Common Blue (Polyommatus icarus)

This champion can no longer be dethroned: the Common Blue! So far, with 106 sightings, this butterfly is the most recorded species in the Biodiversity Challenge 2025.

The Common Blue flies low over the vegetation during the day and hangs upside down in small groups under the plants at night. The eggs can be found on clover and bird's-foot trefoil. After hatching, the young caterpillars feed on the inner tissue of the leaf, leaving the outer layer intact. Some caterpillars are taken by ants and pupate within the ants' nest. The butterflies go through several generations each year and can be seen from May to October.