The frosted elfin is currently under review by the U.S. Fish and Wildlife Service to determine if the species may warrant
federal protection under the Endangered Species Act.
Appearance
Female frosted elfin. Photo courtesy of Dave McElveen
The frosted elfin is a small butterfly in the family Lycaenidae, which includes the hairstreaks and blues. It has a wingspan of about 1.5 inches and short tails protruding from its hindwings. The sexes look similar with dark gray or brown on the top of the wings. The undersides are gray-brown with silver “frosting” on the hindwings and a jagged dark line. Females can be identified by the orange hue on their wings and tend to be slightly larger than males, which have a dark section of scales on their forewing. The larvae are light green with a pale line and dashes along each side and are covered with short white hairs. Their coloration closely matches the plant on which they’re feeding, and they can be difficult to spot; they might be detected only when feeding damage to leaves is seen. Frosted elfin caterpillars are very similar to those of the gray hairstreak, which may also feed on the same host plant.
Frosted elfin eggs
Photo courtesy of Dave McElveen
Frosted elfin larva
Photo courtesy of Dave McElveen
Frosted elfin pupa
Photo courtesy of Dave McElveen
Behavior
Sundial Lupine. FWC Photo
Frosted elfin butterflies do not migrate, but their distribution reflects their specific larval host plants. In Florida, the frosted elfin’s host plant is the sundial lupine (Lupinus perennis); in northern populations outside of Florida, larvae may also feed on wild indigo (Baptisia spp.). Adults have a short flight season from mid-February to mid-April, during which they emerge, mate, lay eggs on lupine plants, and feed on the nectar from a variety of flowering plants. Hatched larvae feed and grow on sundial lupine for about one month. When they reach maximum size (~ 20 mm), larvae then crawl to the base of a lupine plant or just below the soil surface, or leaf litter to pupate. They remain as pupae for about nine months until emerging as adults the following spring.
Habitat
In Florida the frosted elfin occurs in localized populations closely associated with its host plant, the sundial lupine. Its primary habitat is sandhill, which is higher and drier than hardwoods and has sandy soils, a grassy understory, and an open canopy. Sandhill is pine-dominated, with natural or prescribed fire ideally occurring every 2-5 years. Microhabitat conditions are also important for the frosted elfin and its understory host plant and may include low vegetative cover and some intermittent shade.
The frosted elfin was formerly found across eastern North America. It is currently extirpated in Canada and several states and has declined to extremely low numbers in other states. In Florida, the species historically occurred across the northern part of the state, but now its populations are restricted to portions of the panhandle. Florida has the largest known populations in the Southeast, presenting opportunities to support the species’ range-wide conservation.
Threats
Sandhill habitat. FWC Photo
As with many species of wildlife, frosted elfin butterflies are threatened by habitat loss and degradation. Higher, drier habitats like sandhill are often the first to be targeted for residential and commercial development, road building, silviculture, and agriculture. Conservation lands also have competing uses that can limit the frequency and distribution of fire required to maintain the open sandhill habitat needed by the butterfly and its host plant. Research in Florida has also determined that if fire is applied too frequently and/or uniformly across the habitat, it can cause excessive mortality of frosted elfin pupae. Instead, a patchy mosaic of burning is recommended to allow frosted elfins to recolonize patches of sundial lupine after fire.
Conservation and Management
Male frosted elfin. Photo courtesy of Dave McElveen
The long-term conservation of the frosted elfin in Florida is the focus of ongoing partnership efforts by federal and state agencies — including the FWC, academic institutions, nonprofit organizations, and knowledgeable individuals. These partners have drafted a frosted elfin conservation plan for Florida and a best management practices (BMP) document for the species that should be useful to resource managers in the southeast.
An essential aspect of frosted elfin conservation in Florida is locating, managing, and enhancing sundial lupine populations. Conservation lands with recent and historic frosted elfin occurrences are surveyed and monitored to determine frosted elfin status. Protected areas with sundial lupine but no butterflies are being targeted for potential repatriation. In a pilot study in 2022, wild-caught butterflies from northern Florida were translocated to conservation lands with suitable habitat in Georgia, one of the states where the species was extirpated. The apparent success of that project has led to the establishment of a captive colony that will provide stock to repatriate frosted elfins onto conservation areas with suitable habitat across northern Florida. The long-term goal is the establishment and stewardship of multiple, successfully managed frosted elfin populations into the foreseeable future.
How Can You Help?
Join the community science effort to track frosted elfins and their sundial lupine host plant. Uploading photos of these butterflies and plants to iNaturalist will help biologists learn more about where they occur. For more information, see Calling all nature lovers – Help make a difference in Florida butterfly conservation - Tall Timbers.
References
Jue et al. 2022. Effects of frequency and season of fire on a metapopulation of an imperiled butterfly in a longleaf pine forest. Conservation Science and Practice. 12 pp.
McElveen et al. 2020. Life history observations of Callophrys irus (Family: Lycaenidae) in North Florida, USA. Journal of the Lepidopterists’ Society 74 (1): 51-56.
Meyer et al. Submitted. Best management practices for the frosted elfin in Florida and southern Georgia, USA. Draft manuscript submitted to Conservation Science and Practice.