|....................... ......Fly Fishing Yellowstone National Park
Fishing Cold Water - Part Nine - Midges
It's usually difficult to determine if a midge hatch is actually underway. The light
has to be just right for you to see them. I cannot see much of anything within
three feet of me, but I have good vision at a distance. Even so, I still have a
difficult time determining if a midge hatch is actually occurring. When everything
is right from a lighting standpoint, you may see a midge hatch going on right
where you had been looking at the water under different lighting conditions
without seeing anything hatching. Sometimes there's just not enough light to
determine what's going on with midges. You can see them much easier after
they hatch and of course, that tells you a hatch occurred but it's important to
know if it is in progress or if it has ended.
There are other reasons for the difficulty in determining if a hatch if underway.
One is the ultra small size of some of the midges. Anglers commonly tie midges
down to a hook size 32. A size 32 hook is so small there's hardly room for the
gap in the hook. You would think that's small enough but the facts are midges
exist in even smaller sizes. There are over a thousand (1000) species of them
that are found in streams that trout can exist in. It's estimated that there are over
10,000 species world-wide. Entomologist have found over a hundred species of
Chironomid midges on many of the trout streams that have been examined.
Some slower moving, fertile trout streams have even more species.
We have observed midges from the streams of Yellowstone many times, some
times deliberately and sometimes because it was almost impossible to collect
nymphs and larvae in a net without getting midge larvae in it. We normally
place the mayfly and stonefly nymphs and caddisfly larvae, one at a time, into a
white dish to separate and identify them. When we do we always find some
midge larvae and pupae in the dish. They are so tiny it's almost impossible not
to get any of them into the dish. By the way, everything is always put back in the
streams. We never have removed any insect from a stream in the park.
Almost all of the midge larvae and pupae are various shades of light green,
cream or red. The pupae usually have dark wing pad areas but other than that,
they all look about the same. Some are segmented but it's is usually very
subdued shades of those same colors. I don't think it's necessary to have a lot
of different colors of midge patterns and I'm certain in most cases it's a
disadvantage to have those with bead heads, especially if they are bright or
flashy. The only advantage is the added weight of the bead head may help. I
think it is a disadvantage to have any that are bright like some that are tied with
wire, tinsel, etc. I suggest using something plain and in shades of light green,
cream or red. They red ones exist more where there's soft soil on the bottom
and around the banks.
Since there's little difference in the pupae and larvae, I don't think it's critical
which imitation you try first or maybe even which one you use. You are better off
using the right imitation but unless there's evidence of a hatch, there's no
reason to use a pupae imitation. The results probably has more to do with
where you place the fly, meaning up in the water column like the pupae would
be found, or on the bottom like the larvae would be found.
Midge pupae have a difficult time getting through the surface skim in the usual
calm to slow moving water they hatch in. They suspend just below the surface
skim where they are easily picked off by trout and other fish.
If you do happen to see them hatching, fish the pupae imitations. If you don't, I
would still suggest that you try a pupa imitation but only after you had failed with
a larva imitation fished on the bottom. Fish the larvae imitation the same way
you fish a nymph. Use added weight above the fly about eight inches or more
and get the fly on the bottom.
When you fish imitations of the pupae you have several options, but I suggest
fishing it from the bottom all the way to the surface. One method is to fish
without anything but the fly tied on. Grease the leader and tippet and watch your
leader and line for takes.
Another method is to add a small strike indicator above the fly and fish it on the
dead drift. I don't particularly care for this method but many anglers use it
Yet another method is to fish it the same way you would a caddisfly pupa pattern
or down and across, allowing it to rise back to the surface at the end of the drift.
Another way is to fish it behind a larger dry fly. This works great if the trout are
feeding on the pupae high in the water column or just under the surface.
Most of the time, I fish them without anything attached - weight or indicator. I
allow the fly to sink, helping it do so by mending the line. Most of the strikes
occur as the current brings the fly back to the surface.
Of course, I have omitted discussing the dry fly or adult midge imitation. I'm
certain the trout eat them, but I would want to observe the trout rising to them
before I wasted any time fishing an adult imitation. I would guess that we have
caught about sixty percent of the trout we have caught on pupae imitations. I
would guess maybe thirty percent came on larvae imitations. Probably less than
ten percent were caught on adult imitations. That may have more to do with
which fly we fished than what they would have eaten, so I wouldn't place a lot of
importance on that. What I am certain of is that you can catch trout on imitations
of them if you will simply put forth the effort.