Currently, there are 158 valid species of triatomines, all of which are potential vectors ofTrypanosoma cruzi, the etiological agent of Chagas disease. The correct taxonomic identification of triatomines is essential since each species hos a different epidemiological importance. The aim of the study is to compare five species of South AmericanTriatoma. Here we present a comparative study of terminal abdominal segments in females by scanning electron microscopy (SEM) of the speciesTriatoma delpontei,T. jurbergi,T. infestansvar.melanosoma,T. platensis, andT. vandae. The results showed diagnostic characters for the studied species. The dorsal view featured more valuable characters, with seven informative characters. Similarities were observed amongT. delpontei,T. infestansvar.melanosoma, andT. platensis, and betweenT. jurbergiandT. vandae, correlating with previous studies. Thus, female genital characters proved to be reliable and useful in the diagnosis of theTriatomaspecies studied here; additional studies, along with other sets of behavioral, morphological, and molecular data, helped to reinforce the hypotheses found here.