With the heart of winter at our doorsteps, many
fly fishers are counting down the days until they
can get out and wet a line again, while others are
fishing the one bug that hatches year round, the
Fishing the San Juan River, I have learned just
how important midge patterns can be. Midges are
the main staple on this and many other rivers,
especially during the winter season in the southwest.
Midges can be identified by one distinct feature - the
fact that they have two wings. These "true flies"
belong to the order Diptera, family Chironomidae.
While doing research for this article, I found
that a majority of the rivers I read about have
some form of midge hatching throughout the year.
From the Yakima River in Washington to the Yellow
Breeches Creek in Pennsylvania, midges are an
abundant source of food giving trout thousands
of opportunities to eat during the day.
The simplest way to find out whether midges are
hatching in your home waters is to look. This
can be done in many ways; a panty hose sock over
your hand, some type of seine whether it be home
made or purchased from a shop, or just turning
over a rock. Another way of determining what is
in the river is pumping a trout's stomach, but
I do not recommend this method, as it can be harmful
to the fish. However, by looking for this tiny bug,
you can only help increase your catch rate.
The first place to look for midges is near the riverbed,
where most fish are found feeding during the beginning
and end of the day, or in between hatches. With no
prominent hatch occurring, trout are feeding on what
is most available to them.
Once an adult lays the eggs in the water, the
first stage this bug can be found in is the larval
form. Once they have been dislodged from the riverbed,
they wiggle frantically in the current, making them
an easy meal for the trout. The most effective way
of fishing this stage is to use some type of weight
12-18" from your flies, helping you get your flies
in the area the fish are feeding. Although this may
sound easy to do, on the San Juan River, it is vital
to find the exact depth the fish are feeding. Because
midges are so abundant, if you do not get your flies
directly in the feeding lane, you will not have much
success. Trout do not expend much energy to feed on
midges because more are right behind and will be
much easier to eat.
Larvae can be found in various colors as well, with
red being the most productive pattern I have fished.
The other colors include gray, olive, cream, black
and gray with a slight segmentation also present.
The sizes of these range from 4-15mm (#16-26 hook
size) and are also very thin. A great imitation of
this pattern is the simple
Red Thread Larva.
After the larval stage is complete, midges then enter
the pupal stage, where tiny air bubbles are trapped
in the body of the insect and help them slowly rise
to the surface. Because they rise slowly, this makes
them available to feeding trout once again. It may
take a few tries to reach the surface, as the pupa
form can bob in the current until completely riding
just underneath the surface where they wait to emerge
as an adult. Fishing this stage of the midge can be
done in various ways; weight can be used to place the
fly in a certain area, or you can fish it just underneath
the surface as a trailer from an adult form.
Like the larvae form, pupae can be found in various
colors such as brown, black, gray, olive and cream.
There is also a slight segmentation, but the distinct
difference is the prominent thorax that has formed,
giving the bug a tapered look. Many pupae also go
through a complete color change during this stage.
Pupae are often shorter and a bit thicker, being
found in sizes 4-12 mm (#18-26 hook size). Imitations
for this stage of the life cycle can be a miracle midge,
black beauty or trojan midge.
The next stage is in between the pupal and adult stage,
which is the emergence. This is not actually a classified
stage in the life cycle, but when fishing I consider it
one of the most important and key times to fish the midge.
Once the pupae begin their emergence from the riverbed,
they shed the shuck or tube they have been developing
in and ride in the surface film waiting for their wings
to dry. In my opinion, because they are so vulnerable
at this stage, fish key in on this stage more than any
other during the peak of a hatch. You can see trout
breaking the surface with their dorsal fin as they
cruise along sipping on the thousands of emerging
midges trapped in the surface film.
The same colors found in the larval and pupal stage
can also be found in this stage. And like the pupal
form, the thorax can still be prominent and a trailing
shuck, segmentation and wings or gas bubble can also
be found. The size is also similar to the pupal stage,
with most bugs being in the 4-12 mm range (#18-26 hook
size). The pattern I like to use to imitate this stage
is a zebra midge with a trailing shuck made from grizzly
hackle fibers to give the appearance of a segmented shuck.
This can be fished with weight to simulate the rise to
the surface, with a greased leader to keep the fly right
at the surface, or trailing a larger adult pattern as a
dry-dropper. One other way of fishing this pattern is
by letting the fly swing at the end of a dead drift,
to also imitate the emergence of the bug. Other popular
emerger patterns that produce well are the Johnny Flash,
foam-wing emerger and WD-40.
The final stage of the midge life cycle is the adult
stage, where six legs have formed along with the two
wings. Once the midge has left the water, their main
goal is to mate and return to the water where they
will deposit their eggs. Because they return to the
water, they become vulnerable once again to fish
feeding on adults. Another reason trout key in on
this stage is because midges are found in clusters,
which makes for an easy meal.
Like the other stages, adults are also found in the
same colors (black, brown, gray, olive and cream) and
range in size from 4-12 mm (#18-26 hook size). Adults
are fished like any other dry fly pattern, but the most
productive method is to cast to rising fish after timing
each rise. Patterns I like to use to imitate the adult
stage are cluster midges or griffith's gnats as well as
biot midge adults.
Although it is fun to fish the adult stage, I always
trail some type of emerging midge behind an adult to
increase my chance of hooking into a trout.
Even though I have named a few patterns for each stage,
there are thousands more that can be fished in the same
manner that will help you catch picky trout on many
waters throughout the U.S. Searching the internet for
midges is as simple as looking for them on the waters
you fish. A few sites I always like to turn to for
such patterns are,
www.danica.com/flytier/ as well as many others.
A great book that has many patterns with simple
tying techniques is Don Holbrook and Ed Koch's
Midge Magic. But the best way for
you to find what midge patterns will work best
on your home waters is to get your hands wet and
play with the bugs! ~ Jeremy
Credits: Photos of the real insects
were taken by Mike Mora of
For more on Midges see: Midges - Diptera