GENETIC-VARIABILITY AND GEOGRAPHIC DIFFERENTIATION AMONG 3 SPECIES OFTRIATOMINE BUGS (HEMIPTERA-REDUVIIDAE)

Three species of triatomine bugs, Triatoma sordida, T. guasayana, and T. patagonica, were examined by cytogenetic (C-banded karyotypes and m ale meiotic process) and isoenzymatic studies. These three species, wi th different importance as Chagas' disease vectors, were found to be c losely related according to their known ethologic, ecologic, and morph ologic traits. Although they have the same diploid chromosome number ( 2n = 22 constituted by 20 autosomes and art XY male/XX female sex mech anism), each species has a distinct chromosomal behavior during male m eiosis and a specific amount and localization of C-heterochromatic blo cks. Moreover, these chromosome characteristics allowed us to differen tiate two T, sordida populations. Isoenzymatic data confirmed the taxo nomic status of the three species and together with our cytogenetic re sults questioned the species homogeneity of T. sordida.