Cased Caddis are plentiful in the
all the streams of Yellowstone.
all the streams of Yellowstone.
Little Black (Short Horned)
Caddis Adults are not the most
important stage of this insect -
the pupae are. It is much more
productive to fish an imitation of
the pupa than the adult of this
species.
Caddis Adults are not the most
important stage of this insect -
the pupae are. It is much more
productive to fish an imitation of
the pupa than the adult of this
species.
Caddisflies:
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| .............................Fly Fishing Yellowstone National Park |
American Grannom:
Brachycentrus species of
caddisflies are among the most
overlooked insects that trout feed
on in the park. The adults of this
species are known as "Little
Black Caddis". Species of this
same genus are also known as
the "Mothers Day Hatch" in some
locations because they hatch in
the Spring near Mothers Day.
Don't confuse these with the Tiny
Black Caddis. They emerge
entirely differently.
Brachycentrus species of
caddisflies are among the most
overlooked insects that trout feed
on in the park. The adults of this
species are known as "Little
Black Caddis". Species of this
same genus are also known as
the "Mothers Day Hatch" in some
locations because they hatch in
the Spring near Mothers Day.
Don't confuse these with the Tiny
Black Caddis. They emerge
entirely differently.
Caddisflies, especially the net-spinning
species are very plentiful in Yellowstone. The
leaf shredders, free-living, and predator
caddisflies are also present. There are many
different genera with numerous species that
can be found in the park. It is important to be
able to recognize which ones are fairly prevalent
and which ones are usually not.
Most anglers do not recognize a caddisfly hatch
until it is too late to do them any good. They wait
until they spot the adults flying around the banks
or on the stream side vegetation before they
make any effort to imitate them. At that point in
time they may never even touch the water. After
they have hatched the only time they are going
to be important to the angler is when the
females deposit their eggs. This may be a day
or several days away. This may occur at night
and often does. They can attempt to deposit
their eggs several times, repeating the action.
They deposit their eggs sometimes from the air
and don't touch the water. Some species crawl
into the water from the banks and rocks to
deposit their eggs on the bottom. Many of them
dive and paste them on the bottom. Others drop
them by touching the water.
Some of them swim to the surface and hatch
similar to a mayfly. Others emerge on the
bottom and swim to the surface to fly away. Still
many of them crawl out of the water on the
bottom and up on rocks, sticks or the bank to
hatch. Some of them even swim to the surface,
hatch and run to the banks on the surface of the
water. Unless you know which way the
particular species of caddisfly emerges and
how it goes about depositing its eggs, you are
guessing at trying to imitate its behavior. Tying
on an elk hair caddis and fishing it dead drift
works in about 10% of the cases where adult
caddisflies are observed and doesn't work in
about 90% of the cases.
Little Black Caddis:
One of the most important hatches in the park is
the Little Black Caddis usually called the
"Mothers Day Hatch" in many other places.
These are Brachycentridae family occidentalis
species of the Brachycentrus genus. During the
winter or early spring you can observe the
chimney cases attached to rocks in the stream
in most of the streams.
These caddisflies hatch when the water is 48 to
52 degrees F., during the afternoon in a manner
similar to mayflies. This hatch can last up to a
month or more depending on weather stability.
Some streams eliminate this hatch from
anglers with the runoff which occurs at the
same time.
The pupae swim to the surface and hatch into
adults. The adult caddis ride the water a short
time and fly away. They deposit their eggs by
touching the water with their abdomens, so
catching trout during the ovipositing period is
very productive. This usually occurs from
mid-afternoon until dark.
These caddisflies are a hook size 16 or 18,
depending on their sex, in all 3 stages of life.
Another species of this genus, the americanus,
emerges much later in the year. This hatch
occurs in the later part of summer. The
emerging and egg laying activity is very similar
to the first hatch.
Green Sedge:
The Green Sedge, sometimes called the Green
Rock Worm because of its larva stage, can
occasionally be found in some of the park's
streams. The Green Sedges or Rhyacophila
species also usually hatch in sparse numbers.
