Abstract: Results of applying the mass trapping method using the synthetic pheromone (Z, E)-9,12-tetradecadienyl acetate (TDA) to contain the population of Ephestia kuehniella Zeller in alarge traditional flour mill are presented. The surveys were carried out over a period of five yearsto control the infestation and protect the flour mill’s output. Forty-two funnel-traps (one every270m3), each baited with 2mg of TDA (daily release of 13μg), were installed in the mill onMarch 2004 and kept till November 2008; eight additional traps were placed at the exterior of thefacility, especially in the wheat silo area and near the loading equipment. In almost five years, thepheromone traps attracted a total of 54,170 male Mediterranean flour moths. Considering onlythe catch data obtained from the traps located in the internal departments of the mill, 28,360specimens were captured during 2004, 5,856 in 2005, 8,992 in 2006, 2,235 in 2007, and 2,218 in2008. Outside the plant, 1,975 males were trapped in 2004, 1,405 in 2005, 1,005 in 2006, 1,010in 2007, and 1,114 in 2008. From the trap counts obtained it was possible to identify the locationsof the main foci of infestation. During the surveys, the continuous presence of pheromone trapsin the mill, accompanied with other pest control measures, caused a marked decrease of theMediterranean flour moth population from 2004 till 2008. The infestation was maintained at alow level, especially during the last two years of the study, when the IPM program applied in theplant didn’t include any general fumigation but only localized insecticide treatments and carefulcleaning of the various departments (wheat storage bins, processing and packaging areas, millingproducts warehouses and the loading zone) and of the interior of all equipment. As it is notpossible at present to establish the economic injury level of insect infestations in flour mills, thereis a need for investigations into how the effectiveness of Integrated Pest Management programscan be evaluated in a sound way.