"Trout are quite unaware of their exalted status" Harold Blaisdell, The Philosophical Fisherman (1969)
The "Attractor Fly" has been with us for decades and is not the invention of the early 1980's as I once saw proclaimed online. The Mickey Finn, shown above, was created by John Alden Knight in the 1930's and Mary Orvis Marbury invented the Royal Coachman in the late 1800's. Both flies are called attractors because they stand out in the water due to their color combinations. All aquatic life forms exhibit some form of camouflage to survive but not these critters. They are not meant to represent any life form because no life form could survive being eaten by being dressed out in gaudy colors!
Why do trout attack attractors? Aggression and the chance to eat something may be the simple answer. Lets say that Mr. Rainbow is holding next to a rock. Henderickson nymphs are becoming active on the bottom with emergence a day or so away and Mr. Rainbow picks them off as they move by. He's quite familiar with these nymphs and all others in this stream so when a size 12 Royal Coachman wet fly (any gaudy fly will do) with it's snow white wings and orange barred tail comes drifting by he sees it. He's probably never seen anything like this before. What will he do? First off, he's not threatened by the size of the fly. Second, it's now in "his" space so he will attack this strange thing and swallow it if he can. He responds to this fly differently than he would respond to a drifting nymph.
Now comes the battle as to what flies are attractor flies and which are not. I have a simple definition: if your fly has an important element of its construction that makes it truly stand out in the aquatic world then you are fishing an attractor fly. It is a fly that doesn't represent any species because NO SPECIES could live and survive without blending in. An example of a fly that blends in would be the traditional soft hackle fly and an example of a fly that doesn't blend in would be any bead head. Yes, a bead head is an attractor by my definition. If a species of nymph lived in the Swift that had a bright,shiny, gold or silver bulb on the top of it's head it would be on the road to extinction.
What about dry flies? It's funny how many writers call the stimulator an attractor fly when it does so well in June during stonefly time and in Summer during hopper time. It's a good match for those insects.
The rest of the dry fly theory I will leave for another time.
It's time to wring out the last few hours of your 2015 fishing licence. All the rivers are flowing at a perfect level and there are fish to be caught. I still have some openings.....