Tawny Emperor (Asterocampa clyton [Boisduval & LeConte])
Wing span: 1 5/8 - 2 3/4 inches (4.2 - 7 cm).
Identification: Geographically variable. Upperside is chestnut brown; forewing with 2 brown bars in the cell, no white spots, and no eyespots near the outer margin. Hindwing uppersides are orange with black submarginal spots in one form, and all black in the other form.
Life history: Males perch on trees in full sun to watch for females. Eggs are laid in large groups of 200-500 on bark or the underside of mature leaves of host plants. Caterpillars eat leaves and young ones feed gregariously. Third-stage caterpillars hibernate in groups of about 10 inside a dead curled leaf.
Flight: One brood in the north from June-August, two broods in the south from March-November.
Caterpillar hosts: Trees of the elm family including Celtis occidentalis, C. tenuifolia, C. laevigata, C. lindheimeri, and C. reticulata.
Adult food: Tree sap, rotting fruit, dung, carrion. Tawny Emperors almost never visit flowers.
Habitat: Densely wooded riparian areas, dry woods, open woods, cities, fencerows, parks.
Range: North Dakota south to Texas, east to New England through most of the southeastern states. Isolated populations in Florida, southwest New Mexico, and southeastern Arizona.
Conservation: Not usually of ocnservation concern.
The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may 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. Tilden, J. W. 1986. A field guide to western butterflies. Houghton-Mifflin Co., Boston, Mass. 370 pages, 23 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. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Royer, R.A. 1988. Butterflies of North Dakota. Science Monograph #1, Minot State University, Minot, North Dakota. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass.