The introduction of species into new environments has become economically costly and environmentally destructive. Because social insects (ants, bees, wasps and termites) form densely populated, well-protected and long-lived colonies, these insects often become abundant and can profoundly affect the ecosystems they invade. The Argentine ant, one of the world’s most widespread, abundant and damaging invasive species, thrives in California, where it displaces native ants and disrupts ecosystems. Dr. Holway will explore the factors underlying the success of this notorious invader and potential strategies to limit its abundance. Understanding invasive species can form the basis for a better understanding and management of our local ecosystems, which are increasingly under siege from introduced organisms.