none Adoxophyes; HYMENOPTERAN-PARASITES; Ascogaster reticulatus; Parasite sex pheromone identification & source Ascogaster reticulatus; THORACIC-LEGS; Tibial sex pheromone gland identification; PHEROMONES-; Sex pheromone identification & source, lepidopteran host; LEPIDOPTERAN-HOSTS; Adoxophyes; Parasite sex pheromone identification & source A sex pheromone of Ascogaster reticulatus Watanabe (Hymenoptera: Braconidae), identified as (Z)-9-hexadecenal, elicits males' antennal mate-searching behavior. In order to localize the source of sex pheromone production, each body part was separated and extracted with hexane and then subjected to 9-cm Petri dish bioassay. The highest activity was found in thorax extract. Among legs, wings, and thorax, legs have the highest activity. Among fore, middle, and hind legs, hind legs have the highest activity. Among coxa and trochanter, femur, tibia, and tarsus, tibia has the highest activity. From these results, the presence of a tibial sex pheromone gland was suggested.