Secret Flies...or Mastering the Hatch?

[Bulletin Board]

Posted by David Dempsey on 2013-04-26 17:33:12

Interesting comments on Dan's board about secret flies--or secret weapons.

I'm not so sure that any one fly pattern makes a difference--although that is such a loaded topic! Sometimes I think it is far more important to understand the hatch (and the insect that dominates the hatch that day)--assuming one has some basic skills. Sometimes it is perhaps far more important to understand the moods and quirks of a particular watershed!

The short version is that with 20,000 miles (or more) of quality water in this state; 800 different species of Stoneflies; 1200 different species of Mayflies; 2000 different species of Caddis AND 10,000 different species of Chironomid, a person might be better off just focusing on ONE hatch at one time of year AND ON ONE WATERSHED. I know I personally just can't absorb all that--much less remember it ;-)

Over the years, I've had some amazing fishing--AMAZING as in a 120 fish day on one lake. The truth of the matter? Most of them were hatchery fish, podded up and dumber than boards. :lol

I've also been humbled--numerous times--although every failure is an opportunity to learn something new!

The March Brown is an interesting example. EVERYBODY has heard about the March Brown...but hold yer horses: Some of us is fishing the western United States--and the species WE CALL A MARCH BROWN is actually a Rithrogenia species--and a very different bug than what shows up in a lot of fly shops!

I'll 'fess up to not really knowing a lot about the Rithrogenia--as in what species (morrisoni?) but let me throw you a curve: Do these insects vary from watershed to watershed? They apparently do...although what we may be seeing is adaptive coloration or a subspecies variation. I'll leave that for the bug experts to figure out. The important part is that I made a little mental note of the time of year I usually see these insects; what type of water (riffles or flat? slow or fast?). I go a step further: I break out my trusty inexpensive bug net (also handy for netting small fish in your aquarium :lol)and get a good look at the nymphs.

Newflash: The nymph--one of the clinger type of mayflies--changes color pretty dramatically as it gets closer to hatching! That bright to medium olive (and very stout) bug is almost black by the time it lets go of the bottom to begin it's emergence. Meanwhile, the adult (the ones I see) looks an awful lot like an early season Callibaetis (and I know at least one fly shop that has misidentified it as a Callibaetis!!!).

Seeing as how we are on a roll with this observing and learning stuff, what else do we know or think we know about the WESTERN March Brown? Well now, the WMB begins it's emergence almost as soon as it lets go of the bottom. It's exoskeleton is splitting as it heads to the surface...

So what does any of this mean to YOU or your choice of fly patterns?

1) It is a clinger type of mayfly with a barnacle like grip on the bottom so you rarely find it in the drift--which means fishing a deaddrift and hoping something will happen is kinda pointless. :lol Put some movement on the fly (such as the Liesering Lift)--and if you tie, try patterns that suggest an unfurling wing such as the Birds Nest (tied in appropriate colors) or something with a split wing case.

2) Did I say the nymph gets dramatically darker closer to emergence? In a jam, you can fish a generic dark nymph. More importantly, if you like to fish cripples (hint), the trailing shuck should be a dark grey or even black! The abdomen, on the other hand,should be a dark olive and the thorax should be a brownish pale olive with just a hint of grey (blend yer dubbings!).

3) Why is it called a March Brown anyways? Well, just who is buried in Grant's Tomb? ;-) It's one of my favorite early season hatches and big enough that some big fish get seriously interested in rising to it. When do I see it? That depends on how far north I am and at what elevation. However if I am fishing lower elevation valley streams (tailwaters) that support trout, I will see them somewhere around the middle of March. That means I can often find some very nice fish rising to them early March so I plan my trips accordingly. As I fish my way north, I will continue to see them all the way into early May.

4) It's a "clinger", meaning I found the nymph in fast riffle water so does that change where I look for fish? Absolutely--and if you know these valley streams, sometimes it seems like there is 200 yards of featureless riffles so one has to look for the subtle breaks in the current or the rock that is slightly larger than the rest--and large enough to form a small almost indistingishable pocket. In the thick of the hatch or emergence, the fish will often move into these slots to feed; slots that look like they would not normally hold a fish!

5) The mistake some anglers make is to fish flat water. The trout might actually be there but that is USUALLY because some of the bugs are having a hard time getting off the water--which MEANS fish a cripple style pattern!

The whole point here is that there is no SECRET fly. I time my fishing--hopefully--to coincide with the emergence of the WMB--and the pattern changes according to where I want to fish (or where I see the most fish working)and how! There is a period of prehatch activity where you MIGHT find a few of these very dark olive nymphs in the drift but my best fishing will be in the thick of the emergence with some sort of shaggy dog/Birds Nest pattern fished in some moderately heavy riffles just above good holding water or a good hole. If I WANT to fish a dry fly (although some people refer to cripples as "damp" flies) I will watch to see if enough struggling insects are being washed down into flatter water although I can do fairly well picking out the subtle pockets in a riffle and dropping a fly in there!

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