Fig. 1: Tetra Brik milk boxes used for detecting peridomestic Triatoma infestans and installed on the vertical wooden posts (A) or beneath the thatched roof (B) of each structure. The materials are: (1) Tetra Brik milk box cut on one end (2) to allow the introduction of the corrugated paper; (3) entrances; (4) leather languet; (5) wire that holds the box and the languet to the poles. (C) internal central column of accordion-folded corrugated paper. Black smears on the pole in B are triatomine dejecta.