FWS Focus

Overview

Characteristics
Overview

The Karner blue butterfly, an endangered species, is a small butterfly that lives in oak savannas and pine barren ecosystems from western Wisconsin and eastward to the Atlantic seaboard. Historically, it was found in a continuous band throughout its range, but today is found in portions of New Hampshire, New York, Michigan, Wisconsin and Ohio. Wild blue lupine (Lupinus perennis) is the only plant Karner blue larvae, or caterpillars, can eat. Even so, the range of these butterflies and that of their host plant do not completely overlap. Instead, Karner blue butterfly are found predominantly along the northern band of wild lupine's range. 

At the time of listing under the Endangered Species Act, the most important factor causing the decline of the Karner blue butterfly across its range was the loss of habitat due to suppression of wild fires, clearing land for farming and developing land for commercial and residential purposes. Without disturbance activities like fire and grazing, shrubs and trees invade the open savanna and barrens, shading out grass and herbaceous plants like wild lupine. When this happens, only pockets of suitable space remain, which make it hard for butterflies to find more areas with wild lupine. It also limits the amount of suitable habitat that's available. This results in small, isolated populations of Karner blue butterflies. Because the Karner blue butterfly's habitat is very specific, the butterfly is unable to adapt to these changes in its environment. Habitat loss and isolation of these populations, combined with the extremely small size of many of the remaining population, puts many populations at high risk of winking out of existence.

The Karner blue butterfly has also been found to be highly sensitive to both direct and indirect climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change
impacts as was documented in 2019 during the U.S. Fish and Wildlife Service 5-year review. The likely extirpation of the population at the Indiana Dunes National Lakeshore was used as a case study to explore the Karner’s sensitivity and exposure to climate change. Findings indicate that the population’s decline occurred in conjunction with documented warming conditions. Additionally, the documented decline is considered consistent with scientists’ expectations for how a population of a low-motility species at the edge of the climate-induced range would respond. 

Efforts to conserve and recover this butterfly continue to occur throughout the Karner blue range. The U.S. Fish and Wildlife Service prepared the Karner Blue Butterfly Recovery Plan in 2003, which outlines a strategy for recovering the butterfly range-wide. It identifies tasks to restore habitat, as well as ways to stabilize and recover Karner blue populations. A wide variety of partners are committed to protection and restoration of the Karner blue butterfly and its habitat on public and private lands throughout the range. Also, there is a large recovery group that is committed to researching less understood aspects of Karner biology and habitat management.

Scientific Name

Lycaeides melissa samuelis
Common Name
'Karner' Melissa Blue
Karner blue Butterfly
FWS Category
Insects
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Life Cycle

Characteristics
Life Span

The Karner blue butterfly usually has two generations, and thus two flight periods, each year. Timing for each life stage varies slightly by location within the range. Typically sometime in April the first group of caterpillars hatch from eggs that were laid the previous year. The caterpillars then feed only on wild lupine plant leaves. By about mid-May, the caterpillars pupate and adult butterflies emerge from their cocoon-like chrysalis by the end of May or in early June. These adults mate, laying their eggs in June on or near wild lupine plants. The eggs hatch in about one week and the caterpillars feed for about three weeks. They then pupate and the summer's second generation of adult butterflies appears in July. These adults then mate and lay eggs that will not hatch until the following spring.

Reproduction

The Karner blue butterfly usually has two generations, and thus two flight periods, each year. Timing for each life stage varies slightly by location within the range. Typically sometime in April the first group of caterpillars hatch from eggs that were laid the previous year. The caterpillars then feed only on wild lupine plant leaves. By about mid-May, the caterpillars pupate and adult butterflies emerge from their cocoon-like chrysalis by the end of May or in early June. These adults mate, laying their eggs in June on or near wild lupine plants. The eggs hatch in about one week and the caterpillars feed for about three weeks. They then pupate and the summer's second generation of adult butterflies appears in July. These adults then mate and lay eggs that will not hatch until the following spring.

Life Cycle

The Karner blue butterfly usually has two generations, and thus two flight periods, or the time that adult butterflies are on the wing, each year. Timing for each life stage varies slightly by location within the range. Typically sometime in April the first group of caterpillars hatch from eggs that were laid the previous year. The caterpillars then feed only on wild lupine plant leaves. By about mid-May, the caterpillars pupate and adult butterflies emerge from their cocoon-like chrysalis by the end of May or in early June. These adults mate, laying their eggs in June on or near wild lupine plants. The eggs hatch in about one week and the caterpillars feed for about three weeks. They then pupate and the summer's second generation of adult butterflies appears in July. These adults then mate and lay eggs that will not hatch until the following spring.

Characteristic category

Physical Characteristics

Characteristics
Color & Pattern

The male and female of this small butterfly are different in appearance. The topside of the male is silvery or dark blue with narrow black margins. The female is grayish brown, especially on the outer portions of the wings, to blue on the topside, with irregular bands of orange crescents inside the narrow black border. The underside of both sexes is gray with a continuous band of orange crescents along the edges of both wings and with scattered black spots circled with white.

