Southern Dogface
Zerene cesonia (Stoll, [1790])

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Diagnosis: The pattern of the upper forewing of this medium-sized species resembles a yellow "dog face" bordered by black, with a black circle forming the eye. Otherwise, the pattern is similar to the Colias sulphurs, in which genus this species was formerly included. Wingspan: 50 to 57 mm.

Range: In North America, this is mainly a species of the southern U.S. However, it often migrates northward and has been taken three times in Manitoba, at Aweme, Cartwright, and Pine Ridge, in Alberta at Didsbury, and about a dozen times in Ontario, as far north as Lake Simcoe.

Similar Species: The Clouded Sulphur (C. philodice) looks similar to the Southern Dogface on the wing, but lacks the distinctive "dog face" pattern to the upper forewing. [compare images]

Early Stages: The larvae can be green or yellow with black hairy bumps; some have longitudinal yellow and black lines, or yellow and black cross bands, or both. They feed on many legumes but cannot overwinter in Canada.

Abundance: This is a rare stray in Canada.

Flight Season: Adults are most likely to occur in mid- to late summer in Canada during years of strong northward migrations.

Habits: The Southern Dogface tends to be a butterfly of open areas, such as roadsides and pastures.

Remarks: According to Holmes et al. (1991), a significant historical migration of this species extended into Ontario in 1896.

© 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.