Features: The Frosted Elfin (Callophrys irus) is a hairstreak butterfly with brown upper wings and a scattering of pale scales on the underside that give it a frosted appearance. In Ontario, the species once lived in open areas of oak savannah habitat where its larval food plant, the Wild Lupine (Lupinus perennis), grows. Male butterflies are territorial and defend clumps of lupine. Females lay eggs on the flower buds, and the caterpillars feed on the flowers and seedpods. In late summer, the caterpillars build a shelter on the ground by tying leaves together with silk, and they overwinter in the pupal stage. In very early spring, the new adults emerge and fly.

Status: Extirpated Provincially and Nationally

Range: The range of the Frosted Elfin extends from New England west to Alabama and Wisconsin, south to Texas and Florida. In Ontario, it was found at one location near the St. Williams Forestry station in Norfolk County in southern Ontario. It was last recorded there in 1988. Range Maps

Threats: The Frosted Elfin was likely never common or widespread in Ontario - it was only discovered here in 1960 and was only ever reported from one location. Scientists doubt that there were ever more than 100 individuals in the population at any given time. At the Ontario site, natural succession and the planting of pines in the 1940s eventually created shady conditions that lupines could not tolerate. As the lupines disappeared, the butterflies died out. Elsewhere, this species has declined in much of its eastern range as a result of habitat loss. The oak savannah habitat, which the Frosted Elfin depends on, is one of the most threatened habitats today.

Protection: The Frosted Elfin is listed under Ontario's Endangered Species Act, 2007, which protects the species from being killed, harmed, possessed, collected or sold, and protects the habitat from damage or destruction. The Natural Heritage component of the Provincial Policy Statement under the Planning Act provides for the protection of significant portions of the habitat of species listed in regulation under the E.S.A. The site at which this butterfly formerly lived is public land. The Norfolk Field Naturalists have carried out a very successful rehabilitation of the original site by clearing pines and doing prescribed burns to open up the area. Lupines have recolonized and significant patches now exist. A reintroduction program can at least now be contemplated for the species at this site.

Text Sources: Packer 1998

Last Modified Date: September 2009