Recent studies revealed that the sex pheromone of the gypsy moth, Lymantria dispar, (+)-disparlure (+D) [(7R, 8S)-cis-7,8-epoxy-2-methyloctadecane], is used as a pheromonal communication tool not only by L. dispar but also several temperate species of the genus Lymantria. We anticipated that some of the tropical Lymantria spp. possibly use +D as a communication tool, therefore, we set gypsy moth pheromone traps (GMPT) from August 1997 to August 1998 in the two locations in Indonesia; the university forest of Andalas University (UNAND), Padang, West Sumatra, and in the Bogor Botanical Garden (BBG), Bogor, West Java. No moths were caught in BBG, however 115 males of three Lymantria spp. were caught in UNANO. They include L. singapura (93 individuals, 80.9%) was the most abundant species, and L. beatrix (13 individuals, 11.3%) and L. narindra (9 individuals, 7.8%). The internal chemical agents (lures and insecticide) seemed to have been effective approximately 6 months for L. singapura, > 20 weeks for L. beatrix, and > 18 weeks for L. narindra. Lymantria singapura were collected continuously until the end of February with three apparent peaks. The intervals of each peak were approximately 8-10 weeks, The GMPT seemed to be a useful tool for monitoring seasonal flight of L. singapura. L. beatrix captures seemed to have two peaks, L. narindra captures were too few to draw conclusions. To clarify seasonality of moth flight for L. beatrix and L. narindra using pheromone traps will require more intensive research with increased numbers of traps and/or with more effective pheromone lures.