Fire ants could soon become more pervasive in the mountains, according to research from the Highlands Biological Station of Western Carolina University.
A recently published report shows fire ants have managed to acclimate to high elevations in the Southern Appalachians, something that many biologists had long believed could not happen.
“The ants are adapting to the winters here — colonies were found to persist at elevations over 4,000 feet,” said Jim Costa, professor of evolutionary biology at WCU and executive director of Highlands Biological Station.
Labratory tests conducted by Costa’s team showed fire ants collected from higher elevations could withstand colder temperatures than those collected from warmer climes, suggesting the species has undergone evolutionary adaptation.
“So, they are here to stay,” Costa said. “Their ability to adapt is probably going to be aided by climate change as it gets warmer at higher elevations, but our study results suggest that even in a non-warming scenario they would continue to adapt and spread here.”
Fire ants are native to South America, but are now found across 11 southern states, including North Carolina. Previously confined to the Piedmont and coastal counties, they are unfortunately taking root in the mountains as well.
Fire ants inflict extremely painful stings, and enough stings can cause severe allergic reactions requiring hospitalization. Living in colonies, the aggressive insect can attack and kill small animals. The mounds created by colonies are a nuisance for farmers, as well.
Fire ants are ecologically distristructive, too. They are extremely efficient predators, feeding or displacing native insects, which serve as a food source for native songbirds and are wildflower pollinators.
Fire ants are more prone in areas where forests have been disturbed, such as along logging roads and power line corridors.
“The ants get a toehold where there is disturbed soil and sun, from which they can wreak havoc in the adjacent forest,” Costa said. “As the forests here are increasingly fragmented, it opens the door to more and more fire ant colonization.”