Common Wood nymphs are the largest species in the genus. They have two large well-defined eyespots on the forewings, with the rear eyespot at least slightly larger than the front eyespot (sometimes only slightly). The outer part of the ventral hindwings is a little lighter than, or the same shade as, the inner half of the wing.
The immature stages are not known from BC, and the details of the coloration of larvae and pupae (see the description of the genus) are known to be geographically variable.
Common Woodnymphs in southern BC, from Yale eastward, are subspecies ariane (Boisduval, 1852); TL: restricted to 2 miles south of Spanish Ranch, Plumas Co., CA (Emmel et al. 1998a). Subspecies boopis (Behr, 1864), into which BC populations have sometimes been placed, is restricted to California. Subspecies ariane is usually strongly marked on the underside of the wings, with the outer half of the ventral hindwing paler than the basal half. They frequently have a ventral row of one or more small submarginal spots, and sometimes have dorsal hindwing spots. Subspecies incana (W.H. Edwards, 1880) (TL: Olympia, WA) occurs from Vancouver Island south to the Willamette Valley, OR. The underside of the wings is a uniform grey brown, and one spot is always present on each dorsal hindwing. Subspecies ino Hall, 1924 (TL: Calgary,AB) occurs in the Peace River grasslands, and may also occur in extreme southeastern BC near Flathead. The underside of both forewings and hindwings is evenly light grey brown, except for a pale outer band, and there are no submarginal spots.
The name Cercyonis is derived from Cercyon, the son of Poseidon (Opler and Krizek 1984). The common name "woodnymphs" was first used by Holland (1898) in reference to the butterflies' bouncy flight in generally open forest habitat, similar to nymphs bounding through open forests.
Woodnymphs are medium-sized, dark brown butterflies with prominent eyespots on the forewings and sometimes smaller eyespots on the hindwings. The eyespots are usually larger in females than in males, and are set in a lighter band. Woodnymphs have a peculiar bouncing flight, similar to that of ringlets.
Eggs are laid singly on grass blades. They are pale yellow, becoming tan and mottled with orange brown as they mature. They are cylindrical and squat, with a flat top and ridges down the side. First instar larvae are thinly covered with thick curved hairs, and are green with light and dark longitudinal stripes. Mature larvae are slender, green, or yellow green, with light and dark longitudinal stripes down the back and sides. They are thinly covered with hairs, and have two short red tails. Pupae are roughly cylindrical, rounded, and suspended from a cremaster. They are green to yellow green, and in most species have white or yellow markings (Emmel 1969).
Eggs hatch about 10 days after oviposition (at 25°C), and the first instar larvae immediately enter hibernation. By spring the larvae have shrunk to half their original length before they come out of hibernation. Once they commence feeding, they primarily feed at night. There are five (oetus, sthenele) or six (pegala) larval instars. It takes oetus about 2 months to pupate in the wild, and sthenele and pegala 2.5-3 months. Pupation occurs near the base of a grass clump, with the pupa hanging from grass blades. Adults emerge after about 20 days (EmmeI 1969).
Common Woodnymphs are univoltine, and fly from July to September. There are six larval instars, and a female lays 200-300 eggs (Emmel 1969). Adults feed on flowers and on willow and poplar sap.
Larval foodplants in BC are probably grasses. Outside BC recorded foodplants include grasses and sedges such as Tridens flavus, Avena fatua, Stipa, Andropogon, and Carex (Shapiro and Shapiro 1974; Layberry et al. 1998; Bird et al. 1995). Scott (1992) records many other oviposition sites; eggs are frequently laid without being attached to anything, and fall into the litter on the ground.
Common Woodnymphs occur across southern BC in grassy forest openings, clearcuts, roadsides, meadows, and stream banks.
Common Woodnymphs occur from southern BC south to central CA and AZ, and across the continent to the Atlantic.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2019. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
21/11/2019 7:08:30 PM]
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