This new collection of articles includes: factors affecting the evolution of virulence: nematode parasites of fig wasps; host-parasite sexual strategies: transovarian transmission of a microsporidian sex ratio distorter in Gammarus duebeni; wildlife disease and conservation in Hawaii: pathogenicity of avian malaria (Plasmodium relictum) in experimentally infected Iiwi (Vestiaria coccinia). Supplement to Volume 11 of the journal Parasitology.