Dusky Azure (Celastrina nigra Edwards)
Wing span: 7/8 - 1 1/4 inches (2.2 - 3.2 cm).
Identification: Upperside of male gray-black; female dark with areas of gray-blue. Underside of hindwing with prominent black spots in submarginal row.
Life history: Males patrol for females. Eggs are laid singly under young leaflets of host plant. Caterpillars feed on leaves and chrysalids hibernate.
Flight: One brood from April-May.
Caterpillar hosts: Goat's beard (Aruncus dioicus) in the rose family.
Adult food: Flower nectar, including wild geranium.
Habitat: Shady and moist deciduous woods.
Range: Southern Appalachians, Ohio River Valley, central Illinois, and northwest Arkansas.
Conservation: Habitats may be threatened by the spread of garlic mustard (Alliaria officinalis) in the mustard family.
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: Protect habitats from alteration and invasion by exotic plants.
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.