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


Fly Fishing Yellowstone - Green Sedges

The Green Sedge is one of the most common caddisflies there are. It is eaten
by trout in its larva, pupa and adult stages of life. These caddisflies are species
of the
Rhyacophila genus and the Rhyacophilidae family of caddisflies. They
prefer fast moving water and are usually eaten by trout throughout the year.

The larvae move about on the bottom of the stream like an inch worm moves on
a tree limb. They are very available for trout when they are searching for food.
These caddisflies are called Rock Worms by many anglers because of their
larvae. It is a segmented worm like creature that looks rather mean because of
is anal claws. They look a lot like the net-spinning caddisfly larvae except they
only have one dark plate near the head whereas the net spinners have two.
They are predators. Unlike many caddisflies they do not build cases or shelters
until the pupation period. The larvae are probably the most important stage of
life as far as anglers are concerned.

These caddisflies consist of many different species. I am not certain how many
exist in Yellowstone National Park but there are several for sure. They exist in
most all of the rivers and streams as well as the surrounding waters outside the

The adults become a factor when they hatch and again when they deposit their
eggs. The problem is the hatch is almost never concentrated and it is difficult to
know when to expect them to hatch because the different species hatch over so
long a period of time. .  

Copyright 2009 James Marsh
Green Sedge Rock Worms