The latest in Argentine ant research, brought to you by the Ant News Department of Shameless Self-Promotion:

N Roura-Pascual, AV Suarez, C Gomez, P Pons, Y Touyama, AL Wild and AT Peterson. 2004. Geographical potential of Argentine ants (Linepithema humile Mayr) in the face of global climate change. Proceedings of the Royal Society of London, Series B 271: 2527-2535.

Summary. We examined the potential worldwide distribution of the Argentine ant (Linepithema humile) based on current climate models and also in the face of projected future climate change. Native to South America, Argentine ants have invaded broad areas around the world. Our results suggest that Argentine ants still have the potential to spread into areas not currently known to be occupied, particularly in regions of Africa and Asia. Higher latitudes appear to become more suitable for the Argentine ant under global climate change scenarios. Because invasion processes have the potential to alter global biodiversity considerably, this improved knowledge of the potential geography of the Argentine ant should be considered in preventive efforts.

Roura-Pascual et al's study makes use of the native range distribution contained in this recent paper:

Wild, A. L. 2004. Taxonomy and Distribution of the Argentine Ant, Linepithema humile (Hymenoptera: Formicidae). Annals of the Entomological Society of America 97: 1204 - 1215.

Abstract. The taxonomy of an invasive pest species, the Argentine ant, is reviewed. Linepithema humile (Mayr) 1868 is confirmed as the valid name for the Argentine ant. Morphological variation and species boundaries of L. humile are examined, with emphasis on populations from the ant's native range in southern South America. Diagnoses and illustrations are provided for male, queen, and worker castes. Collection records of L. humile in South America support the idea of a native distribution closely associated with major waterways in lowland areas of the Paraná River drainage, with recent introductions into parts of Argentina, Brazil, Chile, Colombia, Ecuador, and Peru.

If you're curious, but in too much of a hurry to download the pdf, the distribution of the Argentine Ant in it's native range looks like this: