If you’re looking for a reliable fly pattern that produces fish in both still and running water, look no further than the cased caddis larva. House-building caddis larvae are a staple food source for trout. Their constant availability makes this pattern a must-have in your fly box, capable of being fished effectively all year round.

This guide, based on the expert tying techniques of Barry Ord Clarke, will walk you through creating a highly realistic, “peeping” cased caddis larva using spun deer hair.

Materials Required for the Cased Caddis

To tie this specific cased caddis larva, you will need the following materials:

• Hook: Mustad Heritage C53SAP (Sizes #6-14)
• Tying Thread: Semperfli Nano Silk 6/0
• Head: E-Z Shrimp Eyes (Black) and 2 Tungsten Hot Spot Beads
• Legs: Brown CDC and Deer Hair
• Body: Brown Deer Belly Hair

Preparing the Hook and Head

1. Mount the Hook: Begin by securing a Mustad Heritage C53SAP terrestrial nymph hook in your vise.
2. Attach the Thread: Attach your Semperfli Nano Silk thread and lay a short thread base. Apply a small drop of gel to prevent the slippery silk from sliding.
3. Prepare the Eyes: Take a double set of black E-Z Shrimp Eyes. Cut down the center to split them.
4. Add the Hot Spots: Thread two tungsten hot spot beads (color of your choice) onto the split shrimp eyes. The rig of the E-Z Shrimp eyes aids in tying them in securely.
5. Tie in the Head: Tie this assembly onto the hook, ensuring it “peeps” slightly over the eye of the hook to represent the emerging larva. Flatten your thread out and wrap up toward the bead.

Creating the Legs and Collar

1. Prepare the CDC: Spin your tying thread counter-clockwise to flatten its profile. Split the thread.
2. Insert the CDC: Using a Petitjean magic clip loaded with brown CDC, insert the CDC into the split thread. This will form part of the collar, providing lifelike movement around the peeping head. Spin the thread to create a CDC brush.
3. Wrap the Collar: Wrap the CDC brush down towards the bead, pulling the fibers forward as you go.
4. Add Deer Hair Legs: Take a small bunch of brown deer hair. Crucial step: Do not stack the ends. You want these to look like rough, uneven legs peeping over the front.
5. Secure the Legs: Hold the unstacked deer hair in position, make a loose wrap, tighten slightly, make a second wrap, tighten, and pull the thread through. Pull all the fibers forward.

Spinning the Deer Hair Body

The body is created using spun deer hair to mimic the thick, protective casing built by the larva.

1. Prepare for Spinning: Bring your tying thread to the rear of the legs. Apply another small drop of gel. Keep your thread short for better maneuverability.
2. First Bunch: Take a bunch of brown deer belly hair. Make one loose wrap, then a second wrap, tightening as you let the hair spin around the shank. Pull the thread through.
3. Pack the Hair: Use a hair packer (like a hair packer tool) to push the spun hair tightly against the front section.
4. Repeat and Fill: Advance the thread slightly and repeat the spinning and packing process until the entire hook shank is filled with densely packed deer hair.
5. Tie Off: Once the body is complete, use a half-hitch tool to push the hair back, tighten on the tool, and then whip finish at the hook eye. Remove the tying thread.

Trimming and Shaping the Case

This is where the magic happens, transforming a chaotic puff of hair into a neat, cone-shaped caddis case.

1. Brush the Fly: Give the entire fly a good brushing to free any trapped fibers.
2. Initial Trimming (Underneath): Start trimming from underneath. Caution: Be extremely careful not to cut the tips of the deer hair legs you secured over the front.
3. Shape the Cone: Use the hook eye as a general guide. Slowly work your way around the fly, creating a rough cone shape.
4. Refine the Shape: Once the basic shape is established, you can start shaving closer, taking a little at a time until you achieve the desired size and profile of the caddis case.
5. Final Touches: If there are stray hairs around the eye, you can carefully use a cautery tool to singe them away. Finally, rough up the legs at the front to enhance the buggy appearance.

This cased caddis larva pattern is an incredibly effective fly. Tie it in various sizes and colors to match the naturals in your local waters, and enjoy the results.