12/03/08

Fishing Cold Water in the Great Smoky Mountains - Blue-winged
Olives - Part Nine

Another hatch that could take place in cold water in the streams of Great Smoky
Mountains National Park is a blue-winged olive hatch. Now as most of you probably
know, there are a lot of different species of mayflies that are called blue-winged
olives. Like some books, we usually break them down into Blue-winged olives, Little
blue-winged olives, Eastern blue-winged olives, and Small blue-winged olives.
The ones that hatch during the winter months in cold water that is between
forty-five and fifty degrees are the Blue-winged olives. There are a couple of
species of Little blue-winged olives that could hatch but they are not significant.
There would be no Eastern blue-winged olives or Small blue-winged olives that
hatch at this time of the year.

The major ones to hatch are the
baetis species. There are also some acentrella,
diphetor, plauditus
and timpanoga species that may hatch since they are bi and
tri-brooded, but the majority of the hatches would be
baetis species. They are also
bi and tri-brooded, depending on the species. Now I am not trying to blow you away
with all these Latin names. The important difference is that most of the
baetis
species are a hook size 18 and 20, although there are a couple species of them
that are not very common in the Smokies that are smaller. Most of the other genera
I listed above that may possibly hatch in cold water, are small or from hook sizes 20
to 26. None of them are really significant but if you happened to be fishing on a
cold day, and there were lots of tiny BWOs present, say for example a size 22, you
may want to use a tiny BWO pattern. What is important is what is happening when
you are fishing.

Even the
baetis hatches are almost never prolific, even under perfect conditions.
When I say perfect conditions, I am talking about a rainy or snowy day. There is just
something about a heavily overcast day that brings on larger blue-winged olive
hatches. Most entomologist think it has to do with the moisture in the air, keeping
them from drying out. Some think that the nymphs can somehow distinguish cloudy
days from clear days with bright, blue-bird skies, even though the nymphs are
under water. I certainly don't know for sure but I do know that they hatch in larger
quantities on the foul weather days. I am writing this article two days in advance of
publishing it and it is snowing outside. Today would be a good day to chance
running into a hatch and I may try that.

Just as important as the hatches of blue-winged olives is the fact that when the
water is in the temperature range I mentioned above, during the month of
December, the nymphs are very likely to be located in the same type of water they
are going to hatch in. They usually hold in shallower, slower moving water such as
pockets, tails of pools, etc. for a few days prior to hatching.
Baetis nymphs are swimmer nymphs. They don't hide beneath the rocks on the
bottom. They act a lot like small minnows. They depend on their ability to flee
quickly from their predators and hide behind small rocks and other things. In other
words, they are exposed to the trout during the pre-hatch period of time. Even if
you don't encounter a hatch, you will likely be able to encounter trout feeding on
the nymphs, provided you place your fly in the right type of water.

The best way to do this is to use little weight, if any, and no strike indicator. If you
must, make it a tiny one. If you make cast into the shallower pockets behind rocks
and boulders, shallow pockets around the bank, slow moving eddies, the tail end of
pools, being careful not to spook any trout that move in and out of the area, you
stand a good chance of catching trout that are feeding on the nymphs. When I say
shallow water, I do not mean water that is only inches deep. I am distinguishing it
from water that is quite deep. Blue-winged olives don't hatch from the bottom of
runs or deep pools. By the way, they don't hatch from the fast water of the riffles
either. They do hatch in the calm pockets within the riffles where they avoid the fast
water.

This type of fishing requires longer than normal cast and longer and lighter than
normal leaders and tippets. I normally use a 6X tippet and at least a ten foot
leader/tippet combination. The emerging duns eventually get caught in the current
seams when they hatch within calm areas of the riffles but not the nymphs. They will
be in the slower moving, shallower water of the pockets or the tail ends and edges
of the pools.

You will find that most of the
baetis species that hatch at this time of the year are a
hook size 18 or 20. The thing that is important about these tiny swimming nymphs is
the fact they are slim. They are not bulky type nymphs. They have long, thin bodies
and slim legs and tails. They can move and dart around like small minnows. The
trout usually shoot into the pockets and slower moving water where they hatch and
try to grab one before it can dart away. You will sometimes see swirls or flashes of
the trout when this occurs. If you are close enough to see them regularly, you are
probably to close to where you should be placing your fly. By the way, wading
around too close will not only spook the trout, it will also spook the swimming
nymphs.

Having a good imitation is important. The trout get a good look at the nymphs in the
slow to moderately moving, clear, cold water they hatch in. That is why our "Perfect
Fly" swimmer, blue-winged olive nymphs are longer and slimmer than normal. They
don't resemble the flat, wide clinger nymphs or the bulky bodied, heavy legged
crawler nymphs. They certainly don't resemble a burrower nymph. They are tied
with goose biots, turkey feather wing pads, dubbing for the thorax and partridge for
the legs and tails. The biots, tied with the barbs out, imitate the tiny gills of the
baetis very well. The partridge matches the natural alternating colors of the real
blue-winged olive legs and tails very well.
Baetis legs and tails are not solid colors.











Our "Perfect Fly" Blue-winged Olive                
 Baetis nymph (one tail missing)
Nymph                                                              Notice the body is 7 mm long or
                                                             .275 inches (quarter inch)


Copyright 2008 James Marsh