Lycaena hyllus
Bronze Copper

Family Description:
Note: This species is referred to with the genus name Hyllolycaena by some authors.

Caterpillar: The caterpillar is yellowish green and is marked lengthwise along the back with a dark green stripe, edged in yellow.
Adult: This is a medium-sized butterfly, large for a Lycaena species, with a wingspan of 1 1/4 to 1 7/8 inches. The male is dark coppery brown on the upperside, with a purple sheen on the forewing. The hindwing is grayish brown and marked with a wide, wavy orange band along the outer edge. The female is yellowish orange on the upperside of the forewing, and marked with a brown band along the edge and dark spots; the hindwing is brown, with a yellow-orange band along the edge, and is also marked with dark spots. Both sexes are yellowish orange on the underside of the forewing, dotted with black and edged with a wide white band. The hindwing is grayish white, dotted with black, and edged with a wide orange band.

Primarily an eastern species, it ranges from Maine west across the northeastern U.S. to eastern Colorado, eastern Wyoming, most of Montana, and the central edge of Idaho. In Canada it ranges from northwestern Alberta south and east to southern Ontario.


It occurs in wet areas including marshes, swamps, wet meadows, and near reservoirs.


Caterpillar: Caterpillars feed on the leaves of docks (Rumex spp.) and knotweeds (Polygonum spp.).
Butterflies drink flower nectar.


There are one to two generations of caterpillars each summer in the northern portion of its range, and possibly three in the south. Eggs overwinter and hatch in the spring. Adults generally fly from mid-June to October.


Males perch to wait for receptive females. Females lay pale green eggs singly on the leaves, petioles, or seeds of host plants; eggs may also be laid on the dead leaves of host plants growing in water.

Idaho Status: Unprotected nongame species.
Global Rank: G5; populations are widespread, abundant, and secure.

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.