Insects and other foods the trout may be eating:
1.   Blue-winged Olives - mostly Little BWO - Isolated hatches
2.   Giant Black Stoneflies - hatching
3.   Cinnamon Caddis - Mostly Abrams Creek
4    Light Cahills - hatching
5.   Midges - hatching in isolated locations
6.   Little Short-horned Sedges - should hatch randomly for 2-3 months
7.   American March Browns - hatching but randomly in isolated locations
8.   Streamers - matching sculpin, baitfish and small crawfish
9.   Little Yellow Stoneflies - hatching
10. Green Sedges - hatching
11. Little Sister Caddisflies - Mostly Abrams Creek
12. Eastern Pale Evening Duns - (called Sulfurs by some)
13. Sulphurs - hatching in isolated areas

We just finished a mayfly species that many call a Sulphur. It was the Ephemerella
which should be called "Eastern Pale Evening Dun". The true Sulphur is the
Ephemerella  dorothea. It  is quite similar to the invaria species but there are
differences in the color, hatch times and even habitat.

The body of the Sulphur is a true sulphur color. The Eastern Pale Evening Dun has
a tannish, yellow abdomen. The Sulphur is usually at least one hook size and
sometimes two hook sizes smaller than the Eastern Pale Evening Dun. These
mayflies usually hatch late in the afternoon from about 4:00 to 7:00 P. M. In most
streams that have them both, the Sulphur hatches approximately two weeks later
than the Eastern Pale Evening Dun. If you happen to fish the South Holston River
Tailwater in Northeast Tennessee, then you may have seen both of these mayflies.
Most everyone call both species Sulphurs and are not aware of the difference. This
is one of the reasons the hatch last so long on the South Holston.

There are only a few areas in most of the streams in Great Smoky Mountains
National Park that have these mayflies. Some streams may not have any. There are
more Eastern Pale Evening Duns than Sulphurs. Where you do find them they
usually exist in large quantities. We have found a few places that have both species
but that is rare. Most of the time, you will only find one of the two.

The Sulphurs like slower moving water than the Eastern Pale Evening Duns they
are often confused with. Generally, in the Smokies you will find Sulphurs where the
stream is falling on a low to moderate decline. You will find them at the heads, sides
and tails of some of the larger pools. Sometimes they will be found near the end of
the longer, slow runs. Wherever you find smooth water, and that isn't many places,
you may find Sulphurs.

Copyright James Marsh 2009
This is a male Eastern Pale Evening
Dun. In case you wonder how I know it
is because of the large tomato looking
eyes. The males in all of this genus
have the large eyes. That includes the
Hendricksons and in the West, the
Pale Evening Duns.

It is not the difference in looks that
makes it worth separating these two
mayfly species. There is a difference
in size but the big difference is the
water in which they live and hatch. It is
different, even the South Holston river
where both exist. This will be explained
as we go along explaining how to
imitate the different stages of life.
This is a Sulphur. Notice the body is
more of a true Sulphur color than the
EPED on your left which is more of a
tanish yellow. This is a female. Again
the eyes tell the difference. All the
females in this genera have the small
flatter eyes.