“ManhattAnts” take over New York City. Researchers have finally identified the invasive insects.

The invasive ‘ManhattAnt’ has been infiltrating New York City since 2011, worrying scientists – who have finally figured out what species the larger-than-average black and red ant is. Since the giant ant appeared in the heart of New York City, its population has begun to spread and, like other pests, it could cause ecological damage.

There is no record of Manhatta ants in the 2009 New York ant survey, and when the insect was first observed, it had a relatively small population, mostly sticking to parks. But now, it’s one of the most common ants in the area, and each year its population has expanded about 1.2 miles — taking the species across the Hudson River into New Jersey.

While the concrete jungle might not seem like the optimal breeding ground for invasive species, several have thrived in the city, including the Asian long-horned beetle.

A research team led by Clint Penick of Auburn University says many invasive species aren’t discovered until they reach “pest status,” and it’s often difficult to identify them and try to prevent their spread.

Using DNA tests and observations of the ants, they determined that they were part of Lasiu emarginatus species from Europe.

Researchers found ManhattAnts where you might expect them – in trees. But they also spotted them on a sixth-floor balcony and inside buildings.

“A colony of L. emarginatus was even found nesting in a small flower planter in the middle of Times Square, far from the street trees or large ornamentals that would normally serve as nesting habitat,” the study, published in May in Biological Invasions . “Often the only non-visual people in Times Square are people dressed as Disney animals, and yet hidden in this flowerpot was a whole society of animal beings.”

Manhatta Ants are not a supercolony, which are large groups of ants that expand and dominate habitats, often displacing other ant species. However, they have rapidly expanded their population and could have a negative impact on other ants and trees.

They adapted their diet to their urban environment by feeding on the honeydew of other tree pests – a sticky substance excreted when the insects eat. This species does well on smooth surfaces, so city concrete is not a problem. They also feed day and night – even when it rains, if the bark of the tree remains dry.

The ManhattAnt’s impact on the ecosystem is not yet known, but they could be serious pests, researchers say. Many people reported ants in their homes, and in 2022, local hardware stores reported selling ant bait when these insects began appearing in New York City apartments.

And researchers have noticed that ManhattAnts dismember other ants on the pavement, meaning they could have a negative impact on local insects.

The fact that they live on the honey of other insects could have an impact on the health of the trees.

With New York City’s 7 million trees removing 51,000 tons of carbon and 1,100 tons of air pollution a year, tree pests are a big concern, researchers say. Trees in New York City reduce residential energy costs by $17.1 million a year, and to replace the city’s trees would cost about $5.2 billion.

Because the species were detected relatively soon after arriving in New York, researchers hope they can assess their possible environmental impacts. They will continue to research the pest and are asking people to report sightings of the species on iNaturalist, which collects photos and data about species in the community.