Butterflies, Pacific Northwest
Silvery blue Butterflies are small, iridescent blue butterflies found in North America and Canada including all of the Pacific Northwest.
Their wingspan is only up to 3 cm wide and they are found in a wide range of habitats, from coastal dunes to prairies. The upper wings of male silvery blue butterflies are shiny light blue with a dark gray border; those of females are darker blue or grayer in color with a wider border. The undersides of the wings in both sexes are gray with black-rimmed white spots.
The silvery blue is widespread in North America, found everywhere from Alaska to Florida and all of Canada. You can see them on all of Vancouver Island.
Male silvery blues search for females as soon as they fly, after mating, the female will lay a single egg on buds of flowers or on new leaves.
The caterpillars can be a variety of colors but all with white hairs. Silvery blues only emerge once a year, and the time of year depends on elevation, June/July at lower elevations and August/September at higher elevations.
Silvery blue butterfly caterpillars feed on the host plants where the female butterflies lay their eggs. These plants can include the American vetch and lupines. The adult butterflies feed on the nectar of various flowers.
Silvery blue butterfly caterpillars have a special structure known as a honey gland, which secretes a sweet substance that attracts ants to feed on it. In what is known as a symbiotic relationship, the ants tend to the caterpillars by keeping them clean and protecting them from predators. These are beautiful little butterflies, quite awesome to observe.