  The dynamics of networks of interacting systems depends intricately on the
interaction topology. When the dynamics is explored, generally the whole
topology has to be considered. However, we show that there are certain
mesoscale subgraphs that have precise and distinct consequences for the
system-level dynamics. In particular, if meso-scale symmetries are present then
eigenvectors of the Jacobian localise on the symmetric subgraph and the
corresponding eigenvalues become insensitive to the topology outside the
subgraph. Hence, dynamical instabilities associated with these eigenvalues can
be analyzed without considering the topology outside the subgraph. While such
instabilities are thus generated entirely in small network subgraphs, they
generally do not remain confined to the subgraph once the instability sets in
and thus have system-level consequences. Here we illustrate the analytical
investigation of such instabilities in an ecological meta-population model
consisting of a network of delay-coupled delay oscillators.
