none Aphidius rhopalosiphi; Praon volucre; POPULATION-DENSITY- MEASUREMENT; Monitoring, potential use of sex pheromones; PHEROMONES-; Sex pheromones, occurrence & potential for use in monitoring Laboratory and field experiments provided evidence for the release of sex pheromones by virgin female Praon volucre Haliday and Aphidius rhopalosiphi De Stefani-Perez (Hymenoptera: Braconidae, Aphidiinae). In Petri dish bioassays, rubber or vermiculite models treated with crude virgin female extracts were frequently approached by males and elicited rapid wing-fanning behaviour and copulation attempts. Delta-shaped water traps containing live virgin females caught large numbers of conspecific males when placed in winter wheat crops. Trapping slightly below crop height resulted in higher catches than trapping above the crop canopy.