Impact of Temperature on the Immune Interaction between a Parasitoid Wasp and Drosophila Host Species
Université Côte d’Azur, INRAE, CNRS, ISA, 06 903 Sophia Antipolis, France
Author to whom correspondence should be addressed.
F.C. present address: Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland.
D.C. and M.P. should be considered joint last authors.
Academic Editors: Foray Vincent, Philippe Louâpre and Thierry Hance
Received: 1 June 2021
Revised: 4 July 2021
Accepted: 12 July 2021
Published: 15 July 2021
Global warming affects most species and their interaction s. Insects are ectotherms, meaning their body temperature is affected by the ambient temperature. This is particularly important for koinobiont parasitoids, insects that keep their host insect alive during development of their eggs and larvae, the host eventually being consumed before adult parasitoids emerge. Temperature changes could therefore affect parasitoids directly and/or indirectly through their impact on the host. Here, we tested the effect of temperature on the parasitic success of two parasitoid lines on two host species, and on each partner independently, to determine whether the host immune response and/or the parasitoid venom proteins, injected with the egg to counteract the host immune response, were affected. The host’s immune defense consists of forming a capsule surrounding the parasitoid egg. In half of the interactions tested, the parasitic success increased with temperature. For one, the increase appeared to result solely from an increased capacity of the parasitoid to escape from a capsule, while for the second, it also appeared to involve a decrease in host encapsulation capacity. Finally, we observed a strong change in venom composition depending on the rearing temperature which may partially explain the change in parasitic success.