none Alloxysta victrix; CHEMICAL-SIGNALS; Volatile cues & induction of hymenopteran host dispersal; HYMENOPTERAN-HOSTS; Aphidius uzbekistanicus; DISTRIBUTION-WITHIN-HABITAT; Enemy induced dispersal Aphidius uzbekistanicus; HYMENOPTERAN-PARASITES; Alloxysta victrix; Enemy induced dispersal Females of the parasitic wasp Aphidius uzbekistanicus, a specialist aphid primary parasitoid, react to the presence of their specialist hyperparasitoid enemy Alloxysta victrix by leaving the area. The wasps leave to increase their reproductive success, because only their offspring, but not the wasps themselves, are threatened by enemy attack. Furthermore, this dispersal is elicited through the action of volatile chemical cues produced by the hyperparasitoids. We provide evidence for 6-methyl-5-hepten-2-one being one of the volatiles eliciting dispersal. The tendency of the wasps to leave areas which are being colonized by their enemies reduces their efficiency as aphid antagonists. Behaviour; Communication; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology Aphidius uzbekistanicus (Aphidiidae); Hymenopteran parasites; Alloxysta victrix; Enemy induced dispersal Alloxysta victrix (Cynipidae); Chemical signals; Volatile cues & induction of hymenopteran host dispersal; Hymenopteran hosts; Aphidius uzbekistanicus; Distribution within habitat; Enemy induced dispersal