Comparative developmental and susceptibility to insecticide of Bolivian and Brazilian populations of Triatoma infestans

The triatomine bug Triatoma infestans probably originated in Bolivia and di spersed passively over wide areas of South America. where it is the princip al vector of Trypanosoma cruzi. In the region of its probable origin this s pecies shows colonization in two different ecotopes, so that it may be enco untered in sylvatic as well as in artificial habitats. The sylvatic coloniz ation pattern is not observed in the rest of its range, where T. infestans is exclusive to man-made habitats. The objective of this study was to compa re several aspects of two T. infestans populations, one from Minas Gerais ( Brazil) and the other from the Cochabamba Valley (Bolivia), with a view to elucidate the factors associated with the different colonization patterns o bserved for this species. The differences between the developmental cycle, weight, capacity to ingest blood and mortality rate of first instar nymphs should indicate more fragility of Brazilian population that may be related to its elimination possibility.