GENETIC-STRUCTURE OF 4 SPECIES OF TRIATOMA (HEMIPTERA, REDUVIIDAE) FROM ARGENTINA

The genetic structure of Triatoma guasayana Wygodzinsky and Abalos, T. sordida (Stal), T. platensis Neiva, and T. infestans (Klug) was compa red by starch gel electrophoresis. In total, 17 enzyme loci were analy zed in T. infestans and 14 loci in the other three species. Zymograms were useful in species identification. Icdh-2 and Hk-1 are diagnostic loci, and Icdh-1, Hk-2, Es-1, and Es-2 are helpful in distinguishing t hese species. The proportion of polymorphic loci for the four species (range, 52.9 to 58.3%) was somewhat higher than that expected from rep orts for other insects. Mean heterozygosity per locus (range, 0.062 to 0.156) was within the range reported for insects in the literature. T he level of heterozygosity was highest for T. guasayana and lowest for T. sordida. Values of genetic distance (Nei's D), identity (Nei's I), and similarity (Rogers's S) indices indicate that the four species ar e well-defined taxa. T. Infestans and T. platensis are die closest (D = 0.45, S = 0.62). T. guasayana and T. sordida (D = 0.77, S = 0.46) fo rm another pair of related species.