Abstract: Julita KORCZYŃSKA, Marta Gajewska, Małgorzata Pilot, Wojciech Czechowski & Alexander Radchenko Dr. Julita Korczyńska (contact author), Laboratory of Ethology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteura 3, PL-02-093 Warsaw, Poland. E-mail: j.korczynska@nencki.gov.pl Dr. Marta Gajewska, Dr. Małgorzata Pilot Laboratory of Molecular and Biometrical Techniques, Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, PL-00-679 Warsaw, Poland. E-mail: mgajewska@miiz.waw.pl, mpilot@miiz.waw.pl Prof. Dr. Wojciech Czechowski, Prof. Dr. Alexander Radchenko, Laboratory of Social and Myrmecophilous Insects, Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, PL-00-679 Warsaw, Poland. E-mail: wcz@miiz.waw.pl, agradchenko@hotmail.com Myrmecol. News 10: 112 Palaearctic wood ants, and particularly the species of the Formica rufa Linnaeus, 1761 group, have been the subject of intensive investigations since the dawn of myrmecology. Nevertheless, they still pose taxonomic problems, and often puzzle field researchers. It occurs that workers within a colony bear intermediate species characters or that individuals from…