How to tie the WD-40 emerger.

This is a very popular pattern in the western United States.  It was originally tied to imitate an emerging midge, but has proved effective as a BWO emerger as well.  I often fish this fly as a dropper off a dry fly or a nymph.

Material needed:
Hook:  Any standard emerger hook (I am using a TMC 2487) size #16-24
Thread:  Olive UTC 8/0
Tail:  Mallard flank dyed yellow to look like wood duck.
Thorax:  fine olive dubbing.
Wingcase:  Mallard flank dyed yellow.

Start your thread about halfway down the shank.

Select some fibers off your mallard flank.

I keep the fibers on the feather until I have them secured to the hook shank.  I do this so if I mess up, I can just re-even the fibers and start over without wasting materials.

Secure the fibers to the hook, and cut the fibers from the steam of the feather close to the stem.

Wrap your thread forward, keeping the mallard flank fibers on the top of the hook shank.

Be sure to leave enough room behind the eye of the hook.

Fold your mallard flank back over the hook shank and tie it down.

Dub some fine olive dubbing onto your thread.  Use a dubbing slightly darker than your thread if possible.

Build up a thorax with your dubbed thread.

Fold your mallard flank wing case over the thorax and tie it down.

Whip finish, and apply head cement.