Little Black Caddis - Adults
|.............................Fly Fishing Yellowstone National Park
Newly Hatched Adults:
The newly hatched adults are sometimes eaten on the surface before they depart the
water. As I said in the previous article, I think many more pupae are eaten than adult
but that does not mean that the trout will not take a dry fly imitation of the adults. They
will certainly do just that. Many anglers use the dry fly exclusively during the hatch.
The occidentalis body is a dark gray/brown color with a green or tan line on it. Wings
are gray with black veins showing. These caddisflies are normally imitated using a size
14 to 16 hook. The males are one hook size smaller than the females. Normally the
water is fairly cold, approximately 50 degrees, when the Grannoms hatch. They do ride
the water for a short time before they fly off to the banks.
Sometimes it is so cold in the mornings during the hatch, that the adults are almost
dormant. I have seen many occasions when you could pick up several of them off of the
rocks and plants when they made no effort to fly off. It is usually mid-afternoon on the
cold days after a hatch has started before the adults start flying. On these cold days,
the hatch will start during the warmest part of the day.
As mentioned before, the adult females usually start the egg laying process prior to the
end of the hatch. For some time, maybe an hour or two, there are usually a lot of
caddisflies on the water. The females either deposit their eggs on the surface of the
water or they dive and deposit the ball of eggs they carry. The trout eat them in both
Fly patterns have been developed for both types of egg layers - wet fly to imitate the
divers and a dry fly to imitate those that deposit their eggs on the surface. There are
also spent patterns for the adults that have died and are floating on the water. You
have your choice of three different ways to imitate the adults.
When the egg laying first starts, the most productive fly is probably still the pupa
imitation. At some point, the hatch will stop and things change. At that time I suggest
you try a dry imitation of the female egg layers. You should fish this in a dead-drift
fashion where you see the most activity. If this doesn't work very well, I suggest you
change to a wet imitation and try that. I would fish the wet fly down and across. Most of
the time the dry fly will work great but factors such as the water and air temperature can
affect this activity and results.
Very late in the day near dark there may be a lot of spent caddisflies on the water. They
usually collect in the eddies and slow, calm pockets along the banks. If the dry or wet
imitation of the egg layers is not producing well, and you notice spent caddisflies on the
water, then you may want to try a spent imitation.
Coming Up Next:
LIttle Black Caddis - Fly Pattern Colors
Copyright 2008 James