Lycaena heteronea, the blue copper, is an American butterfly that belongs to the gossamer-winged family.

The butterfly is named so because of the bright blue hue of the upper side of the males' wings.

Blue coppers are seen on the west coast of the United States and the southwest region of Canada, particularly British Columbia and Alberta.

Blue copper larvae sometimes form mutualistic associations with Formica francoeuri, an ant species.

Blue coppers are in flight season from April to August, but they vary in different parts of North America.

Although the presence of Eriogonum attracts blue coppers, the quality of the plant determines whether the butterfly settles in that place.

The caterpillars do not have a wide selection of plants that they can feed on, primarily three buckwheat (Eriogonum) species.

Adults have a wide range of plants that they can feed on, including buckwheat, green rabbitbrush, Chrysothamnus viscidiflorus, asters, yarran, gaillardia, fiddleneck, wallflower, and milkweed.

The females lay their eggs one at a time on bracts, modified leaves, or underneath the host plant.

Their color ranges from dull blue to green, which helps the caterpillar to blend in with its surroundings and increase its chance of survival.

After emerging from the chrysalis, females begin their search for a high quality host plant for larvae.

However, the species is decreasing in certain parts of California because of the increase in fires that burn down the trees in the open forest where these butterflies reside.

Some larvae in California have been reported to be facultatively myrmecophilous because they have been observed in association with Formica francoeuri Bolton, an ant species formerly known as F. pilicornis Emery.