Johansen's Sulphur (Colias johanseni) (Troubridge & Philip, 1990)

Diagnosis: The upperside is a dull yellowish orange with a broad black band on the outer margin of the wings in males and with a series of blurry yellow patches in the outer band in females. Like Mead's Sulphur (C. meadii), males have a pale sex patch at the base of the hindwing. The underside of the hindwing appears green because of a dense layer of black scales over the dark yellow ground colour; the silver discal spot in the centre of the wing is surrounded by pink, which is usually extended into a streak that points towards the wing margin. Both fore- and hindwings usually have a submarginal row of dark spots. Wingspan: 35 to 38 mm.

Subspecies: None, but see Remarks below.

Range: This butterfly is known only from the type locality near Bernard Harbour, Nunavut.

Similar Species: Johansen's Sulphur occurs with and can be confused with the Hecla Sulphur (C.hecla). Males of hecla lack the pale sex patch at the base of the hindwing; females of hecla are larger and have the underside of the hindwing yellow green rather than grey green. See also Remarks below. [compare images]

Early Stages: The early stages are unknown; adults are associated with sweet-vetch (Hedysarum spp.), the probable larval food plant.

Abundance: Adults are fairly common, but only found on a few suitable hillsides near Bernard Harbour.

Flight Season: The Type Series of Johansen's Sulphur was collected between 3 and 17 July 1988.

Habits: Troubridge and Philip (1990) state that Johansen's Sulphur is restricted to dry steppe-like tundra and flies in a characteristic zigzag pattern up and down the hillsides, so that it can be distinguished from the Hecla Sulphur even on the wing.

Remarks: Johansen's Sulphur is closely related to Mead's Sulphur of the Rocky Mountain region andto Colias hyperborea Grum-Grschimaîlo, from northeastern Siberia, and Scott (1986) treated all three as a single species. Differences in appearance and habitat are comparable to those between manyColias species and we treat all three as distinct species. The rediscovery of Johansen's Sulphur is an interesting success story. A single specimen was collected by Fritz Johansen in 1916 on a hill near Bernard Harbour and identified as Mead's Sulphur. Since no other specimen resembling it was found again in many years of collecting in northern Canada, the specimen was largely ignored as being mislabelled, misidentified, or an aberrant Hecla Sulphur. Jim Troubridge and Kenelm Philip used Johansen's diary to relocate the same hill 72 years later and rediscover this interesting sulphur.

© 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.