.......................  ....................  ...Fly Fishing Yellowstone National Park
New KISS Bug Series - Part 60

Little Sister Caddisfly

The Little Sister adult Caddisflies become important when the females are depositing their eggs. They do
this on the surface of the water, or by diving to the bottom. It depends on the particular species of the
caddisflies called Little Sisters. If they paste the eggs on the bottom, the caddisflies rise back to the surface
to drift in the current and die, or in some cases, to fly away to repeat the process later.

The Little Sister caddisfly egg laying activity can occur at the same time they are emerging. The egg laying
usually starts near the end of the emergence period and last for an hour or two during the time you can
see well. Egg laying continues on into the night in many cases. As mentioned before, the later in the
season and the warmer the weather and water is, the more likely they will deposit their eggs during the

In many case you may not be able to fish during egg ovipositing but for a hour or so because it usually
doesn't start until after sunset. On overcast or rainy days, egg laying can start much earlier. If you find the
Little Sister Caddisflies emerging and depositing their eggs at the same time, fish an imitation of the pupa.
It's almost always more effective than imitating the egg layers.

If you watch carefully, you will be able to see the caddisflies dipping to the water when they are depositing
their eggs. Of course, that is the area where you want to place your fly. It isn't exactly easy to see them in
the low light conditions they deposit their eggs in. In many cases, the splashes or rises of the feeding
trout will clue you in on where the trout are feeding on them.

You can try to imitate the skittering manner in which the caddisflies flutter around on the surface but I find it
best just to use a dead drift. I spook more trout than I catch trying to get fancy.

The trout will also eat the spent flies after they have finished their egg laying duty but this usually occurs
mostly after dark. If you think this is taking place, drift your fly in the area of the spent females.
Copyright 2012 James Marsh
Little Sister Caddis
Availability to trout:             
Hook Size:                          
Type of water:                    
Emergence time:                
Duration of hatch period:

Hydropsychidae cheumatopsyche
Throughout the park in most all streams
Moderate to slow
Late afternoons
2 weeks to a month