Frosted Elfin (Callophrys irus [Godart])
Wing span: 1 - 1 1/4 inches (2.5 - 3.2 cm).
Identification: One short tail on the hindwing. Upperside brown; male with long oval dark spot on leading edge of forewing. Below, postmedian line of forewing is irregular; that of hindwing is faint. Hindwing with submarginal black spot above tail.
Life history: Eggs are laid singly on flower buds of host plant; caterpillars eat flowers and developing seedpods. Chrysalids hibernate in loose cocoons in litter beneath the plant.
Flight: One flight from March-April in the south, May-June in the north.
Caterpillar hosts: Members of the pea family (Fabaceae): wild indigo (Baptisia tinctoria) and lupine (Lupinus perennis); occasionally blue false indigo (B. australis) and rattlebox (Crotalaria sagittalis).
Adult food: Flower nectar.
Habitat: Open woods and forest edges, fields, scrub.
Range: Occurs in local colonies from Maine west across New York and southern Michigan to central Wisconsin; south along Atlantic coast and Appalachians to northern Alabama and Georgia. Isolated colony in eastern Texas, northwest Louisiana, and southwest Arkansas.
Conservation: Populations are often small and local. Callophrys irus hadros of east Texas is particularly limited.
The Nature Conservancy Global Rank: G3 - Very rare or local throughout its range or found locally in a restricted range (21 to 100 occurrences). (Threatened throughout its range).
Management needs: Maintain habitat by controlled burns or other physical means.
Opler, P. A. and G. O. Krizek. 1984. Butterflies east of the Great Plains. Johns Hopkins University Press, Baltimore. 294 pages, 54 color plates. Opler, P. A. and V. Malikul. 1992. A field guide to eastern butterflies. Peterson field guide #4. Houghton-Mifflin Co., Boston. 396 pages, 48 color plates. Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates.
Author: Jane M. Struttmann
State and Regional References:
Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998. The Butterflies of Canada. University of Toronto Press, Toronto, ON. 280 pp. Nielsen, Mogens C., 1999. Michigan Butterflies and Skippers: A Field Guide and Reference. Michigan State University Extension, East Lansing, MI. 248 pp. Opler, P.A. 1998. A field guide to eastern butterflies, revised format. Houghton Mifflin Co., Boston.