Little Black Caddis
|.............................Fly Fishing Yellowstone National Park
The "Little Black Caddisfly" is probably better known from its larva stage. The chimney
cases they exist in (see image below) are very unique. The hatch is probably better
know by it name, the "Mothers Day Hatch". They may hatch on Mothers Day in some of
the streams in Yellowstone National Park, but the fishing season is closed at that time.
The Little Black Caddisflies will be hatching in some of the streams when the season
first opens. The Firehole and Madison Rivers both have hatches of the Little
Black Caddis that will most likely be occurring when the season first opens. It
can last until the first of July. In some of the streams in Yellowstone, fishing the hatch
may be affected by the Spring runoff.
The "Little Black Caddis" is the Brachycentrus occidentalis, if you care to know the
scientific name of the insect. There is another species in the park, the Brachycentrus
americanus, that hatches in some streams in the park during July and August, but it is
usually not very intense. At that time of the season, many other far more important
species of aquatic insects as well as the terrestrials, are available for the trout to eat.
For that reason, we will not include any detailed information regarding fishing the
The Brachyentridae family of caddisflies, called the “Short Horned Caddisflies”, which
includes the Brachycentrus genus, is one of the most prevalent families of caddisflies
found on water that supports trout. If it were not for the late date of the opening of the
season in the park and for the effects of Spring runoff, it would probably be considered
one of the top hatches in the park. About the only good part is that except for the Blue-
winged Olives, there is little else hatching at the time the Little Black Caddis hatch when
the season first opens. This means that if conditions are right, on some streams, the
Little Black Caddis hatch can still be significant. If you fish Yellowstone during the first of
the season, you should be prepared to fish this hatch.
Coming Up Next:
LIttle Black Caddis - Larvae
Copyright 2008 James Marsh
The chimney cases the Little
Black Caddis live in during the
larva stage of life, amaze me.
These larva can crawl around
extremely well. They remind me
of little motor homes.