Lustrous Copper (Lycaena cuprea) (W. H. Edwards, 1870)

Diagnosis: This is the brightest of our coppers. The nominate subspecies, in the U.S., has a lustrous coppery-red upperside, hence the common name. It is an average-sized copper (wingspan: 23 to 30 mm) and is variable in colouring, with some high-altitude duskier forms. It has small black dots (larger in females) on the upper and undersides. The light grey underside has a copper flush on the forewing.

Subspecies: The Canadian populations are subspecies snowi, with a brassy-copper upperside and a darker grey underside. Some authors have listed this as a separate species in the past. A single female from the Caribou Pass west of Pink Mountain, British Columbia, was described as subspecies henryae (Cadbury), based on the tiny size of the black spots on the hindwing. A series from Banff, Alberta, indicates that this represents variation within snowi and not a distinct subspecies.

Range: The Lustrous Copper is a butterfly of western mountain ranges in North America. It is found in several ranges in southern British Columbia, including the Kootenays and Selkirks, and also in the front range of the Rocky Mountains in Alberta and British Columbia as far north as Caribou Pass.

Similar Species: The Ruddy Copper (L. rubida) has few if any black dots on the hindwing underside. [compare images]

Early Stages: The larva is green, with a red lateral line and red flecks on the back. The larvae of subspecies snowi are reported to feed on Mountain Sorrel (Oxyria digyna) and docks (Rumex spp.) (Scott, 1986).

Abundance: The Lustrous Copper is local and uncommon.

Flight Season: It is on the wing in late July and August in Canada.

Habits: This copper is found in high mountain meadows and alpine slopes above treeline. It can also be seen along rocky streambeds in the mountains.

Remarks: The two subspecies of the Rocky Mountain region (subspecies snowi and subspecies artemisia Scott), which occur from Canada to New Mexico, have a sufficiently different appearance and habitat from the nominate form (subspecies cuprea), which occurs in California and Oregon, that they have been treated as separate species by some authors.

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.