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Montana Field Guide

Montana Field Guides

Ruddy Copper - Lycaena rubidus

Native Species

Global Rank: G5
State Rank: S5

Agency Status


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General Description
[From Ferris and Brown 1981; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002] Forewing 1.6-1.9 cm. Sexually dimorphic. Uppersurface of males fiery red-orange with narrow black border and unchecked white fringe, female brown to dull orange-brown with black spots and dull orange marginal zigzag, narrow black border and unchecked white fringe. Undersurface of both sexes gray-white or pale tan-white with orange flush on forewing disk, hindwing with only tiny black spots if any, lacking orange zigzag of uppersurface.

One flight; mid-June to July at low elevation, mid-July to August at high elevation (Scott 1986). Mid-May to August, mainly June at low elevation and July to August at high elevation and in north (Glassberg 2001). Late June to mid-August in central Colorado (Emmel 1964), mid-June to early September in south-central Colorado (Scott and Scott 1978), mid-May to late-August in Oregon and Washington (Pyle 2002; Warren 2005).

Diagnostic Characteristics
Best determined by the wings of both sexes with a thin black line at margin and white unchecked fringe; the uppersurface of males fiery red-orange, females brown to dull orange with black spots; undersurface of both sexes off-white with an orange flush on the forewing disk and the hindwing with very small black spots if any at all.

Species Range
Montana Range Range Descriptions


Range Comments
Southern Alberta and southwestern Saskatchewan south to northern New Mexico, southern Utah, southern California, east to central North Dakota and Nebraska, west to eastern Washington and Oregon (Scott 1986; Opler and Wright 1999; Glassberg 2001), not yet reported from British Columbia (Guppy and Shepard 2001); 1402 m to 3353 m elevation in Colorado (Brown 1957; Scott and Scott 1978; Ferris and Brown 1981), 24 m to 1829 m elevation in Oregon (Warren 2005). In Montana, reported from at least 31 counties across the state (Kohler 1980; Stanford and Opler 1993; FLMNH Lepidopterists' Society database). Locally common to abundant over most of range, locally rare at eastern and northern edges (Glassberg 2001).

Observations in Montana Natural Heritage Program Database
Number of Observations: 1

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)


Well-drained sandy and gravelly areas, sagebrush steppe, juniper flats, pine forest glades, gentle slopes in moist meadows, near streambeds, alluvial washes (Emmel 1964; Scott 1986; Opler and Wright 1999; Glassberg 2001; Pyle 2002). In the Greater Yellowstone Ecosystem, reported in dry montane meadows and sagebrush near streams (Debinski and Pritchard 2002).

Food Habits
Larval food plants include Rumex (several species) and Oxyria (Scott 1986, 1992; James and Nunnallee 2011). Adults feed on flower nectar (including Achillea, Anaphalis, Apocynum, Asclepias, Berteroa, Centaurea, Chrysothamnus, Cirsium, Cleome, Erigeron, Eriogonum, Euphorbia, Helianthus, Heterotheca, Medicago, Melilotus, Potentilla, Psoralea, Rudbeckia, Sedum, Senecio, Solidago, Symphyotrichum) and mud (Pyle 2002; Scott 2014).

Reproductive Characteristics
Females lay eggs singly at or near base of larval host plant on twig, dead leaf, wood chip, dirt, in litter; eggs overwinter (Scott 1979, 1986, 1992; James and Nunnallee 2011). Eggs hatch in captivity 4-6 days after exposed to late-spring temperatures, develop from egg-hatch to pupation in 19-22 days (depending on temperature), nearly half that time as L4 instar, pupate on host plant or inert surface, adults eclose (emerge from pupae) in 10-17 days. Larvae solitary, build no nest, retreat to base of host plant to hide, feed on host plant leaves (James and Nunnallee 2011). Eggs associated with ants (Formica altipetens) in Arizona, possibly overwinter in ant nest (Funk 1975), larvae tended by ants (F. pilicornis) in captivity in California (Ballmer and Pratt 1991). Males territorial, perch conspicuously throughout the day on vegetation < 1 m tall in dry gullys, along streams, dirt trails, meadows to wait for passing females (Scott 1975b, 1986; Warren 2005; James and Nunnallee 2011).

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Citation for data on this website:
Ruddy Copper — Lycaena rubidus.  Montana Field Guide.  .  Retrieved on , from