Fly Fisherman Throwback: Nymph-Design Heresies

Editor's note: Flyfisherman.com will periodically be posting articles written and published before the Internet, from the Fly Fisherman magazine print archives. The wit and wisdom from legendary fly-fishing writers like Ernest Schwiebert, Gary LaFontaine, Lefty Kreh, Robert Traver, Gary Borger, Joan & Lee Wulff, Vince Marinaro, Doug Swisher & Carl Richards, Nick Lyons, and many more deserve a second life. These articles are reprinted here exactly as published in their day and may contain information, philosophies, or language that reveals a different time and age. This should be used for historical purposes only.

This article originally appeared in the June 1989 issue of Fly Fisherman magazine. Click here for a PDF of the print version of "Nymph-Design Heresies."

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When fly fishermen talk about nymph patterns, translucency almost always ends up in the discussion. Fly tiers may have been led down the wrong road for the right reason when it comes to translucency. What are the most popular nymphs in use today? The Hare's-ear Nymph leads by a wide margin, both in sales by catalogs and fly shops, and in the fly boxes of America's fly fishermen. Other popular materials for making the bodies of nymphs include peacock herl for nymphs like the Zug Bug, pheasant-tail fibers for the various versions of the Pheasant-tail Nymph, and dubbing furs like rabbit, fox, Australian opossum, and otter. These body materials form the nymph's silhouette.

"Translucency," we parrot, "we must have translucent flies to catch trout." John Atherton, the father of the "impressionistic" theory of fly-tying (according to this theory, mixed colors are used to produce a lifelike pattern seen in natural insects), used seal's fur and peacock herl for their "wonderful translucence." G.E.M. Skues admitted his artificial flies were opaque, but he suggested that because of "light partly transmitted and partly reflected" by the artificial, it might give the impression of translucence.

Translucent? Hare's-ear fur, pheasant-tail fibers, peacock herl, and rabbit fur? Fuzzy, yes. Buggy, you bet. But they're not translucent, unless the clothes you're wearing can be considered translucent. Let me show you why they shouldn't be translucent.

Have you ever looked at the surface of the water after a heavy hatch? After the hatch, just a casual glance at the water reveals clumps of shed skins of the hatching flies, left behind like Clark Kent's clothing in a phone booth. These empty skins, or "shucks," as they have come to be known, are translucent, especially when held alongside a drifting mayfly nymph that hasn't hatched yet. But a live mayfly nymph is opaque.

A trout does not take his feeding lightly. It is not a game. He does not get curious or inquisitive or impatient or angry–he eats or he dies. During the height of a hatch, trout take nymphs just under the surface or in the surface film. Fish that cannot tell the difference between an empty, translucent shuck and the real nymph are weeded out by natural selection. Trout must select against translucent flies.

There are two other reasons why trout mistake for food flies made of materials like hare's-ear fur and pheasant-tail fibers: The movement of many tiny fibers mimics the lifelike actions of a nymph, and reflectiveness imitates a certain stage of the nymph's life cycle. Both factors are more important than translucence.

Just before an insect hatches, it develops a pocket of air between the outer skin of the nymph and the new, inner skin of the adult fly. Biologists haven't decided where the insects get the air. Some say it comes from internal biological processes; others maintain that the bugs swallow some of the air that is in solution underwater. The air between the two skins creates an effect like mirrored sunglasses.

The tinsel and wire used for a hundred years to imitate the segmentation of a mayfly nymph may appeal to fish more because of the reflective properties the two materials have rather than the appearance of segmentation that they create.

The work done by Gary LaFontaine for his book, Caddisflies, and his development of caddis pupae patterns using Antron® yarn (it has three-sided fibers that trap air bubbles and give a high degree of reflectivity) has convinced me that reflectiveness is the most important property in a nymph-imitation material when there is an insect emergence in progress.

Seal's fur, like hare's-ear fur, adds fish attraction to almost any fly. Is it effective because it's translucent? If you hold a piece of seal's fur up to the light alongside a hunk of processed wool, it's difficult to decide which material is more translucent. Wool has not distinguished itself as a popular tying material for nymphs, so maybe translucency isn't the important quality. If I was a seal, I'd want a coat that traps insulating air bubbles, much as Antron® yarn (developed for use as a rug yarn that repels stains) does.