Size & Shape

The Karner blue butterfly is a small butterfly with a wingspan of about one inch, often compared to the size of a postage stamp. 

Characteristic category

Food

Characteristics
Food

Karner blue caterpillars feed only on the leaves of the wild lupine (Lupis perennis) plant. Adults feed on the nectar of flowering plants. Because the caterpillar can only successfully feed on wild lupine, the reproductive success of Karner blue butterflies is critically dependent on the wild lupine.

Characteristic category

Similar Species

Characteristics
Similar Species

The Karner blue butterfly is a subspecies of the Melissa blue butterfly. The Melissa blue typically has three broods, whereas the Karner only has two.The Karner caterpillars feed only on wild lupine and the Melissa blue may feed on various legumes of the pea family including Astragalus, Glycyrrhiza, Lotus, Lupinus and Medicago species. 

Characteristic category

Habitat

Characteristics
Habitat

Adult karners can fly up to about 1.4 miles across open landscapes. Adults will mate and then lay eggs on wild lupine plants. Karner caterpillars feed on wild lupine leaves and are commonly tended by ants. It appears the ants protect the caterpillars from some natural enemies and that the ants in return collect a nectar from the caterpillar. Once mature, the caterpillars pupate. 

Grassland

Land on which the natural dominant plant forms are grasses and forbs.

Rural

Environments influenced by humans in a less substantial way than cities. This can include agriculture, silviculture, aquaculture, etc.

Characteristic category

Behavior

Characteristics
Behavior

Adult karners can fly up to about 1.4 miles across open landscapes. Adults will mate and then lay eggs on wild lupine plants. Karner caterpillars feed on wild lupine leaves and are commonly tended by ants. It appears the ants protect the caterpillars from some natural enemies and that the ants, in return, collect a nectar from the caterpillar. Once mature, the caterpillars pupate. 

Geography

Characteristics
Range

Karner blue butterflies once occurred in a nearly continuous narrow band across 12 states and the province of Ontario, Canada, but it has been eliminated from seven of those states and Ontario. Today it is found in portions of New Hampshire, New York, Michigan, Wisconsin and Ohio.

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Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

10 Items

Listing

Critical Habitat

Listing

Listing

Recovery Plan

Recovery Plan

Habitat Conservation Plan

Safe Harbor Agreement

Five Year Review

Five Year Review

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Listing

Jul 3, 1978

Jul 3, 1978 Listing (Threatened)
Proposed Endangered or Threatened Status with Critical Habitat For Ten Butterflies or Moths
  • Publication type: Proposed
Item 1

Critical Habitat

Jul 3, 1978

Jul 3, 1978 Critical Habitat
Proposed Endangered or Threatened Status with Critical Habitat For Ten Butterflies or Moths
  • Publication type: Proposed
Item 2

Listing

Jan 21, 1992

Jan 21, 1992 Listing (Endangered)
ETWP; Proposed Endangered Status for the Karner Blue Butterfly
  • Publication type: Proposed
Item 3

Listing

Dec 14, 1992

Dec 14, 1992 Listing (Endangered)
ETWP; Determination of Endangered Status for the Karner Blue Butterfly; 57 FR 59236 59244
  • Publication type: Final
Item 4

Recovery Plan

Dec 5, 2001

Dec 5, 2001 Recovery Plan (Document Availability (non-FR))
Notice of Availability of the Karner Blue Butterfly (Lycaeides melissa samuelis) Technical/Agency Dr…
  • Publication type: Draft
Item 5

Recovery Plan

Sep 19, 2003

Sep 19, 2003 Recovery Plan (Document Availability (non-FR))
Notice of Availability of the Approved Recovery Plan for the Karner Blue Butterfly (Lycaeides meliss…
  • Publication type: Final
Item 6

Habitat Conservation Plan

Feb 22, 2005

Feb 22, 2005 Habitat Conservation Plan (Document Availability (non-FR))
Proposed Low Effect Habitat Conservation Plan for Michigan Electric Transmission Company, LLC
  • Publication type: Draft
Item 7

Safe Harbor Agreement

Oct 10, 2007

Oct 10, 2007 Safe Harbor Agreement (Document Availability (non-FR))
Eastern New York Chapter of the Nature Conservancy, Enhancement of Survival Permit
  • Publication type: Draft
Item 8

Five Year Review

Mar 18, 2009

Mar 18, 2009 Five Year Review (Information Solicitation)
Notice of initiation of review; request for information on nine listed Midwestern species
  • Publication type: Notice
Item 9

Five Year Review

Apr 17, 2017

Apr 17, 2017 Five Year Review (Information Solicitation)
Initiation of 5-Year Status Reviews of Eight Endangered Animal Species and Request for Information
  • Publication type: Notice
Item 10