Males are bright sky blue in colour with a fine black line to the edge of the wings and a white border. Females are brown in colour becoming blue towards the body, with orange crescents towards the edges of the wings. Both males and females have pale brown undersides with black spots and orange crescents. The caterpillar reaches 1.6 centimetres in length, has a dark green body with dark spines, and yellow bands along the back and sides. Find out more!

The caterpillars of the Adonis Blue are always found with ants! The ants protect the caterpillars in return for a sugary substance that they produce.

The Adonis blue is the rarest of the blue butterflies in the UK. It is found on sunny, south-facing grassland that is rich in herbs. It doesn’t travel far, so colonies can become isolated and vulnerable to extinction if their habitat is disturbed.

This species has two broods per year, so adults can be seen from mid-May until the end of June, and then from early August until the end of September. Both caterpillars and adults feed on Horseshoe Vetch.

The flat whitish eggs are laid on the underside of terminal leaflets of horseshoe vetch Hippocrepis comosa. There are no alternative foodplants.

The butterflies choose plants which are in full sunlight, in sun-baked positions at the edge of rabbit scrapes, paths or other patches of bare ground. The eggs are laid singly, but often several females will visit a particular favoured plant, and consequently as many as 30 can be found in very close proximity.