Experiments to determine the effectiveness and time required to sample for males of the European corn borer,Ostrinia nubilalis(Hübner), with blacklight, water-pan,Heliothis-cone, and delta-wing traps, along with sweep-net samples of grassy areas near potato fields were conducted at four sites in 1990 and 1991 on Prince Edward Island. Compared with the blacklight trap, the water-pan trap caught 1.72 times more males in 1990 and 1.97 times more males in 1991. TheHeliothis-coneand delta-wing traps, and sweep-net samples were ineffective for male European corn borer. Blacklight traps required significantly more time to sample than any of the pheromone-based traps. A waterpan trap is an effective tool to monitor adult males of the European corn borer in potatoes on Prince Edward Island. In 1992, the mean number of males per pan trap per week was 7.4 for the Iowa strain, 1.1 for the New York strain, 0.6 for the hybrid strain, and 1.1 for an unbaited trap. This suggests that the Iowa strain predominates in the population of European corn borer on Prince Edward Island.