There are essentially two larva stages of the caddis life cycle, the only major difference is species other than that is how they live in their laval stage which amounts to the fact they either make a case and reside in it during their growth or they are termed as free swimmers or net spinners.
In either cases both are vulnerable to trout either by the fact that trout pick them up from the stream bed or they become vulnerable during the stages of behavioral drift. That is when the larva by choice choose to use the natural movement of the stream to move further downstream.
In the case of our tail waters often as not caddis larva are forced to move as water levels rise and fall or are subject to the force of water flow that dislodges them from the substrate, either way there are many zones through the White River system that contains many millions of caddis larva of the different species known to habit our waters.
Depending on the caddis species and the available matter which would include aquatic vegetation, gravel, sand all of which are if you like house building materials. Some species are in fact very particular in so far as what they choose to use to form the case which is also a means to identify specific species.
Bear in mind also that after the egg of the larva is deposited by the adult caddis there is growth, in some cases caddis larva will produce a case as long as 2 inches, often known as stick caddis, in this case generally formed from small sticks.
There are many fly patterns tyed to represent either the free swimmers or cases caddis, that said in general terms it is not necessary to go to great lengths to tie elaborate fly patterns, all that is generally needed is a good representation of the caddis case. Often as not due to the fact that you need to fish the fly close to the river bed losses can be high.
In our case for the White River, caddis larva particularly at this time of the year are a good bet for sure, more to the point both Bows and large Browns love ’em. Do not let the high water deter you from fishing caddis larva, sure the water levels may change but the larva are still there.
Past two days at Rim have produced for my fisherman some 1st class fishing.
Many of the materials you need for these flies are low cost such as peacock herl, hares ear dubbing in different colors of tan and olive.
You may add a bead head or another preferred alternative is to lead the hook shank, which is one of my preferences or you can use the free bead method which gives you the choice of both bead color and weight.
My rigs are set up by 4 methods and generally include a dropper,normally a white tail midge.
If there is one big mistake anglers make it is fishing weight either too close to the fly or too much weight or both, it is largely a issue related to your overall leader length and the drift time to allow for the flies to sink to the productive zone.
1st Rig is simply build by tying a stop knot 1ft below this a detached dropper 1ft below that is the position for the tail fly, normally the caddis larva is tied to the dropper, weight is added above the stop knot.
2nd Rig is built by tying a dropper, 1ft to 15 ins below a stop knot 1ft to 15 inches below the tail fly is tied. Weight is added above the stop knot.
3rd Rig is built by tying a dropper, 1ft to 15 inches below a bead of choice, put on the leader then the caddis larva is tied for the tail fly.
4th Rig is built by tying a dropper, 1ft to 15 inches below the second dropper, below that 1ft to 15 inches, next you tie a stop knot, your weight is added above this stop knot.
Why do l choose to use different rigs, the answer is very simple, they all cause the flies to drift in a different manner to the stream bed, one of which will be the lost productive, the other main reason is due to the nature of the substrate l am fishing over, is it clean gravel, rocky bottom. Further the above rigs are also related to all other means of fishing a two fly nymph rig.
There are many variations tied to represent caddis cases, that is more close copy by sticking to the hook shank small stones, grit, sand, snails and so on, not to mention those patterns termed as peeping caddis with and without legs. My long term experience is this, they may look real good in the vice are they more practical than a simple pattern, l have never found this to be the case !!
I prefer to tie my flies on small jigs hooks sizes 12/14 and in some cases where there are larger cases larva 10s and even size 8 long shank hooks.
Weight can be added either by bead or a lead wire underbody, the deal is this, you need to fish the fly close to the river bed, too much weight and you will have hang ups and lost flies. My rigs explain further how to rig up for your drifts. The advantage of jig hooks is they hang up way less
Two tips l will give you is not too make the patterns too flashy, black and copper beads are good if you use them. 2nd reverse rib the fly body with peacock herl or ostrich herl, this adds more effect to the fly body.
Caddis larva that are non case makers are a different deal here so far as suitable fly patterns. Two being most used is the green inchworm and hydropsychidae larva all be it this species forms a caddis case.
Dave Phillips with a rare Rim Shoals Trophy Rainbow Trout measures 22″ x 16″. Caught on a DW Cased Caddis _ Davy Wotton image. July 2016