How virulent should a parasite be to its vector?
Appendix A. A full presentation of a general Evolutionary Stable Strategy (ESS) analysis for virulence of vector-borne parasites. A vector-borne parasite is one which can exploit two potential hosts on adjacent trophic levels, i.e. where one feeds on the other. Here we consider an insect predator prey system where a parasite can exploit either of these biologically similar hosts for reproduction and for dispersal. This general ESS model serves as a basis to explore how spatial heterogeneity and dispersal can affect the parasites virulence in the two hosts. Single patch model Suppose prey fall into two categories, susceptible individuals (S) and infected individuals (I), as do predators (U and V respectively) (Fig. 1 in text). Parasites can be transmitted through excretion and subsequent ingestion of free parasite P, and also during predation.
