green weenie

Guest Blogger: Mary S. Kuss

You don’t have to know much about fly fishing to realize how incredibly complex it can be. It’s a sport of many aspects, any of which can be of prime importance in any given situation. Success, in terms of fish caught, can be rather elusive, especially for the beginner. Yet no practitioner, regardless or experience, knowledge or skill, is immune from failure.
What are some of the factors with which the fly fisher must contend on any given day? Uncontrollable things like weather and water conditions, when and where to fish, what strategy and tactics to employ, one’s casting ability (or lack thereof), what rod and reel outfit is best, what wading gear and clothing should be worn, how long and of what design should the leader be, what length and diameter should the tippet be, what amount of weight should be used on a nymphing rig, what type of strike indicator (if any) and its location on the leader—the list goes on and on.

Finally, of course, there’s the question of the fly. It’s amazing how many fly fishers gloss over all of those other considerations and focus with laser intensity on the fly. Part of this, I suppose, is because the fly seems like the simplest part of the whole equation—the easiest thing to figure out and control. After all, it’s the point of connection between you and the fish. Everything else should be secondary.

Yet there is nothing that confuses the fly fisher so much, and nothing that we agonize over more, than fly selection. And there’s nothing harder for a fly fishing instructor to explain to a student.
The paradigm everyone assumes is that a fish tries to eat an artificial fly because it is imitating some natural food item. It is simply amazing the mental gymnastics and flights of fancy and imagination to which some people will go to make this explanation work. The really funny thing is that after you’ve been fly fishing for a while your thinking and perception actually alter to conform to your beliefs about flies.
Try showing one of your favorite “imitative” flies to a non-fly-fisher and ask them what the fly looks like. Of course your average individual may not be familiar with aquatic insects like mayflies and caddis. But everyone knows what an ant or beetle looks like, right? One day I was answering the questions of a non-angler about fly fishing. I pulled an ant pattern from my fly box to show them—assuming that this would be something familiar to which they could relate. When asked what it looked like, this individual replied, “A spider?” This begs the question of what my ant pattern looks like to the trout it is intended to catch.
I’ve heard in conversations with fellow fly fishers, and read in books and magazines, the most convoluted explanations of what certain flies are “imitating.” Of course there’s no conclusive means of determining whether these ideas are true or not. Still, unquestionably, some of them border on the absurd.

This Green Weenie is supposed to imitate the Fall Webworm caterpillar.
This Green Weenie is supposed to imitate the Fall Webworm caterpillar. Really?

There’s the great Green Weenie debate. Just what does this bizarre looking fly imitate? The most common explanation you’ll hear is that “It’s an Inchworm, of course.” Or, “It’s a caddis larva.” Now I’ve seen many Inchworms in my day, and many caddis larvae. To my eye, the Green Weenie bears only the most superficial resemblance to either. And it works the year around, even in the dead of winter when there are most assuredly no Inchworms present. As for the caddis larvae explanation, it’s a little more feasible but not much. I’ve seen some very bright green caddis larvae, but none that were fluorescent chartreuse. And although there are a few exceptions, the vast majority of caddis larvae are not nearly as large as the typical Green Weenie, tied on a size 12, 3X-long hook.

Fall Webworm caterpillar
Fall Webworm caterpillar

The most creative explanation I ever heard about why Green Weenies work is that, during the autumn season at least, they are imitating a Fall Webworm caterpillar. I was puzzled by this, since these insects are a sooty black in color. Yes, I was told, but the insides are bright green. In the interests of “science,” I caught a Webworm and tore it open. Sure enough the insides were green, but certainly not fluorescent chartreuse. And I could also not figure out how a trout would manage to tear the caterpillar open and see the inside of the insect, or why it would do so.
I once read an explanation of why the Royal Coachman dry fly worked so well. The writer posited that the two round humps of peacock herl were a good imitation of an ant.
Some people deal with these kinds of contradictions by simply refusing to use any “attractor patterns,” disdainfully referring to them as “junk flies.” Personally, I find this righteousness rather contrived. We do not know, nor can we ever know, what the fish think our flies are. Of course everyone is entitled to his or her opinion and to choose the flies they fish on any basis they wish. It’s important to understand, however, that this is a personal philosophical position and not an absolute truth that anyone should feel bound by.
None of that, of course, is of any help in choosing what flies to use. You do have to have what scientists call a “model,” some set of premises to inform your choices. The hatch-matching paradigm is where most people start, and once an angler has a good understanding of how this works he or she often wants to believe in it as if it were an article of faith. That’s why so many fly fishers are actively annoyed when someone comes along with some outlandish attractor pattern and it outfishes the accurate insect imitation that they have so carefully chosen.
The most successful fly fishers are those who have settled on an overall approach to fly selection, but are not wedded to it. They are willing to be flexible and shift gears if their preferred strategy is not working. Fly fishing is not a science, in the final analysis, it’s an art. Practice your art with an open mind and a cheerful sense of exploration and you will enjoy the sport in all of its infinite variety. Take failures to catch fish in your stride. They are essential to the full enjoyment of the success that, with patience and persistence, will ultimately come your way.


  1. This is the most reasonable explanation of fly selection I have ever read, plus it meets my own experience. I often use “greenie weenies” to CATCH TROUT. I do like attempting to tie something similar to a natural insect, but I neither have time from other activities, like watching TV, or the skill. I often use a professional guide to help me when I can’t get a friend (I do have a few friends, but few who fly fish) to go along mainly because I’m 76 and my wife worries. I really enjoy what a guide can teach me about the whole game of fly fishing, but I can catch trout without a guide. I suppose I’m just hiring a professional ‘friend’ to talk with and to learn from. Thanks for the article!!!!

  2. I always thought the fly was tied to attract the fisherman rather than the fish. The fish don’t buy the fly, the fisherman does. I think any attractant would get the better of the fishes curiosity.
    One day in 1971, I was tying a Hopper Fly and it all came unwound on the hook. Just a blob of different colors of feathers. Red, Yellow and brown. I decided to keep it and try it someday. I was fishing a small creek west of Lima, MT when I saw a flash in the bottom of this hole. I thought I’d test it, so I put on the blob of feathers and thru it up stream from the hole and let it float down. As soon as it floated over the hole, this beautiful Rainbow Trout came up real slow and grabbed it and took it down under. It all seemed like slow motion. Needles to say the battle was on. I won. It was a 3 pound beauty!
    Moral of this story is the fish is the decider of what to eat! So don’t be afraid to experiment.

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