[Presence of Triatoma sordida Stäl, 1859 in urban ecotopes, of the city of Corrientes, Argentina].

With the intention of verifying the presence of T. sordida Stál 1859 in urban ecotopes in Corrientes city, Argentina, both, human dwellings and an extradomiciliary habitat were taken as a basis. A complete T. sordida population census was carried on in Mitre Park pigeon house and 400 pigeon nests (Columbia livia) were dissected. The triatomineos samples that had been detected in human dwellings were sent to the Arthropods Laboratory by their inhabitants. These triatomineos were classified systematically and according to their age class. Their feces were examined under a microscope 400 x, so as to identify Trypanosoma cruzi. Six eggs, 45 first-instar nymphs, 110 second-instar nymphs, 226 third-instar nymphs, 303 fourth-instar nymphs, 1.103 fifth-instar nymphs, 12 females and 11 males were collected from the pigeon house. The presence of this species was verified in the 27 houses, situated in 8 different neighborhoods in the city; 13 eggs, 33 different instar nymphs, 27 females and 9 males were captured, 82 samples altogether. No triatomineo was infected by T. cruzi. T. sordida adults moved towards the houses in Spring and Summer. Of the material found in human dwellings 33% was female. The adaptation of T. sordida to extra-domestic habitats and their tendency to invade human houses has thus been verified. This fact should be taken into account in vector control programs.