New York Natural Heritage Program
Frosted Elfin
Callophrys irus (Godart, [1824])

Habitat [-]
The key habitat feature is an abundance of the foodplant or, perhaps, many moderate-sized patches of the foodplant within a few hundred acres or more, and associated with remnant pine barrens, oak savannas, or dry oak forest. The grassland/herbaceous checkoff revers only to right of ways and airports not natural grasslands. There are two varieties of Frosted Elfins, one that feeds mostly on the flowers or seed pods of Wild Blue Lupine (Lupinus perennis), and another that feeds on leaves and stems of Wild Indigo (Baptisia spp.), primarily the native Baptisia tinctoria in New York. Populations will feed on only of these plants or the other, even when both types of plants are present. Lupine feeders occur in the Albany area, western New York, and on Long Island, while Wild Indigo feeders occur on Long Island. Frosted elfins are not likely to be found in stands of foodplants that have been isolated for a long period of time. This species nearly always occurs in clusters of populations that function as metapopulations and small habitat patches may be unoccupied in some years. Females disperse within the habitat and larvae can turn up in appropriate habitat where adults are not usually seen. The most typical habitats are utility right-of-ways and, at least in neighboring states, airport approach zones. A few populations of the lupine feeders occur partially in more natural settings in the Albany Pine Bush and the Rome Sand Plains. No populations of the Wild Indigo (Baptisia spp.) feeders are known to occur in natural settings in New York. Typical habitat features include a shrubby or partially open aspect and a high density of the foodplant, although the observations of Albanese et al. (2006) may not apply fully to the lupine feeders which seem more capable of using open grassland with no tall shrubs or trees. Nectar might also be an important habitat feature.

Associated Ecological Communities [-]
  • Coastal oak-heath forest
    A low diversity, large patch to matrix, hardwood forest that typically occurs on dry, well-drained, sandy soils of glacial outwash plains or moraines of the Atlantic Coastal Plain. The forest is usually codominated by two or more species of scarlet oak, white oak, and black oak.
  • Hempstead Plains grassland
    A tall grassland community that occurs on rolling outwash plains in west-central Long Island. This community occurs inland, beyond the influence of offshore winds and salt spray.
  • Pitch pine-heath barrens
    A shrub-savanna community that occurs on well-drained, sandy or rocky soils. The most abundant tree is pitch pine and the shrublayer is dominated by heath shrubs.
  • Pitch pine-oak forest
    A mixed forest that typically occurs on well-drained, sandy soils of glacial outwash plains or moraines; it also occurs on thin, rocky soils of ridgetops. The dominant trees are pitch pine mixed with one or more of the following oaks: scarlet oak, white oak, red oak, or black oak.
  • Pitch pine-oak-heath woodland
    A pine barrens community that occurs on well-drained, infertile, sandy soils. The structure of this community is intermediate between a shrub-savanna and a woodland. Pitch pine and white oak are the most abundant trees.
  • Pitch pine-scrub oak barrens
    A shrub-savanna community that occurs on well-drained, sandy soils that have developed on sand dunes, glacial till, and outwash plains.