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.
References:
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:
Glassberg, J. 1993. Butterflies Through Binoculars: A Field Guide to Butterflies in the Boston-New York-Washington Region. Oxford Univ. Press, New York, N.Y. 160 pp. Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998. The Butterflies of Canada. University of Toronto Press, Toronto, ON. 280 pp. Opler, P.A. 1998. A field guide to eastern butterflies, revised format. Houghton Mifflin Co., Boston. Woodbury, E.N. 1994. Butterflies of Delmarva. Delaware Nature Society, Inc., Tidewater Publishers, Centreville, MD. 138 pp. [NOTE: this book only treats True Butterflies (Papilionoidea). It does not treat Skippers (Hesperioidea).]