Julia (Dryas julia Fabricius)
Wing span: 3 1/4 - 3 5/8 inches (8.2 - 9.2 cm).
Identification: Forewings elongate. Male bright orange above and below; upperside of hindwing with narrow black border on outer margin. Female duller orange, with more black markings above.
Life history: Males patrol all day for receptive females. Eggs are laid singly on new growth; caterpillars feed on leaves. Adults forage along a set route of nectar sources each day in a behavior known as "trap-lining".
Flight: Throughout the year in southern Florida and South Texas, strays to the north in summer.
Caterpillar hosts: Passion-vines including Passiflora lutea in Texas.
Adult food: Nectar from flowers including lantana and shepherd's needle; probably others.
Habitat: Subtropical hammock openings and edges, and nearby fields.
Range: Resident in Brazil north through Central America, Mexico, West Indies, peninsular Florida, and South Texas. Strays north to eastern Nebraska.
Conservation: Not usually required, but habitat in South Texas is limited.
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.
Author: Jane M. Struttmann
State and Regional References:
Brown, F.M., Eff, J.D., and B. Rotger. 1957. Colorado Butterflies. Denver Museum of Natural History, Denver. Ferris, C.D. and F.M. Brown. 1980. Butterflies of the Rocky Mountain States. University of Oklahoma Press. Norman. 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. 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.