Interactions between human-induced environmental change and disease dynamics are one of the most pressing and poorly understood issues facing scientists this century. Vector-transmitted pathogens such as West Nile virus, malaria, and dengue fever, all carried by mosquitoes, or soybean mosaic virus and barley yellow dwarf virus carried by aphids are of particular concern as leading causes of emerging human, plant, and animal diseases. This project will develop a general theory of vector-transmitted pathogens and test that theory using as a model system barley yellow dwarf virus, one of the most economically important diseases of grass crops worldwide. The experiments will be carried out in grasslands in California . The project will test how changes in the environment (moisture and nitrogen availability) interact with changes in plant species diversity and composition to alter aphid behavior, thereby controlling pathogen transmission. The general mathematical theory will allow us to predict the effects of human activity on a variety of plant and animal hosts and their pathogens using a single framework.
This study is of both scientific and societal significance, particularly as threats from vector transmitted pathogens to both human health and the agricultural economy increase. It will provide a general understanding about the interactions between pathogens, biodiversity, and community structure.
