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Fly Fishing

> Pale, or white nymphs., Page 2

Brown, P.B. 1993. Soft-shell crayfish: A new crop for the Midwest. p. 654-656. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.
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Regardless of temperature, there was a biphasic response of molting activity. That response became more dramatic as temperature increased from 20° to 30deg.C. In general, a large number of crayfish molted within the first 5 to 10 days (as many as 64% of the population reared at 30°C), followed by a quiescent period, then another period of molting. This observation has important management implications. …

Native midwestern crayfish will molt in controlled situations and that molting is influenced by water temperature. Molting activity is relatively rapid, with a large percentage occurring within the first 10 days. The response, regardless of temperature, was biphasic and probably reflects individuals in different stages of the molt cycle when acquired. Those that were near stage E (ecdysis) in the molt cycle molted within the first 5 to 10 days, while those is earlier stages required approximately 15 days to molt. Management options are now available to aquaculturists that will allow more carefully manipulated molting activity patterns in populations of native midwestern crayfish. …

As Falsifly says, I doubt many fish would pass on ANY nymph; At least in most streams where trout cannot afford to be too choosy. And, if the insects are anything like crayfish, they'd be hunkered down and well concealed when molting.

I've done particularly well on this fly when creeks are roiled following rains. It's a go-to then and I think it's particularly visible in those conditions, and that may be all there is to it. Why not...chartreuse? Aesthetics I guess. I like to THINK I'm matching something in nature, when again, visibility may be all there is to it. But, I'll pitch chartreuse to any lake-run fish without qualm. Weird animals we are.

Picked up a copy of 'Stoneflies for the Angler,' by Eric Leiser and Bob Boyle, published in 1982.

I haven't seen many angling books on stoneflies, and this one is pretty informative.

One of the chapters is entitled, 'The secret of the white nymph.' The authors describe how when some (many?) nymphs molt, they turn white for a few hours while their shell hardens and darkens.

The white nymphs don't move around much in that state, but if they get washed downstream, it sounds like trout hammer them.

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Swisher & Richards have to say about it in "Emergers" (c. 1991, p.69) :

"Each time [stonefly nymphs] undergo this "shedding" their color changes to a much lighter shade. Most species, except the very dark genera, become almost pure white.

"At these times, that trout are particularly susceptible to an imitation tied in the Curled Stone pattern, only very light in color. The tails, body, hackle, wing pads, and antennae are very light cream and the ribbing is light yellow. We call the pattern the Albino Stone. Trout prefer this pattern if they can get it, much as a smallmouth bass prefers soft-shelled crayfish over hard-shelled crayfish...."

They then go on to describe their "soft and resilient" pattern:
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If you look on page 116 of "The Orvis FLy Pattern Index, Complete and Unabridged" by John R. Harder (c 1978, 1990), you find the following recipe for the Shedding Stone Fly
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