Giant Sulphur (Colias gigantea Strecker)
Wing span: 2 - 2 3/4 inches (5.1 - 7 cm).
Identification: Upper surface of male yellow with narrow black borders; lower surface without submarginal black spots. Female with 2 forms, yellow or white; both may have black border reduced or lacking.
Life history: Third-stage caterpillars overwinter.
Flight: One flight from June-July.
Caterpillar hosts: Dwarf willow (Salix reticulata).
Adult food: Flower nectar.
Habitat: Willow bogs.
Range: Alaska south along Rocky Mountains to Wyoming.