The Green Sedge rock worm or larvae are free
living larvae that are readily taken by trout. They
do not build cases except the short period of
time when they change to the pupae stage.
They are available throughout the year. There
are several species of them in the park. They
range in hook size from 14 to 18. You will find
them in the fast water and riffles. The larva
stage is by far the most important stage to
imitate. The adult stage of this mayfly is rarely
found in numbers large enough to justify
imitating. It is best to imitate the larvae stage of
the Green Sedge.
Little Black (Short-Horned Sedges) Caddis:
Little Black Caddis, also called Short-Horned
Sedge, are fairly plentiful in some of the
streams. These are saddle cased larvae. You
will find the Glossosoma montana species to be
the most important and plentiful. They are
about a hook size 20 to 22. The emergers are
the most important stage because they emerge
mid-stream and stay on the water until they get
to the banks. They dive to deposit their eggs.
You would imitate this with a wet fly imitation.
Tiny Black Caddis:
Micrasema bactro, called Tiny Black Caddis, are
occasionally found in some of the park's
streams. These are a hook size 20. These
crawl out of the water usually on rocks to hatch
during the day and deposit their eggs in the
afternoons. They hatch when the water is about
45-50 degrees.
Spotted Sedges:
You will find that the net-spinning caddisflies
are by far the most important of the caddisflies
in Yellowstone. These are mostly Hydropsyche
species called Spotted Sedges.
The pupa stage is the best stage of life to
imitate. The egg ovipositing can also create
some action from the trout. This happen just
before and after dark. These are a hook size 16
to 18.
Little Sister Caddis (Little Olive Sedge):
Cheumatopsyche species or Little Sister
Sedges also hatch in some of Yellowstone's
streams. These are also net-spinning
caddisflies. It is best to imitate the pupae stage
of this caddisfly. The egg layers can be imitated
effectively just before dark. These are a hook
size 20-22.
Great Gray Spotted Sedge::
The Arctopsyche grandis, called the Great Gray
Spotted Sedge, are present in some of the
park's streams. This is a large caddisfly, usually
a hook size 10 The problem with them for
anglers is that they both emerge and deposit
their eggs during the night.
Long Horn Sedges:
The Oecetis genus of long horn caddisflies
have species that are prevalent on some
streams in Yellowstone. There is both a spring
and a fall emergence of these caddisflies. We
have seen these long horn caddisflies on the
Madison, Firehole, all the stream feeding into
Yellowstone Lake and the upper Yellowstone
River. These are a hook size 16.
White Miller:
The Nectopsyche species, or White Miller,
emerges on some rivers, especially the
Firehole and Madison. It has two emergences,
one in the spring and another in the late
summer and early fall. This hatch last a long
time and is very prolific. The trout eat the
emergers and the egg layers. Hook size 16.
Click on the image to enlarge.
Note that this appears to be tan and in fact it
looks more like the Oecetis than the white or
cream colored White Miller but it is a White
Miller in dim light.
Speckled Peter:
The Helicopsyche borealis is a small caddisfly,
about a hook size 20, found for the most part in
the Madison and Firehole Rivers.
Little Brown Caddis:
The Lepidostoma pluviale or Little Brown
Caddisfly hatches for about a month on some of
the streams in the park. This caddisfly emerges
in the evenings. They are a hook size 18.
Great Silver Stripped Sedge:
There are some Hesperophylax species,
mainly designatus, that exist on certain streams
in the park. We have seen these during the
month of August on Pelican Creek and the
Yellowstone River. They are a very large
caddisfly, about a hook size 8.
Others:
There are several other species of caddisflies
found in the park but none of them that we have
encountered hatch in large quantities. If you
have larva, pupa and adult imitations of the
above caddisfly species we feel sure you will
have something close enough to imitate any of
the other species you may encounter.
Copyright 2007 James Marsh
species are very plentiful in Yellowstone. The
leaf shredders, free-living, and predator
caddisflies are also present. There are many
different genera with numerous species that
can be found in the park. It is important to be
able to recognize which ones are fairly prevalent
and which ones are usually not.
