The Common Blue is the most widespread of the blue butterflies in Britain, and as the name suggests, it is one of the most common butterflies in Europe. The males are a striking bluish-violet colour, but females are brown with orange spots near the margins of the wings. In both sexes, the undersides of the wings are greyish brown with blackish spots and orange crescents towards the margins of the wings.The caterpillar has a stout body, which tapers towards the tips. The head is black and the body is green. A darker green line bordered with white passes along the center of the back. There is also a whitish-green line along the sides.Caterpillar length: up to 13 mm.Wingspan: 25 – 40 mm/arkive.org/
Polyommatus Icarus, Argus Bleu , Common Blue