Foetal caddis grub

 

There are over 470 species of Caddis flies in Australia and they all lay their copious numbers of eggs in water.  Given the numbers of caddis pupa (or nymphs) that hatch it's not surprising that Caddis fly pupa form arguably the largest part of a trout's diet. Caddis flies are of the order Trichoptera and whilst the habits of the grubs are varied from a fly fishers perspective they basically they fall into two groups:

The first are are the the cased such as the stick caddis and sand caddis;

The second are the uncased caddis that are represented by this 'foetal caddis grub' which of course is based on the Czech nymph style of fly. There are two sub groups here: There are nest or retreat building caddis that in their aquatic grub or nymph stage build nests that vary from pebbles glued together with a secretion to silk screens at the entrance of various nooks and crannies in the river bead. In either case these caddis are easily dislodged by changing water flows, foraging fish, animals or fly fishers and at that stage they are increasingly vulnerable to trout.

The third group are the free swimming caddis grubs. These caddis grubs move amongst the detritus matter and the rocks foraging for food and partners and of course drift in the current assuming the foetal position or free swim in the current as they migrate down stream. The uncased caddis have quite a few similarities. They often adopt a curved foetal position and when they are free swimming they are more elongated still with a curved back but with a lifted head. The have short tail like filaments, have bodies of around seven or eight segments that may have abdominal gills at each segment, have darker heads with two or three segments and have 3 or more sets of legs below the head or toward the front of the grub. Sizes range from 10mm to 25mm. Colours include darker creams, fawn, light browns and olives through to dark browns and olives.

My preferred colours are light brown, light olive and hares ear each with slightly darker thoraxes and sand with a touch of orange or pink. All are tied with olive backs and heavily weighted so that they get down to where the fish are sitting.

March brown grub has olive scud back, brown dubbing and black seals fur thorax. Olive grub has olive scud back, hares ear dubbing and black seals fur thorax. Sand caddis has olive scud back, cream dubbing and orange seals fur thorax.

Materials for olive

 

Hook Thread Weight Rib Casing Body Thorax
Knapek G #10 to #14 Black 0.15 lead wire Fine copper wire Olive scud back Olive Dubbing Black seals dubbing

Process

 

A
  1. Wind the thread from the 95% position to the start of the bend of the hook.
  2. Tie in a length of lead wire in the middle third of the hook shank.

 

B
  1. Wind the lead wire forward in touching turns.
  2. When you get to the front of where the lead wire was tied in step the wraps of lead down to the hook shank and take 3 or 4 extra turns of lead wire being careful not to crowd the eye of the hook. This step will add to the symmetry of the final shape of the fly.

 

C
  1. Select a small amount of dubbing and tie that in behind the lead wire with the strands trailing behind like a loose tail.

 

D
  1. Tie a length of wire in behind the lead under-body. Make the thread wraps tight as its important to be able to pull the wire firmly when later ribbing the fly.

 

E
  1. Tie a length of scud back in behind the lead under-body and over the copper wire.
  2. Stand the copper wire out to the side and take two final wraps of thread over the scud back but behind the copper wire.

 

F
  1. Using the single strand dubbing technique dub a uniform along the rear two thirds of the fly.

 

G
  1. Using the single strand dubbing technique dub a uniform along the front third of the of the fly taking care not to crowd the eye of the hook.

 

H
  1. Pull the scud back over the top of the fly and tie it off directly behind the eye of the hook.
  2. Don't stretch the scud back too tight as even tight wraps of thread may not hold it in position especially when you get to the final step of varnishing the head of the fly.

 

I
  1. Wind the copper wire forward along the body using the copper wire as a rib that cuts the body into 8 or 9 segments.
  2. Take one final wrap of the copper wire behind the eye of the hook and lock it into position with a couple of tight wraps of thread.
  3. Break off the excess copper wire whilst holding the hook.

 

J
  1. Build up a small but neat head of thread.
  2. Trim the thread and whip finish and varnish the head.
  3. Trim the tail to size by pinching rather than by scissors.