The aggregation pheromone of Riptortus pedestris (F.) (Hemiptera: Alydidae) is known to attract its egg parasitoids Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) and Gryon japonicum (Ashmead) (Hymenoptera: Scelionidae). Distribution and composition of these
egg parasitoids were compared in a soybean field in the presence and absence of aggregation pheromone-baited traps for two consecutive years. Three traps were installed on the edge of a soybean field, first without and then with aggregation pheromone in a before‐after design, and changes
in parasitism were assessed on nonviable host eggs released at distances of 9, 18, 27, and 36 m from the trap. A significant interactive effect of pheromone installation and distance was found in egg parasitism by both parasitoids. Parasitism on eggs recovered from 9 m away was up to 2.2 and
3.2 times higher in presence of pheromone than without pheromone for O. nezarae and G. japonicum, respectively. Parasitism by O. nezarae was always higher than that by G. japonicum, but their relative abundance, clutch size, and sex ratio were not affected by pheromone
installation, irrespective of distance from the trap. In conclusion, aggregation pheromone increases abundance of parasitoids up to 18 m from trap installation points and does not affect the relative abundance of parasitoid species.
Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.