About Plebejus argyrognomon (Virgstrassir, 1779)
Plebejus argyrognomon has a wingspan of 28–34 mm. These small butterflies exhibit sexual dimorphism. Males have violet-blue wing uppersides, with a narrow black border and white fringe. Females have dark brown wing uppersides, with orange lunules bordered in black along the outer edge that are especially visible on the hindwings. For both sexes, the wing undersides are light beige, marked with several black spots surrounded by white rings, an orange stripe, and a marginal row of black spots with silvery blue-green centers. Fully grown caterpillars reach up to 20 millimeters in length, and are pale green with orange-brown longitudinal stripes. This species is similar in appearance to Plebejus argus, Plebejus idas, Plebejus pylaon and Polyommatus escheri. The wing underside of Plebejus argyrognomon is similar to that of Plebejus argus and Plebejus idas, but it has a more gray background color and relatively smaller black spots. This species occurs in Central and Southern Europe, the Caucasus, the mountains of Southern Siberia, Mongolia, and the Amur River region. In Japan, it is found in agricultural areas. These butterflies live in grassy, flowery areas at elevations between 200 and 1,500 metres (660–4,920 ft) above sea level.
