spent gnat

spent gnat

n
(Angling) an angler's name for the spinner of various mayflies, esp Ephemeris danica and E. vulgata, particularly when lying spent on the water surface after mating and egg-laying
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014