Spotted Sedge
.............................Fly Fishing Yellowstone National Park


04/16/08

The spotted Sedge or species of the
Hydropsyche genus of caddisflies, is one of the
most important aquatic insects in Yellowstone National Park. It may be the most
important aquatic insect in the park. It certainly rivals the Blue-winged Olives and
Pale Morning Duns. One reason it is so important is its lengthy hatch time. You will find
them on the water of the various streams in the park for about the entire season. We
show them starting to hatch on the Firehole River as early as the opening of the
season.Another reason they are important is their sheer numbers. At times some of the
streams
are covered with Spotted Sedges.
The final part of the hatch, the egg laying activity, doesn't occur until very late in the
day. It is usually well after sunset and sometimes as late as almost dark before the
caddis really get started depositing their eggs. The advantage of this as I see it, is that
you can fish very late in the day after other hatches have ended. There maybe some
mayfly spinner falls going on at the same time, but basically, this just makes for a full
dayof fishing.
Nationwide, the Spotted Sedge is considered the most important caddisfly there is. It
is estimated that they represent as much as half of the caddisflies eaten by trout. I
would guess that is true of Yellowstone National Park.
Don't come to Yellowstone without being prepared to imitate the Spotted Sedge. I
suggest that you be prepared to imitate three stages of life - the larva, pupa
and adult. In the upcoming articles, we will cover the detail of imitating the
Hydropsyche
caddisflies or Spotted Sedges, whichever you like to call them.  

Coming Up Next:
Spotted Sedges -
Hydropsyche species - Larvae

Copyright 2008 James