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.
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.
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.
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.
Government of Ontario. 2018. Karner Blue Evaluation. Retrieved from: https://www.ontario.ca/page/karner-blue-evaluation
COSEWIC. 2019. COSEWIC status appraisal summary on the Karner Blue Plebejus samuelis in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xviii pp. https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/cosewic-assessments-status-reports/karner-blue-2019.html
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