Cytogenetic characterization of solitary wasp (Brèthes, 1906) (Hymenoptera, Vespidae) with insights into the chromosomal evolution in the genus.

Cytogenetic studies have enabled the characterization of the chromosomal macrostructure and microstructure and have contributed to the understanding of the evolution of wasp karyotypes. However, studies on Eumeninae solitary wasps are scarce. In this study, we characterized the karyotype of (Brèthes 1906) and compared it with previous data from other (Wesmael, 1836) species to shed light on the chromosomal diversity of the genus. A chromosome number of 2 = 24 in females and  = 12 in males was observed. Comparing the karyotype with that of another species showed variations in the morphology of some chromosomal pairs. The presence of two larger chromosome pairs, almost entirely heterochromatic, and the predominance of subtelocentric chromosomes with heterochromatic short arms in support the occurrence of fissions in . A single site of ribosomal genes was observed in , in addition to a size polymorphism of these rDNA clusters between the homologues of some analyzed females. This polymorphism may originate from duplications/deletions due to unequal crossing-over or amplification via transposable elements. The (GA) microsatellite is located exclusively in euchromatic regions. Our data show that different rearrangements seem to shape chromosomal evolution in species.