Perhaps in our search for a substitute for seal (seal's fur is unavailable to most buyers) we should lean more toward synthetics like Antron® than toward some of the natural substitutes. Angora goat wool just doesn't make it.

Movement Makes It Work

Frank Sawyer, the famous riverkeeper on the River Avon in Britain and the developer of the Pheasant-tail Nymph, gave a passing nod to translucency, but he placed greater emphasis on the movement of the material in the water. Sawyer thought pheasant-tail herl was the only material that would mimic the rapid movement of a mayfly's gills in the water, and he was the first person to use this material as a nymph body. Now, 40 years after Sawyer developed it, the Pheasant-tail Nymph is still the most popular, and deadliest spring­-creek nymph.

Recent studies by fish ecologists have strengthened Sawyer's case. Studies of predator/prey systems show that sight-feeders like trout must see movement in their prey. It's easy for us to see movement in swimming or darting minnows or crayfish, but what about nymphs, larvae, or pupae drifting in the current? It has been hypothesized that trout key into the movement of a mayfly's abdominal gills or a stonefly's thoracic gills. By using this facility, a trout can distinguish a mayfly lying motionless on a rock, or drifting in the current.

Jim Leisenring, an American wet-fly tier and fisherman who fished in Pennsylvania in the first half of this century, was another advocate of translucency. He was famous for his soft-hackled flies tied with slender, tightly dubbed bodies and no more than a turn or two of hackle. Although some of his flies were tied with relatively translucent seal's fur, other patterns used mole and muskrat. When I studied his style of tying, however, I discovered that he dubbed thin fur bodies on a dubbing loop and then twisted the loop into a tight rope around two pieces of thread.

The halo around one of Leisenring's patterns when wet is not translucency at all, but tiny fibers of fur sticking out at right angles, a result of the twisting process. It's exactly the same effect you get with pheasant tail, and one of Leisenring's patterns even called for a body of twisted crow-wing herl.

Success on the Bottom

There are two kinds of nymph fishing. One style, the most common, is fishing to trout that are actively feeding because of a hatch; the other is educated blind­fishing to fish that are near bottom or not interested in surface food. Fishing nymphs at the beginning or height of an insect emergence is the easiest approach, and during such periods, fuzzy, reflective, translucent flies are most effective. Even if you don't see a blanket hatch of mayflies on the water, there are few hours during the day when there isn't some kind of insect emergence onstream. How many times have you been fishing a weighted nymph "right on bottom" when you see a vicious boil on the surface and suddenly you're tight to a trout?

Few fishermen can effectively fish nymphs near the bottom to trout that are disinterested in insect emergence.

I've been fortunate to know and learn from a few superb nymph fishermen, people who can take trout when the rest of us are blaming the wrong water temperature or lack of hatches for our failure to catch fish. I've noticed a number of similarities among these top-notch nymph fishermen: They use one or two patterns exclusively; they have absolutely no interest in what is hatching. They fish straight upstream to get an absolutely dead drift, and the flies they use are made of opaque, quick-­sinking materials–sometimes even of hard materials like lacquered floss or stripped quills.

Carl Coleman is the first great nymph fisherman I met, and he's still one of the best. I first saw Carl in action when I was about 14 years old. I was tying flies for a little tackle shop Carl had in his house, and as an incentive to finish my orders on time, he promised to take me fishing. Carl fished a special fly–a March Brown nymph. It was the only fly in his shop that I was not allowed to tie commercially. Only Carl tied that March Brown nymph.

When I asked Carl one evening while fishing about the effectiveness of his nymph pattern, he replied, "Tom, I have a confession to make. I don't really know why the trout love this March Brown nymph so much. I've spent the last 15 years perfecting this fly by having the trout tell me what they want. I've tried all kinds of fuzzy materials for the body, materials that you think might work better, but every time I get away from the lacquered, brown-floss body ribbed with white floss, I don't catch as many fish."

"But why do you call it a March Brown nymph?" I asked.

"That's just for the customers who come into the shop. You know, I think the trout take my nymph for a small crayfish. Every big brown trout I've ever killed has had crayfish in its stomach, and they seem to prefer the small ones. You guys can preach all you want about no-kill, and I believe in it–but don't forget that you'll never know exactly what a trout is feeding on until you kill it."

