Extension Communications 3614 Administrative Services Building Ames, Iowa 50011-3614 (515) 294-9915

8/29/03

FOR IMMEDIATE RELEASE

Contacts:
Mary Harris, Reiman Gardens, (515) 294-2567, maharris@iastate.edu
Jean McGuire, Continuing Education and Communication Services, (515) 294-7033, jmcguire@iastate.edu

Saving the Regal Fritillary

Mary Harris
Curator
Christina Reiman Butterfly Wing

Working at the Christina Reiman Butterfly Wing, a public exhibit of live butterflies, I often overhear our visitors lamenting, "I just don't see as many butterflies outside as I used to." These comments occur following a walk through the butterfly wing, where hundreds of butterflies from around the world can be seen year-round. Visitors are reminded of the abundance of native butterflies they had seen many years ago in Iowa.

This summer at Reiman Gardens, we have provided a nectar smorgasbord throughout the 14-acres of outdoor gardens. At this time of year, the outdoor gardens should be aflutter with the wings of many species of native butterflies however; only two or three species are present.

One of the butterfly species that we should be seeing at the Gardens is the Regal Fritillary, Speyeria idalia. According to the USGS Northern Prairie Wildlife Research Center, the Regal Fritillary in Iowa is "rapidly vanishing or declining in much of its range." The primary reason for the Regal's absence is loss of habitat: the tall grass prairie. In Iowa and neighboring Illinois, less than 1% of native tall grass prairie and wetland habitat remain. Without the host plants found growing in these habitats species like the Regal Fritillary have disappeared.

The disappearance of the Regal Fritillary is a tremendous loss. This butterfly is one of the largest of all our natives with a wingspan that can exceed 4 inches. Fritillaries, including the Regal's forewings, are often rusty orange with black veins and spots. The Regal is particularly beautiful with dark blue-black hind wings bordered by two rows of cream-colored spots in the female. In the male, the marginal row of spots is rusty orange. The undersides of the wings of both sexes are brown with very large silvery white spots.

The Regal Fritillary depends on violets; primarily bird's foot violet, Viola pedata, as host material for the caterpillars. Areas containing these violets are now scarce leaving this butterfly, as Barry Williams has written, "in the unfortunate predicament of being a rare species in a rare habitat."

Even in areas where the violet host plant is present, violets are a cool season plant. Violets tend to leaf out and bloom during the spring when temperatures in the tall grass prairie habitat are still cool. When the temperatures rise, violets desiccate until the next growing season the following spring. The Regal Fritillary must coordinate its reproductive effort to coincide with the phenology of its host plant.

To accomplish this coordination adult female Regal Fritillary butterflies deposit their eggs in late August. After approximately 10 days, the first instar caterpillars emerge from the egg. These tiny caterpillars will pass the winter in the leaf litter and become active again in the spring when the violets begin to expand. The larvae will feed until they pupate in late spring. Regal Fritillary males begin to emerge in June and a couple of weeks later the females emerge and mating occurs.

The adult female Regal Fritillary diapauses (enters a resting state) to pass the hot summer months before she deposits eggs for the next generation. These traits of adult diapause and over wintering by the fragile first instar larva have created difficulties for researchers attempting to captive-rear this butterfly species. If these difficulties can be overcome, captive-reared individuals could be reintroduced to areas that have been restored to tall grass prairie.

Diane Debinski, a member of the Iowa State University Ecology, Evolution and Organismal Biology Department, and her students in cooperation with Reiman Gardens are working toward this goal of reintroduction. Adult female Regal Fritillaries will be collected in southwestern Iowa and brought to the butterfly lab at the Gardens. These captive females will be provided with the conditions necessary for egg deposition. The eggs will be collected and the emergence of the neonates awaited.

Once these tiny caterpillars have emerged we will have the difficult job of simulating the appropriate conditions for the larvae to over winter. If successful, and if the neonate and subsequent caterpillar stages feed, we plan to release these animals next summer at the Neal Smith Prairie.

We also hope to be able to release Regal Fritillaries into the Butterfly Wing so that visitors to Reiman Gardens can see this magnificent representative of Iowa's once vast native prairie habitat.

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Editors: A color photo, suitable for publication, is available at right. Click on the thumbnail photo to go to the fullsized photo. The picture's fullsize photo is 288K. Caption: Regale Male

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