Time-course analysis of Drosophila suzukii interaction with endoparasitoid wasps evidences a delayed encapsulation response compared to D. melanogaster

PLoS One. 2018 Aug 2;13(8):e0201573. doi: 10.1371/journal.pone.0201573. eCollection 2018.

Abstract

Drosophila suzukii (the spotted-wing Drosophila) appears to be unsuitable for the development of most Drosophila larval endoparasitoids, be they sympatric or not. Here, we questioned the physiological bases of this widespread failure by characterizing the interactions between D. suzukii and various parasitoid species (Asobara japonica, Leptopilina boulardi, Leptopilina heterotoma and Leptopilina victoriae) and comparing them with those observed with D. melanogaster, a rather appropriate host. All parasitoids were able to oviposit in L1 and L2 larval stages of both hosts but their propensity to parasitize was higher on D. melanogaster. A. japonica and, to a much lesser extent, L. heterotoma, were the two species able to successfully develop in D. suzukii, the failure of the parasitism resulting either in the parasitoid encapsulation (notably with L. heterotoma) or the host and parasitoid deaths (especially with L. boulardi and L. victoriae). Compared to D. melanogaster, encapsulation in D. suzukii was strongly delayed and led, if successful, to the production of much larger capsules in surviving flies and, in the event of failure, to the death of both partners because of an uncontrolled melanization. The results thus revealed a different timing of the immune response to parasitoids in D. suzukii compared to D. melanogaster with a lose-lose outcome for parasitoids (generally unsuccessful development) and hosts (high mortality and possible reduction of the fitness of survivors). Finally, these results might suggest that some European endoparasitoids of Drosophila interact with this pest in the field in an unmeasurable way, since they kill their host without reproductive success.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila / growth & development
  • Drosophila / immunology
  • Drosophila / parasitology*
  • Drosophila melanogaster / growth & development
  • Drosophila melanogaster / immunology
  • Drosophila melanogaster / parasitology
  • Female
  • Host-Parasite Interactions
  • Larva / parasitology
  • Male
  • Oviposition
  • Time Factors
  • Wasps / physiology*

Grants and funding

A. Iacovone was funded by the French Provence Alpes Côte d’Azur region through the Suzukill program and the Department of Plant Health (SPE) (http://www.spe.inra.fr) from the National Institute for Agronomic Research (INRA). This work was supported by the European Union’s Seventh Framework Program for research, technological development and demonstration, under grant agreement N◦ 613678 (DROPSA)(http://dropsaproject.eu) and performed in the context of the “Investments for the Future” LABEX SIGNALIFE: program reference ANR-11-LABX-0028 (http://signalife.unice.fr). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.