Attraction of Cnaphalocrocis medinalis (Lepidoptera: Crambidae) males in Southeast Asia to female sex pheromone traps: Field tests in southernmost China, northern Vietnam and southern Philippines with three synthetic pheromone blends regarding geographic variations

Field tests of three types of synthetic sex pheromone blend (Japanese blend: Z11-18:Ald (55 μg), Z13-18:Ald (500 μg), Z11-18:OH (120 μg) and Z13-18:OH (180 μg), Indian blend: Z11-16:Ac (50 μg) and Z13-18:Ac (500 μg) and Philippine blend: Z11-16:Ac (500 μg) and Z13-18:Ac (10 μg) based on geographic variations in sex pheromones so far reported) for the rice leaffolder moth, Cnaphalocrocis medinalis Guenée (Lepidoptera: Crambidae), were performed at Nanning, in southernmost China, Hanoi, in northern Vietnam, and on Bohol, an island in the southern Philippines. In all of these tests, only the Japanese blend attracted significant numbers of male C. medinalis, while neither the Indian nor the Philippine blend showed any attractiveness to the males. The results at Nanning and Hanoi, from which the Japanese population may originate from, support the current inference about the migration routes of C. medinalis. On the contrary, the results on Bohol, in the Philippines, were unexpected and showed the presence of a population responding to the Japanese blend, but not to the Philippine blend.