Adult of Spodoptera exigua populations were monitored in Sekinchan using pheromone traps between 28 January 2003 and 24 April 2004. They were captured all the time in the studied area, although the numbers fluctuated. The highest number of adult catches per trap per day was 6.63 individuals between 15 to 22 August 2003, followed by 6.52 individuals between 19 June to 4 July 2003. The lowest number of adult catches per trap per day was 0.65 individuals between 5 to 22 November 2003. In general, capture increased in the middle part of the year with four capture peaks occurring between April and August 2003. Thus, this date could be used as a benchmark to determine when and if population levels are high enough to have the potential to cause economic damage to crops in Sekinchan, Selangor.