“It doesn’t imitate anything”. That’s the response the 15-year old me got from a fly shop guy when I asked what a Royal Wulff was supposed to imitate. As a young fly angler, I was slowly learning entomology and trying to match up the different insect species with their feathered doppelgangers. Some patterns (like the Royal Wulff) just didn’t add up. They didn’t look like anything in nature. So what were they supposed to be? It was then explained to me that some flies aren’t meant to be imitations, rather, they’re “attractors”. On some level, it made sense. But I was left with the burning question of, “if they don’t imitate anything, why would fish take them?”
A couple of decades later, I look back on that conversation with a completely different perspective on attractor patterns. In fact, I have come to realize that it’s not 100% true that attractors don’t imitate anything. They just don’t imitate a specific species. But they do imitate characteristics that trout observe in their habitat and this is why they work. And “imitate” might not even be the best word. For many patterns, a better word would probably be “exaggerate”.
Many (but not all) attractors work because they take some characteristic of a trout’s food source and give it a hyperbolic interpretation. There are several characteristics that attractors imitate. Let’s look at a few and see why they matter.
The Chernobyl Ant doesn’t look like anything found in nature (well, not on this planet), yet it consistently catches fish. Why? Because it’s big and floats. And big and floats = hopper = big, high protein meal. The main trigger here is the sheer enormity of the Chernobyl Ant. You could probably tie it in pink and paint little hearts all over it and it would still be attacked with the same ferocity. Size matters and while diminutive flies can have their own attractor quality, giants that make a violent splash down can also trigger a response merely from their size.
Trout see a lot of differently shaped insects in there daily hunt for food. Some are wormlike (like caddis larvae), some are muscular monsters with robust apparatus (like stoneflies), some are mere dashes (like midge larvae), some are little sailboats (like mayfly duns), some are little airplanes (like mayfly spinners), and some are stealth bombers (like adult caddis). Even though they claim to not imitate any specific aquatic or terrestrial insect, every attractor takes some form that trout are accustomed to seeing. The Royal Wulff isn’t a direct mayfly imitation, but with its upright wings, thorax, and tail, it clearly takes the form of a mayfly dun as opposed to, say, a caddis pupa. Familiar shapes help trout identify what’s food and what isn’t.
Whenever I turn over rocks in a stream, I’m always struck by how bland most nymphs and larvae are compared to the flies in a typical fly shop. Of course, colors in aquatic insects can vary greatly by region (or even stream), but for the most part, the nymphs look the same. Granted, some caddis larvae are a very bright green, but I’ve never seen a sulphur nymph in nature that was as bright of a yellow as some of the imitations I’ve seen. Yet, the garish imitations work. Why? Because they have taken the subtle trigger of the yellow color and exaggerated it. Especially in fast flowing streams, trout don’t have a lot of time to inspect something rushing by to determine if it’s food or flotsam. They have to make a decision quickly, or they will lose potential food to the current or a competitor. So the more things you can take off their checklist, the more likely they will deem something as food and take it. Attractors like Humpies, the Royal Wulff, Partridge & Orange, the Grizzly King, etc. all take colors trout are exposed to to a hyperbolic level. And it obviously works.
The Renegade is another pattern that doesn’t look like anything in nature but it’s got one thing going for it: iridescence The alluring sheen of the peacock herl body mimics the iridescence found in many terrestrial food sources like beetles, and many aquatic insects like emerging caddis or mayflies. Many attractors exaggerate iridescence to exploit that trigger. And today, we have a lot of materials to work this into our fly designs: holographic tinsel, pearlescent Mylar, glass beads, etc. I’ve seen some midge patterns that were lit up like a Christmas tree but they work because they exaggerate the gasses insects give off upon emergence. This iridescence is one more clue that tells trout that thing floating by is food.
Many streamer patterns don’t look like much in the box, but as soon as they hit the water, they come alive. Strips of rabbit fur undulate, rubber legs pulsate, hackles open and close. Probably nothing says “food” more to a predator than movement. And some attractors like the sakasa kebari use this trigger to great effect. With its prominent, forward facing hackles pulsing with each tug of the line, the sakasa kebari looks alive underwater. And the fact that it has even more movement that most real swimming insects makes it all the more effective. It seems fish (like theatre goers) are suckers for hyperbole “on stage”.
OK, OK, you’ve got it. Attractors imitate (and often exaggerate) characteristics of a trout’s natural food source. Obviously, a lot more examples could be given but I think the takeaway here is simple: when designing or choosing an attractor pattern, it’s important to figure out which characteristics it is imitating. Different patterns will work better in different situations. Something with a lot of flash might spook fish in clear water. Something big and dark might be easier for the trout to see in high or off-colored water. Something with lifelike movement might perform better on high-pressure waters where most anglers fish a nymph in a dead drift.
I think it’s important to realize that not every attractor pattern works everywhere. As a case in point, many people (including myself) typically think of the Killer Bug as a universal attractor. It could be interpreted as a scud, a crane fly larva, caddis larva, etc. And on my home waters, it does seem to work almost every time I tie it on. But I’ve talked to people in different parts of the country who have fished Killer Bugs exhaustively without one strike. There are fish there. They’re technique is good. So why isn’t it working? My guess is that the fish in the streams they’re fishing simply don’t see the qualities a Killer Bug exudes in their menu. Maybe they don’t have scuds in those streams, or all the insects tend to be a much darker color. Who knows. But it’s clear that they do not recognize it as food.
I’d argue that it might be just as important to choose the right attractor for the right situation as it is to choose the right fly when you’re trying to directly match the hatch. And once you understand the different elements attractors highlight, then you can make a better selection and ultimately, be more successful.