First cytogenetic characterisation of the parasitoid wasp Brachymeria (Pseudobrachymeria) vesparum (Hymenoptera: Chalcididae)

Cytogenetic analyses have been widely used to understand evolutionary processes and to resolve taxonomic uncertainties in insects. In particular, the mapping of specific chromosomal regions can provide insights about the genome organisation and interspecific relationships. Considering the importance of this approach and the scarcity of chromosomal data in some groups of Hymenoptera, this study provides the first cytogenetic characterisation of the parasitoid wasp, Brachymeria (Pseudobrachymeria) vesparum Bouček, 1992 (Hymenoptera: Chalcididae). This species was characterised by 2n = 10 metacentric chromosomes. The heterochromatin was located at pericentromeric and terminal regions, being particularly conspicuous due to occupying a large part of chromosomes from pair 2. In addition, guanine–cytosine-rich blocks (GC⁺) were detected in the interstitial region of two chromosomal pairs. The data obtained were found to be useful for inferring the chromosomal rearrangements involved in speciation within Brachymeria, in addition to providing cytotaxonomic markers for further comparative cytogenetic studies.