – 1995

Regal Fritillary Butterfly (Speyeria idalia)

JPG -- species photo gif--species map

Status: Former Candidate (Note: As of February 28, 1996, this species is no longer listed as a Candidate species. However, it remains a species of management concern.)
Historical Status:: The original range of the regal fritillary was from the central east coast, then west to Montana and Colorado, and then south to Oklahoma.
Present Status:: The regal fritillary is extirpated (no longer exists) in Canada, most of New England, and the Ohio Valley. It is presently found only in scattered populations. It seems to be rapidly declining in the prairie states. It is now restricted in North Dakota to the southeastern and south-central counties. It is commonly found in the Sheyenne National Grasslands in southeastern North Dakota.
Habitat:: The regal fritillary is always associated with open grass-like areas. Tall grass prairie is typical habitat in the western part of its range with bluestem grass being an indicator of the proper habitat. In the east part of its range the regal fritillary is found in damp meadows and marshy areas.
Life History:: The butterflies emerge from their over winter larval (caterpillar) state in late June to early July, with the males emerging a week before the females. Milkweed, thistles, and clover are used by the adults as nectar sources. The males patrol areas throughout the day looking for receptive females. They are especially active in late morning and early afternoon. After mating, the females diapause (rest) until late summer, when the eggs are laid singly on a variety of plants. The larvae feed during the night and are obligate violet feeders (they feed only on the leaves of violets). During the day the larvae move away from the violet plant and hide. Unlike some other species of butterfly, the larvae of the regal fritillary do not build nests. The larvae may reach 1 3/4 inch in length and are mostly black in color. The regat fritillary is wide ranging compared to many other butterfly species.
Aid to identification:: Like many true butterflies, the regal fritillary has a club-like appearance at the end of the antennae. The wingspan of the regal tritillary ranges from 3 to 4 inches. The orange color and black and white hind wings are good identifying characteristics. Flight is rapid, fluttery, and tireless, with the black hind wing readily visible.
Reasons for decline:: Loss of native habitat is the main reason for the decline. Pesticides are also a problem. Loss of nectar sources due to herbicides may be a problem.
Recommendations:: Remaining pockets of tall grass prairie should be protected. Pesticide use should be restricted where regal fritillaries are found.
Comments:: The "regal" in the regal fritillaries name comes from its majestic, regal-like appearance. The U.S. Fish and Wildlife Service in North Dakota is currently conducting a population status on the regal fritillary.
References:: Butterflies of North Dakota by Ronald Royer, 1988.

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