There are over 600 mayfly nymph species, of which most are brown, and very similar in appearance to the Pheasant Tail Nymph.
Originally tied by Frank Sawyer, this pattern has been tweaked over the years, and continues to catch amazing numbers of fish. Keep a good selection of this trout fly.
The Bead Head Pheasant Tail accurately matches the Hatch of the following Mayflies: