North America has a history of exotic pests that extirpate individual tree species, with Emerald Ash Borer serving as our modern example. In our current, ever-globalizing society there is significant risk for future outbreaks that may impact all of our trees from the urban forest to our woodlands. This presentation by Extension Horticulture Educator Ryan Pankau, examines past outbreaks on our continent to compare and contrast what we have learned historically with the current pests threatening our native trees.