Sex pheromone of the rice leaffolder moth, Cnaphalocrocis medinalis (Lepidoptera : Crambidae): Synthetic Indian and Philippine blends are not attractive to male C-medinalis, but are attractive to C-pilosa in the South-Western islands in Japan

Field bioassays with 3 different types of synthetic pheromone blends (Japan ese, Indian and Philippine blends) based on geographic variation in the sex pheromones in Cnaphalocrocis medinalis were performed in 1998 and 1999 in the South-Western Islands of Japan. Only the Japanese blend attracted C med inalis males, while neither the Indian nor the Philippine blend showed attr activeness, as in the Japan mainland. However, both the Philippine and the Indian blends attracted males of a different species, C pilosa, which is cl osely related to C medinalis. Geographic variation in the sex pheromones of C medinalis as well as the relationship between C medinalis and C pilosa a re discussed.