We tested deltamethrin (K-Othrine 50 FW) in the control of triatomine bugs, in an semi arid area with about 56.6% of houses bug infested. We used in 402 Domiciliary Units, 125, 75, 60 or 50 ml per pump of 10 liters, equivalent, if appliedon 250m², to 25,15, 12 and 10 mg/m². The invasion, colonization and cumulative indices in the houses and the positivity index in shelters near houses were very low and similar in the four groups during the 15 months of evaluation, indicating that lower doses could replace 25 mg/m². T. infestans, followed by T. pseudomaculata, predominated in and near the houses, after spraying.
Deltamethrin; Chagas disease; Prophylaxis; Semi-arid; Triatominae