Hatches Made Easy:

Little Short-Horned Sedges (Glosssoma sp) - Larvae and Pupae

03/02/08

The Little Short-Horned Sedges are one of the most plentiful caddisflies in the
Smoky Mountains National Park. Glossosoma
nigrior is probably the most
common species in the park. I'm sure that anyone who has fished the streams of
the Smokies has seen these caddisflies in both their larva and adult stages of
life. Most anglers would pay them little attention because they are so small. The
adults are tiny black caddisflies with short horns (antennae) as their name
implies. The females are usually a hook size 20 and the males even smaller or a
size 22. The thing that makes them worthy of mention is the fact that they can
hatch in large quantities.

Larvae:
These are saddle case larvae, so named for their horse saddle looking cases.
The larvae get under the saddles however, not on top of them. These are small
domed cases with openings at each end. When they are not bothered, they tend
to stick their heads and legs out of the case. These little cases stick to the rocks
very well and I wonder if the trout ever attempt to eat them when they are in the
cases. They can and do move around on the rocks to feed even though they
are difficult to remove from them.
Although I have read in every fly fishing book that mentions caddisflies that the
larvae of these caddisflies are important in the behavioral drift, I cannot verify
that. I know they come out of their cases and build larger ones and are probably
caught in the currents when they do that. Even though we have taken stream
samples of the drift many times, I have not found any of the little cream looking
worms or larvae of the Little Black Short-horned Sedges in the samples. For that
reason and the fact that I don't know whether or not the trout eat them in their
cases from the rocks, I cannot personally suggest that you fish imitations of the
larvae.

Pupae:
These caddisflies hatch both in the early spring and another smaller hatch
occurs in the fall. We show them on our hatch charts for the Smokies as
hatching in May or early June. I am going to modify that to include April because
According to my records, I have found them in April. I did not catch this error
until I started writing this article.
The hatch last a long time and can vary in intensity. If you start seeing a lot of
them crawling around on the rocks and banks you will know they have hatched.
Unfortunately, that is usually too late to fish the pupa stage of the hatch. That
would indicate many of them had already hatched.
These caddisfly pupae use their middle legs to swim to the surface. They can
hatch on the surface but more often, they run on the surface to the banks or
rocks to hatch into adults out of the water. You see this activity occurring often.
Again, even though I have read that it is important to imitate this stage of the
hatch, I have not experienced any results from trying to do so on the few
occasions I have tried. I think that is most likely just a matter of timing. Most
likely, when I attempted to imitate the hatch the majority of them had already
become an adult.
You can certainly try fishing the pupae stage of the hatch. I just cannot
personally recommend it as a results of my own experience. This is disturbing in
a way because on several occasions I have seen hundred if not thousands of
the adult caddisflies on rocks and the banks of the streams in the Smokies. I
would like to hear from any of you that have been successful fishing the pupa or
larva stage of this hatch.

Coming Up Next:
Little Black Short-horned Sedge - Adults and Fly Pattern Colors

Copyright 2008 James Marsh