Dorcas Copper

Resident in north eastern North America (Scott 1986). Habitats are CANADIAN TO HUDSONIAN ZONE, FOUND IN BOGS, DRIER SITES IN MAINE, SALT MARSHES IN NEW BRUNSWICK. Hosts plants are usually shrubs with most known hosts from largely restricted to one family, ROSACEAE. Adults visit cranberry flowers. Eggs are laid on the host plant Vaccinium oxycoccos (Ericaceae) singly. Individuals overwinter as (fully developed) eggs, often under water. There is one flight each year with the approximate flight time JUN15-JULY15; JUL15-AUG15 in more northern parts of their range (Scott 1986).

Males patrol and perch for females (Scott, 1986).

Not of concern.

One yearly brood, adults most common from early to late July.

Alaska to south-central BC, east to the Avalon Peninsula of Newfoundland (Layberry et al. 1998). Essentially a boreal species, absent from the prairies.

Very similar to the Purplish Copper (L. helloides). The Dorcas Copper is slightly smaller with a wingspan of 19 to 27 mm (helloides: 23 to 33 mm). The orange band on the hindwing upperside is reduced in dorcas, and the dark border of the forewing is wider. The forewing shape is not as pointed as it is in helloides. The male dorcas specimen illustrated in Bird et al. (1995) is actually a Purplish Copper. Northern boreal populations are most similar to the nominate subspecies. The taxon florus, described from the Crowsnest Pass region, may be a subspecies of dorcas, or possibly a separate species altogether (Kondla and Guppy 2002). In Alberta, it occurs only in the southern mountains (contra Layberry et al. 1998).

Bogs and fens of the boreal region and moist meadows in the southern foothills.

The immature stages have been described for Michigan populations; the egg is white, and larvae are pale green with a dark green dorsal line and faint, white oblique bands (Nielsen 1999). The egg overwinters, and hatches in April (Newcomb 1910). Adults nectar at water hemlock and marsh cinquefoil in Saskatchewan (Hooper 1973).

The larval foodplant is unknown in Alberta; in Michigan, eggs and larvae are found on Shrubby Cinquefoil (Potentilla fruticosa) (Nielsen 1999). This plant may be used throughout the Dorcas Copper's range, although populations also occur in habitats where P. fruticosa is absent.