Grey Copper
Lycaena dione (Scudder, 1869)

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Diagnosis: The grey upperside of this largest (wingspan: 31 to 36 mm) of North American coppers is unique. The male has some orange scaling and a small black dot along the margin of the hindwing. The female has some orange spots on the upperside and a more extensive orange band on the hindwing. The underside is pale whitish brown with extensive black dots and the orange hindwing marginal band is more prominent in the eastern parts of the range.

Subspecies: None; see Remarks below.

Range: Widespread in the Great Plains region of the U.S., the Grey Copper extends into Canada in the Prairies, north to Edmonton, Alberta. The only known population in British Columbia is from Elizabeth Lake near Cranbrook, where it is endangered owing to habitat alteration around the lake (Guppy et al., 1994). It also occurs across southern Manitoba and at several locations in northwestern Ontario east of the Manitoba border.

Similar Species: See Remarks below.

Early Stages: The mature larva is green, yellow green, or orange, with dark orange stripes dorsally. In Canada it feeds on a variety of species of dock, including Curled Dock (Rumex crispus) and Western Dock (R. occidentalis).

Abundance: The Grey Copper is generally uncommon and local, but it has been reported to be common in some localities (Klassen et al., 1989).

Flight Season: Flies from late June to mid-August in Canada.

Habits: This butterfly is typically found in wet areas on the Prairies, including streamsides and roadside ditches where docks grow. It has a very rapid and jerky flight and is difficult to follow with your eyes.

Remarks: Three names require discussion here. Lycaena xanthoides (Boisduval) is a large copper that occurs on the Pacific coast of California and Oregon. The underside of the hindwing is pale brown with small darker brown spots and a short, narrow orange band on the wing margin. Lycaena dione is similar in size, or slightly larger, and occurs throughout the Great Plains region. The underside is pale whitish brown with small very dark, almost black, spots and a long, broad orange marginal band. Similarity in appearance has resulted in these two taxa being lumped as subspecies for many years. In between the ranges of these two taxa is Lycaena editha (Mead), a smaller copper that occurs in the Rocky Mountains, Sierra Nevada, and Great Basin. It has a brown underside with larger, slightly darker, brown spots that tend to run together and fuse. Scott (1986) noted that the ranges of xanthoides and editha come together in northern California and form a zone of intergradation, so he treated all three names as subspecies of xanthoides. The ranges of editha and dione overlap broadly in Montana and there is no evidence of hybridization. As a result, we treat Lycaena dione as a distinct species. Whether or not editha is a subspecies of xanthoides is still open to question because Pratt et al. (1991) provide evidence to show that there is little, if any, hybridization between xanthoides and editha in California. Lycaena editha has been reported to occur in southwestern Alberta (Ferris and Brown, 1981; Scott, 1986), but we have found no material to support this. It occurs in Montana adjacent to the Alberta border and could occur in Waterton National Park.

© 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.

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