Am. J. of Tropical Medicine & Hygiene Vol 57(6), 1997, pp. 732-739 

Genetic variability and geographic differentation among three species of triatomine bugs (Hemiptera-Reduviidae).

Francisco Panzera/1, Sonia Hornos/1, Jorge Pereira/2, Rosario Cestau/1,3, Delmi Canale/4, Lileia Diotaiuti/5, Jean Pierre Dujardin/6, & Ruben Pérez/1

1. Sección Genética Evolutiva, Facultad de Ciencias, Montevideo, Uruguay

2. Cátedra de Genética, Facultad de Agronomía, Montevideo, Uruguay

3. Departamento de Genética, Facultad de Medicina. Montevideo, Uruguay

4. Centro Ref. de Vectores, Serv. Nal. de Chagas, Córdoba, Argentina

5. Centro de Pesquisas R. Rachou, Fiocruz, B. Horizonte, M. Gerais, Brasil

6. Instituto Boliviano de Biología de Altura, La Paz, Bolivia

Three species of triatomine bugs, Triatoma sordida, T. guasayana, and T patagonica, were examined by cytogenetic (C-banded karyotypes and male meiotic process) and isoenzymatic studies. These three species, with different importance as Chagas disease vectors, were found to be closely related according to their known ethologic, ecologic, and morphologic traits. Although they have the same diploid chromosome number (2n = 22 constituted by 20 autosomes and an XYd/XXY sex mechanism), each species has a distinct chromosomal behavior during male meiosis and a specific amount and localization of C-heterochromatic blocks. Moreover, these chromosome characteristics allowed us to differentiate two T. sordida populations. Isoenzymatic data confirmed the taxonomic status of the three species and together with our cytogenetic results questioned the species homogeneity of T. sordida.