Figure 1: The enemy release hypothesis as an explanation for (a) increased exotic performance is the product of (b) three factors, which are modulated by (c) seven contexts. Three factors: 1) the difference in per-capita effect of enemies (compare damage on leaves); 2) the difference in enemy diversity, which incorporates enemy abundance (number of individuals) and richness (number of species); and 3) host adaptation, which involves changes in exotic growth (plant size) and defence (shield size). Changes in any one factor will benefit the exotic, assuming the other factors are held constant (e.g. reductions in enemy impact will lead to release, even if enemy diversity remains unchanged). The influence of these factors and our ability to detect them changes with seven contexts. Each panel in (c) shows two hypothetical studies that examine different levels of a given context, and so would give contrasting support for the ERH. While context dependence is visualised in terms of two different exotic species, the contexts are equally applicable to a single exotic species arriving to different native communities, or different source populations of a single exotic species invading the same native community. All images in public domain (phylopic.org) except shield (Akash Yadav, Noun Project).