The researchers think that the Asian needle ant's ability to tolerate cooler temperatures may play a significant role in its ability to push out Argentine ants. During cold weather, both ant species become fairly dormant and cease reproducing, limiting their activity and driving their populations down. However, the Asian needle ants become active again much earlier beginning to reproduce and build new nests in Argentine ant territory as early as March, while the Argentine ants remain inactive until late April or early May. "The Asian needle ants essentially get a head start," Spicer Rice says.
"If the Asian needle ant is effective at displacing a dominant species and it is then it could be the next major invasive ant species," says Dr. Jules Silverman, a professor of entomology at NC State and co-author of the paper.
"The Asian needle ant is moving into forests and urban environments at the same time," Spicer Rice says. "And because it is active at cooler temperatures, it could move into a very broad range of territory." The Asian needle ant has already been found in areas ranging from Alabama to New York City to Oregon.
The rise of the Asian needle ant is bad news. Asian needle ants have venomous stings, which can cause allergic reactions in some humans. Asian needle ants also appear to be driving out native ant populations in forests including native species that play important roles in ecosystem processes, such as dispersing seeds.
|Contact: Matt Shipman|
North Carolina State University