My research interests are rooted in evolutionary biology but span multiple disciplines in biology. At the heart of my research program is the use of flies in the genus Drosophila to understand the evolutionary genomics of host-parasite interactions. Much of my research is focused on endoparasitoid wasps, which are readily observed infecting Drosophila in nature and can be very specialized to particular host species. These wasps lay single eggs in Drosophila larvae and consume flies from the inside out. Flies mount cellular and behavioral defense responses against wasps, but wasps have adaptations for finding host fly larvae, suppressing host cellular immunity, and manipulating host behavior. I use a variety of "omics" tools to understand the molecular genetics of fly cellular immunity and wasp virulence, as well as patterns of host immunity and pathogen virulence coevolution across fly and wasp phylogenies. For example, I am sequencing a number of parasitic wasp genomes to understand how wasp virulence genes are recruited from the normal wasp gene pool and repeatedly replaced by newer gene duplicates. I am also making inroads into the evolution, genetics, and neurobiology of behaviors that flies use to avoid being infected by the wasps and to cure themselves once they are infected, including various self-medication behaviors.