Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszainoka, 135km (84 miles) southeast of Budapest, June 23, 2013. Millions of these short-lived mayflies engage in a frantic rush to mate and reproduce before they perish in just a few hours during "Tiszaviragzas" or Tisza blooming season from late spring to early summer every year. REUTERS/Laszlo Balogh (HUNGARY - Tags: ENVIRONMENT ANIMALS SOCIETY)