The Large Pine Weevil, Hylobius abietis, is one of the most important pests in European coniferous forests. The ectoparasitoid Bracon hylobii is known to cause around 50% larval mortality. Chemical volatiles are among the most important stimuli involved in the host location. In the present study, a 4-arm olfactometer and a 2-choice wind-tunnel were used to test the behavioural responses of B. hylobii females to four odour sources from the host-plant/host-insect complex. For each odour, the behaviour of twenty virgin females was individually recorded in an olfactometer, whereas twenty virgin and twenty mated females were individually tested in a wind-tunnel. The following behavioural parameters were analysed: a) time spent walking; b) time spent stopped; c) total time spent in each arm; d) total speed; e) net speed; f) the rate of turning per unit distance walked; g) rate of turning per second. Comparison between odours shows clear differences in the behavioural parameters analysed. In particular, the bark disc/larva complex is the only odour source able to elicit behavioural responses of both naive and mated females. As strong responses were obtained only using experienced females, this suggests that previous searching activities increase the ability of B. hylobii to find its host. Behaviour; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Abiotic factors Hylobius abietis (Curculionidae); Hymenopteran parasites; Bracon hylobii; Female parasite responses to host plant host complex odours; Plant hosts; Conifers Bracon hylobii (Braconidae); Behaviour; Coleopteran hosts; Hylobius abietis; Female parasite responses to host plant host complex odours; Chemical factors none