After giving Hoss's question a lot of thought, I have to say that the one fly pattern I would pick above all others to be consistently most effective on both lakes and streams would be an Ant pattern. Ants are the most prolific insects to be found on earth, exceeding the weight of all the people found on this planet by a considerable margin. Aquatic insects make up only 5% of the total insect population on the planet, with terrestrial (land based) insects making up the other 95% of the insect kingdom. From the opening day of trout season in late April here, to the last day of the season in mid November, an ant pattern will consistently catch fish, and not just trout. On small streams, 50 or more percent of what the trout eat is made up of terrestrial insects. I usually start my fishing in the morning with a down-wing caddis pattern as a searching fly. Caddis are largely nocturnal in their mating habits and will return to the stream to drink water in the morning before retiring to the stream side foliage to hide through out the heat of the day. But once the heat begins to rise and the wind begins to come up, I put on a terrestrial fly pattern and they do a great job of catching fish for me on both lakes and streams. I fish beetle, spider, and hopper patterns in addition to ant patterns, but the ant patterns have proven to be the most consistent fish catchers for me.
For those who might be interested in seeing the extent to which I have looked into fly pattern effectiveness, you may want to read the fiollowing piece and see the pictures of some of the fly patterns I use: http://www.tenkarausa.com/forum/view...hp?f=15&t=2099
Last edited by Golden; 09-18-2013 at 06:55 AM.