It’s not uncommon to hear about a certain plant or animal becoming an invasive species and taking over a specific region. New York City is no exception, and one of the metropolis's recent cases pertains to Lasius emarginatus, an ant species native to central European forests. Surprisingly, although this species isn’t known for its dominance in any European urban area, it has thrived in Manhattan, earning the nickname “ManhattAnt.” In fact, in less than 15 years, this invader has become one of the most numerous ant species in the Big Apple.
The “ManhattAnt,” a medium-sized dark brown ant with a reddish-orange midsection, first appeared in New York City in 2011. As scientists are discovering, this invasive ant species is expanding its territory by about a mile yearly and has already been spotted in New Jersey and Long Island. Experts predict that ManhattAnts could eventually outgrow their nickname and reach as far north as Maine and as far south as Georgia.
Although most ants prefer the dark, moist environments provided by soil and leaves, ManhattAnts are comfortable on city sidewalks—even though this behavior has not been observed in their native Europe. They’re also impressively good climbers and have been spotted on high-rise rooftops. Researchers have also noted their speed and aggression toward other ants. Their speed may be one of the reasons they’ve thrived in New York City, as they’ve been able to outcompete other species for resources. And they don’t seem to be particularly picky eaters, sometimes chowing down on human food, though their favorite meal is honeydew—not the melon, but a sugary substance excreted by aphids and certain tree-dwelling bugs that feed on plant sap.
Although the “ManhattAnt” is not harmful to humans, there is concern about the negative effects these invasive ants could have on local ecosystems, particularly trees, as they may encourage the growth of honeydew-producing pests that eat plants. They could also displace other ant species that perform very specialized roles within their ecosystems. Scientists admit that they still know very little about this particular ant species, but they plan to monitor their impact on the environment closely.
Watch out for that ant:
- There are approximately 800 ant species in North America.
- Manhattan’s most numerous ant species, the pavement ant (Tetramorium immigrans), is another European transplant, though it has been living on New York City streets for around a century.
- Now that they have realized how dominant it has become in New York City, scientists are closely monitoring the spread of the ManhattAnt. You can log your own ManhattAnt sightings on the website iNaturalist.
