Edwards' Hairstreak (Satyrium edwardsii [Grote & Robinson])
Wing span: 1 1/8 - 1 1/2 inches (3 - 3.8 cm).
Identification: One tail on the hindwing. Underside of hindwing pale brown, with postmedian band of dark brown oval spots; blue tail-spot not topped with orange.
Life history: Males perch on trees to watch for females. Eggs are laid in bark crevices of young hosts. Young caterpillars eat buds during the day. Older caterpillars eat leaves at night and hide during the day in ant nests at the base of the host tree. In return for protection, the ants feed on honeydew produced by the caterpillars.
Flight: One flight from June-July in the north, May-July in the south.
Caterpillar hosts: Scrub oak (Quercus ilicifolia) and occasionally black oak (Q. velutina).
Adult food: Nectar from various flowers including dogbane, goldenrod, meadowsweet, milkweeds, New Jersey tea, staghorn sumac, and white sweet clover.
Habitat: Oak thickets in rocky open habitats including sand barrens, shale barrens, and limestone ridges.
Range: Eastern United States from southern Canada and southern Maine south to northeast Texas, central Missouri, and northern Georgia.
Conservation: Not usually required.
The Nature Conservancy Global Rank: G4 - Apparently secure globally, though it might be quite rare in parts of its range, especially at the periphery.
Management needs: None reported.
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. Shapiro, A.M. 1966. Butterflies of the Delaware Valley. American Entomological Society Special Publication. Philadelphia, PA. 79 pp. Tietz, H.M. 1952. The Lepidoptera of Pennsylvania. The Pennsylvania State College School of Agriculture Agricultural Experiment Station. State College, PA. 194 pp. Wright, D.M. 1995, Atlas of Pennsylvania Butterflies. Special Private Publication, Lansdale, PA. 22 pp.