.............................Fly Fishing Yellowstone National Park

Midges - Larvae, Pupae and Adults (Chironomidae)

One thing for sure is that if you are fishing a midge larvae, you are fishing something
that is plentiful in any of the streams in Yellowstone National Park. They are especially
plentiful in streams with soft bottoms but they exist in all of them. Midges have several
generations a year. Normally the larvae are buried in the stream bottom but they come
out and they do get caught in the drift. Trout eat them year-round. They come in just
about every color - reds, green, brown, tan, cream, etc. and about the only way you can
determine which color is best is by trail and error.
Normally I do not like fishing multiple flies. I don't think two is better than one. In the
case of the midge, I can recommend fishing larvae patterns below another heavier fly
not because it provide two opportunities to take trout, but because it add weight to the
otherwise almost weightless fly. The is especially useful in Yellowstone because of the
no-lead rule. Non-toxic weights are just not as heavy as lead and using a heavy fly such
as a stonefly or mayfly nymph, helps sink the fly. You want to keep the fly drifting very
near the bottom.

Trout eat the pupae more than any stage of the midge's life. They are directly exposed
to the trout during the hatch. The pupae slowly reach the surface skim as they drift
downstream. Getting from the bottom to the surface may take them some time and
move the pupae a long distance downstream, especially when they get caught in fast
currents. Once they reach the surface skim their problem becomes getting through it.
That can be a problem in the slick water of pools, eddies and calmer water. Many of
them get eaten by sipping trout trying to get through the surface skim. That is where
you want your imitation to drift. Just under the surface skim.
You may want to use a dry fly in front of the pupa imitation to act as a strike indicator. It
is not easy to detect strikes without an indicator because the trout sip them in so easily.
Otherwise, you may want to use a very small indicator ahead of the fly. If you are not
using an indicator and have problems keeping track of your fly, try moving the fly an
inch or two after it starts the drift to determine exactly where it is. It will leave a tiny wake
that you can easily spot. From then on, if you concentrate on your line and leader, you
can see the strikes affect on the line and leader. The line and leader will pause or
change the way they drift when a trout takes the fly. If you are fishing smooth, slick
water you may be able to actually see the ring or surface disturbance the trout makes
during the take.

Many of the adults have a problem leaving the water in very cold weather. They must
dry their wings before they can fly off. In addition, the process of getting through the
surface skim usually leaves a lot of cripples. There may be quite a few adults on the
surface of the water. Under these conditions, a dry fly imitation of the midge will take
some fish during the hatch, but usually not as many as the pupae imitations.
The adult males and females are on the surface of the water during the time they mate.
They sometimes form clusters mating. When the females lay their eggs, they usually
crawl down into the water and paste them on plants or the substrate. The dead (spent)
males and females collect in eddies and pockets along the bank and behind boulders
where they are often eaten by trout.
If you see a lot of midges on the surface of the water you may try a dry fly imitation of
the adult, otherwise, I would not recommend it.
Again, midges hatch year-round and are eaten by trout year-round. It is just that during
periods of early or late season very cold weather, it may be the only good option for
catching trout.   

Coming Up Next:
Midge - Fly Patterns

Copyright 2008 James