The lifecycles of the organisms involved in the circulation and transmission of the
Trypanosoma cruzi agent of Chagas disease are intimately related. It appears that these cycles
begun after an adaptive process in the quaternary, Mezozoic, Cretaceus, over 90 million years
ago. Gradually, the triatomines became intermediate hosts and vectors of the protozoan infection
to mammals when the enzootic infections contaminated omnivorous mammals, particularly
skunks, armadillos and ant-eaters. Hematophagy resulting from a biochemical requirement for the
insect growth has contributed to approximate triatomines and mammalians. Triatomines adapted
to human dwells generated the endemic Chagas disease. This chapter describes and characterizes
the habits of triatomines, which are important to understanding T. cruzi transmission by the
insect-vector, its control and disease prevention. The success obtained with the spray of
pyrethroids insecticides to control the triatomines intradomicile recommends a lot more actions to
prevent repopulation of the human dwells with the repulsive insect-transmitters of the T. cruzi
infections.
