Triatoma brasiliensis is considered as one of the most important Chagas
disease vectors in the northeastern Brazil. This species presents chromatic
variations which led to descriptions of subspecies, synonymized by Lent and
Wygodzinsky (1979). In order to broaden bionomic knowledge of these
distinct colour patterns of T. brasiliensis, captures were performed at
different sites, where the chromatic patterns were described: Caico, Rio
Grande do Norte (T. brasiliensis brasiliensis Neiva, 1911), it will be
called the "brasiliensis population"; Espinosa, Minas Gerais (T.
brasiliensis melanica Neiva & Lent 1941), the "melanica population" and
Petrolina, Pernambuco (T. brasiliensis macromelasoma, Galvao 1956), the
"macromelasoma population". A fourth chromatic pattern was collected in
Juazeiro, Bahia the darker one in overall cuticle coloration, the "Juazeiro
population". At the sites of Caico, Petrolina and Juazeiro, specimens were
captured in peridomiciliar ecotopes and in wilderness. In Espinosa the
specimens were collected only in wilderness, even though several exhaustive
captures have been performed in peridomicile at different sites of this
municipality. A total of 298 specimens were captured. The average
registered infection rate was 15% for "brasiliensis population" and of 6.6%
for "melanica population". Specimens of "macromelasoma" and of "Juazeiro
populations" did not present natural infection. Concerning trophic
resources, evaluated by the precipitin test, feeding eclecticism for the
different colour patterns studied was observed, with dominance of goat
blood in household surroundings as well as in wilderness.