Sulfur Imitations? [Archive] - Fly Fishing Forum

: Sulfur Imitations?

06-11-2003, 01:02 AM
I hear a lot of talk about sulfur mayflies. What dry fly patterns imitate the "sulfur mayflies"? What about the Light Cahill? Do sulfur mayflies vary greatly in their color (ie., yellow, brown, tan, creme. etc.)?

06-11-2003, 01:36 AM
when I lived in the east and fished the WB Delaware I always did well on the sulfur hatch using a quigley cripple pattern with a bit of orange mixed into the yellow dubbing, especially in the thorax. The color of the naturals does vary, but since the hatches are on the heavy side, it can sometimes be helpful to make your fly stand out from the naturals AND the imitations

06-11-2003, 06:47 AM
Sulphurs are meant to represent "ephemerlla dorothea" (and a whole host of others that are yellow-colored flies. Because of the veriations in color, (whitish-buff to brilliant yellow), you can sometimes get away with a light cahill or a pale morning dun, or other times the naturals may require a bright sulphur-colored imitation. There are patterns called simply "sulphur dun", and they can be found in any good book on fly patterns.

In general, here in the east, true mayflies start out early in the spring as larger (size 10s and 12s) and darker flies (e.g. Hendrickson), and as the year progress to lighter colored and smaller (16s and 18s), with the sulphur being an example.

(I won't bore you with the survival reasons for this so as not to be long winded.)


06-11-2003, 11:27 PM
Bob -

Curious what you are thinking about survival. At least one hypothesis that I have read has to do with wing drying rate - big dark wings dry faster in cool weather (early season) and later in the season when temps are warmer a small light colored wing will absorb energy and dry just fine. Not sure how this applies to a hatch that really picks up at dusk (???)

I'd also think that there is a relationship between fecundity and body size (there usually is, especially within a species).

what are you thinking here?

Steve, the steelheader longing for a good sulfur hatch

06-12-2003, 07:00 AM
One day when I was fishing in the Catskills, I ran into a New York stream biologist, and somehow the color and size issue of the flies came into the conversation. He said that when mayflies emerge, and before they transform from duns to spinners, they fly to the vegetation streamside to transform. Early in the season, there are really no leaves to blend in with, and they rest on relatively bare branches where they blend in better. Later in the year, when the leaves and light green colors persist, the shades of yellow blend in. So it's a "camouflage" thing for protection from insect predators. He also said that size was related, too, but this conversation took place many years ago, and I forgot the details. (In advancing age, memory is the second thing to go!)

I'm sure that light (and subsequent heat) absorption does play a role, but then, how do you explain late evening and night hatches when light (and heat energy) doesn't amount to much, and temperatures are cooler??

Anyway, made sense to me at the time.