Summary of host characters used as explanatory variables in analyses of parasitoid community composition.

These are categorised as describing gall morphology, host resource availability, or gall spatiotemporal niche. Character states for all gall types are given in Table S2. Gall morphology character states were defined as defensive on the basis of their demonstrated efficacy in single species studies [27],[34]. Categorical characters with many state changes in our species set [21],[23]�C[25],[41],[43] provide multiple independent contrasts and are labelled as labile.aPlease see Material and Methods for justification of classifying oak hosts at the section rather than species level.