Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. 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. (Photo by Laszlo Balogh/Reuters)





A man holds a long-tailed mayfly (Palingenia longicauda) in the Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)





Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)





Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)





Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)





A photographer takes pictures of long-tailed mayflies (Palingenia longicauda) at Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)





A man holds a long-tailed mayfly (Palingenia longicauda) in the Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)





Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)





Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. (Photo by Laszlo Balogh/Reuters)