ИСТИНА

Chromosomes of about 240 chalcid species are studied up to now. Techniques for analyzing karyotypes of this superfamily include the so-called “traditional” (chromosome morphometrics, C-banding, AgNOR-banding etc.) and “modern” methods of differential segmentation of chromosomes (e.g. staining with base-specific fluorochromes) as well as fluorescence in situ hybridization (FISH), chromosome microdissection and immunocytochemical assays. Among the Chalcidoidea, the haploid chromosome number can vary from n = 3 to n = 11, with a clear mode at n = 6 and a second local maximum at n = 10. Previously, chalcid families were generally subdivided into the so-called “low-numbered” and “high-numbered” ones having n = 3-7 and 8-11 respectively, with just a few exceptions. Most families belonged to the first group, whereas higher chromosome numbers were characteristic of Mymaridae, Eurytomidae, Encyrtidae and some Aphelinidae. However, main lineages of Chalcidoidea now include both “high-numbered” and “low-numbered” members. In this group, most chromosomes have two long arms, i.e. they are either metacentric or submetacentric, but acrocentrics and/or subtelocentrics also can predominate, especially within karyotypes of certain Chalcidoidea with higher chromosome numbers. The following main types of chromosomal mutations are characteristic of chalcid karyotypes: inversions, fusions, translocations, polyploidy, aneuploidy and B-chromosome variation. Although karyotype evolution of this superfamily was mainly studied using phylogenetic reconstructions based on morphological and/or molecular characters, chromosomal synapomorphies of certain groups, e.g. particular members of the Eurytomidae, were also revealed. Taxonomic implications of karyotypic features of the Chalcidoidea are apparently the most important at the species level, especially among cryptic taxa.