FWS Focus

Overview

Characteristics
Overview

The frosted elfin is a small, non-migratory butterfly that has experienced population declines across its historic range due to habitat loss. Frosted elfin depend upon pine barrens, a rare habitat type characterized by fire-dependent conifers, dense thickets of scrub oak, and grassy openings that support specialized plants like wild indigo and wild blue lupine — host plants frosted elfin larvae need to survive. 

In 2018, a team of scientists completed an interim Species Status Assessment for the frosted elfin, synthesizing the best available science from across the species' range to develop a clear picture of its current condition and needs. Equipped with information from the status assessment, the U.S. Fish and Wildlife Service is working proactively with states and other partners to develop and implement conservation efforts that support the needs of this butterfly.

Since 2019, the Service has been coordinating range-wide surveys in partnership with state agencies and nongovernmental organizations to see if they can find frosted elfin in any of the places where they were last seen. The Service will be reviewing the butterfly’s status in 2023 to determine whether or not it needs federal protection.

Scientific Name

Callophrys irus
Common Name
Frosted Elfin
FWS Category
Insects
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

Frosted elfin are small butterflies with short tails projecting from their hindwings.

Measurements

Wingspan: 0.87 to 1.42 inches (22 to 36 mm)

Color & Pattern

The upperside of the wings of frosted elfin are uniform dark gray brown in color. The underside of the wings is also largely gray brown, but variegated, with a dusting of pale scales on the outer edge of the hindwing, with a dark spot and an irregular dark line.

Characteristic category

Life Cycle

Characteristics
Life Cycle

The entire lifecycle of a frosted elfin is completed within one year. Adults emerge in spring and lay eggs, eggs hatch into larvae that rely on specific host plants of wild lupine or wild indigo, larvae pupate by late July on or near host plants, and remain in this state until the following spring.

Characteristic category

Habitat

Characteristics
Habitat

Frosted elfin and many other species — including whip-poor-will, eastern towhee, eastern hognose snake, and the federally endangered Karner blue butterfly — depend on pine barrens. This rare type of habitat is characterized by sandy soil, an overstory of fire-dependent conifers, and grassy openings that support plants like wild blue lupine and wild indigo. Frosted elfin lay their eggs on these two plants alone; their larvae need to feed on them to survive.

Grassland

Ecosystem with large, flat areas of grasses.

Geography

Characteristics
Range

The frosted elfin butterfly was once found from Florida west to Texas, and north to Ontario. Today, its range is uncertain. The species is now likely extirpated in Ontario, Canada, and the District of Columbia, Georgia, Illinois, and Vermont.

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