Introduction to the study of chromosomal and reproductive patterns in Paraneoptera Ilya A. Gavrilov-Zimin1, Snejana M. Grozeva2, Valentina G. Kuznetsova1, Dmitrii A. Gapon1, Andrei S. Kurochkin3, Katia G. Trencheva4 1Zoological Institute, Russian Academy of Sciences, Universitetskaya emb. 1, St. Petersburg, 199034, Russia; 2Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Blvd Tsar Osvoboditel 1, Sofia 1000, Bulgaria; 3Samara State University named after S.P. Korolev (National Research University), Akademika Pavlova str. 1, Samara 443011, Russia; 4University of Forestry, Blvd Kliment Ochridski 10, Sofia 1756, Bulgaria Corresponding author: Ilya A. Gavrilov-Zimin (
[email protected]) Abstract This paper opens the monographic issue “Aberrant cytogenetic and reproductive patterns in evolution of Paraneoptera”, prepared by a Russian-Bulgarian research team on the basis of long- term collaborative studies. In this first part of the monograph, we provide the basic introductory information, describe the material involved and the methods applied, and give terminology and nomenclature of used taxonomic names. Keywords Aphids, cicadas, lice, moss-bugs, psocids, psyllids, scale insects, thrips, true bugs, whiteflies, zorapters Introduction The predominant reproductive strategy in eukaryotic organisms is bisexual reproduction which involves the formation and fusion of gametes, namely sperm from the testes and eggs from the ovaries. This is also true for all major insect groups, in which, however, bisexuality is often combined with numerous aberrant modes of reproduction (White 1973; Ivanova-Kazas 1995; Simon et al., 2003; De Meeûs et al. 2007; Vershinina & Kuznetsova 2016; Leather & Hardie 2017; Gokhman & Kuznetsova 2018). These latter can characterize high-rank taxons or be found in separate genera and species within a group that mainly reproduces bisexually.