Patterns of spread in biological invasions dominated by long-distance jump dispersal: insights from Argentine ants

*[Invading organisms may spread through local movements giving rise to a diffusion-like process and by long-distance jumps, which are often human-mediated. Using a combination of literature review, museum records, and personal surveys, we reconstruct the invasion history of the Linepithema humile, a widespread invasive species, at 3 spatial scales. Although the inherent dispersal abilities of Argentine ants are limited, in the last century, human-mediated dispersal has resulted in the establishment of this species on 6 continents and on many oceanic islands. Human-mediated jump-dispersal has also been the primary mode of spread at a continental scale within the USA. The spread of the Argentine ant involves 2 discrete modes. Maximum distances spread by colonies undergoing budding reproduction averaged 150-m/year, whereas annual jump-dispersal distances averaged 3 orders of magnitude higher. Invasions that involve multiple dispersal processes, such as those documented here, are undoubtedly common.]