Karner Blue

Plebejus melissa samuelis (Nabokov, 1944)

Karner Blue butterfly
Carly Voight

Insecta (Insects)
Lycaenidae (Blues, Coppers, Hairstreaks, Elfins)
State Protection
Listed as Endangered by New York State: in imminent danger of extirpation in New York. For animals, taking, importation, transportation, or possession is prohibited, except under license or permit. For plants, removal or damage without the consent of the landowner is prohibited.
Federal Protection
Listed as Endangered under the Federal Endangered Species Act
State Conservation Status Rank
Critically Imperiled in New York - Especially vulnerable to disappearing from New York due to extreme rarity or other factors; typically 5 or fewer populations or locations in New York, very few individuals, very restricted range, very few remaining acres (or miles of stream), and/or very steep declines.
Global Conservation Status Rank
Critically Imperiled or Imperiled globally - At very high or high risk of extinction due to rarity or other factors; typically 20 or fewer populations or locations in the world, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines. More information is needed to assign either G1 or G2.


Did you know?

Karner blue larvae and ants have a unique relationship. The larvae produce secretions that ants find tasty. In return, the ants protect the larvae from predators.

State Ranking Justification

There are four recovery units and New York. Parts of Albany and Saratoga counties have undergone habitat restoration and the populations are showing signs of recovery. Sites that are not actively managed typically have fewer than 100 butterflies present. This species does not persist well if the total July brood for the metapopulation is fewer than 1,000 adults. This Federally and State-listed species is completely management dependent in New York, and is the case in most or all of the remaining portion of the range.

Short-term Trends

There has been restoration efforts in the Albany Pine Bush Preserve and the Saratoga Sandplains. In Albany, there has been a population increase trend since 2007. First brood estimates went from 700 individuals in 2007 to 8400 individuals in 2014. Second brood estimates were 850 individuals in 2007 and increased to 14,200 individuals in 2014 (Albany Pine Bush). The increase is the result of extensive restoration efforts that includes the removal of non-native vegetation, controlled burns, planting native vegetation, and reintroduction efforts. In 1997, the Albany Pine Bush Commission estimated approximately 5 ha of suitable habitat. As of 2014, there are approximately 168 ha of suitable habitat (Albany Pine Bush). Similar efforts have been made in the Saratoga Sandplains. Population estimates in western Saratoga County, including Saratoga Airport, often have at least 500 to 1000 butterflies. While the suitable habitat has expanded on managed parcels of land, there are some small, remnant populations that continue to decrease in size due to succession and loss of wild lupine. Some of these populations are now extirpated. Glens Falls has remnant populations. At some sites, the current population sizes are not known.

Long-term Trends

The Albany area population has declined by over 90% from what it apparently was in the 1970s and the population was probably even higher originally. The Tonawanda, Brooklyn, and Sullivan County populations are extirpated, as are the Rome and Watertown populations, if they really existed. The Warren County populations are now small remnant colonies. The decline has probably been less at the Saratoga locations.

Conservation and Management


The threats include habitat loss, degradation, and fragmentation, invasive species, fire suppression, inappropriate management of wild lupine, mosquito spraying and the use of other insecticides, and browsing of lupine by herbivores, primarily deer. There is also a concern that a reduction in winter snow pack and other changes, due to climate change, threaten this species. Such threats could be of particular concern in New York, which has a warmer climate and is farther south than most of the current range for this butterfly.

Conservation Strategies and Management Practices

Karner Blue habitat management requires some labor-intensive strategies because natural disturbances (e.g., fire) are often suppressed. Management techniques that mimic natural disturbances include mowing, herbicide use, and prescribed fire. These practices will help maintain open habitat for wild lupine to persist as well as other nectar species by controlling succession and invasive species. Management plans should be site specific and planned with appropriate government agencies. When mowing is used, it's important to clean mowers and all equipment before and after use to prevent the spread of invasive species to other sites. Site disturbances should be timed to minimize directly harming Karner Blue. Mowing should be timed after wild lupine have senesced, mowers should be set at 6 to 8 inches above ground, and preferably after the first frost (Gifford and O'Brien 2010). No more than half of a Karner Blue subpopulation should be mowed (Gifford and O'Brien 2010). All Karner Blue life stage are vulnerable to fire. Prescribed fire should contain no more than a third of a site in a given year and adjacent thirds should not be burned in consecutive years (Gifford and O'Brien 2010). Refugia is important for Karner Blue and other animals. If there is a lack of lupine and nectar species at a site, Lerg and Carnes (2007) suggests planting wild lupine along with at least three first brood nectar species and three second brood nectar species. Herbivores, especially deer, have reduced wild lupine and important nectar sources. Insecticide use should be minimized as much as possible. When absolutely needed, attempt to find insecticides that target the desired insect. Treatment should be avoided when Karner Blue are active. There has been increasing concerns about climate change and potential loss of species. Lerg and Carnes (2007) recommend maintaining a large, diverse landscape with topographic heterogeneity when possible. You should also consider searching for potential habitat to the north. This may be more challenging as the ecosystems used by Karner Blue are not widespread. Another concern is extreme weather events (e.g., tornado, torrential rains, unseasonably cold or hot weather). Large, buffered metapopulations may help reduce loss from these weather events. Restoration of sites may be needed depending on the severity of damage. Another issue on a landscape scale to consider is the presence of other rare Lepidoptera, such as Frosted Elfin (Callophrys irus) that also use wild lupine as a larval food plant.

