Mitchell's Satyr Butterfly

Neonympha mitchellii mitchellii

Description

Mitchell's satyr is a medium-sized butterfly of the Satyridae subfamily of the Nymphalidae family. It has a wingspan of 1.5-1.7 in (3.8-4.4 cm) and is rich brown overall. The lower surfaces of all four wings show a series of yellow-ringed, black, circular eye-spots with silvery centers. There are two orange bands across the posterior wing edges and lighter orange bands across the wing centers. The species has also been known by the names Cissia mitchellii and Euptychia mitchellii.

Behavior

The host plant for Mitchell's satyr is believed to be a sedge, possibly more than one species. Adults are active during a brief two-to three-week period in the summer. In early-to mid-July females lay eggs, which hatch in seven to 11 days. The larvae overwinter on sedge leaves and emerge the following May to continue their growth and pupation. The species has a single, short flight period each summer, which lasts about a week for the individual butterfly, and for about three weeks for the local population (late June through mid-July). Mitchell's satyr is relatively sedentary and has a slow, low-level flight pattern.

Habitat

This butterfly is restricted to wetland habitats known as prairie fens, which are characterized by calcareous soils fed by carbonate-rich water from seeps and springs. This uncommon habitat, which is often part of larger wetland complexes, is characterized by tamarak (Larix laricina ), poison sumac (Toxicodendron vernix ), dogwood (Cornus spp.), and a ground cover of sedges (Carex spp.), shrubby cinque-foil (Potentilla fruticosa ), and other prairie species.

Distribution

Mitchell's satyr was first described in 1889 from specimens collected in Cass County, Michigan. It has been known from about 30 locations in four states. Its historic range included southern Michigan, northeastern Indiana, and northwestern Ohio. In addition several separate populations were known from New Jersey.

It is believed that Mitchell's satyr survives at only 15 sites in nine counties in southwestern Michigan and northeastern Indiana. Intensive surveys of historical sites and suitable habitat were conducted between 1985 and 1990. No populations were found in Ohio, and a population found in New Jersey was eliminated by collectors soon after the area was surveyed.

The U. S. Fish and Wildlife Service (FWS) considers the species Endangered in Indiana, Michigan, and Ohio.

Threats

The main threats to surviving populations of Mitchell's satyr are collectors and the conversion of the butterfly's unique wetland fen habitat. One Michigan site has been destroyed by urban development, and several other sites in Michigan and Ohio have been converted to agricultural use.

Collectors, however, are the greatest immediate threat to the species. Mitchell's satyr is considered a prize specimen by many butterfly collectors and it is clear that collectors have been responsible for the loss of a number of populations, including two in New Jersey. Several Michigan sites are under strong collecting pressure. About one-third of the surviving populations are extremely vulnerable to local extinction through collection, and all known sites are susceptible to this danger.

Conservation and Recovery

Because of the continuing threat from collectors and the fact that half of the known populations had vanished in a period of five years, on June 25, 1991, the FWS listed Mitchell's satyr as endangered on an emergency basis. This gave the species protection under the Endangered Species Act during its 1991 flight period, and, it was hoped, eased the pressure from collectors. Mitchell's satyr received long-term protection as an endangered species on May 20, 1992.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1 Federal Drive
BHW Federal Building
Fort Snelling, Minnesota 55111
Telephone: (612) 713-5360
http://midwest.fws.gov/

References

Martin, M. L. 1987. "Mitchell's Satyr (Neonympha mitchellii ) in Indiana." Michigan Natural Features Inventory, Lansing.McAlpine, W. S., S. P. Hubbell, and T. E. Pliske.1960. "The Distribution, Habits, and Life History of Euptychia mitchellii (Satyridae)." Journal of the Lepidopterist Society 14 (4): 209-225.