I recently had the pleasure of speaking to entomologist, fly tyer, and fly fisherman Dave McNeese. When Dave was young he traveled to New York to spend time with fly tyers like Art Flick, Elsie Darbee, Ray Smith, and Roy Steenrod. He has been doing scientific study on fish and insects since 1963. Dave has been instrumental in the study of the effect of UV products for fly tyers and is an expert in dying materials. He’s helped Bill Black of Spirit River tremendously with their UV2® line of fly tying materials. To read more about Spirit River UV2®, read my previous post on FrankenFly.
Dave says the UV factors in wildlife are used to a high degree. The structure of certain insect’s eyes that need pollen from a specific flower are guided by the UV signature within the flower itself. Predatory fish are like predatory birds as both use UV to hunt their prey. For example, the sparrow hawk can spot a mouse down on the ground in broad daylight by seeing the phosphorus in their urine trail they leave behind. In mayflies, females are amazingly protected by creation because they hardly have any UV, while males are often fed upon because of their color. Refraction is a big part of this. Light passes through and it develops other colors.
Jungle cock eyes are highly visible to steelhead because they contain a reflective polish for instance. Dave mentions you could actually replace synthetics in steelhead flies and use UV2® products instead because it will take care of the reflective color the synthetics show off. He has been testing this theory for years. One example is by adding a light colored material like a pinkish orange to the sides of his Hare’s Ear Nymph which has proved to be more effective in catching fish for him than a normal Hare’s Ear.
Some UV materials can be used sparingly, like Spirit River’s UV2® Enhancer. When working with Enhancer it’s best to mix small amounts into some natural dubbing or mix it with natural fur like beaver or otter for example. You have to keep in mind that the entire body of a mayfly does not glow. Only small parts will have a UV reflective aspect to them. This is why you should only need a small amount mixed in instead of using only the UV2® Enhancer by itself. Spirit River does have their own UV2® dubbing mixes that have a mix of 15 to 30% UV2® already in them.
Dave emphasizes that trout have incredible eye sight. Their eye sight is several times greater than a human’s. As a trout moves closer to its prey their color spectrum increases. This is good information to keep in mind when designing your flies.
Hopefully this gives you a basic idea of reflective UV in nature. This is the reason you see large lure companies developing more types of UV lures because they hire their own scientists to study and learn this information and relay that information when producing new enhanced products to catch fish. There is a world out there we don’t fully understand. If you’re not a scientist it’s difficult to obtain the information. Dave is lucky to be in contact with the leading entomologist at Oregon State University, Dr. Paul Hammond, who provides his expertise.
We are just now starting to scratch the surface in the fly fishing world with UV products and like “colors” it will take years of experimentation to learn what works and what doesn’t. It’s exciting to be in the beginning stages of this new development and I’m looking forward to where this might take us in the future.