Startling genome discovery in butterfly project reveals impact of climate change in Europe

Project to study all 11,000 species of butterflies and moths finds two species in the act of being created from one'

The chalkhill blue has some surprising claims to fame. For a start, it is one of the UK's most beautiful butterflies, as can be seen as they flutter above the grasslands of southern England in summer.

Then there is their close and unusual relationship with ants. Caterpillars of Lysandra coridon - found across Europe - exude a type of honeydew that is milked by ants and provides them with energy. In return, they are given protection in cells below ground especially created for them by the ants. Chalkhill blues thrive as a result, though their numbers are now coming under threat.