Tips for Identifying Karner Blue Butterflies

How do I know that the butterfly I'm looking at is a Karner blue?

The Karner blue butterfly, Lycaeides melissa samuelis, is in the Lycaenidae (gossamer-winged butterfly) family. The adult Karner blue butterfly is about the size of a nickel, with a wingspan of about an inch, and it can be identified by the bands of orange spots on the underside edge of its wings. The top sides of the male's wings are deep sky blue, while those of the female are darker blue and brown with orange spots on the edges of both hind wings. The dorsal sides of the males' wings are deep sky blue with black margins bordered by a white band, while those of the female are darker blue and brown with orange crescents on the edges of both hind wings.

Both sexes can be identified by the bands of orange crescents on the undersides of both the fore and hind wings. Karner blues are the only small blue butterflies that have orange crescents on the undersides of both the fore- and hind-wings. Positive identification of a Karner blue requires that you observe these orange crescents on the underwings of the butterfly.

Compare Karner Blue with other Blue Butterflies

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	Karner Blue	Eastern-Tailed Blue	Spring Azure	Silvery Blue
Male			Image Not Available
Female			Image Not Available
Underwing
Occurrence of Adult Phase	Two flight periods; one beginning in late May and the second in mid-July.	Three broods, starting in April and continuing through October.	Prominent in early spring and persists throughout the growing season.	Present at the same time as Kbb first flight.
Underwings	Orange crescents along the margins of both the fore and hind underwings.	Two orange crescents on the underwings.	No orange crescents, underwings are light blue or gray with irregular black spots.	No orange crescents, underwings are gray with a row of black dots.
Dorsal Wings	Male's dorsal side is light blue with black margins bordered by a white band. The dorsal side of the female is dark blue to brown with orange crescents along the edges of the hind wings.	Orange crescents on edges of the dorsal side of both hind wings. Key feature is the presence of a small tail on each of the hind wings.	Dorsal view looks very similar to male Kbb.	Dorsal view looks very similar to male Kbb.
Habitat	Associated with sand and brush prairies, and oak barrens where wild lupine is present.	Can occur in Kbb habitat but also uses a variety of habitats including mesic prairies, wetlands, and old fields.	Associated with woodlands, fields, wetlands.	Found near open woodlands and open areas.