C-banding and DNA content in three species of Belostoma (Heteroptera) with large differences in chromosome size and number

C-banding was carried out on Belostoma elegans (2n=26+X1X2Y) (♂), B. micantulum (2n=14+XY) (♂) and B. oxyurum (2n=6+XY) (♂) (Belostomatidae, Heteroptera). The C-bands always have a telomeric localization and no interstitial bands were detected. An inverse relationship between chromosome size and chromosome number exists, and besides, an inverse relationship between chromosome size and the size of the C-bands was observed. The DNA content was determined in all three species. B. elegans has a C content of 1.55±0.06 pg, B. micantulum has 0.88±0.04 pg and B. oxyurum had 0.53±0.04 pg. Considering the male meiotic characteristics, the chromosome complement and the results of C-banding and DNA content, the karyotype of B. oxyurum probably originated through autosomal fusions. The karyotype of B. micantulum and B. elegans could have originated through autosomal fusions or fragmentations respectively; with the information available up to now it is not possible to discard any of the two pathways.