Basics of DNA barcoding suppose the creation and operation of an extensive library based on reliably (including possibility for validation) identified specimens. Therefore, information concerning morphological identification of the individual samples used for DNA barcoding, for example, identification keys and descriptions used, must be clearly explained. In addition, the maximum available data set of sequences must be used. Access to currently private data appears to be of special interest, especially when such possibility is provided by the database regulations, because it encourages the cooperation of research and saves both time and resources. The cryptic aphid species complexes Aphis oenotherae-holoenotherae and A. pomi-spiraecola are used to illustrate the above statements.