The project has two aims. The first is to use advanced genomic analyses to provide knowledge that can guide spatial planning of conservation of semi-natural grasslands to maintain genetic variation that enables evolutionary adaptation and long-term persistence of associated butterfly populations. The second is to generalize the knowledge gained as guidelines for the use of genetic data to assess genetic erosion in insect populations. To achieve these aims, we will use an approach, where the first steps will provide understanding that inform the development of the fourth in which methods and results are translated into guidelines and recommendations. 1. Address how fragmentation of grazed semi-natural grasslands affects genetic diversity and evolvability 2. Investigate how reductions in genetic variation compared to historical levels depend on habitat fragmentation, species and historical levels of genetic variation 3. Address what landscape properties and species characteristics affect gene flow 4. a) Develop guidelines for genetic assessment of insect population diversity and connectivity and b) inform semi-natural grasslands management for maintaining sufficient within-species insect diversity to ensure long-term persistence The long-term goal is to develop guidelines for monitoring genetic diversity to enable efficient management to preserve it.