Species At Risk

Karner Blue

(Lycaeides melissa samuelis)

Extirpated (no longer found in Ontario)

Karner Blue
Karner Blue occurrences map


The male Karner Blue is a small beautiful butterfly with a wingspan of 2.5 centimetres, or about the size of a quarter. Its deep blue wings have black edges and a white outer fringe. Females are similar but are a darker, purple-blue to purple-brown in colour, with a row of dark spots with orange crescents along the wing edges. The undersides of both the male and female wings are light silver- grey with black dots and orange crescents along the outer edges. The larva of the species is covered in very fine hairs and for protection from predators, it matches the color of the green leaves of the plants it lives on.

The female Karner Blue lays eggs on or near wild lupine, the sole food source of the larvae. Two butterfly broods are produced each year. In spring, eggs that were laid the previous year metamorphose to produce a first brood of caterpillars. These caterpillars pupate and adult butterflies emerge in May. These adults then mate and lay eggs in June. After a week, the eggs hatch and the resulting caterpillars feed for three weeks before pupating into adult butterflies in late summer. Adult butterflies that emerge in late summer mate and lay eggs that do not hatch until the following spring.

Action we are taking:

Current Range

The Karner Blue occurs in isolated populations from New Hampshire and New York, west through southern Ontario and states bordering the Great Lakes to Minnesota. The Karner Blue is extirpated from some of the states throughout its range, but some jurisdictions (e.g. Ohio and New Hampshire) have initiated reintroductions.

Historical Range in Ontario

The most recent occurrences of Karner Blue were recorded in southwestern Ontario at Port Franks and St. Williams in the late 1980s. However, evidence suggests that Karner Blue was historically more widespread with records from Toronto, London and Sarnia.

Why It Disappeared from Ontario

Habitat loss is responsible for the decline of the Karner Blue throughout its range. Much of Ontario’s original savannah and barren habitat have been destroyed by development or taken over, through natural succession, by plants that create shady conditions. These conditions are unsuitable for the growth of wild lupine which requires open, sunny areas. Suppression of wild fires that once kept areas open and free of shade-producing shrubs and trees is another factor contributing to the loss of this increasingly rare habitat.


The habitat of the Karner Blue is restricted to where wild lupine grows – in sandy soils, sandy pine barrens, beach dunes, and oak savannahs.


Help Make Sure We Don’t Lose More Endangered Species in Ontario

  • The Ministry of Natural Resources tracks species at risk such as Karner Blue. You can use a handy online form to report your sightings to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful. nhic.mnr.gov.on.ca.
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Private land owners have an important role to play in species recovery. You may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats. For more information visit: ontario.ca/speciesatrisk.
  • Volunteer with a local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.

Did you know?

In 1944, novelist Vladimir Nabokov first identified the Karner Blue butterfly, which takes its name from the hamlet of Karner in New York state.

Did you know?

The Karner Blue has a lifespan of about five days as an adult butterfly.

Did you know?

Karner Blue caterpillars feed exclusively on the leaves of the wild lupine. The adult butterfly does not depend on lupine exclusively, and feeds on a variety of flowering plants.

Did you know?

Karner Blue caterpillars have a mutually advantageous relationship with mound-building ants, which protect the caterpillars from predators like spiders and parasites. In exchange, the caterpillars excrete a sugary substance which is consumed by the ants.

Did you know?

Declines in wild lupine populations and savannah and barren ecosystems are also responsible for the extirpation of two other butterfly species in Ontario, the Frosted Elfin and Eastern Persius Duskywing.

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.