Frosted Elfin (Callophrys irus) (Godart, 1824)

Diagnosis: A drably coloured elfin with a grey-brown upperside in the male, more reddish in the female. There is less contrast on the underside between the colour at the base and the outer part of the wings than in other elfins. There is a greyish dusting of scales towards the base of the wings, a stubby tail on the hindwing, and a dark spot on the underside just above it. Wingspan: 22 to 24 mm.

Subspecies: Only the nominate subspecies is (or was) found in Canada.

Range: Fairly widespread in the eastern U.S., it has been found in Canada only in southern Ontario.Historically colonies existed in Ontario only near St. Williams. Old records from Pinery Provincial Park were examined and proved to be misidentifications of Hoary Elfin (C. polia).

Specimen collection data

Similar Species: Henry's Elfin (C. henrici) lacks the dark spot above the tail and has contrasting reddish-brown and yellow-brown shading below. [compare images]

Early Stages: The pale blue-green larva has several white lines down the back, one on the side, and oblique white dashes in between. It has only been recorded on Wild Lupine (Lupinus perennis) in Ontario, but it could also feed on Wild Indigo (Baptisia tinctoria) as it does in New York State (Shapiro,1974).

Abundance: Everywhere in its range, it tends to be very localized to the area of the foodplant. In Ontario, it was never common and numbers have declined at St. Williams to the point where it is now probably extirpated (Holmes et al., 1991).

Flight Season: Adults are on the wing from mid-May to early June in Ontario.

Habits: The Frosted Elfin occurs in open second-growth oak-pine woods and nearby roadsides where patches of lupines grow. Colonies of this butterfly appear to be unstable.

Remarks: The Frosted Elfin has been placed on the list of endangered species in Ontario. However, since it has not been seen in the province since 1988, this action may have been taken too late. Members of the Toronto Entomologists Association are monitoring the situation.

© 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.