Abstract
The Asian spotted wing drosophila, Drosophila suzukii, has recently become a serious pest of soft fruits in Europe. Classical biological control through the introduction of larval parasitoids from its native range in Asia is presently being considered. However, host specificity of potential biological control agents has to be determined to avoid releasing species that may have unintended non-target impacts. Larvae of six different European non-target fly species and the target D. suzukii were exposed either on diet or blueberries to three Asian larval parasitoids, Asobara japonica, Leptopilina japonica, and Ganaspis cf. brasiliensis, and one European species, Leptopilina heterotoma. Asobara japonica showed the lowest specificity, attacking and developing in all Drosophilidae. Leptopilina japonica successfully parasitized two non-target Drosophilidae, D. melanogaster and D. subobscura, with one singly progeny emerging from D. immigrans. Ganaspis cf. brasiliensis had the highest level of specificity but variations occurred between two geographical populations tested. A Japanese population was strictly specific to D. suzukii, whereas another population from China parasitized D. suzukii, D. melanogaster and sporadically D. subobscura. The European L. heterotoma successfully developed in D. melanogaster, D. subobscura and occasionally in D. immigrans, but nearly all eggs and larvae in D. suzukii were encapsulated. These results show that Ganaspis cf. brasiliensis is the species with the highest potential for biological control, but more studies are needed on its taxonomic status and the existence of biotypes or cryptic species varying in their specificity before field releases can be conducted in Europe.
Highlights
Globalization and climate change speed up the spread of new invasive pests, causing an estimated agricultural loss of more than $1.4 trillion per year worldwide (Pimentel et al 2001)
L. heterotoma, was highly attracted to D. suzukii with 73.3% of the females laying eggs (POF) in the D. suzukii larvae
In our study, the Kunming population of the supposedly similar parasitoid species showed less specificity, as it very successfully parasitized D. melanogaster and D. suzukii in the blended diet, whereas in earlier trials, we had failed to rear the same population in an artificial diet without fruits (Girod et al 2018a)
Summary
Globalization and climate change speed up the spread of new invasive pests, causing an estimated agricultural loss of more than $1.4 trillion per year worldwide (Pimentel et al 2001). Drosophila suzukii Matsumura (Diptera, Drosophilidae), or spotted wing drosophila This fly of East Asian origin was first found in 2008 in Europe and North America and, in just a few years, it invaded several continents Recent studies indicated that natural enemies from Asia may provide a better area-wide control of D. suzukii’s populations in the invaded areas than larval parasitoids from Europe and North America [e.g. Leptopilina heterotoma Thompson (Hymenoptera, Figitidae)] that are rarely able to complete their development in D. suzukii (Chabert et al 2012; Poyet et al 2013; Gabarra et al 2015; Rossi-Stacconi et al 2015; Daane et al 2016). Current practices usually include laboratory host specificity tests as a first step to define the fundamental host range of the potential biological control agent (van Driesche and Murray 2004; Bigler et al 2006; van Lenteren et al 2006)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
