Of all the invasive species in all the world, fire ants are among the most annoying—and dangerous. The tiny red ants, native to South America, not only boast a painful sting but they actively enjoy biting.
That's something people from California to Taiwan have discovered in the last two decades as Solenopsis invicta has spread to these once foreign shores. And now scientists know who to blame, thanks to some genetic detective work: travelers and trade from the southeastern U.S.
Surveying more than 2,000 colonies in 75 different places around the globe, the researchers found that the ants outside of South America all originally derived from the population accidentally imported to the southeastern U.S. in the 1930s.
In fact, the only exceptions were the colonies in Taiwan, which came from California. Of course, the California population came from where? You guessed it: the southeast U.S. where the fire ants wreak some $6 billion in economic damage annually.
Fortunately, there is a cure. The phorid fly injects its eggs into the ants, and the subsequent maggot feasts on the ant's head until it explodes. That's a fight the ant can't win.