Karner Blue Butterfly

Lycaeides melissa samuelis

Description

The Karner blue butterfly has a wingspan of 0.87-1.26 in (2.2-3.2 cm). The dorsal side of the male is silvery blue or dark blue with narrow black margins. The females are grayish brown dorsally, with irregular bands of orange inside the narrow black border on the upper wings. Both sexes are slate grey on the ventral side with the orange bands showing more regularity, and black spots circled with white.

Behavior

This butterfly usually has two broods each year. Eggs that have overwintered from the previous year hatch in April. The larvae feed on wild lupine leaves and mature rapidly. Near the end of May, they pu-pate and adult butterflies emerge very late in May in most years. The adults are typically in flight for the first 10-15 days of June, when the wild lupine is in bloom. Females lay eggs on or near the wild lupine plants. The eggs hatch in about one week and the larvae feed for about three weeks. Then they pu-pate, and the second brood adults appear in the second or third week of July. This time, the eggs are laid among plant litter or on grass blades at the base of the lupines, or on lupine pods or stems. By early August, no adults remain, and these eggs do not hatch until the following spring.

The Karner blue butterfly frequently occurs with other rare butterfly species such as the Persius duskywing (Erynnis persius ) and the frosted elfin (Incisalia irus ).

The presence of wild lupine is essential to the occurrence and survival of this species. Unaltered by humans, a pine-barren ecosystem is likely to be a mosaic of interspersed woody vegetation, such as pitch pine and scrub oak and more open areas characterized by wild lupine, grasses, and other plants such as spreading dogbane (Apocynum androsaemifolium ) and New Jersey tea (Ceanothus americanus ) which serve as nectar for adult butterflies.

Habitat

The habitat of the Karner blue butterfly is characterized by the presence of wild lupine, a member of the pea family. Wild lupine is the only known larval food plant for this butterfly and is, therefore, closely tied to the butterfly's ecology and distribution. In eastern New York and New Hampshire, the habitat typically includes sandplain communities, and grassy openings within very dry, sandy pitch pine/scrub oak barrens. In the Midwest, the habitat is also dry and sandy, including oak savanna and jack pine areas, and dune/sandplain communities. It is believed that this species originally occurred as shifting clusters of populations, or metapopulations, across a vast fire-swept landscape covering thousands of acres. While the fires resulted in localized extirpation, post-fire vegetational succession promoted colonization and rapid population buildups. Periodic disturbance is necessary to maintain openings in the canopy for wild lupine to thrive. A variety of other understory plants associated with the habitat serve as nectar sources for the adult butterflies.

Distribution

The distribution of this species is very discontinuous, and generally follows the northern limits of wild lupine. Eight major population clusters of the butterfly were known historically from portions of Wisconsin, Michigan, Minnesota, Indiana, Illinois, Ohio, Massachusetts, New Hampshire, Pennsylvania, New York, and Ontario. Over the past 100 years, this species' numbers have apparently declined rangewide by 99% or more. More than 90% of the decline occurred in the last 10-15 years. It is now extirpated from Massachusetts, Pennsylvania, and Ohio.

The New York Natural Heritage Program maintains a state list of approximately 50 individual Karner blue butterfly sites, comprising about 10 site-clusters, all found in the area known as the Albany Pine Bush and at scattered locations extending about 40 mi (64 km) to the north. Once the site of a massive Karner blue butterfly population, Albany Pine Bush is the locality from which the butterfly was first described. There are also unverified records of this species in Manhattan and Brooklyn from the mid-1800s. A decline of 85-98% in the Albany Pine Bush over the past decade has been noted, exclusive of one site that has remained stable. The decline in population has been described as dropping from numbers of around 80,000 in 1979, to around 1,000 in 1987, to 100-200 in 1990. North of the Albany Pine Bush, one disturbed site located at an airport has persisted with numbers estimated around 14,000 in 1990. This population is several times larger than all the other New York sites combined. The majority of extant Karner blue butterfly sites in New York are in municipal and private ownership. Other landowners include a State Park, The Nature Conservancy, and Saratoga County.

In New Hampshire, the Concord Pine Barrens along the Merrimack River support the only remaining occurrence of this species in New England. The sole population is extremely low in numbers and occurs on a privately owned, 2-3-acre (0.81-1.21-hectare) site within a power line right-of-way bordering an industrial park, and on the grounds of a nearby airport. The results of 1990 surveys reported by The Nature Conservancy showed a decline in the population size from an estimated 2,000-3,000 individuals in 1983 to an estimated 250-400 individuals in 1990. During that survey, the species was not found at two other sites in the Concord Pine Barrens where it had been documented in 1983.

