Lycaena rubidus
Ruddy Copper

Family Description:
Note: This species is listed with the genus name Chalceria by some authors. Ferris’ Copper (Lycaena ferrisi), previously included as a subspecies of L. rubidus, is a newly described species nearly identical in appearance and ecology to the Ruddy Copper, and occurs only in the White Mountains of Arizona and New Mexico.

The caterpillar is brown and marked lengthwise with dark red and yellow along the back. It can reach an average, full-grown length of 3/4 inch.
Adult: This is a medium-sized butterfly, with a wingspan of 1 1/8 to 1 5/8 inches. The male is bright coppery orange on the upperside, lightly marked with dark spots and edged thinly in black. The female varies in color from golden yellow to dark brown clouded with yellow; the wings are marked with dark spots, and the hindwing has a golden yellow wavy band just in from the edge. Underneath, both sexes are yellowish gray to grayish white. The underside of the forewing is spotted with black while the underside of the hindwing may be unmarked or lightly dotted with black.

This species ranges from southern British Columbia and Alberta south through the northwestern U.S. to central California, eastern Arizona, and northern New Mexico, and east as far as western North and South Dakota and Nebraska. It occurs through much of Idaho.


It occurs in open areas such as sagebrush steppe, prairies, fields, and along streams.


Caterpillar: Caterpillars feed on various species of dock (Rumex spp.).
Adult: Butterflies drink flower nectar, most frequently from shrubby cinquefoil (Potentilla fruticosa).


Eggs overwinter and hatch in the spring, and the resulting brood is the only generation of caterpillars each summer. Each caterpillar undergoes four stages of growth, called instars. Adults generally fly from the end of May to the beginning of September. Butterflies are swift fliers, and may pursue each other.


Males perch to wait for receptive females. Females lay eggs singly at or near the bases of host plants.

Idaho Status: Unprotected nongame species.
Global Rank: G5; most populations are widespread, abundant, and secure. Ferris’ Copper, however, is ranked T1, which means it is critically imperiled because of extreme rarity and is imminently vulnerable to extinction.

Ballmer, G. R. and G. F. Pratt. 1988. A survey of the last instar larvae of the Lycaenidae of California. Journal of Research on the Lepidoptera 27:1-81.

Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies.   Second Edition.  Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.