Hatches Made Easy:

Little Black Caddis
1/29/08

The "Little Black Caddisfly" is probably better known from its larva stage. There
are thousands of chimney cases in many of the streams in the park that look
identical to the
Brachycentrus numerosus, a very common species of caddisfly
that exist throughout the Eastern U. S. The Little River has a huge amount of
them, for example. When they hatch they also look identical to the
numerosus
species except for a small tan or green line on the body of the numerosus
species.
Brachycentrus spinae
is the only officially species that I can find listed for the
park. I believe there are other species of the American Grannom in the park. I
realize that there can be very small details to do with specific parts of caddisflies
that make them one species or another. I am not an entomologist and cannot
say for certain, but more importantly, anglers do not really need to. The
differences in appearance and behavior are not obvious enough to see with the
naked eye and I don't believe the trout care one way of the other which species
they are. I am interested in knowing and I will be in contact with some people at U.
T. that I am certain will know. They are doing extensive studies (for non fishing
reasons) on caddisflies.
There is also an
appalachia species that I believe exist in the park but I have no
way of determining that at the present time. The Brachyentridae family of
caddisflies, called the
“Short Horned Caddisflies”. is one of the most
prevalent families of caddisflies found on water that supports trout. The larvae of
these species form dark square cases made of small sticks. I am certain many of
you have seen these chimney cases dangling from rock and anything else they
can attach to in many of the streams.
The species that hatch in the Smokies are usually called
"Little Black Caddis"
elsewhere in the East. They hatch in the early spring about the same time the
Blue Quills and Quill Gordon's hatch. They emerge in the middle of the day very
similar to the way the typical mayfly emerges.  
Species of the
Brachycentrus genus swim to surface when emerging. The
females lay their eggs on the surface of the water or dive to lay them on the
bottom, or use both methods, depending on the species. The major species of
them in the Smokies deposit them on the surface of the water. Trout feed on all
stages; the larva, pupae, adult, and egg layer. Most species inhibit medium
flowing trout streams but they also exist in the moderate sections of fast water
streams.
Practically anywhere else in the nation these same caddisflies hatch, they are
considered a very important hatch. People travel from coast to coast just to fish
the Arkansas River hatch in Colorado each April. We spent a month chasing this
hatch in Colorado six years ago. Throughout the West, hatches of a slightly
different species, the
Brachycentrus occidentalis, that are very hard to tell apart
from the
numerosus species, are considered a very important event. This hatch
is called the "Mothers Day Hatch". They are one species of the same
Brachycentrus Grannoms groups of species that exist here.
I have never heard anyone as much as mention these caddisflies in relationship
to the Smokies although I feel certain they are those that fish the hatch. You will
hear anglers say "Black Caddis" and I guess this is one of the species they are
referring to. There are several other families and genera of black caddisflies,
however, all of which are not even remotely similar in behavior.
Last year there was a huge hatch of these Grannom caddisflies on the LIttle
River that lasted for almost a month. Angie and I caught lots of trout using
emerger imitations during the hatch and adult imitations during the egg laying
process. We will go through this hatch in the coming articles.
Update:
After I had written this, much sooner than I expected, I got a reply from Jason
Robinson, Research Specialist at U. T. I had communicated before with Jason
Robinson though the forum at Jason Neuswanger's excellent site,
www.troutnut.com.

Here is Jason Robinson's reply to my email.
     
Coming Up Next:
Fishing the Little Black Caddis Hatches

Copyright 2008 James Marsh