Statistical analysis
We used the Kruskal–Wallis test to see (1) if there were differences in
host breadth, cross-species transmission connections, and graph density
across parasite species; (2) if there were differences in eigenvector
centrality across host species; and (3) if there were differences in
epidemic size of different parasites across host species. For the
centrality and epidemic size data, we looked at each parasite species
separately. For all comparisons, if the Kruskal–Wallis test suggested a
significant main effect, we then used the Conover–Iman test with
Bonferroni corrections for pairwise comparisons across parasite or host
species.
We used R version 4.2.3 for all of the data processing and statistical
analyses. We used the “frame2webs” function in the bipartite package
(Dormann et al. 2008) to construct host adjacency matrices and the
igraph package (Csardi and Nepusz 2006) to calculate network metrics
such as graph density and centrality.