Speaking for myself, I have often instructed others, in the tying of W.B.’s that they most often suggest leeches and oh, also, maybe dragon nymph’s, baitfish, or damsel nymphs. Well, recently at a class taught by a very knowledgeable tyer and entomologist, he advised that in hundreds of lakes in worldwide travels and in the thousands of stomach samples he had taken, leeches made up an insignificant portion of trouts’ diets, even when there were heavy leech populations. Interestingly also, he said that the color is less critical than we fuss about so maybe a yellow bugger maybe just as effective as a typical black, brown, green bugger. I would hedge the bet here and have a variety of colors. I have had numerous instances in which green was it…not black or red or mottled brown. And, of course, I can recall instances of a different color being the go to color…so be prepared with colors, sizes, and varities of thickness/leanness.
So, if that is the case, what is the reason for the success of a Wooly Bugger? The instructor, mentioned above, suggested it is the mere suggestiveness of the pattern that triggers the attack not the matching of any precise nymph. So, that being said, it is the presentation that is critical. In my teachings it should rarely be a chuck and wait presentation. Whether you are matching the hatch or searching with a suggestive/stimulating pattern, presentation should be the key. What are you suggesting and do you know how the critter you are imitating behaves underwater?
You will improve your success rate significantly on lakes by understanding presentation and visualizing the fly’s actions eight feet down and forty feet back. Also, use a clear/camo intermediate (Type I) line with a WF Floating and Type III-IV as available options.
I think if one is imitating damsels or dragons then the thickness of the body, density of the palmered hackle and the tail will be critical for the appearance/action and then, of course, the presentation and location will be important.