In this paper the authors investigated the mechanism for Wolbachia mediated dengue virus blocking in insects. Using the Drosophila model and mutations in the Toll and Imd pathways‚ the authors showed that neither pathway is required for expression of the dengue virus blocking phenotype in the Drosophila host‚ and therefore dengue virus blocking in insects is more complex than simple priming of the host insect innate immune system.