Special monographic issue entitled “Aberrant cytogenetic and reproductive patterns in evolution of Paraneoptera”. The issue will be authored by a Russian-Bulgarian research team including Prof. Dr. Snejana Grozeva and her colleagues from the Institute of Biodiversity and Ecosystem Research in Sofia and the Zological Institute RAS in St. Petersburg. The issue will include 6 or 7 papers, each with its own Doi and its own publication date.