Common Wood-Nymph

The Common Wood-Nymph is a widespread satyr butterfly (subfamily Satyrinae, family Nymphalidae) found across much of the United States and southern Canada. It is one of the most variable North American butterflies, with populations differing dramatically in the size of the yellow forewing patch and the number of eyespots from region to region.

Despite its name, the Common Wood-Nymph is more a butterfly of open grassy habitats than deep woodland, frequenting prairies, meadows, and roadsides rather than closed-canopy forest. Its caterpillars feed on grasses, tying the species closely to grassland ecosystems.

Its bouncing, erratic flight low over vegetation and its habit of quickly diving into grass when disturbed make it a distinctive, if sometimes hard-to-approach, sight in summer fields.

• Large brown satyr butterfly with one or two prominent black eyespots, each with a white or bluish pupil, near the forewing tip.
• Many populations show a bold yellow-orange patch surrounding the forewing eyespots, though this patch is greatly reduced or absent in some regional forms.
• Hindwing is plain brown with a few smaller eyespots along the margin.
• Underside is finely mottled brown providing camouflage in dry grass.
• Larger and generally darker brown than the Little Wood-Satyr, with fewer but bolder eyespots.

Ranges across most of the continental United States and southern Canada, in open grassy habitats including prairies, hayfields, roadsides, open woodland edges, and old fields. Adults fly in mid- to late summer, typically from July through September depending on region.

Adults fly with a distinctive slow, bouncing flight low over grass, often dropping abruptly into vegetation to evade predators or observers. They feed on flower nectar as well as sap and rotting fruit, and males patrol grassy areas searching for newly emerged females. Caterpillars feed on a variety of native grasses and, as adults, the butterflies contribute to pollination of late-summer wildflowers.

Eggs are laid singly on or near grass blades in late summer. Newly hatched caterpillars do not feed before winter, instead entering dormancy shortly after hatching and overwintering in leaf litter as tiny first-instar larvae. In spring they resume feeding on grasses, developing through several instars before pupating. There is one generation per year across most of the range.