Why North Carolina's newest invasive ant species poses a triple threat
An invasive ant species native to East Asia has spread across North Carolina, causing health and environmental issues. These ants are stealthy, travel in small groups, and can live anywhere in the state.
Despite not being as large or aggressive as other invasive insects like the fire ant, this foreign invader from Asia might pose a greater threat to humans and the environment. They have already spread to almost all 100 counties, including mountainous regions, an area even fire ants haven't conquered.
"They are sneaky, but the real concern is their name, the Asian needle ant," says Dr. Christopher Hayes, a structural pest management expert. "They have a large stinger, and it can deliver a powerful punch."
First reported in the US in the 1930s, Brachyponera chinensis, or the Asian needle ant, has only been recognized as a pest in North Carolina over the past two decades. However, these small ants, similar in size to sugar or carpenter ants, often go unnoticed.
"They have expanded slowly and quietly, but now they've reached a critical point," Hayes explains. "You can't miss a fire ant mound, but you might miss an Asian needle ant nest in your mulch pile."
The sting of these ants can be quite painful. Experts warn that a single sting can cause symptoms ranging from localized pain to anaphylaxis, especially in those with compromised immune systems or bee sting allergies.
The Asian needle ant's sting is more dangerous than the fire ant's. While fire ant stings have a 0.5% chance of triggering a severe allergic reaction, the needle ants have a 3% rate, making them a more significant threat.
Despite their non-aggressive nature, these ants can be challenging to manage. They are skilled at finding food sources, often leading them into homes and schools, increasing the likelihood of painful interactions with humans.
Their small size and solitary or small-group movement make them difficult to spot and manage. Traditional ant baits are often ineffective against them, and they can form 'super colonies' with multiple nests and queens, making eradication challenging.
The most alarming impact of these ants is their effect on North Carolina's native habitats. They are ecosystem invaders, rapidly colonizing forest ecosystems and outcompeting local insect populations, which can disrupt seed dispersal and have a significant impact on these ecosystems.
With the ants now established, eradicating them is not an option. Instead, they are expected to expand further north and into higher elevations due to climate change. Controlling them is also challenging, as traditional treatments and baits are ineffective.
Homeowners may need to seek expert help from pest management companies or local extension offices to manage infestations. Dr. Hayes advises, 'If you see them, try to kill them. They shouldn't be here.'
For more information, residents can send photos of suspected Asian needle ants to the NCState Extension's Plant Disease and Insect Clinic for identification. The WolfPest app and local county extension offices provide pest management options.
This story was supported by the Green South Foundation, the Prentice Foundation, and the Z. Smith Reynolds Foundation, with the USA TODAY Network maintaining full editorial control.
