Every June, This River in Hungary Blooms With Millions of Mayflies – A Truly Unique Sight

Every summer, tourists swarm to the River Tisza to witness the ‘Tisza blooming,’ the spectacular mating of mayflies, when millions of the aquatic insect’s larvae usually hatch and mature in a single week.

Image credit: Hortobágy National Park Directorate
The mating of mayflies is unique not only in Hungary, but now also in the world. Even Aristotle mentioned these short-lived insects, famous for their beautiful mass mating dance, and called them Ephemeron (living but for a day). The Hungarian equivalent, ’tiszavirág’ is also used to denote a short life.

The mayfly (Palingenia longicauda), also called the long-tailed mayfly and giant mayfly since it is the largest mayfly species in Europe, measures 12 cm (4.7 in) from head to tail. Female Tisza mayflies usually lay about 7-8000 eggs on the surface of the water, and their development lasts for 3 years. The end of this period triggers their spectacular mating, the ‘Tisza blooming’, which is most undisturbed in warm, windless weather.