The C-banding karyotype as well as the meiotic process of Acupalpus elegans and Bembiodion minimum were studied. A. elegans had an asymmetrical karyotype with meta- and submetacentric chromosomes: its meioformula was n=20+XY. In spermatogenesis, chiasmatic meiosis with diffise diplotene was observed. C-banding showed the existence of heterochromatin in the paracetnric regions of amost all chromosomes. In B. minimum, the diploid number was 24 (n=11+XY). The species had a symmetrical karyotype with all metacentric chromosomes. Female chiasmatic meiosis and very low chiasma frequency in the male were observed. The C-band positive segments were located in the terminal regions of chromosomes.