A few years ago, I concluded that a lot of the flies they tied would not be as effective these days. For three reasons:
1. The year after year; and increasing each year; fishing pressure on the streams and trout.
2. The application of "relatively" recent understanding of insects, their behavior, etc.
3. The development of new materials
Byron I could only aree with you on one of your reasons that being fishing pressure. Trout, unless they have been conditioned by constant exposure to certain flies are no smarter today than they were a thousand years ago. I do believe that resident trout can be "conditioned" to recognize the difference between real food and artificial flies to some extent. However given a new generation of fish that have not had extensive pressure any fly or lure that has caught fish in the past will catch fish today and in the future. Note that I am agreeing on the aspect of fishing pressure only. Modern tying materials do not make old patterns that catch fish ineffective nor does our better understanding of insects and their behaviour. If you had said that the older patterns would not be 'as' effective as the newer ones then maybe I would also agree to that to some extent. I hope I'm not being redunant here seeing as I have not read the whole thread.