Caddisflies (Insecta, Trichoptera) and stoneflies (Insecta, Plecoptera) are crucial quality elements for ecological water quality monitoring as part of efforts implemented by the EU Water Framework Directive. In the past years DNA barcoding has become an effective taxonomic tool for the determination of difficult or cryptic species. The aim of the project was to generate DNA barcodes of caddiflies and stoneflies from Vorarlberg and to add this important information to the Red Lists of Vorarlberg.

A total of 275 COI barcodes could be created from 66 caddisfly and 50 stonefly species, representing 44% and 71.4% of all species occurring in Vorarlberg. Reference sequences for 15 caddisfly and 48 stonefly species were generated based on Austrian specimens for the first time. The dataset further comprises 2 caddisfly and 12 stonefly species that were hitherto not included in the international barcode reference library BOLD. Thus, the study provides important base line data that contributes to national and international efforts to collate comprehensive reference data of DNA barcodes.