Can information on pathogen ecology lead to a better understanding of disease spread?

Vector-borne plant diseases have complex ecology due to the interactions between and among the different organisms directly involved in such systems. Furthermore, abiotic and other biotic factors also affect pathogen spread. Although multiple approaches have been successfully used to study the epidemiology of such systems, most are based on surveys of symptomatic plants and/or insect vectors, in addition to alternative host plants. Generally, however, these approaches have the implicit assumption that pathogen biology is uniform and genetic diversity is limited within populations. We propose that phylogenetic and population genetic approaches can be used to infer the history of epidemics and provide a better understanding of disease ecology at local and landscape levels. We will use studies with an aphid-borne virus and a leafhopper-borne bacterium as examples of the value of incorporating molecular ecology tools into research efforts aimed at interpreting the epidemiology of insect transmitted plant pathogens.