Invasive Large Gland Ant Spreads Across Germany, Threatening Biodiversity and Infrastructure

The invasive ant species Tapinoma magnum, known as the "Large Gland Ant," is expanding its range throughout Germany. It outcompetes native ants, forms massive "supercolonies" that can contain millions of individuals, and damages urban infrastructure by undermining sidewalks, garden walls and even nesting in electrical boxes. The ants also foster large populations of aphids, leading to excessive honeydew deposits on ornamental plants.

First recorded in 2009 at a tree nursery in Ingelheim, the ant likely arrived via imported Mediterranean trees. It is now monitored in several German states, especially Baden‑Württemberg, Hesse and Bavaria. Local authorities advise residents to report sightings, photograph nests, and use control methods such as steam‑treated water, hot water, or diatomaceous earth. A recent citizen‑information event in Stockstadt highlighted the threat and discussed mitigation strategies, including the purchase of a steam‑cleaning device already used successfully in Karlsruhe.