Fig 1. Methods used to detect and quantify different effects in the network: (A ) Direct trophic and non-trophic interactions were measured through gall dissection or direct observation; (B) Density effects were effects on a node’s density or trait following the exclusion of another node; (C) Three-way interactions were measured by how direct interactions changed in different contexts defined by the exclusion or density of a third node; and four-way interactions were measured by how the dependence of an interaction on the densities of other nodes changes in each context of exclusion of a fourth node.