10.6084/m9.figshare.8246168.v1 Louise Solveig Nørgaard Louise Solveig Nørgaard Ben L. Phillips Ben L. Phillips Matthew D. Hall Matthew D. Hall Supplementary material from Can pathogens optimize both transmission and dispersal by exploiting sexual dimorphism in their hosts? The Royal Society 2019 host–parasite trade-off virulence meta-populations range expansion Daphnia magna Pasteuria ramosa 2019-06-08 11:10:37 Journal contribution https://rs.figshare.com/articles/journal_contribution/Supplementary_material_from_Can_pathogens_optimize_both_transmission_and_dispersal_by_exploiting_sexual_dimorphism_in_their_hosts_/8246168 Pathogens often rely on their host for dispersal. Yet, maximizing fitness via replication can cause damage to the host and an associated reduction in host movement, incurring a trade-off between transmission and dispersal. Here, we test the idea that pathogens might mitigate this trade-off between reproductive fitness and dispersal by taking advantage of sexual dimorphism in their host; tailoring responses separately to males and females. Using experimental populations of <i>Daphnia magna</i> and its bacterial pathogen <i>Pasteuria ramosa</i> as a test-case, we find evidence that this pathogen can use male hosts as a dispersal vector, and the larger females as high-quality resource patches for optimized production of transmission spores. As sexual dimorphism in dispersal and body size is widespread across the animal kingdom, this differential exploitation of the sexes by a pathogen might be an unappreciated phenomenon, possibly evolved in various systems.