In Wisconsin, 33 of 36 historical occurrence sites were surveyed during 1990. Survey results revealed that the species was found at only 11 of the 33 historical sites visited. Although 23 previously unknown populations were discovered, the numbers of Karner blue butterfly observed were very small at most sites. Only three sites had 50 or more individuals observed, with none greater than 100. At least half of Wisconsin's populations are small, isolated, and cannot be considered secure or viable in the long term. However, a very good number of quite sizeable populations occur on publicly owned properties offering good opportunities for long-term protection and management. Over three-fourths of the Wisconsin sites are on publicly administered lands, including Necedah National Wildlife Refuge, Department of Defense, Wisconsin Department of Natural Resources, and County Forest.

The Karner blue butterfly has declined throughout its range in Michigan. It still occurs in six of seven counties from which it was known historically, but the existing populations are greatly reduced and have become highly fragmented within expanses of suitable habitat.

Surveys in Indiana in 1990 yielded the following results: this species was reconfirmed at one known site, and was rediscovered on three of seven historical sites. Searches at 27 sites identified as potentially suitable for the species yielded six new locations for the species. However, all extant sites in Indiana are in two population clusters within two counties. Six sites are located on Indiana Dunes National Lakeshore, and other landowners include a county park and recreational department, a school district, and The Nature Conservancy.

During the 1990 surveys of 50 potentially suitable sites in Minnesota, the Karner blue butterfly was located in two areas. Both sites are on a State Wildlife Management Area, in the vicinity of one of the historical locations. Studies conducted in 1991 revealed three new sites within 0.5-3 mi (0.8-4.8 km) of the sites surveyed in 1990. Low numbers of individuals were observed at all five sites, with none greater than 14.

This species was presumed extirpated from Illinois until the species was relocated there in August 1992. A total of seven butterflies, including five males and two females, were reported from a lupine site in the northern part of the state.

Threats

Throughout its range, changes in the habitat occupied by this species resulting from silviculture, urbanization, and the declining frequency of wild-fires are largely the reasons for its decline. Modification and fragmentation of remaining areas are continuing threats to the survival of this butterfly. In addition to direct destruction of suitable habitat, urbanization has led to fire suppression on interspersed habitat; in the absence of fire, vegetational succession has made this habitat unsuitable.

Although in the past there have been large scientific collections of the Karner blue butterfly, they are not believed to be a significant factor in the decline of this species. However, any future take could potentially damage recovery efforts.

Disease and predation have not been documented as factors in the decline of this species.

As the continued survival of this species is dependent on the presence of wild lupine, any actions or lack thereof, that affect populations of wild lupine will affect Karner blue butterfly populations.

With small, isolated, and declining populations, this butterfly is particularly vulnerable to extinction.

Extreme isolation will prevent the influx of new genetic material, leading to highly inbred populations that have low viability and/or fecundity.

Vegetation control measures implemented during the fall of 1990 at the Concord site opened habitat for the butterfly's obligate food source, wild lupine, and seeds collected have been planted in several test plots. If these plantings are successful, the butterfly population should increase.

Conservation and Recovery

In March of 1991, the U. S. Fish and Wildlife Service (FWS) and conservation groups persuaded the New Hampshire Department of Environmental Services to deny the city of Concord's application to spread municipal sludge over 200 acres of remnant pine barren habitat at the city airport.

FWS's New England Field Office, the State of New Hampshire, and The Nature Conservancy continue to work with the city of Concord to set aside pine barren preserves for the butterfly and other rare species.

Contacts

U.S. Fish and Wildlife Service
Regional Office
Federal Building
Fort Snelling
Twin Cities, Minnesota 55111
http://midwest.fws.gov/

U.S. Fish and Wildlife Service
Regional Office
300 Westgate Center Dr.
Hadley, Massachusetts 01035
http://northeast.fws.gov

New England Ecological Services Field Office
22 Bridge St., Suite 1
Concord, New Hampshire 03301-4986
Telephone: (603) 225-1411
Fax: (603) 225-1467

Massachusetts Natural Heritage and Endangered
Species Program
Division of Fisheries and Wildlife
Route 135
Westborough, Massachusetts 01581
Telephone: (508) 792-7270, extension 200
Fax: (508) 792-7275

References

Schweitzer, D. F., 1989. "Fact sheet for the KarnerBlue Butterfly with special reference to New York." The Nature Conservancy, internal document, 7 pp.

U.S. Fish and Wildlife Service 14 December 1992. Federal Register. Rules and regulations. 57 (240): 59236-59243.