Southern Hairstreak (Fixsenia favonius) (J.E. Smith, 1797)

Diagnosis: The Southern Hairstreak is very similar to the Satyrium hairstreaks found in eastern Canada and some researchers feel that it is best placed in the genus Satyrium with them. The upperside of the wings is greyish brown with a wedge-shaped orange patch near the hindwing margin between the two "tails." The underside of the forewing is brown, lacking the central discal spot of the Satyrium hairstreaks. The main difference in appearance between this and other similar species is that the black and white median line on the hindwing underside forms a distinct "W"-mark above the blue patch. Wingspan: 24 to 38 mm.

Subspecies: Subspecies ontario occurs from extreme southern Ontario to Texas; until recently it was treated as a separate species, but it hybridizes with the southern subspecies favonius where their ranges meet (Scott, 1986; Opler and Malikul, 1992).

Range: This species is widespread from New England south to Florida and west to Arizona. It is rare and local in the northeast. Subspecies ontario was described by Edwards from a specimen taken at Port Stanley, Ontario in July 1868. It has been reported a few times since then in southwestern Ontario (Holmes et al., 1991); we have been unable to confirm any records other than the type specimen, so we have not included them on the distribution map. Similarly, Klots (1951) lists it from Quebec, but there are no known specimens to verify this record.

Similar Species: All eastern Satyrium hairstreaks. See Diagnosis above.

Early Stages: The larvae are yellowish with green dorsal stripes and a yellow lateral stripe. They have been reported to feed on several species of oaks of which White Oak (Quercus alba) is the only one that occurs in Canada; hawthorn (Crataegus spp.) may also be a foodplant in the northeast.

Abundance: The Southern Hairstreak probably does not breed in Canada. There are only rare historical records.

Flight Season: In the Finger Lakes region of New York, south of Lake Ontario, the butterfly is on the wing in July, but it flies in mid-June in Pennsylvania.

Habits: In the northeastern U.S., the Southern Hairstreak is found mainly in oak and oak-pine woods on shale barrens. Adults nectar in nearby meadows on flowers such as New Jersey Tea (Ceanothus americanus), Dogbane (Apocynum spp.), and White Sweet Clover (Melilotus alba).

Remarks: While this species may no longer occur in Canada, it may also have been simply overlooked because of its similarity to several other, more common hairstreaks. It is also possible that this has never been a resident species in Canada, but occasionally strays over Lake Erie, as does the White-M Hairstreak. Subspecies ontario was formerly treated as a distinct species and called the Northern Hairstreak, and favonius was called the Southern Hairstreak. With the two "species" now combined into one the latter name seems more appropriate since the species is most common in the southern U.S. and barely reaches Canada.

© 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.