My lab studies the ecology and evolution of pathogens, and how pathogens drive the evolution and population dynamics of their hosts. Two major questions that we ask are, how does host variation affect pathogen epidemics and pathogen evolution? And, how does pathogen variation modulate the effects of pathogens on host population dynamics? We attempt to answer these questions by first constructing mathematical models of host-pathogen dynamics, and then by testing the models using a combination of experiments and observations of epidemics in nature. We use insect pathogens as test systems, but the general usefulness of the advanced computing techniques that we use has led to studies of human papillomavirus and salmon conservation. Insect pathogens play a key role in preventing the destruction of forests, and this role has driven new projects on the ecology and economics of biological control, and on the effects of climate change on insect outbreaks.