Invasive insects cost local government and homeowners millions of dollars and are a threat to forest health and productivity throughout the United States. Predicting how increasing rates of global trade will result in new establishments of potentially damaging invasive species is a question of critical importance to the development of national and international policies aimed at minimizing future invasions. Over time, successive introductions have depleted the number of potentially invasive species available overseas but increases in imports have compensated for the effect of this depletion. Forest Service scientists developed a model that predicts future numbers of new species invasions based upon the abundance of species within invasion pathways. In this model, the most abundant species are likely to invade first, while the many rare species are likely to invade only under high pathway, or import, volumes. This mechanistic model is applied to make predictions of numbers of bark beetles likely to invade the U.S. from Europe over the next century, but the model is widely applicable for predicting future invasions of all taxa and provides insights into how increases in rates of imports counteract the species pool depletion effect, resulting in the continued establishment of new species.