Research Needs

Some research has shown that early spring mowing benefits the survival of the first brood larvae (Gifford and O'Brien 2010). Additional studies are recommended to determine if this is a beneficial management strategy. The severity of mosquito spraying to larvae and adults needs to be evaluated if it occurs in the vicinity Karner Blues, since aerial spraying for mosquitoes is more prevalent in New York than most other northern states and may involve large areas.



Karner Blue can be found in extensive pine barrens, oak savannas or openings in oak woodlands, and unnatural openings such as airports and right-of-ways that contain wild lupine (Lupinus perennis), the sole larval food source. Historically, fire usually played a role in maintaining these early successional habitats.

Associated Ecological Communities

  • Calcareous pavement woodland (guide)
    An open canopy woodland that occurs on very shallow soils over flat, striated outcrops of calcareous bedrock (limestone and dolomite).
  • Pine barrens vernal pond (guide)
    A seasonally fluctuating pond and its associated wetlands that typically occurs in pine barrens. The water is intermittent, usually a pond in the spring but sometimes losing water through the summer to become a mostly vegetated wetland at the end of the summer. These ponds and wetlands may be small.
  • Pitch pine-oak forest (guide)
    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-scrub oak barrens (guide)
    A shrub-savanna community that occurs on well-drained, sandy soils that have developed on sand dunes, glacial till, and outwash plains.
  • Successional northern sandplain grassland (guide)
    A meadow community that occurs on open sandplains that have been cleared and plowed (for farming or development), and then abandoned. This community is usually dominated by low, dry turf of sedges and grasses less than 30 cm (12 inches) tall, and include patches of open sand and patches of soil covered with mosses and lichens.

Associated Species

  • Frosted Elfin (Callophrys irus) (guide)


New York State Distribution

Currently, the only known occupied sites are clustered in Albany, Schenectady, Saratoga, and Warren Counties and represent remnants of two or three once large metapopulations. Historically there were also specimens, or at least reports from Watertown, Tonawanda, Rome, Sullivan County, and Brooklyn (Shapiro 1974).

Global Distribution

The Karner Blue is currently found in Minnesota, Wisconsin, Michigan, northern Indiana, and New York. It has been extirpated from Illinois, Iowa, Ohio, Ontario, Pennsylvania, Massachusetts, New Hampshire, and Maine, but was reintroduced in New Hampshire and Ohio. It was falsely reported from North Carolina and Manitoba.

Best Places to See

  • Albany Pine Bush (Albany County)
  • Saratoga Sandplains (Saratoga County)

Identification Comments

General Description

Karner blue is a small, silvery blue butterfly with orange crescents on the margins of the underside of the wings. The dorsal surface of the male is all violet-blue, as compared to the dorsal surface of the female, which is dull purplish-blue near the body and turning a dull brown away from the body. The dorsal surface of the lower wings also have orange crescents along their bottom edges.

Identifying Characteristics

Karner blue has a wing span of approximately 1 inch, about the size of a nickel. Male dorsal wings are deep violet-blue with black margins that have a white border while females are a dusky brownish-blue with orange spots on the edges of the hind wings. Ventrally, males and females are similar, wings are gray with scattered black spots with white borders and bands of orange crescents on the edges of the fore and hind wings. Karner blue are the only small butterfly with this orange crescent banding . Larvae are pea green and covered with fine hairs.

Characters Most Useful for Identification

The combination of marginal orange spots on the underside of all wings and lack of tails on the hindwings is diagnostic. The males have no orange at all above. The females have some orange on the hindwing above and always have some blue near the body on upper side of all wings.

Best Life Stage for Proper Identification

The adult is the best life stage for identification. The eggs and larvae can be identified by an expert.


It is unlikely to be seen more than a few yards from patches of wild lupine, although wandering individuals do occur up to a mile or more away from main breeding areas.


Larvae feed only on the native wild lupine in nature. The adults take nectar from many kinds of low growing flowers, native or otherwise.

Best Time to See

The exact phenology varies from year to year and colony to colony. Those in the most open habitats tend to be about a week ahead of those in more wooded places. There are always two annual generations. The eggs overwinter and hatch, but not all at once, around the middle of April. The larvae mature mostly in late May and pupate. Adults emerge in late May to early June and are active for two to three weeks. The eggs from these adults hatch in a few days and the larvae are mostly mature in early July. Second brood adults fly for about three weeks and peak numbers usually occur for about a week in the second half of July. The eggs laid by these adults hatch the following spring.

  • Reproducing
  • Larvae present and active
  • Eggs present outside adult
  • Pupae or prepupae present

The time of year you would expect to find Karner Blue reproducing, larvae present and active, eggs present outside adult, and pupae or prepupae present in New York.

