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Click here for a selection of Sulphur imitations.

Family Ephemerellidae has only one genus-Ephermerella.

When you see these it's Sulphur time

Common Names

Compara Duns, Pale Evening Dun,Sulphur, Little Marryatt, Pale Watery
Dun, GrayFox


Ephermerella dorothea

Dorothea nymphs are crawlers. They are quiet water dwellers found in flats and runs. They flourish in limestone streams especially in silt.

Nymphs swim laboriously with a peculiar wiggle..


Duns, have three tails and emerge May 15th through the end of June. Hatches are usually between 7 pm and dusk and usually last ½ hour. The best fishing is after sunset..

Dorothea spinners are pale yellow, have three tails and fall at dusk  Body size is 6.5 to 7.5 mm,  size 18. They jettison their eggs a safe distance above the stream above the riffles.

Ephermerella rotunda and invaria


Rotunda and invaria nymphs are crawlers.


Rotunda duns emerge in the early evening in May and continue through early June.

Invaria hatch in May through June in late afternoon.


Spinners are dark brown, and fall at dusk.  Rotunda body size is 16, invaria is 14.



The first Sulphur activity is usually caused by invaria & rotunda not dorothea.


Nymphs swim laboriously with a peculiar wiggle.

Anglers should seek appropriate sites along banks as well as behind boulders and deadfalls. Use deep running, weighted nymphs during hatchless hours

Some hatch into sub-imagos a foot below the surface. Fish Little Marryatt or Pale Evening Dun patterns wet style with jerks.

Try parachute patterns, in the surface film, during emergergence.

Joe Kohler introduced us to a nymph pattern which is a killer. Joe uses olive thread to tie in a few wisps of Lemon Wood Duck, 1/3 the length of the hook, for the tail. He dubs a cigar shaped body with dark brown angora rabbit and whip finishes. The fly is complete.


Be observant. During this hatch trout are extra selective to silhouette, size and color. Size difference is considerable. Are Trout taking dorothea (18) or the larger invaria or rotunda?  Are they taking duns or spinners?

Use size #16, if you get refusals go to #18. If the dun imitation is pale yellow and about #16, species doesn't matter to you.

Duns take off quickly so emerger patterns (parachutes) and spinners may be better fishing. Tie some orange at the Thorax, try to wind the hackle so the orange is apparent.


Position yourself to cast downstream and cast up and across into the fading light.

Cast to one side or the other so the fish has to turn his head to suck in the imitation.


A little twitch will sometimes put an extra "something" into the drift


(I borrowed these formulas from Gary Borger)

Top Water

One foot-Maxima Cameliion .013, hard monofiluiment

Four feet- Maxima Cameliion .010, hard monofiluiment

Four Feet-4 or 5x, soft monofilament

Six inches-7 or 8x, soft monofilament


Four feet- Maxima Cameliion .20, hard monofiluiment

One foot-5 or 6x Maxima Cameliion .013, hard monofiluiment

Four feet- 2x or 3x, soft monofilament

One foot-5 or 6x, soft monofilament


Tippets that are to thin can result in twisted tippet.

Use the following formula:

Fly size                      Tippet size

#14                             5 or 6x

#16 & 18                    7 or 8x


We suggest 8 foot, four or five weight rods with medium action.


We like double tapered, four or five weight lines in colors.


When in doubt as to which pattern to use try a Compara dun!

When you see these iSulphurs are over.

sulphur nymph
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