Divergence in host–parasite interactions during the cane toad's invasion of Australia

Coevolutionary host–parasite “arms races” can be disrupted by new evolutionary forces imposed biological invasions, affecting both host and parasite densities, as well their traits. The spread of cane toads (Rhinella marina) parasitic lungworm (Rhabdias pseudosphaerocephala) across tropical Australia provides an ideal opportunity to study a perturbed system. We conducted cross-infection experiment using common-garden-reared lungworms from three regions (comprising long-established, intermediate, recently invaded sites Australia) quantify traits the (infectivity virulence) (resistance tolerance). Specifically, we assessed whether patterns co-adaptation were better explained spatial distances versus time since separation populations. Infection success was highest when long-established populations exposed close invasion front lowest frontal parasites older This suggests that infectivity resistance have increased over course invasion. In contrast, most virulence/tolerance not consistently or decreased during Higher burdens associated with feeding performance in faster growth lungworms, counter-intuitive results suggest manipulation parasite.