Strong genetic differentiation between fragmented alpine bush-cricket populations demands preservation of evolutionary significant units

The eastern alpine bush cricket, Anonconotus italoaustriacus Nadig, 1987, is a grassland species historically present in a few disjunct ranges in north-eastern Italy and High Tauern in Austria. The species has recently been included in the Red List of the International Union for Conservation of Nature (IUCN) as an endangered species with a decreasing population trend. Information regarding the genetic structure of endangered insect populations and the delineation of evolutionary significant units (ESUs) are nowadays a useful and integral component of many conservation plans. The genetic differentiation of A. italoaustriacus populations was studied through the analysis of four fragments of the mitochondrial DNA in five disjunct populations, covering the entire Italian geographical distribution known for this taxon and partially the Austrian distribution. Results revealed a strong geographical structure among populations and complete absence of gene flow suggesting the need to protect these evolutionary distinct lineages. Divergence time estimation analyses suggested that an ancient separation of bush-cricket populations occurred approximately 1-1.5 Mya. Since the A. italoaustriacus populations represented genetically differentiated entities, conservation efforts should consider each population as a management unit. Conservation actions, preceded by detailed ecological studies and focused on monitoring, preserving and enlarging the existing habitat patches are thus proposed.