About Cupido minimus Füssly, 1775
Cupido minimus, the small blue, has distinct wing coloration by sex. Males have dark brown wings scattered with bright blue speckled scales, while females have no blue speckling. Both sexes share the characteristic silver wing underside marked with black spots. Males have a bluish tint at the base of their wings, matching the tint of their upper wing surface. Wingspan ranges from 16 to 27 mm, and males are typically smaller than females. This species is often confused with the female Osiris Blue, because the female Osiris Blue has similar coloring to the male small blue.
Cupido minimus occurs across Europe, Asia Minor, Transcaucasia, Tian-Shan, western Siberia, central Siberia, southern Siberia, the Russian Far East, Amur, Mongolia, Magadan, and Kamchatka. It inhabits calcareous grasslands, abandoned quarries, railways, embankments, woodland edges, and woodland clearings.
All recorded larval food plants of this butterfly are legumes, and include Oxytropis campestris, Astragalus alpinus, Lotus corniculatus, Anthyllis vulneraria, Melilotus, Coronilla, Medicago, Astragalus glycyphyllos, and Astragalus cicer. In the UK, small blues lay eggs, live, and feed exclusively on kidney vetch. Females get all their nutrients from plants, while males extract salts and minerals from carrion, dung, and mud puddles.
