In collaboration with colleagues from Hungary, we have published a pan-European study detailing the current status of species diversity and distribution of two important groups of aquatic insects (Coleoptera, Heteroptera). Subsequently, we defined very precisely the level of DNA barcoding data in international reference databases used for efficient species determination. In total, the study analyzed faunistic and barcoding data on more than 1500 species. The results of the study confirmed that, despite several barcoding campaigns, DNA barcodes are only available for approximately 50% of the species from the European fauna of both study groups. Read more here http://dx.doi.org/10.1016/j.scitotenv.2022.160922.