The central aim of my research is to elucidate the processes driving fluctuations in population abundance across time and space. I address theory that is relevant to conservation of native and beneficial insects as well as management of agricultural and forest pests. My approach blends field experiments, analysis of spatial data, and theoretical modeling.

My current research has four foci: 1) the role of multitrophic interactions and weather in the spatial synchrony and periodicity of forest-insect outbreaks; 2) the effects of climate change on the outbreak dynamics of forest-defoliating insects; 3) the ecological interactions driving the expansion or contraction of species’ range borders; and 4) the influences of landscape structure on plant-herbivore interactions.

First Name: 
Assoc. Dir. Blandy Farm, Research Professor
Computing ID: 
Research Area: 
Graduate Students: 
Melissa Hey (Ph.D.) Clare Rodenberg (Ph.D.)
Large-scale spatiotemporal population dynamics of forest-defoliating insects I am interested in why population abundance tends to fluctuate synchronously across space and why the populations of many species exhibit cyclical "boom-or-bust" dynamics. I have been working on these questions by studying spatial and temporal patterns in the outbreaks of forest-defoliating insects and using these patterns to inform mechanistic simulation models that allow me to study the roles of underlying biotic (e.g., natural enemies) and abiotic (e.g., Moran effects induced by weather) processes. My primary study subject is the gypsy moth, one of the most damaging forest pests in North America. My main collaborators in this area are Derek Johnson (Virginia Commonwealth University), "Sandy" Liebhold (U.S. Forest Service), and Patrick Tobin (U.S. Forest Service). Effects of climate change on population dynamics of forest-defoliating insects Many studies predicted that climate warming would increase the frequency and severity of outbreaks of forest-defoliating insects. Though some species show these responses, the few studies that have examined the outbreak histories of defoliator species, have revealed few generalities in their responses to climate change. Interestingly, one of the more common effects seems to be collapsing of population cycles. I am using a variety of time-series analysis techniques to study temporal variation in population dynamics and to uncover the underlying climatic drivers. One of my main collaborators in these efforts is Dietrich Klimetzek (University of Freiburg).