About Polyommatus thersites (Cantener, 1835)
Polyommatus thersites, commonly known as the Chapman's blue, is a butterfly species belonging to the family Lycaenidae. Its distribution ranges across southern Europe, Morocco, Lebanon, Asia Minor, Iran, and extends through the Palearctic region to Siberia and the Tian Shan. It is a small butterfly that exhibits both generation dimorphism and sexual dimorphism. In the first (spring) generation, the upper side of the wings is blue with grey hindwings; females of this generation also have a submarginal line of orange spots. For the summer generation, females are brown and retain the same submarginal line of orange spots, while males of this generation are lighter and lack these orange spots. For the spring generation, both sexes have grey-colored hindwing undersides; summer generation individuals have sandy brown hindwing undersides. The wing underside is ochre, marked with black dots outlined in white, and has a submarginal line of orange spots. The underside of the forewing is yellow grey in summer females. Polyommatus thersites resembles Polyommatus icarus, but is smaller, and neither sex has basal spots on the underside of the forewing. The larvae of this butterfly feed on species in the genus Onobrychis: specifically O. arenaria, O. peduncularis, O. sativa, and O. viciifolia.
