The famously pesty South American fire ant (Solenopsis invicta) has plagued the southern regions of the United States since the 1940s. Although they achieved legendary status as one of the most damaging insects in the United States, for half a century they never moved beyond the North and South American ranges.
About 10 years ago, though, all that changed. Solenopsis invicta suddenly started appearing elsewhere: Taiwan, China, Australia. Did these arrivals mark a new wave of invasion from South America, perhaps hitchhiking on the global soy trade?
A new study by Ascunce et al in this week’s Science answers that question with a resounding No. It turns out the Asian invasions are our fault. The dense fire ant populations in the United States served as a launch pad for all three Australasian incursions.
source: Ascunce, M.S. et al 2011. Global Invasion History of the Fire Ant Solenopsis invicta. Science 331: 1066-1068 DOI: 10.1126/science.1198734