Three designs of pheromone-baited flight trap for the larger grain borer, Prostephanus truncatus (Horn) were compared in a daily-trapping trial in Ghana. Japanese-beetle (JB)-type traps, composed of a funnel surmounted by a cross-vane, captured two to three times more beetles than delta- and box-type sticky traps, which are currently the most commonly used designs. Japanese beetle traps have now been adopted by the Ghana National Trapping Network for P. truncatus. The higher efficiency of the JB traps has led to the discovery of the borer in two important maize-growing areas which had previously recorded zero catches using sticky delta-type traps. Analysis of correlation between replicates suggested that JB traps were the most consistent of the three trap designs (r = 0.88). The mode of entry of P. truncatus adults into different trap types, which may explain variations in catches from the different traps, is discussed.