Similar Species

  • Spring Azure (Celastrina ladon)
    Spring Azure are prominent in the early spring. It looks similar to male Karner Blue. However, Spring Azure has no orange spots on the the dorsal or ventral wings while the male and female Karner Blues have orange crescents on the ventral wings and females also have orange on the dorsal hind wings.
  • Eastern Tailed-blue (Cupido comyntas)
    This species looks very similar to Karner Blue. The distinguishing feature is that Eastern-tailed Blue has a small tail on each hind wing while the Karner Blue does not. Karner blue are larger than Eastern-tailed blue. Female Karner Blues have some orange on the hindwings above and, unlike the Eastern Tailed-blue, always have some blue near the body on upper side of all wings. Both sexes are also larger than tailed blues.

Karner Blue Images


Karner Blue
Plebejus melissa samuelis (Nabokov, 1944)

  • Kingdom Animalia
    • Phylum Arthropoda (Mandibulates)
      • Class Insecta (Insects)
        • Order Lepidoptera (Butterflies, Skippers, and Moths)
          • Family Lycaenidae (Blues, Coppers, Hairstreaks, Elfins)


  • Lycaeides melissa samuelis Nabokov, 1944

Comments on the Classification

Some experts suspect this will prove to be a full species and the number of species in this genus is not well understood. In New York, the Karner Blue is considered a subspecies of the Melissa Blue (Plebejus melissa) because no published works have revised the taxonomy to elevate this subspecies to species status.

Additional Resources


Allen, T.J., J.P. Brock, and J. Glassberg. 2005. Caterpillars in the field and garden. Oxford University Press, New York. 232 pp.

Brock, J. P., and K. Kaufman. 2003. Butterflies of North America. Kaufman Focus Field Guides, Houghton Mifflin Company, New York, NY 284 pp.

Gall, L. F. 1985. Measuring the Size of Lepidopteran Populations. Journal of Research on the Lepidoptera. 24(2):97-116.

Gifford, Neil A. and Kathleen O'Brien. 2010. Karner Blue Butterfly recovery plan for the Albany Pine Bush meta-population recovery unit. Appendix D.

Givnish, T., Menges, E., and Schweitzer, D.F. 1988. Minimum area requirements for long-term conservation of the Albany Pine bush and Karner blue butterfly. Consultants report prepared for the City of Alabny, NY, Malcom Pirnie, Inc.

Glassberg, J. 1993. Butterflies through binoculars: A field guide to butterflies in the Boston-New York-Washington region. Oxford University Press: New York. 160 pp.

Glassberg, J. 1999. Butterflies Through Binoculars: The East. Oxford University Press, New York, New York. 400 pp.

Iftner, D. C., J. A. Shuey, and J. V. Calhoun. 1992. Butterflies and Skippers of Ohio. Ohio Biological Survey Bulletin. New Series, Vol. 9, no. 1, xii + 212 pp., 40 color plates.

Lerg, John and Cathy Carnes. 2007. Karner Blue Butterfly threats summary table.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

New York State Department of Environmental Conservation. 1998. Karner blue butterfly (Lycaeides melissa samuelis) Nabokov. New York State recovery plan. Unpublished draft.

Opler, P. A., and A. D. Warren. 2002. Butterflies of North America. 2. Scientific Names List for Butterfly Species of North America, north of Mexico. C.P. Gillette Museum of Arthropod Diversity, Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado. 79 pp.

Opler, P.A. and G.O. Krizek. 1984. Butterflies East of the Great Plains, an illustrated natural history. Johns Hopkins University Press. Baltimore. 294pp.

Opler, P.A. and V. Malikul. 1992. A field guide to eastern butterflies. Houghton Mifflin, Boston, MA. 396 pp.

Schweitzer, D.F. 1994a. Prioritizing Karner Blue Butterfly Habitats for Protection Activities. Chapter 19, pp. 173-183 in: Andow, D.A., R.J.Baker, and C.P. Lane (eds.) Karner Blue Butterfly: a symbol of a vanishing landscape. Misc. Publ. 84-1994 Minnesota Agric. Expt. Station, Univ. of Minnesota, St. Paul, MN. 222 pp.

Schweitzer, D.F. 1994b. Recovery goals and methods for Karner Blue Butterfly populations. Chapter 20, pp.185-193 in Andow, D.A.; Baker, R.J. and Lane, C.P. (eds.) Karner Blue butterfly: a symbol of a vanishing landscape. Misc. Publ. 84-1994 Minnesota Agric. Expt. Sta., St. Paul, MN. 222 pp.

Shapiro, A.M. 1974. Butterflies and Skippers of New York State. Search 4:1-60.

U.S. Fish and Wildlife Service (USFWS). 1992. Determination of endangered status for the Karner Blue butterfly [Lycaeides melissa samuelis]. Federal Register 59236-59244.


About This Guide

This guide was authored by: Shaw, Hollie Y.

Information for this guide was last updated on: June 28, 2019

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Plebejus melissa samuelis. Available from: https://guides.nynhp.org/karner-blue/. Accessed May 26, 2024.