The other evening a friend and I were walking along Ash Creek (Lassen County CA) when we came upon several saepiolus blue butterflies (Plebejus saepiolus). Also called greenish-blues, these small butterflies are about an inch and a half across. They can be found throughout most of Canada and the Western United States in bogs, open forests, meadows, stream edges, open fields – anywhere that clover grows.
The sexes of saepiolus blues look different, at least on the upper side. Males are irridescent blue-green with a black border edged in white around the wings. Females are orangish brown with a touch of blue at the wing base. The underside of both sexes is a pale gray with rows of irregular black spots and a blush of blue-green at the wing bases. There is a bit of orange on the bottom spots of the lower wings, sometimes difficult to see. It is easy to think the male and female are two different species since they look so different.
Saepiolus blues go through the same four life stages as other butterflies – eggs, larvae, pupae and adults. The adults lay eggs in clover buds. The species of clover does not seem to matter. Caterpillars eat the clover flowers over the first summer. The half-grown caterpillars then hibernate throughout the winter and resume feeding on clover and continue developing the following spring. After the pupae stage the adults feed on the nectar of flowers (including, but not necessarily clover flowers) until they lay eggs and begin the cycle again.
Aricia is another genus name used for this lovely little butterfly. And note that in two of the pictures the saepiolus blues are on clover.