ManhattAnts Are Taking Over New York City

Rats are synonymous with New York and there are New Yorkers who have even made the bold claim that it is the most rat-infested place on earth! [Read my post "Wanted: Director of Rodent Migration" published December 06, 2022 – it was then claimed that New York has two million rats!]

Now, it seems they have competition. They are the invasive "ManhattAnts" – this insect acquired the said nickname because there was no immediate match to any previously named species – and they are taking over New York City and spreading quickly. Since appearing on Manhattan in 2011, the species has become one of the island’s most dominant ants, and scientists formally identified it only this year.

 

 

 

 

 

 

 

 

 

 

 

While it’s not a completely new species, it is still a surprising arrival from Europe called Lasius emarginatus, according to a study "The ManhattAnt: identification, distribution, and colony structure of a new pest in New York City, Lasius emarginatus" published on May 28, 2024 in the journal Biological Invasions, Vol. 26, pp 2759–2772. Researchers had suspected the ants were L. emarginatus, but this paper confirms their identity with 93 to 99 percent certainty.

 

Since the ManhattAnt’s original Broadway debut, it has seized a place among the city’s most dominant ant species. And there’s no sign it’s slowing down. The ManhattAnt has expanded out of Manhattan and has been spreading at a rate of more than one mile per year into New Jersey and Long Island, per the study.

 

“We predict that they could expand as far north as Maine and as far south as Atlanta, Georgia”, Clint Penick (left), a biologist at Auburn University and co-author of the study, tells NPR’s Nell Greenfieldboyce. “This is an ant that could become quite common throughout the East Coast”. 

 

Despite its success in Manhattan, L. emarginatus isn’t dominant in any areas in its native Europe, and it isn’t especially known as a species adapted to urban spaces. This makes its New York City takeover even more unexpected.

 

Beyond being an annoyance to high-rise dwellers, the invasive ManhattAnt might pose a serious ecological threat. Some researchers worry about the impact the species could have on the city’s tree population, which removes 51,000 tons of carbon and 1,100 tons of air pollution each year while saving $17.1 million in residential energy costs. 

 

The ants feed on honeydew, a sugary substance secreted by aphids and other pests – and as a result, they form mutually beneficial relationships with these tree-damaging insects, per the paper.

 

It's “entirely possible” that ManhattAnts could hurt trees in the city, the study’s lead author Samantha Kennett (right), an urban ecologist at Clemson University, tells NPR. “I wish we could just see what they were doing all the time”.

 

For now, it seems like the ManhattAnt is living its big city dream – but it might soon be looking to upsize to a nice spot in the suburbs as the species continues to spread.