ENZYME POLYMORPHISM AMONG TRIATOMA-INFESTANS (HEMIPTERA, REDUVIIDAE) COLONIES

Allozyme variability in populations of the Chagas's disease vector Tri atoma infestans (Klug) was investigated by means of starch gel electro phoresis. Samples were taken from nine laboratory colonies established with individuals collected at different localities across the range o f this insect in South America. Zymograms for proteins coded by a tota l of 17 loci were obtained. Allele frequencies, proportion of polymorp hic loci (P), mean heterozygosity per locus (H), similarity (S), and i dentity (I) indices, genetic distance (D), and gene flow among populat ions were estimated. Mean values for P = 58.53% and for H = 0.095, ind icating an important level of genetic variability. There was remarkabl e similarity among the colonies (mean I = 0.9946). Estimated gene flow among populations was high. However, on the basis of the known natura l history of T. infestans, the uniformity of allele frequencies among populations may be interpreted as the result of the recent and rapid d ispersal of the species from the site of origin in the Cochabamba Vall ey, Bolivia.