For a long time I thought crane fly larva were just slow moving, docile creatures that would eventually hatch to become the large flying insects some people think are giant mosquitos. I’ve been tying and fishing patterns for years intended to simply drift along the bottom and resemble the crane fly in its larval state. It’s hard to go wrong with a Walt’s Worm or a Sexy Walt's tied on a size 12 or 14 barbless jig hook. But, while stream sampling, I’ve come across larva better than 2 inches in length and in a variety of colors. I've also found crane fly larva have the unique ability to flatten out their lower segments and swim remarkably well. So, I started tying this simple pattern in hopes of imitating the swimming motion and, so far, I’ve been more than pleased with the results.
For a hook, I start with an Orvis Tactical Barbless jig hook and add to it an 1/8” slotted black tungsten bead. After inserting the hook point into the bead’s small hole, slide the bead around and get it correctly seated behind the hook eye. Then, secure the assembly firmly in your tying vise.
For thread, I’m going to use 70 Denier black ultra thread, but there’s no reason you can’t bump up to heavier 140 if you like. Start your thread on the hook shank behind the bead and take wraps rearward before snipping or breaking off the tag. Cut a 4 or 5 inch segment of 25 pound test leader material free from the spool. This will be enough for numerous flies. Secure one end of the mono to the hook shank right behind the bead and take wraps of tying thread all the way back to the bend, then double the material over to form a loop. After a few thread wraps, draw the loop down so it’s about a hook gap in length, then snip the excess off behind the bead. Continue taking thread wraps to secure the doubled-over mono to the top of the hook shank. This loop is really critical and, without it, the long tail of the fly will easily foul in the hook bend. End with your tying thread all the way back at the base of the loop. A light coating of super glue over the thread wraps will help to lock everything in place and make the fly more durable.
Select a single natural brown rabbit zonker strip and separate the fur a 1/2” or so up from its bottom end. Wetting your fingers will help to control the fur. Place the cleared area on top of the hook shank and take 3 or 4 really firm wraps of tying thread to secure it. Then, pull the remainder of the strip back and take thread wraps all the way up to behind the bead. You can then begin wrapping the zonker strip around the hook shank. These wraps should be slightly overlapping. When you get to the bead, anchor the strip with a few tight turns of tying thread and then snip the excess zonker off close. Take a few more wraps to make sure the strip is well secured. Neaten things up with an ample thread collar followed by a 5 or 6 turn whip finish. A second whip finish over top of the first can't hurt. Then snip or cut your tying thread free. If you have any bits of trapped fur, snip them off close but it really doesn't matter.
Invert the hook and snip off the fur from the underside of the shank to clear the hook gap. As you can see, the bare rabbit hide starts to resemble the crane fly larva segments. Break out your head cement, Sally Hansen's or whatever, and give the thread wraps a liberal coating.
The finished fly should look something like this. The mono loop really is a critical component and one that should not be omitted or you'll be constantly having to unfoul the tail.
I’ve had success both dead drifting the pattern as well as swinging and swimming it, and I firmly believe it’s the fly’s motion that garners the trout’s interest.
As stated earlier, I’ve been extremely happy with how this pattern performs. The next step is trying it in different colors to see if it makes a difference. So far, however, natural brown has worked just fine.