04/28/09

Insects and other foods the trout may be eating:
1.   Blue-winged Olives - mostly Little BWO - Isolated hatches
2.   Giant Black Stoneflies - starting any day, nymphs active
3.   Hendricksons - hatching
4.   Cinnamon Caddis - Mostly Abrams Creek
5    Light Cahills - Starting any day
6.   Midges - hatching in isolated locations
7.   Little Short-horned Sedges - should hatch randomly for 2-3 months
8.   American March Browns - hatching
9.   Streamers - matching sculpin, baitfish and small crawfish
10. Little Yellow Stoneflies - hatching
11. Eastern Green Drakes - starting any day Abrams Creek
12. Green Sedges - hatching

Fishing Conditions Update:
As you probably know, the last few days have been exceptionally warm for this time
of year with temperatures ranging as high the mid eighties at 2500 feet elevation.
That has caused a huge increase in the water temperatures. Last Saturday, the
increase in water temperature was welcome. It got about as easy to catch trout as it
gets. Sunday and Monday was a different story. By yesterday (Monday) we had
experienced two days of water temperatures well above normal. This probably
resulted in some hatches, such as the Hendricksons, ending prematurely. I will
leave them up for another day or so to double check and make sure. It also
probably started some hatches prematurely. It probably created low catch results
for most anglers.

Whenever the water temperatures suddenly increase of decrease drastically, the
immediate results is usually not good. It creates a short period of inactivity in the
feeding habitats of the trout. It also creates changes in the hatch activity of the
aquatic insects. It could possibly have started some hatches like the Little Sister
Caddisflies and Green Drakes in Abrams Creek. It did start the Light Cahills hatch a
little prematurely. Starting tomorrow we will experience some more rain and drops in
the temperatures that will bring conditions back closer to normal. The drops in
water temperatures will throw some curves in the hatch patterns for about a day
and the fishing should return to being rather easy and more predictable.

LIght Cahills: (I am repeating last years info on these mayflies because it is
confusing to many anglers)

The Light Cahill common name is one of the most confused common insect (fly)
names used in the Smokies and elsewhere in the East for that matter. The
Stenacron genus, not to be confused with its sister genus, the similar sounding
Stenonema genus, includes one important species, the interpunctatum. This
mayfly is commonly called the Light Cahill.  

This mayfly is very similar to some of the
Stenonema species (that were recently
changed to
Maccaffertium species) which accounts for some of the confusion.
For example, the old
Stenonema ithaca (now the Maccaffertium ithaca) is often
called a Light Cahill. It is also called a Gray Fox, adding even more confusion
the Gray Fox common name. Because of the confusion, you will hear anglers
mention that Light Cahills are hatching all the way from April until the middle of
September. Some of the mayflies they are referring to are not Light
Cahills.

Some of the other mayflies the Light Cahill is confused with are the old
Stenonema (now Maccaffertium) mediopunctatum, carolina, and modestum
species. These are usually and correctly (if there is such a thing as a correct
common name) called Cream Cahills. They will hatch later in the year.

The Light Cahills are also confused with the
Heptagenia group of mayflies or the
Little Yellow Quills that hatch later in the season. That is why you will hear
anglers still taking about Light Cahills late in the Summer and early fall
months.

There is a reason for all this confusion. The duns of these various species look
much alike.

Summary:
Now I am sure all of the above scientific names are also confusing, especially to
those who are just getting started. I would make this plain and simple if it were not
for those guys who would respond with a lot of corrections in my over simplification.
Some want it simple as moon pie and RC cola and some want it as accurate as a
snipper. Scientific names are necessary in order to designate the insect I am
referring too or otherwise I would not use them. If I used common names only, there
would be even more confusion. For example, if I called a
Maccaffertium Ithaca a
"Gray Fox" many anglers would think I was referring to a
Maccaffertium varcium or
the old March Brown common name. I could give dozens of such examples.
Common names vary from region to region, book to book and angler to angler. In
order to make it simple, what I and most of the fly fishing community refer too as a
"Light Cahill" is the
Stenacron interpunctatum.

These mayflies hatch from the last week of April until the end of June, depending
mainly on the weather and elevation of the stream. This hatch usually only
last two to three weeks at any one location but the overall duration from the
streams at the lower elevations to the higher elevation, can last up to eight
weeks. These mayflies can be found in the tiny brook trout streams as well as
the larger watersheds at the point they exit the park.

As I said above, it is easy to understand some of the confusion in the common
name "Light Cahill". There is not a great deal of difference in the appearance of
some of the
Maccaffertium Stenacron and Stenonema species. They are all
clinger nymphs that look fairly similar. However, there are differences in the
behavior of some of these various species that warrant attention.

The
Heptagenia group of mayflies (often confused as Light Cahills) are also
clingers but behave quite differently. When we review the "Cream Cahills" you
will find that some of those species are different colors. Some of them found in
the park are almost white. Some of them have heavily mottled wings. The
sizes of these mayfly species can vary a hook size of two and of course, the
hatch times vary greatly. For now, lets focus on the real "Light Cahill", the
Stenacron interpunctatum.

Copyright 2009 James Marsh