Overview
- Videos that circulated on TikTok showed millions of white insects swarming at Duisburg Hauptbahnhof and along the Rhine, including Düsseldorf's riverfront and the Rheinkirmes, over the weekend.
- Experts and local conservation groups identified the insects as mayflies, principally the species Ephoron virgo, which spend two to three years as aquatic larvae before emerging as short‑lived adults that mate in flight.
- Bright artificial lights at night drew many emergent adults away from the river to well‑lit areas such as the Duisburg station, causing large numbers to die on land and miss egg‑laying.
- Authorities and conservationists say the terrestrial mortality does not appear to threaten the overall population because enough individuals usually return to water to reproduce during these synchronized emergences.
- The event reflects a longer recovery: mayflies were largely absent from the Rhine for decades but began returning after water‑treatment upgrades in the early 1980s, and such episodic swarms are an important food source for the river ecosystem.