Isozyme Evidence of Lack of Speciation Between Wild and Domestic Triatoma Infestans (Heteroptera: Reduviidae) in Bolivia1

Abstract

Wild and domestic Triatoma infestans from the Cochabamba region of Bolivia were virtually identical at 19 gene loci coding for enzymes. No allele was distinctive of either the wild or the domestic populations. Hence, there is no evidence that the 2 populations are different species. Domestic populations separated by 20 km showed statistically significant differences in allelic frequencies; this is compatible with the hypothesis of other authors that migrations of T. infestans are limited when feeding conditions are satisfactory. Fifteen trypanosomatid stocks isolated from wild T. infestans were shown by isozyme analysis to be Trypanosoma cruzi. This provides evidence that wild T. infestans are involved in the Chagas' disease cycle. The T. cruzi isozymic strains from wild T. infestans were genetically similar to those isolated from domestic T. infestans in the same region. This supports the hypothesis that there is no speciation between wild and domestic T. infestans, and that wild and domestic T. cruzi cycles may overlap in this region.