Most anglers do not recognize a caddisfly hatch
until it is too late to do them any good. They wait
until they spot the adults flying around the banks
or on the stream side vegetation before they
make any effort to imitate them. At that point in
time they may never even touch the water. After
they have hatched the only time they are going
to be important to the angler is when the
females deposit their eggs. This may be a day
or several days away. This may occur at night
and often does. They can attempt to deposit
their eggs several times, repeating the action.
They deposit their eggs sometimes from the air
and don't touch the water. Some species crawl
into the water from the banks and rocks to
deposit their eggs on the bottom. Many of them
dive and paste them on the bottom. Others drop
them by touching the water.
Some of them swim to the surface and hatch
similar to a mayfly. Others emerge on the
bottom and swim to the surface to fly away. Still
many of them crawl out of the water on the
bottom and up on rocks, sticks or the bank to
hatch. Some of them even swim to the surface,
hatch and run to the banks on the surface of the
water. Unless you know which way the
particular species of caddisfly emerges and
how it goes about depositing its eggs, you are
guessing at trying to imitate its behavior. Tying
on an elk hair caddis and fishing it dead drift
works in about 10% of the cases where adult
caddisflies are observed and doesn't work in
about 90% of the cases.
Little Black Caddis:
One of the most important hatches in the park is
the Little Black Caddis usually called the
"Mothers Day Hatch" in many other places.
These are Brachycentridae family occidentalis
species of the Brachycentrus genus. During the
winter or early spring you can observe the
chimney cases attached to rocks in the stream
in most of the streams.
These caddisflies hatch when the water is 48 to
52 degrees F., during the afternoon in a manner
similar to mayflies. This hatch can last up to a
month or more depending on weather stability.
Some streams eliminate this hatch from
anglers with the runoff which occurs at the
same time.
The pupae swim to the surface and hatch into
adults. The adult caddis ride the water a short
time and fly away. They deposit their eggs by
touching the water with their abdomens, so
catching trout during the ovipositing period is
very productive. This usually occurs from
mid-afternoon until dark.
These caddisflies are a hook size 16 or 18,
depending on their sex, in all 3 stages of life.
Another species of this genus, the americanus,
emerges much later in the year. This hatch
occurs in the later part of summer. The
emerging and egg laying activity is very similar
to the first hatch.
Green Sedge:
The Green Sedge, sometimes called the Green
Rock Worm because of its larva stage, can
occasionally be found in some of the park's
streams. The Green Sedges or Rhyacophila
species also usually hatch in sparse numbers.
The Green Sedge rock worm or larvae are free
living larvae that are readily taken by trout. They
do not build cases except the short period of
time when they change to the pupae stage.
They are available throughout the year. There
are several species of them in the park. They
range in hook size from 14 to 18. You will find
them in the fast water and riffles. The larva
stage is by far the most important stage to
imitate. The adult stage of this mayfly is rarely
found in numbers large enough to justify
imitating. It is best to imitate the larvae stage of
the Green Sedge.
Little Black (Short-Horned Sedges) Caddis:
Little Black Caddis, also called Short-Horned
Sedge, are fairly plentiful in some of the
streams. These are saddle cased larvae. You
will find the Glossosoma montana species to be
the most important and plentiful. They are
about a hook size 20 to 22. The emergers are
the most important stage because they emerge
mid-stream and stay on the water until they get
to the banks. They dive to deposit their eggs.
You would imitate this with a wet fly imitation.
Tiny Black Caddis:
Micrasema bactro, called Tiny Black Caddis, are
occasionally found in some of the park's
streams. These are a hook size 20. These
crawl out of the water usually on rocks to hatch
during the day and deposit their eggs in the
afternoons. They hatch when the water is about
45-50 degrees.
Spotted Sedges:
You will find that the net-spinning caddisflies
are by far the most important of the caddisflies
in Yellowstone. These are mostly Hydropsyche
species called Spotted Sedges.
The pupa stage is the best stage of life to
imitate. The egg ovipositing can also create
some action from the trout. This happen just
before and after dark. These are a hook size 16
to 18.
