Laboratory choice trials to identify repellent substances against Drosophila suzukii.
Drosophila suzukii Matsumara (Diptera: Drosophilidae) is an invasive pest species, which damages soft-skinned fruits worldwide. As feasible control measures against this fruit fly are still lacking, the present laboratory study was carried out to identify potential repellent substances as part of alternative management options. Four essential oils (celery oil, patchouli oil, catmint oil, peppermint oil) and five selected additional substances (2-undecanone, butyl anthranilate, p-menthane-3,8-diol, icaridin, 1-octen-3-ol) were tested for their repellent effects on D. suzukii adults with a modified Direct Airborne Repellent Test. 1-octen-3-ol (5%, 10%) deterred D. suzukii flies effectively, celery oil (10%, 50%) showed a moderate repellency. No repellent effect was achieved with the other tested substances. To identify potential oviposition deterring effects a choice test with different host fruits applying neem oil and 1- octen-3-ol was carried out. No oviposition deterring effect was achieved with neem oil whereas with the 1-octen-3-ol treatment no oviposition was obtained. Methodical aspects and the trial results are discussed.