Pathological effects of Blastocrithidia triatomae (Trypanosomatidae) on the reduviid bugs Triatoma sordida, T. pallidipennis and Dipetalogaster maxima after coprophagic infection

ABSTRACT. Developmental time and mortality in nymphs of the reduviid bugs Triatoma sordida (Stål), Triatoma pallidipennis (Stål) and Dipetalogaster maxima (Uhler) were studied in uninfected groups and in those infected with Blastocrithidia triatomae Cerisola et al. (Trypanosomatidae). In T. sordida and T. pallidipennis, major vectors of Chagas' disease in Brazil and Mexico respectively, infection with B. triatomae was associated with slight developmental retardations in the final instars, and increased mortality in the pre-adult instar. These effects were less evident in T. pallidipennis, but in this species a total infection rate of only 5–15% was achieved, compared with about 45% in T. sordida. In contrast, D. maxima was strongly affected by B. triatomae: nymphal development was retarded and complete mortality occurred in some groups exposed to infection, although not all bugs were infected.