Other Common Names
Purplish Copper (used in the Rocky Mountain Region)
Synonyms and other taxonomic changes
Currently, the following names are all listed as belonging to Lycaena dorcas:
- arcticus Ferris, 1977 (northwest Canada & Alaska)
- castro Reakirt, 1866 [There is some confusion as to the typification of castro, and the name could end up a synonym L. helloides, with the name sangremar Scott, 2008 taking it's place under L. dorcas.] (south from s. Wyoming in Rockies; distinction from florus seems weak)
- claytoni A. E. Brower, 1940 (from Maine & adjacent New Brunswick)
- dorcas W. Kirby, 1837 (ne. US and e. Canada; east from NW Territories, Manitoba & Minnesota)
- florus W.H. Edwards, 1884 (Wyoming northward through Rockies to the Arctic Coast)
- megalocerus Ferris, 1977 (Bighorn Mountains, Wyoming; averages lighter than florus, but otherwise similar)
- michuron Scott, 2006 (from Michigan; distinction from typical dorcas is weak)
Lycaena dospassosi McDunnough, 1940 (from Canadian Maritimes) is treated as if a distinct species.
Identification
Distinguished from the similar Purplish Copper (
L. helloides) by the reduced orange band on the edge of the hindwing upperside (vs. extensive orange band in Purplish Copper), the brownish-orange underside of the wings (vs. grayish-yellow in Purplish Copper), and geographic range (see maps in links listed under Internet References below).
Bog Coppers (
Lycaena epixanthe) may sometimes fly in the same areas, but the upper sides look "plainer" with fewer dark spots in males and usually less orange coloring (if any) in females. The undersides are yellowish to whitish and not orangey as in
L. dorcas & L. helloides.
Lilac-bordered Coppers (
Lycaena nivalis) have the lower hind wing yellowish toward the base and pinkish or purplish on the outer half, not orange. Above they look very similar to Dorcas and especially to Purplish Coppers.
Range
Depends on how the species is defined. Traditionally Boreal North America from Alaska, across Canada, to New Brunswick and Maine (with some breaks). With the inclusion of Rocky Mountain populations the range is expanded south through Montana, Wyoming, Idaho, Utah, and Colorado into Arizona and New Mexico. [and perhaps into Oregon?]
Habitat
Primarily moist meadows and boggy areas where host plants are found.
Season
Apparently usually (if not always) single-brooded (??), flying in summer. Mostly July or August, sometimes into September.
Food
Larvae feed on Shrubby Cinquefoil (Dasiphora fruticosa [aka. Potentilla fruticosa]) and other Cinquefoils (Potentilla species) - family Rosaceae. In the Rocky Mountains there are reports of Whortleberry/Blueberry as larval hosts (Vaccinium species) - family Ericaceae, but many if not most populations of these butterflies are strongly associated with Cinquefoils. Adults also nectar at Cinquefoil flowers, but will visit many other species of flowers when available (often Composites - family Asteraceae).
Remarks
The distinctions of Lycaena dorcas from closely similar Lycaena helloides have been (and remain) problematic. The two "species" are very closely related and very similar. Traditionally only populations from boreal regions and from the Upper Midwest have been included within L. dorcas, but more recent treatments also include Dasiphora / Potentilla feeding populations from the Rocky Mountains. This leaves the status of other mountain populations from further west a bit shaky as well.
Some authors would include all as one adaptable and wide-ranging species, while others favor splitting the group into several species. The Cinquefoil feeding populations from the Rocky Mountain region may end up being separated as the species Lycaena florus, and populations from the far east in Canada have been separated out as L. dospassosi. [And, other segregate species have been proposed.]
Currently, Rocky Mountain populations are included under
Lycaena dorcas in the '
Butterflies of America' web site and in Johathan Pelhams '
Catalogue of the Butterflies of the United States and Canada'.
Internet References
live adult images plus text description and other info (Wisconsin Butterflies)
pinned adult images plus info and Canadian range map (CBIF)
pinned adult images plus info and US range map (Nearctica.com)
