This fly was my go-to nymphing fly last year especially at my favorite little brook trout lake.  My supply was completely demolished by the end of the year.  I just finished tying a dozen of these and every one looked different.  It is not an easy tie.  There are various ways to get the legs.

This is an Ian Colin James pattern.  He lists it as a steelhead fly and as one of his favorites in many situations for all manner of trout and bass.  His are larger versions.  He did have the instructions on his website but I see they are taken down.  It took me awhile to figure out (remember) how to tie it!  I'm sure those legs move around quite a bit in the water and might trigger a backswimmer response.  You can't see it on the photos but I put a small butt tag of pearl mylar.

Since Brian Chan passed around his fly box with flies at least two sizes smaller than mine, I've been on a quest to make my flies smaller.  I think that when fish are released, they learn a little about how they were fooled.   And so it is important to get a closer representation if you are in that situation.  That is not as  much a concern around Ontario/Quebec as there are few C&R waters (and consequently a much poorer trout  fishery.....so much so I will do more local warm water fishing next year).

 
The tieing trick are the legs.  You can use one pheasant church window or two.  I prefer one.  Pinch the tip, smooth rest of the fibers back and tie it backwards onto the shank with the stem towards the rear.  Dub, then bring the feather forward.  Spread the fibers so you can tie down and bring the shell back over.  Repeat.  You could make a larger thorax at the front or at the middle.  I don't think the fish care.

I use yellow or grey rabbit fur at the rear and Black and Red Dazzle Dubbing for the thorax(s).  Ian says that all flies should have at least two distinct colours on them.  I think he is right.

This is my favorite crayfish pattern.  I got it from "Bob Sheedy's Top 50 Stillwater Patterns".  There are a few flies in there that I use often.   The recipe is complicated so I won't attempt to describe it here.  You will simply have to buy the book from my friend Bob.  I can rarely get my flies to look like the pattern books but I can tell you this one catches fish!  And in my area here it is particularly effective for brookies in those waters that have these critters (which are many).  By the end of the season I'm usually down to one skinny scarecrow of a fly after starting off with a bunch.   Rainbows like them too as well as bass.  Well, bass like everything.   I make my tails a bit bigger as well as the legs because I think pushing more water is an attractor.


They are tied backward because this is how they escape danger, by swimming backward.   The eyes I'm using are a bit big but that is what I have and I don't think it really matters.  I use different colour and thicknesses of wire....again only personal taste.   It doesn't matter whether one arm is bigger than the other because that is the way it is with most of the naturals but I know it would bug some fly tyers if they tried to get them even and it didn't work out that way, LOL


Because brookies are often found around logs and snags, always have a few extra.  I had very good luck at Kenauk's Collins Lake this spring with these.  I also lost quite a few to snags.

This was the best fly for me this fall searching for Rainbows.  I have been fishing this fly for many years.   The top version is misnamed because the original intent is for the use of Rabbit fur strips like you see on the lower picture.  This one is Mink. On the advise of Joe Humphreys who came to our club in November, I went to the hobby shop to buy less expensive wire, only to find that this wire doesn't stay put when you are winding.  So you can see some sloppy winding here.  It doesn't matter to the fish and that is what is most important. 


This fly has more action than any other Leech pattern with the possible exception of the Jansen Leech which uses marabou.  The added weight of the wire makes the fly bob up and down when retrieved at the right speed.   Each time the wire ties the fur down, it creates a bit of a separation.  I believe this also aids in the action of the fly.


There is a danger in having too long of a tail with leech patterns as trout tend to sip leeches rather than take them in whole.   So you can get some nibbling happening.  What you see above is the maximum I recommend. 


The colour is a bit off in this photo.  The mink I have is actually much darker.  The black rabbit version was the best colour but not by much.   Browns and olive work well too.


The wiggly look of the backing or hide also gives a 'worm' like appearance.  Another aspect of this design is that some leeches have a copper strip down their bellies.  The wire hints at this feature.


To tie:  After putting on a thread base, start at the back with your thread tieing down the hide, then use the wire.  Go four to five turns then repeat ending up at the head.   Wetting the fur helps in separating the strands.  I use regular floor varathane as my head cement, lightly diluted with water.  I also give the underside a coating as it does tend to rotate.   The advantage of these water soluble urethanes is that  they are translucent upon application and you can see what you have covered.  Then it clears.

As far as hook size is concerned, I have been tying my flies smaller and smaller.  The above versions are size 10.  I tie them as small as size 14.

In cutting your rabbit or mink strips, try for as narrow as you can.  The sparser fir strips have more action.  My thicker versions have ended up in my bass box (they are less fussy).


Fast and slow retrieves work.  I sometimes use two or three different colours in a row to see which one is working better.   Always keep multiple flies about 2 ft apart.


Brian Chan says you can use small versions of leeches during chironimid hatches.   The trout use them to cork in the tiny buzzers to prevent them from spilling out.  They don't have a valve to hold them in the stomach.   It is always more fun to fish leeches than chironomids.


I can guarantee you will catch fish with this fly at any time of the year assuming of course that there are trout (or anything else) where you are fishing.   Tie them by the dozen.  Mine are all beaten and chewed up.