Fire ants evolve into a fearsome hybrid: 'Anything can really happen'
- - - Fire ants evolve into a fearsome hybrid: 'Anything can really happen'
Gareth McGrath, USA TODAY NETWORKJune 28, 2025 at 4:01 AM
Southern states familiar with an invasive, stinging ant are facing a new foe: A hybrid bug that combines the fierce red fire ant and the hardy black fire ant.
Imported fire ants have spread from their native South America to the United States with help from accidental human transportation, a lack of predators and warming temperatures thanks to climate change – potentially bringing upper elevations in the Appalachians and colder Mid-Atlantic state areas into colonization danger.
The invasive fire ants first hitched a boat ride to Alabama in 1918. Since then, they've marched into over a dozen states, according to the U.S. Department of Agriculture's Animal and Plant Health Inspection Service.
Now, experts say two species of invasive fire ants found in the United States are crossbreeding, creating an even nastier and hardier bug.
The USA TODAY Network investigated the emerging threat this spring. Here's what to know:
What are imported fire ants?
Fire ants are famous for forming into large balls of living matter during flooding events, allowing them to literally float down to new locations. After Tropical Storm Helene dropped record-levels of rain across much of western North Carolina last fall, that ability has officials especially worried about how the natural disaster might have helped the invasive species spread to new areas, said Joy Goforth, plant pest administrator with the state agriculture department.
Their venom, similar to a bee's or wasp's, results in a painful, itchy pustule or blister on the skin. A very small portion of the population are hypersensitive to ant venom and can experience lethal allergic reactions, according to the Texas Imported Fire Ant Research and Management Project at Texas A&M. Even healthy individuals, however, may experience severe reactions such as anaphylactic shock if they suffer from a multiple stinging incident.
Treatments for stings are limited, with Texas A&M recommending stings be treated as you would stings of other insects. Keep them clean and intact to avoid secondary infections.
Considering a mature colony can include up to 400,000 worker ants, a queen can lay up to 1,000 eggs a day, and that there can be several colonies per acre of land, fire ants can sometimes seem like the perfect pest.
"Right now, it just seems they are very adaptable, and that includes moving their nests further underground in the higher elevations where the temperatures are more constant year-round, to some degree outsmarting the environment," said Amy Michael, entomological programs manager with N.C. Agriculture.
Where have fire ants spread?
They've spread across every county of Florida, Georgia, Alabama, Mississippi, Louisiana and South Carolina. They've reached across most of North Carolina, Tennessee, Texas and Arkansas, and have infiltrated parts of Virginia, Oklahoma and New Mexico, according to national data.
"While eradicating them would be the goal in a perfect world, we really are at the point now where we are trying to manage their impacts and their spread," Michael said.
Hybrid fire ants are bad news
Mother Nature has thrown a new wrinkle into the mix − a new hybrid ant that's a merger of the two invasive fire ant species that have reached U.S. shores.
Dr. Scotty Yang, assistant professor in the Virginia Tech Department of Entomology, said hybridized fire ants are the result of interbreeding between red and black fire ants. The outcome is a fire ant that has the strength and ornery disposition of the fiercer red fire ant with the better tolerance of colder temperatures found in black fire ants.
Yang said the hybrid ants have become the explorers and front guard for the fire ant invasion into colder and more northerly areas, becoming the dominant fire ant species in the upper elevations of Tennessee, Georgia, North Carolina and Virginia.
And they are proving to be very successful, with a dozen Virginia counties added to that's state fire ant quarantine map just last year. Yang said viruses that impact "normal" fire ants also have less of an impact on the hybrids, making them less likely to forage and thus less likely to carry poisoned bait back to their mounds.
"In some respect, the viruses help them survive," he said.
Researchers are still trying to determine why the ants decided to crossbreed.
"But once you introduce a species to a new place, anything can really happen," Yang said.
A fire ant colony can contain up to 500,000 worker ants, with a queen colony often consisting of several mounds.Living with fire ants
After more than 60 years in North Carolina, officials in the state stress that it's no longer a question of eradicating the invaders.
Michael said several fire ant control measures are available at garden and home improvement shops that target different stages of the ants' and colony's development. The best strategy involves treatments that allow bait to be brought back into the mound, Michael said.
Treating mounds when they appear quickly, especially those near concrete and brick walls where heat radiating from those materials allows the ants to stay active longer, also is important for good control.
Michael told USA TODAY that North Carolina's agriculture officials continue to conduct surveys in the counties outside the current quarantine area.
"Yes, they are very adaptable, and yes, they can spread pretty quickly," Michael said. "But there are tools out there that are available to residents and businesses to help try and mitigate the impacts and their spread."
As fire ants spread, watch out for stinging Asian needle ants, too
Fire ants sound bad enough, but another invasive ant species with an ominous name are also spreading through the country: stinging Asian needle ants.
"Asian needle ants" are small and difficult to spot, blending in until they make themselves known with a sharp sting that has led to life-threatening anaphylactic shock in some cases. They've been recorded in about 20 states and are widespread along the East Coast, experts say.
"Imagine somebody inserting a needle directly into your flesh," said Benoit Guénard, a professor of ecology and entomology at the University of Hong Kong who studied the ants in North Carolina. "It's a very sharp, acute pain but it's quite local."
Read more about Asian needle ants here.
Reporter Gareth McGrath can be reached at [email protected] or @GarethMcGrathSN on X/Twitter. This story was produced with financial support from the Green South Foundation and the Prentice Foundation. The USA TODAY Network maintains full editorial control of the work.
Contributing: Jeanine Santucci and Elizabeth Weise, USA TODAY
This article originally appeared on Wilmington StarNews: Invasive fire ants evolve into a fearsome hybrid
Source: AOL General News