Carl fished his nymph with a 6 1/2-foot Superfine bamboo (this was before the introduction of graphite). No light tippets for this guy, 3X in the riffles and 4X in the pools with slow-moving water. No split-shot on the leader. Carl weighted his flies with as much lead as he could squeeze on the hook shank, and his #10 March Brown nymph entered the water with all the grace of an acorn falling from a hundred-foot-tall oak. This occurred before strike indicators became common, so Carl was fastidious about keeping the end of his floating line greased, so he could detect strikes. The short rod and heavily weighted fly dictated a direct upstream approach, and that was the only way Carl fished his nymphs.

This dead-drift, upstream-nymphing technique with Coleman's March Brown nymph has worked for me in trout streams throughout the country, from the Madison in Montana to New York's Ausable. It's been successful even though his nymph is anything but translucent.

I use a longer rod, and I also hold my rod high to keep everything but my leader off the water to obtain that dead-drift, and I even–Carl forgive me–use strike indicators. But that ugly, opaque, quick-sinking March Brown nymph produces trout when nothing else does as long as I pay attention to water types.

Nymphs and Water Types

From 20 years of casting heavily weighted nymphs, mostly in the East, I know you don't need to study entomology to successfully blind-fish deep with weighted nymphs. There is a nymph or two that works for each type of water throughout the season, with only a reduction in size required as the season progresses.

I can tell if the March Brown nymph will be effective on certain water by simply looking at a river. Is the river's bottom composed mainly of large cobbles of flat slabs? If so, crayfish are likely to be there, and if there are no crayfish, then large, flat nymphs like stoneflies or flattened mayfly nymphs in the genus Stenonerna or Epeorus are a likely possibility. The profile of the March Brown nymph and the invertebrates in this kind of water consists of a robust body and prominent legs. The March Brown nymph works for these foods in nonhatch situations, where imitating a specific insect or crustacean is not as important as suggesting an edible profile to the trout.

On the other hand, in a spring creek, with lush aquatic vegetation and a marl bottom, or in a river whose bed is composed of fine gravel, like the Battenkill or Michigan's Au Sable, the March Brown nymph is virtually useless. Look at the bottom. Where would a big, flat nymph hide in the land of silt or fine gravel? (I know the March Brown nymph does not have a flat body, but as long as the fish see a wide profile, I don't think they care. Look at the success of Charlie Brooks's stonefly nymphs tied "in the round.")

The mayfly nymphs in a spring creek or a river, with a fine-gravel bed have a completely different profile. They are swimming or crawling nymphs, with skinny shapes better adapted to this environment. Their legs are insignificant, and they are tucked under the body most of the time, so they aren't worth imitating. All you need is a skinny body and a suggestion of a thorax-like a Sawyer Pheasant-tail.

The Pheasant-tail is an old standby for me in rivers where the March Brown won't work. It's an English pattern, and I couldn't help monkeying with the dressing, so I worked up two pheasant-tail clones with an olive cast, because most of the swimming and crawling nymphs in our American trout streams are more olive in color than rust. One variation is just the standard Pheasant-tail pattern tied with olive-dyed pheasant tail. The other is a pattern tied with various feathers from the skin of a wood duck, and it is the most successful spring-creek nymph I've ever used.

The Blue Quill is another nymph I use frequently in waters with swimming nymphs, especially where I find Baetis. This pattern originated on a small, limestone spring creek in upstate New York.

One season, the pattern underwent an evolution that shows just how simple a nymph can be, especially in spring creeks. There was a regular crowd of fly fishermen who haunted this stream, including an old Indian named Lee, who was known for his simple patterns.

Lee took the tails, quill body, and wingcase off the Blue Quill nymph and renamed it the No-quill. It seemed to work just as well, even though it was no more than a white thread body and a thorax of turkey-wing fibers wound over fine lead wire. But then he went too far and left off the thread and turkey fibers, proudly naming the fly "Lee's Zinger." Lee kept catching trout as fast as the rest of us, but he became a pariah, because no one could accept him catching as many trout as we were while he was using just a few turns of lead wire around a hook.

The next season, Lee returned to the stream fishing Blue Quills, and nothing was ever brought up again about the No-quill or Zinger. But I must confess, I still have a few No-quills tucked away in the back of my nymph box.

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Tom Rosenbauer is a fly-fishing author who has published numerous books for Orvis, which he has work for over 30 years. Rosenbauer is also the host of the Orvis Fly Fishing Guide Podcast which has been syndicated on the Internet since April 2008.

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