The Neotropical Chagas' disease vectors are classified as members of the reduviid subfamily Triatominae. However, this classification has been suggested to be incorrect, and the suggestion has been treated as fact by some authors; the suggestion is that some (all?) groups in Triatominae had different nontriatomine reduviid ancestors. In this article I raise this question explicitly and ask other questions ancillary to it. I do not answer these questions. Of particular interest is the systematic position of Linshcosteus, the only genus of Triatominae all of whose species occur outside the New World (in India). Related to this question is that of the origin(s) of the several species and populations probably derived from the tropicopolitan Triatoma rubrofasciata (De Geer). Answering these questions is of more than academic interest, for if triatomines had more than one nontriatomine ancestor, and therefore are not phylogenetically close, it is impossible to generalize what is known about one group to others, and this inability may hinder control of these disease vectors. It is therefore vital (literally!) to determine if Triatominae is a holophyletic group and, if not, to determine which groups now classified as triatomines are related to which others. This determination may best be accomplished with a cladistic analysis of the genera now included in Triatominae. Some comments on cladistics are presented in an Appendix.
Insecta; Chagas' disease; Trypanosoma cruzi; Rhodnius; Linshcosteus; cladistics
