Data Driven Models of Pathogen Competition in Gypsy Moth Populations

Start: 04/24/2013 - 1:15pm
End  : 04/24/2013 - 2:15pm

Applied Math Seminar

Eli Goldwyn (UC Davis)


Host-pathogen epidemic models are commonly used to predict the population dynamics of infectious diseases. Of particular interest, both mathematically and ecologically, is the interaction between multiple competing pathogens interacting within a single host. Natural multi-pathogen systems are often difficult to study because repeated epidemics in the same system are rare and because competition between pathogens is often intermittent leaving one of the pathogens to dominate the dynamics of the system. We consider disease dynamics of gypsy moth populations because they exhibit short repeated epidemics caused by a viral and a fungal pathogen, with each of these pathogens often occurring simultaneously with high density. We use a system of ordinary differential equations to model the populations of the host and the pathogens, and perform maximum likelihood analysis by comparing our model results to field collected data. Field data and previous theoretical models suggest that the viral pathogen is strongly density dependent, while the fungal pathogen is highly dependent on the weather. Our preliminary results support this and further explore the relative roles of density dependence and weather fluctuation in driving the dynamics of this system. Additionally, as the gypsy moth is a non-native forest-defoliating pest that causes widespread economic and ecological damage in North America, we analyze the results of our host-pathogen model to determine effective ways of pest management.