Euphyes dukesi

It lives in the eastern United States and in a small portion of southern Ontario, Canada, in three distinct populations.

[6][7] Dukes' skipper is found in scattered locations around the eastern United States and a small portion of southeastern Canada.

[8] There are three distinct regionally clustered populations: Its full distribution consists of the Canadian province of Ontario and the following US states: Alaska, Arkansas, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Michigan, Missouri, Mississippi, North Carolina, Ohio, South Carolina, Texas, and Virginia.

[9] The split distribution between coastal plains and the Great Lakes area is unusual for North American butterflies, and it is hypothesized that it may be due to population displacements during the Pleistocene glacial intervals, followed by dispersal through the vegetational corridors of the Mississippi and Mohawk valleys when the ice sheets retreated.

[3] Adults feed on flower nectar of various plants including buttonbush (Cephalanthus occidentalis), common milkweed (Asclepias syriaca), swamp milkweed (Asclepias incarnata), Joe-Pye weed (Eupatorium maculatum), blue mistflower (Eupatorium coelestinum), pickerelweed (Pontederia cordata), hibiscus species (Hibiscus), sneezeweed (Helenium autumnale), alfalfa (Medicago sativa), and red clover (Trifolium pratense).

[6][7][10] The divergence of two subspecies may have occurred due to isolation of Florida and other populations during the Wisconsinian glaciation or an earlier glacier event, with boreal forests acting as barriers.