- a stonefly, Leuctra geniculata, of the English chalk streams, esteemed by trout and therefore by anglers
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Examples from the Web for willow fly
This fly is therefore omitted, and the Willow-fly and the Yellow-Sally only are described.
The Willow-fly, when it falls on the water, has its wings sometimes in one and sometimes in the other of these positions.