Researchers Confirm First Established Population of Invasive Asian Needle Ant in Germany

Researchers from the Senckenberg Research Institute and Natural History Museum Frankfurt have confirmed the first established colony of the Asian needle ant in Germany, discovered in Stuttgart's Rosenstein Park in June 2025. The find, led by researcher Brendon Boudinot, was published in March 2026 in the specialist journal Zootaxa. The colony included offspring, a detail researchers say is critical because it indicates the population is capable of overwintering and has likely become established rather than representing a handful of accidentally introduced individuals. The species, Brachyponera chinensis, is classified by the European Union's Union list of invasive alien species as particularly problematic due to its harmful effects on native ecosystems and its potentially life-threatening stings. The discovery has prompted warnings from scientists about the ant's capacity to spread further across Germany.

A zoo visit sparked the chain of discovery The chain of events that led to the confirmed find began with a chance observation. A biology student from Stuttgart and his mother noticed unusual ants during a visit to Wilhelma Zoo, located just under two kilometers from Rosenstein Park. The student recalled that the two workers he spotted appeared somewhat slimmer and darker than native species, and displayed behaviors that set them apart, according to the University of Hohenheim. That initial sighting directed researchers toward the park, where Boudinot's team subsequently found a complete colony. Scientists suspect the ant may have arrived in Stuttgart as a stowaway in potted plants, a common pathway for invasive insect species. Maura Haas-Renninger from the State Museum of Natural History Stuttgart, a co-author of the published paper, noted that winged queens were also found in Rosenstein Park, suggesting the ants may already be spreading independently.

„The fact that we found winged queens in Rosensteinpark shows that the ants could already be spreading on their own here” — Maura Haas-Renninger via ZEIT ONLINE

Sting can trigger anaphylactic shock in humans The Asian needle ant poses a direct risk to human health. Its stings can trigger severe allergic reactions, including life-threatening anaphylactic shock, according to experts from the Senckenberg Society for Nature Research. The European Union elevated the species to its highest danger classification in 2025, reflecting concern about both its ecological and medical impact. Beyond human health, the ant is known to undermine parks, structures, and gardens, attack livestock, and displace native ant species and other animals. Invasive ants more broadly cause significant damage worldwide, and the needle ant has already demonstrated this pattern in the United States, where it has displaced native species across several states since its introduction.

„We were able to discover a complete colony of the Asian needle ant with offspring in the park. That shows that it is not just a matter of individual introduced animals, but very likely a local population capable of overwintering.” — Brendon Boudinot via Spiegel Online

Species traveled from East Asia to US, then Europe The Asian needle ant is native to East Asia, including Japan. It was first recorded outside its original habitat in the southeastern United States in 1932, having likely traveled via cargo ships carrying plant goods. The species subsequently spread across multiple US states. In Europe, it was first detected in Naples in 2020, with further specimens later found in Italy at Lake Como. The EU added the species to its Union list of invasive alien species in 2025. The ant was previously known under the scientific name Pachycondyla chinensis until a reclassification in 2014.

The Stuttgart find represents the northernmost confirmed establishment of the species in Europe to date. Researchers note that climate change is making it easier for invasive species to spread into previously inhospitable regions, and the international plant trade continues to serve as a primary vector for undetected introductions. The ants can also travel in containers or in travelers' luggage, making interception difficult. Scientists are calling for active measures to prevent further spread, in line with the obligations imposed by the EU's invasive species regulation. The Rosenstein Park, which borders a botanical garden and houses Stuttgart's Museum of Natural History, represents a particularly sensitive location for such an introduction given its ecological significance.

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