Caddisflies (Trichoptera) together with stoneflies (Plecoptera) and mayflies (Ephemeroptera) are among the most important indicators for ecological status assessments of freshwaters compliant with the EU Water Framework Directive. In Austria roughly 310 species of caddisflies are known that inhabit various species-specific aquatic habitats as larvae, including high mountain springs as well as lowland standing water bodies. Additionally, the group comprises great numbers of small-scale endemic species exhibiting distinct distribution patterns that could serve to identify habitats that are particularly worthy of protection. The particular relevance of DNA-barcoding for applied freshwater ecology is the enhanced taxonomic resolution and thus the potential for inclusion of all larval stages in existing assessment schemes imparted. Further, a full inventory of all local varieties of the Austrian caddisfly fauna and their distinct genomic characteristics will be obtained. This information permits the assessment of evolutionary and phylogegraphic hypotheses, the identification of reservoirs of genetic diversity and the examination of biodiversity patterns on global scale. The project aims to record the Austrian caddisfly fauna and to instigate augmentation of existing bio-indication methods. Additionally, the inherent genetic diversity of the Austrian caddisfly fauna as relevant to biodiversity conservation will be assessed for the first time.