Influence of vibrational cues on G1 Ganaspis cf. brasiliensis host searching behaviour

The larval parasitoid G1 Ganaspis cf. brasiliensis (Hymenoptera: Figitidae) has been selected as the best candidate to release for classical biocontrol programs of spotted-wing drosophila (SWD). The parasitoid shows high specificity and prefers to attack 1st and 2nd instar host larvae within freshly infested fruits. While long- and medium-range host location heavily rely on chemical stimuli, the detection of the host in its microhabitat is likely mediated by the vibrations produced by the larvae inside the fruit pulp. We identified and described a variety of vibrational cues emitted by SWD larvae of different age and at different infestation densities, and create an artificial signal that could be reproduced into uninfested fruit. We performed bioassays to investigate whether G. brasiliensis uses mechanical cues to discriminate between suitable and unsuitable host patches. The wasp reactions were analyzed considering the
time spent foraging on the fruit and the number of ovipositor insertions. We discuss our findings in relation to the parasitoid's behavioural ecology.