Long-tailed mayfly swarm
Yearly few days long swarming of the long-tailed mayfliy (Palingenia longicauda) on the river Tisza in Tiszakürt (some 135 km south-east from Budapest), Hungary. Monday, 15. June 2009. ATTILA VOLGYI The long-tailed mayfly larves live 3 years under water level in the river banks then swarm out for a one day period of their life to die after mating.