Frosted Elfin (Callophrys irus), listed as Threatened in Wisconsin, has been found in pine barrens, oak savanna, and edges of sandy oak/pine forest. Wild lupine (Lupinus perennis) is the larval host plant and grows on sandy soils under canopy in dry oak/pine forest where it may occur sparsely and in a vegetative state. Frosted elfins are most often found in habitat where the lupine is common to abundant, and the patch size is very large (at least 2-2.5 acres). Adults are present from early-May to mid-June and usually fly for 21-30 days.
