Hatches Made Easy:

Blue-winged Olives - Duns and Spinners
January (1/12/08):

Dun:
Baetis duns have two tails with a very tiny hind wing. Some species do not have
a hind wing at all, but this minor difference is not important at all and we point it
out, just for identification purposes. Like the name implies, the bodies of most
duns are a green or emerald - olive color with gray highlights and the wings are
a shade of gray.

Dun Presentation:
Some of the early hatches or first of the bi-brooded hatches, the duns have a
little trouble drying their wings in preparation to fly away. That means the duns
will ride the surface for a few feet. Now to simplify this, everything we said in the
last post relative to the emerger presentation applies to the dun imitation, except
it is fished dry on the surface. This is very demanding trout fishing. If the skies
are very overcast, or it is raining or snowing, then there may be a lot of the
olives on the surface. You may even need to concentrate on individual rising
fish. Remember, these duns want be in the fast water (unless they are trapped
and carried downstream), they will be in the slow to moderate speed water. Go
back and read the
emerger presentation. We have had more success with the
dun patterns during this hatch than anything, including the nymphs. This may be
because we like the dry fly over nymphs but we usually try to fish the most
productive way. Sometimes, in cold water, we have noticed that they simply will
not hit the dry imitations even though you see them on the surface. If this
happens, we go to the nymph. We just don't fish it on the bottom. We grease it
up and float it in the surface skim.

Spinner:
Before we start, some of you may not even know what a spinner is. When
the mayflies hatch into duns and fly off into the bushes, they will change stages
of life into what anglers call spinners. They become sexually mature in layman
terms. They actual shed their outer covering. They become brighter in color and
actually change colors. The legs and tails usually become much longer and the
wings become transparent. They mate and the males quickly fall to the banks
and on the water to die. The females fly off into the bushes again and when
ready (from a few hours to the next day or two, depending on many things) they
return to the water to deposit their eggs. Most of them dive and deposit them on
the bottom, plant stems and rocks. Some deposit them on the surface and a few
even drop them from the air. When they finish depositing their eggs, they too
began to die and fall on the water. As soon as these males and female spinners
die, their wings become spent or lie flat on the water.

Some anglers consider the spinner of little or no importance, not having seen
spinner falls of little olives in great numbers. In the Smokies, this includes us. For
one reason, many times (depending on the time of year) this occurs very late in
the afternoons and even into the evenings. In cold weather, they can occur
earlier during the day. In hot weather, they may occur in the early mornings.
Spinner falls depends greatly upon the specific water involved but is directly
comparable in size to the hatch. The female usually dives under the water to lay
her eggs but may also crawl in from the shoreline. When she is finished, she
washes away with the currents sometimes beneath the surface and sometimes
floating on the surface. This is why we have a pattern for the diving spinner and
one for the spent wing spinner but we will discuss flies later.

Spinner Presentation:
The blue winged olives are very difficult to see, especially in low light conditions.
This may account for the fact that many anglers think the spinner fall of olives is
not very important. They simply do not notice them.
You can rig to imitate the spinner as a dropper behind or near the surface of a
more visible dry fly. This is helpful in seeing the small flies. You can also try
fishing the spinner dry. Let the trail and error method determine which method
you use. All in all, we have had little success in the Smokies with Blue-winged
olive spinner falls. That may not always be the case. It may be a result of the
times, places and way we have approached it. It may be that we haven't noticed
them. When we have taken samples from the surface skim with our nets (we
have a permit for this from the National Park Service), we have found lots of the
spinners near dark and early in the morning following hatches.
If you see the
baetis diving (hitting the water like some caddisflies do to deposit
their eggs), you should try a diving pattern. Again, this will take place at the ends
of the long runs, heads and tails of the pools, eddies, calmer pockets and in
general slow water -not the fast water.
If you find spent flies on the water that have collected in calm areas, then you
should try the spent pattern of the olives. They are almost impossible to see, so
keep that in mind. Most likely you could spot the trout sipping them for the slow
water much easier than find the spinners on the water.
In the Smokies, we have had little luck with this. In Yellowstone's Madison and
Firehole rivers, for example, we have had great results. We think it is a matter of
the intensity of the hatches and they are usually far more prolific in Yellowstone.
We would appreciate any helpful information that any of you may pass on to us
and our readers.

Summary:
This hatch is usually a matter of being at the right place at the right time. Just be
prepared with imitations of the nymphs, emergers, duns, diving or wet patterns
to match the egg layers and spent spinners.  
Don't fish these patterns in the fast water. Concentrate on the slow water areas.
Again, this is not an easy hatch to fish, especially when there are only a few flies
here and there. Most of the water in the Smokies is more suited for clinger
nymphs. The little swimming nymphs are only found in isolated areas of the
streams. Sometimes this is only a few large pockets behind boulders and along
the banks. The end or tail-outs of riffles may also produce.
Another big point to remember, is often when they are hatching, it is the only
thing that is hatching. This is especially true in the cold water seasons.  In those
cases, the Blue-winged Olives may become very important.

Coming Up Next:
Blue-winged Olives - Fly Patterns

Copyright 2008 James Marsh