Researchers at the United States Department of Agriculture’s Center for Medical, Agricultural, and Veterinary Entomology have used theDNA of the red fire ant ( Solenopsis invicta )to study the path of theirsuccessive invasions during its expansion across three continents.
According to the authors of the work, published in Science , the ant arrived in the United States from Argentina and managed to establish itself successfully in the south of the country for more than 90 years. From the United States he traveled to California, the Caribbean, China, Taiwan and Australia in at least nine different invasions.
The scientists, led by Marina Ascunce of the Florida Museum of Natural History, analyzed genetic variations among 2,144 fire ant colonies from 75 locations around the world to study their expansion. The findings support the presence of a classic “bridgehead” effect, whereby a single population that has been established by a recent invasion becomes the source of repeated invasions to new areas.
Fire ants probably went from South America to the United States as “stowaways” on cargo ships . The authors point out that the increase in trade and travel could be behind the global expansion of this species of insects.
Red fire ants are very aggressive . They primarily attack other species of ants, which in the southern United States has practically led to the extinction of native species.
