Summer has returned to Europe. The butterflies, less so.
Since 1991, more than half of Europe's grassland butterflies have vanished, according to the European Environment Agency's grassland butterfly index. The latest data from 2023 show no sign of recovery.
The reasons are not hard to find. Across much of Europe, the grasslands these butterflies depend on have been lost, fragmented, or abandoned. Agricultural intensification and heavy pesticide use have made what remains even more hostile.
This matters beyond butterflies.
They pollinate crops and wild plants and serve as food for birds and other animals. Because butterflies are fragile and sensitive to changes in their environment, their decline is a clear signal that something is going wrong in the broader ecosystem, including with other wild pollinators and insects.
That is why it has become a key measure in Europe's efforts to reverse the biodiversity crisis.
The EU Nature Restoration Regulation requires member states to reverse pollinator decline by 2030. Countries must choose at least two of three indicators – including the grassland butterfly index – and put measures in place to show increasing biodiversity in agricultural ecosystems by 2030.