Colias nastes
Colias nastes, the Labrador sulphur, is a butterfly in the family Pieridae. In Europe, it is found in the north of Norway and Sweden and on rare occasions in Northern Finland. It is also found in North America, specifically in Alaska, Canada, and the Rocky Mountains, Washington, Montana and on Greenland. In Asia, it is found in the Altai Mountains, the border regions of Russia, China, Mongolia, Kazakhstan, the Sayan Mountains, the north of Siberia, and in the Chukotka Autonomous Okrug. Description. The wingspan is 31–45 mm. "C. nastes" is dark grey green with grey-black margins and  red fringes. The female is more yellowish and has more distinct yellowish submarginal spots on both wings. The under surface of the forewing is impure whitish, with greenish-yellow scales, the rose-red fringes are conspicuous, the hindwing is yellowish green, lighter at the margin, the white median spot is bordered with red and distally to it is placed a diffuse red spot, the rose-red fringes are broader than on the forewing. The female has a somewhat lighter under surface and on the forewing some small black submarginal spots. Biology. The butterfly flies from May to August depending on  the location. The larvae feed on "Astragalus" species, especially "A. alpinus" and "A. frigidus". In North America it is also recorded on "Trifolium repens" and possibly "Vaccinium" species.