Haplogonatopus oratorius (Westwood) (Hymenoptera, Dryinidae) is a parasitoid wasp of the small brown planthopper, Laodelphax striatella Stal (Homoptera, Delphachidae). To evaluate host location and recognition by H. oratorius, we investigated the behavioral response of female wasps to volatiles, vibration signals, and cuticular hydrocarbons emitted by L. striatella. The wasps did not show any positive response to host or plant volatiles but were strongly attracted to a playback of host calling vibrations and host hydrocarbons. These results suggest that the host hydrocarbons and vibration signals are important cues for the identification of suitable host resources.