Mottled Duskywing (Erynnis martialis [Scudder])
Wing span: 1 1/8 - 1 5/8 inches (2.9 - 4.2 cm).
Identification: Upperside: Brown background and irregular dark bands contribute to the mottled appearance of both wings. Freshly-emerged butterflies have a purplish iridescence. Male has a costal fold containing yellow scent scales; female has a patch of scent scales on the 7th abdominal segment.
Life history: To wait for females, males perch and patrol on ridges and hills during the day, sitting on the ground or on tips of twigs. Females deposit eggs singly on the host plant. Fully-grown caterpillars hibernate.
Flight: Two broods from April-September.
Caterpillar hosts: Wild lilacs including New Jersey tea (Ceanothus americanus) and redroot (Ceanothus herbaceus var. pubescens) in the buckthorn family (Rhamnaceae).
Adult food: Nectar from flowers of bush houstonia, gromwell, hoary vervain, and other plants.
Habitat: Open woodland, barrens, prairie hills, open brushy fields, chaparral.
Range: Massachusetts and southern Ontario west across the Great Lake states to Minnesota; south to South Carolina, the Gulf Coast, and central Texas. Isolated populations in eastern Wyoming, eastern Colorado, and western South Dakota.
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. Stanford, R. E. and P. A. Opler. 1993. Atlas of western USA butterflies including adjacent parts of Canada and Mexico. Denver and Fort Collins, CO. 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:
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.