Karner Blue

(Lycaeides melissa samuelis)

Status: Extirpated (COSEWIC 2019, ESA 2009)

Table of Contents:

Species Identification
Diet
Habitat and Range
Biology and Behaviour
Threats/Reasons for Being Extirpated
Recovery Strategies
How You Can Help

Species Identification:

Karner Blue males are small, approximately the size of a quarter (2.5 cm). The wings are deep iridescent blue outlined with thin black edges and a white fringe. Females are similar in size with dark purple or purple-brown wings. The wings have a row of dark spots and orange crescents along the edges. The undersides of the wings of both the male and females are light silver-grey with a similar dot and crescent pattern. The larva is the same colour of the light green plants on which it lives, which is Wild Lupine.

Diet:

The larvae of the Karner Blue feed exclusively on the leaves of Wild Lupine, which are generally only found in sandy soils of pine barrens, oak savannas, and lakeshore dunes. Adult Karner Blue feed on the nectar of a variety of wildflowers, but some of their favourites include Butterfly Weed, Wild Strawberry, Raspberry, Goldenrod, and Blazing Star.

Map taken from Government of Canada: https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/cosewic-assessments-status-reports/karner-blue-2000.html#_Toc264561123

Habitat and Range:

The Karner Blue has not been observed in Canada since 1991. The last recorded sighting in Ontario was at Port Franks and St. Williams in 1988. The range of the Karner Blue extended from New York State, across Southern Ontario to Southern Wisconsin. Today, the Karner Blue populations only occur in the United States, and are patchy and not often identified. Ohio and New Hampshire have initiated reintroductions of domesticated Karner Blue populations in an attempt to save the species.

Karner Blue can only survive in areas where Wild Lupine plants grow, such as savanna and barren habitats. However, much of these habitats in Ontario have either been destroyed or altered. In order for Wild Lupine and other wildflowers to thrive, there must be regular natural wildfires to ensure that savannas and barrens do not get overgrown with trees that will block the wildflower’s sunlight. This is also occurring in the United States, where there is now very little suitable habitat for both Wild Lupine and the Karner Blue. While Wild Lupine can be found throughout Ontario, especially in The Land Between, it is suspected that Karner Blue needs large, uninterrupted spaces of Wild Lupine.

Biology and Behaviour:

Two groups of Karner Blue are hatched each year; first, the eggs that were laid in the late summer of the previous year hatch in the spring. These eggs grow into adults which in turn lay eggs in mid summer. These eggs hatch, producing the adults that will lay the eggs that will overwinter and hatch in the following spring. Eggs are laid on the leaves of Wild Lupine plants. The larvae feed for approximately three weeks before pupating and emerging as adults. Adult Karner Blue only live for approximately 5 days, giving them enough time to lay eggs for the next generation. Since they do not live for very long as adults, their range is only about a kilometre or less. The Karner Blue also has a symbiotic relationship with ants. The larvae secrete a sugar that ants will harvest, in exchange for protection from parasitic wasp wasps or flies that may lay eggs on them.

Threats/ Reasons for being Extirpated:

1. Habitat loss: Much of the specific habitat where the Wild Lupine can thrive has been lost due to urban development and wildfire suppression. The Wild Lupine is the only plant that the Karner Blue larvae can hatch and grow on. The loss of the open, sunny, oak savanna habitat that Wild Lupine depends on has been detrimental to the Karner Blue, ultimately resulting in its extirpation. While Wild Lupine can be found in small scattered areas throughout Ontario (especially more north), there are not enough plants or a large enough uninterrupted area to sustain the Karner Blue. Urbanization over the years has either destroyed or altered what little open savanna habitats Ontario has, which is thought to be the number one reason why the Karner Blue can no longer be found here.

2. Wildfire suppression: The suppression of forest fires in oak savannas and other previously open-canopied areas is another contributor to Karner Blue and Wild Lupine habitat loss. The proximity of these habitats to developed areas has resulted in the closure of the canopy in many previously open canopy areas. This succession of the forest has resulted in habitat conditions that are no longer suitable for the Wild Lupine on which the Karner Blue depends, as Wild Lupine requires dry, open, sunny habitat. Fire suppression near urban development was thought to be important to keep people safe, but has resulted in the extirpation of the Karner Blue, as well as many other species that rely on natural wildfires for succession and preservation of their habitats.

Recovery strategies:

The first step to recovering Karner Blue species is to once again create suitable habitat for them. A recovery strategy is being prepared for the Karner Blue with the ultimate goal of creating oak savanna habitat for the butterfly to be reintroduced to Norfolk, Lambton, and Northumberland counties. Similar reintroduction efforts have been successful in the United States. Volunteer Wild Lupine and wildflower planting efforts are underway in areas across Southern Ontario.

How can you help?

Report sightings of Species at Risk to The Land Between or iNaturalist. This helps researchers keep track of populations.
Volunteer to participate in Wild Lupine, wildflower, or other native plant planting sessions in your area to help restore suitable habitat for the Karner Blue, and other previously extirpated or at risk species.
Plant native, pollinator friendly plants in your garden to help support other pollinators like the Karner Blue.
Use only natural, safe pesticides and fertilizers on your property that will not harm important insect species like the Karner Blue.