I.D. insects- A general question

[Mike Connor]

Thats about as simple as it can get , nice photos Philip.

Often in such conversations the idea of a trouts prey image is discussed, Mike may have mentioned it above, an interesting item to discuss in its own right.

Could there be a case to be answered that many anglers / fly tiers have an equivalent fly image based on the types of flys they prefer to use or have been brought up using and so end up with a box where often one size fits all for various families of flies.

Take spiders for example, many have an image that a spider should be skinny silk body, one and a half or two turns of concentric hackle - throw in a little bit of dubbing behind the hackle or use three or four turns of hackle and it looks wrong because of the preconcieved image.

While the one size fits all, works in many instances, is it a calculated thing that has many anglers going this route or is it a case of the preconcieved fly image dictates what an individual will fish with any confidence.

Just a thought !!!

Indeed, I believe that is the case with the vast majority of anglers, they have a certain perception of how an artificial fly should appear. Unfortunately this blinds many to how a natural fly actually appears. This also affects artificial fly design and choice by those anglers.

The major point here being that one needs artificial flies that look like natural flies to the fish. Of course one can only make these in accordance with human perceptions, and in a lot of cases this obviously works very well otherwise people would not catch fish on the results. However, too strong an "idealisation" or preconception of various flies tends to result in very poor imitations. Observations are not made carefully, things are not thought out, merely the preconception is propagated.

TL
MC

[flyfishwithme]

And then throw in size. I think I posted a chart on here sometime ago that showed the size of food delivered from the stomachs of river trout. The average was 5mm. Now I am not saying that all flies should be small but I am suggesting that we often dress flies on hooks that are too large.

[Mike Connor]

That, by the way, also relates to one of my "core theories" on fly-fishing. Although I still try to find out as much as possible about what a trout may perceive and I read all the literature I can obtain on it, I have not really worried about it much for a very long time, because it makes no difference. Artificial flies are based on human perceptions, they always have been. The only real problem is that most anglers do not look at what they are trying to imitate in the right way under the right conditions.

Many flies like spiders, flymphs, and so on, work exceedingly well under many circumstances, many others do not. The reason that some of these flies work so well is that many of the preconceptions in this case just happen to coincide with effective imitations. This is fine as far as it goes, but if you want to invent or improve artificial flies to make them more effective then you have to abandon more or less all such preconceptions to start with and look very carefully at the naturals under the right conditions. You can still use data which has been collected for you, the fact that some materials work better for certain flies for instance, but if you ignore various preconceptions then you look at things with "new eyes", and often come to new conclusions, most especially so if you look at the naturals under the right conditions.

One very basic error which is often made is to wet a fly and then look at it in air. This is completely pointless, flies look completely different when SUBMERGED!

Wetting them and looking at the results in air does not tell you anything useful at all in regard to their appearance and behaviour under water.

TL
MC

[Mike Connor]

And then throw in size. I think I posted a chart on here sometime ago that showed the size of food delivered from the stomachs of river trout. The average was 5mm. Now I am not saying that all flies should be small but I am suggesting that we often dress flies on hooks that are too large.

Basically I would agree with that in general terms, but the problem is in fact more complex and arises because many people equate hook size to fly size. This is also pointless, although it is obviously convenient, even though it can be exceptionally misleading, as a term of general reference. In order to be a good imitation a fly should be of the right size to suit the natural fly REGARDLESS OF THE SIZE HOOK IT IS DRESSED ON! Of course a fly dressed on a hook which allows a dressing close to the size of the actual insect always looks better and will usually catch better than others, although there are plenty of exceptions.

Virtually everybody nowadays uses the hook size to indicate fly size when in point of fact there is no real relation at all. If you dress a 5 mm fly on a 9 mm hook, does that make it a 9mm fly? No, of course not. Even the material lengths and dimensions are stated in relation to hook sizes, INSTEAD OF IN RELATION TO THE NATURAL INSECT!

I Have never seen any point at all in this.

TL
MC

[flyfishwithme]

All very good points Mike.

[fflutterffly]

You remember the game in grammar school, telephone, when a student was whispered a word of phrase and by the end of the row it had turned into something totally different. That's what this forum is like. I love it! You ask a question and by the end of the thread you have more information than when the first person answered. Great stuff. Things to think about.

[Otter]

And then throw in size. I think I posted a chart on here sometime ago that showed the size of food delivered from the stomachs of river trout. The average was 5mm. Now I am not saying that all flies should be small but I am suggesting that we often dress flies on hooks that are too large.

I would concur totally on this and it falls in line very nicely using generic suggestive patterns, if the bulk of the food available to the trout is 5mm then a 5mm pattern is more likely to suggest something in their diet. I have also never bought into the theory that the size of hook does not matter, I prefer to keep the hook size as close as possible to the size of the fly i am tying even if it ain't aesthetically pleasing to my eye.

As to colour.
Season before last I tied up some small simple cdc damps that proved very effective for some small spurwings (i think), yellow pearsalls body well waxed. For some strange reason I was on the river thurs to sunday ( mrs otter must have been away ). On the Sunday I was taking a reasonable number of trout when the river exploded and I can honestly say that darn near every cast produced a take to this fly - reason , a massive hatch of iron blues. This perplexed me somewhat as to why this fly was working at all as all previous experience in Iron Blue hatches was that the trout became very selective and the penny did not drop for a few days. The fly on the cast had been previously used the previous days and had darkened considerably and more in tune in terms the dark body of the Iron blues
A few days later it failed miserably for the small olives but a freshly tied one did the trick. A lesson there in the long term effects of waxing the silk and also that colour or at least degree of light vrs dark can matter. Needless to say I now carry these in lightly waxed , heavily waxed and unwaxed - or as Mr miagi would say in that old film Karate Kid, Wax on , wax of Daniel san.

[flyfishwithme]

You remember the game in grammar school, telephone, when a student was whispered a word of phrase and by the end of the row it had turned into something totally different. That's what this forum is like. I love it! You ask a question and by the end of the thread you have more information than when the first person answered. Great stuff. Things to think about.

Known as 'chinese whispers'....

[Roadkill]

One very basic error which is often made is to wet a fly and then look at it in air. This is completely pointless, flies look completely different when SUBMERGED!

Wetting them and looking at the results in air does not tell you anything useful at all in regard to their appearance and behaviour under water.

TL
MC

Minor quibble here Mike, IMO tyers need to understand the possible color shifts and translucency effects of their wetted materials like silk in particular and looking at them in the air is better than a blind concentration on the look of a dry wet fly. Behavior of the fly materials like the dubbing or hackle under water is a whole different matter.

[Mike Connor]

The quibble is not unreasonable and colour changes are important I think, but it is easy to hold a fly or a piece of dubbing in a clear glass of water. Also, the actual appearance of many dubbings and hackles changes when they are submerged. Water supports fine dubbings and hackles when they are submerged, wetted flies in air will often simply collapse. This is especially important on soft hackles and fine dubbings.

TL
MC