Eight hundred and sixty six bio-sensors for the passive detection of triatomine bugs, were tried in intra-domiciles of thirteen municipalities of an endemic area of Triatoma sordida in the North of Minas Gerais State, Brazil. This species is nowadays the most captured in Brazil and mainly in the above region. The sensors were examined every three months, corresponding to four times in the first seven municipalities (six hundred and forty two sensors, with a maximum positivity of 0.5%) and two times in the other six (two hundred and twenty two sensors, with a maximum positivity of 2.7%), showing results significantly inferior in comparison with the routine man-hour research performed in the same municipalities, including in terms of intra-domestic infestation index. Despite the simplicity and good acceptance of the sensors by the population they were demonstrated to be inadequate for triatomine research under the conditions of this trial, in terms of efficacy and cost-benefit.