Rhynocoris punctiventris (1, 3, 4, 6b, 7) and R. iracundus (2, 5, 6a), 2n (♂) = 28 (24A + X1X2X3Y). Routine staining (1–4), FISH with 18S rDNA (green) and telomeric (TTAGG)n (pink) probes (5–7). 1, 5 spermatogonial metaphase 2 early condensation stage with four sex chromosome bodies 3, 6a, b metaphase I (MI) 4, 7 metaphase II (MII) with four sex chromosomes located in the center of the ring formed by autosomes. Hybridization signals of the (TTAGG)n probe are seen at the ends of chromosomes, and the signals of 18S rDNA FISH are seen on the Y chromosome and on one of the X chromosomes in both species (5–7). Scale bars: 10 μm.