Mottled Duskywing
Erynnis martialis (Scudder, 1869)

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Diagnosis: A medium-sized dark grey skipper (wingspan: 25 to 29 mm), the Mottled Duskywing has a slight purplish gloss, and a very mottled appearance on the upperside of all wings, especially when fresh. The mottled hindwing pattern is created by light yellow-brown spots and dark brown spots, both of which contrast with the hindwing colour.

Range: Erynnis martialis is found throughout the eastern U.S., reaching into Canada only in southwestern Quebec, southern Ontario, and southeastern Manitoba.

Similar Species: The purplish gloss and very mottled appearance should be enough to distinguish it from other eastern duskywings. However, other species have often been confused with it, especially worn specimens that take on a more mottled appearance.

Early Stages: The larvae are stout, light green in colour with a dark head. They feed in leaf-nests on New Jersey Tea (Ceanothus americanus) and Oval-leaved Redroot (C. ovatus), Rhamnaceae, and hibernate as mature larvae.

Abundance: A rare, and very local, species throughout its Canadian range.

Flight Season: There is one generation, from mid-May to late June in most of the Canadian range, and a second one, from mid-July to late August in extreme southwestern Ontario.

Habits: This species is usually seen nectaring or on wet sandy roads in the company of other species of Erynnis, and usually outnumbered by them.

Remarks: The habitat requirements of its foodplants, usually dry sandy areas or limestone alvars, are met only very locally in the east, and are often in areas subject to severe development pressures. There are only about five extant colonies in Ontario, and one at La Trappe, in Quebec; a well-known locality at Norway Bay, Quebec, on the Ottawa River northwest of Ottawa, has been destroyed by cottage development.

© 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.

The Toronto Entomologists' Association thanks Agriculture and Agri-Food Canada for providing the content and computer code for this web page.