Lepidoptera.pro taxonomy is mainly based on Karsholt, J. Razowski (eds.), 1996. The Lepidoptera of Europe: a distributional checklist, plus some updates sourced by the Fauna Europaea website (families/subfamilies and, less, genera/species), Catalogue of the lepidopterous fauna of Russia (edited by S. Y. Synev, 2008, genera/species info), and, occasionally, other online and offline references such as funet.fi, so as some species originated from outside Russia and Europe as a whole.
Species in the catalogue are those for which this site has separate pages with photos or/and additional info. Species in the database are those for which no information other than their names and systematic position is available on the site.