Little Sister Caddis (Little Olive Sedge):
Cheumatopsyche species or Little Sister
Sedges also hatch in some of Yellowstone's
streams. These are also net-spinning
caddisflies. It is best to imitate the pupae stage
of this caddisfly. The egg layers can be imitated
effectively just before dark. These are a hook
size 20-22.
Great Gray Spotted Sedge::
The Arctopsyche grandis, called the Great Gray
Spotted Sedge, are present in some of the
park's streams. This is a large caddisfly, usually
a hook size 10 The problem with them for
anglers is that they both emerge and deposit
their eggs during the night.
Long Horn Sedges:
The Oecetis genus of long horn caddisflies
have species that are prevalent on some
streams in Yellowstone. There is both a spring
and a fall emergence of these caddisflies. We
have seen these long horn caddisflies on the
Madison, Firehole, all the stream feeding into
Yellowstone Lake and the upper Yellowstone
River. These are a hook size 16.
White Miller:
The Nectopsyche species, or White Miller,
emerges on some rivers, especially the
Firehole and Madison. It has two emergences,
one in the spring and another in the late
summer and early fall. This hatch last a long
time and is very prolific. The trout eat the
emergers and the egg layers. Hook size 16.
Click on the image to enlarge.
Note that this appears to be tan and in fact it
looks more like the Oecetis than the white or
cream colored White Miller but it is a White
Miller in dim light.
Speckled Peter:
The Helicopsyche borealis is a small caddisfly,
about a hook size 20, found for the most part in
the Madison and Firehole Rivers.
Little Brown Caddis:
The Lepidostoma pluviale or Little Brown
Caddisfly hatches for about a month on some of
the streams in the park. This caddisfly emerges
in the evenings. They are a hook size 18.
Great Silver Stripped Sedge:
There are some Hesperophylax species,
mainly designatus, that exist on certain streams
in the park. We have seen these during the
month of August on Pelican Creek and the
Yellowstone River. They are a very large
caddisfly, about a hook size 8.
Others:
There are several other species of caddisflies
found in the park but none of them that we have
encountered hatch in large quantities. If you
have larva, pupa and adult imitations of the
above caddisfly species we feel sure you will
have something close enough to imitate any of
the other species you may encounter.
Copyright 2007 James Marsh
The net spinner's larvae are
small as you can see from this
one in my hand. Trout will take
them in a three stages of life.
small as you can see from this
one in my hand. Trout will take
them in a three stages of life.
Great Gray Spotted Sedge is a
very large caddisfly that is
common in Yellowstone.
very large caddisfly that is
common in Yellowstone.
Some species of caddisflies
crawl into the water to deposit
their eggs.
crawl into the water to deposit
their eggs.
Adult Caddisflies are often
difficult to identify even down to
the genus level. You get a much
better opportunity of identifying
them in their larvae stage of life.
difficult to identify even down to
the genus level. You get a much
better opportunity of identifying
them in their larvae stage of life.
The Chimney Case Caddis or
the American Grannom.are
easy to identify.
the American Grannom.are
easy to identify.
Net spinning larvae have 3 dark
plates behind their heads. They
feed from a silk thread strung out
from their little houses.
plates behind their heads. They
feed from a silk thread strung out
from their little houses.
Rock Worms are the larva stage
of the Rhyacophila family. These
are free-living caddis. The adults
of these are called Green Sedges
and are not as important as the
larva or pupa stage. You can
easily tell these from the
net-spinners. They only have one
dark plate behind their heads.
The net-spinners all have three.
of the Rhyacophila family. These
are free-living caddis. The adults
of these are called Green Sedges
and are not as important as the
larva or pupa stage. You can
easily tell these from the
net-spinners. They only have one
dark plate behind their heads.
The net-spinners all have three.
There are many species of
caddisflies that exist on streams
in Yellowstone that are not very
plentiful. This little tan colored
adult is one of a few we have
found that we are not certain of
as to species.
caddisflies that exist on streams
in Yellowstone that are not very
plentiful. This little tan colored
adult is one of a few we have
found that we are not certain of
as to species.
Thumbnails - Click to enlarge
Thumbnails - Click to enlarge