Fig. 4 : C-banded spermatogonial prometaphases of Triatoma melanosoma (a) and T. infestans (b). Both species present 22 chromosomes (20 autosomes + XY). Six autosomal pairs show C-blocks either in one (morph A) or in both chromosomal ends (morph B). The Y chromosome is completely heterochromatic. The rest of autosomes (morph C) and the X chromosome do not have any C-bands. Magnification: 2000X.