[Focal and total residual insecticide spraying to control Triatoma brasiliensis and Triatoma pseudomaculata in Northeast Brazil]. 
To efficiently control the triatomines Triatoma brasiliensis and Triatoma pseudomaculata, a field trial was performed to compare conventional versus focal spraying of deltamethrin 5% SC at 25 mg a. i./m2 and the slow-release organophosphate malathion 8.3% SR at 2g a. i./m2.  The assay took place in the county of Boa Viagem, Ceará State, with 1541 households, randomly separated into 4 groups.  Two of them received focal spraying: PT, treated with deltamethrin indoors and in the peridomicile, and PL, which received slow-release malathion in the same circumstances.  The other groups received conventional, i.e., total application: PT with deltamethrin in the intra- and peridomicile, and PL, which was treated with deltamethrin indoors and slow-release malathion in the peridomicile.  Entomological surveys at 6 and 12 months post-treatment showed better results for mixed treatment, the PL group, probably due to good indoor performance for the pyrethroid and better performance of the slow-release formulation under the hostile peridomiciliary conditions.  Domestic animal shelters underwent numerous modifications over the course of the year, fostering reduced insecticide performance in the peridomicile.