Assessment of an exotic parasitoid, Asobara japonica (Hymenoptera, Braconidae), against the pest spotted wing Drosophila, Drosophila suzukii ; Évaluation d'un parasitoïde exotique, Asobara japonica (Ichneumonoidea, Braconidae), contre le diptère ravageur Drosophila suzukii (Diptera, Drosophilidae)

Drosophila suzukii is an emerging pest fly in the United States and Europe, mostly on cherry and strawberry crops. In this study, we assessed Asobara japonica , a Japanese larval parasitoid of D. suzukii and other drosophila flies, as a classical biological control agent. We intent to assess the specificity and the efficiency of this braconid wasp, in order to frame an request file for its introduction in France, containing an environmental impact assessment part. On one hand, non-choice laboratory trials in nutritive medium vials have been carried out. The results showed that the parasitoid wasp is able to perform its pre-imaginal development in four species out of the five tested ones: D. subobscura , D. melanogaster , D. suzukii , and D. busckii . The last species, D. immigrans , doesn’t let A. japonica develop to the adult stage, but nevertheless endures a parasitism-induced mortality. On the other hand, the semi-natural trial on strawberry plants demonstrate that the wasp is able to locate, parasitize and develop in the larvae within the strawberry fruits. But these results do not give any evidence for A. japonica capacity to control D. suzukii populations in a strawberry crop. The trials let us compare the three different wasp strains. The IR strain seems to be the more efficient and specific on D. suzukii . According to these very results and the literature, we know that the use of A. japonica is not the best biological control solution against D. suzukii . The present work can be a baseline for the assessment of other exotic parasitoid wasps from survey missions in Japan. ; Drosophila suzukii est un ravageur émergent aux États-Unis et en Europe, principalement des productions de cerises et de fraises. Dans cet essai, nous avons étudié Asobara japonica , un parasitoïde japonais larvaire de D. suzukii et d’autres drosophiles, comme agent potentiel de lutte biologique par acclimatation. L’objectif est d’évaluer la spécificité et l’efficacité de cet hyménoptère pour constituer un dossier de demande ...