Abstract: Transposable elements (TEs) are parasite DNA sequences that are controlled by RNA interference pathways in many organisms. In insects, antiviral immunity also is achieved by the action of small RNAs. We used Drosophila and different viruses to analyze the reciprocal impacts of viral infections on TEs. We found that the antiviral response modulated TE transcript amounts, with the clearest effects in somatic tissues. In addition, using Drosophila C Virus, we found that TEs are involved in a dual response: on the one hand TE control is released upon DCV infection, and on the other hand TE transcripts are associated with a reduction of viral replication. This discovery highlights a pivotal role for TEs in the long-term arms race between a virus and its host.