Phengaris arion (image) Helmholtz Association Caption Phengaris arion (Large Blue) is a globally endangered species that is declining rapidly in every European country. It needs extensive grazing of its grassland habitat to maintain the correct ant species, which its caterpillars feed on for much of the year. It became extinct in Britain in 1979 but has since been successfully reintroduced following changes habitat restoration and implementation of suitable grazing regimes. Credit Chris van Swaay Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.