Common Wood Nymph (Cercyonis pegala [Fabricius])
Wing span: 1 3/4 - 3 inches (4.5 - 7.6 cm).
Identification: Geographically variable. Wings are brown. Upperside of forewing has 2 large yellow-ringed eyespots. Lowerside of hindwing has a variable number of small eyespots. Southern and coastal butterflies are larger and have a yellow or yellow-orange patch on the outer part of the forewing. Inland butterflies are smaller and have the yellow forewing patch reduced or absent.
Life history: Males patrol for females with a dipping flight through the vegetation. In late summer, females lay eggs singly on host plant leaves. Caterpillars hatch but do not feed, instead hibernating until spring.
Flight: One brood from late May-October. Females emerge later than males.
Caterpillar hosts: Purpletop (Tridens flavus) and other grasses.
Adult food: Rotting fruit, flower nectar.
Habitat: Large, sunny, grassy areas including prairies, open meadows, bogs, and old fields.
Range: Southern Canada and the continental United States except for most of the Southwest and Texas, southern peninsular Florida, and northern Maine.
Conservation: Isolated populations in Great Basin wetlands may be of 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:
Nekola, Jeffrey C. 1995. County Distribution Maps of Iowa Butterflies and Skippers. Dept. of Natural and Applied Sciences, Univ. of Wisconsin, Green Bay, WI. 30 pp. Opler, P.A. 1998. A field guide to eastern butterflies, revised format. Houghton Mifflin Co., Boston.