Defense Presentation Title: The Role of Bridgehead Effects on the Global Spatiotemporal Spread of Invasive Insects

Advisor: Dr. Ross Meentemeyer, Ph.D. Graduate Program Director and Director, Center for Geospatial Analytics

Abstract: Invasive insect species threaten biodiversity, agriculture, human health and economies worldwide. Although there has been considerable work done to describe and model invasive insect spread at local to regional scales, there have been comparatively few efforts that describe and simulate the timing, location and drivers of global-scale international insect invasions. A critical yet understudied factor is the bridgehead effect, where previously invaded non-native regions serve as hubs for subsequent invasions—a phenomenon that has yet to be quantified for most insect taxa. Accurate data on the rate, quantity and location of global invasions are essential to making accurate forecasts and effectively managing the damaging effects of invasive insects. This dissertation addresses key knowledge gaps by being the first to quantify the bridgehead effect and global invasion rates for a diverse assemblage of invasive insects, integrating descriptive and modeling approaches to examine their roles alongside invasion origins in spatiotemporally shaping global invasion patterns.