|....................... .................... ...Fly Fishing Yellowstone National Park
New KISS Bug Series - Part 14
The Blue-Winged Olives:
Blue-winged Olive nymphs can exist and feed in streams with plenty of current. They can cling tightly to
rocks and the stems of plants when they feed in current. They use an up and down motion of their
abdomen and tail to swim.
The nymphs emerge in the surface skim but the trout will eat them well before they emerge and below the
surface as they rise to the surface to hatch. If the water is very cold, in the low forties for example, it may be
the only way the trout will eat them. They may not take the emergers on the surface.
One method of fishing the nymph is to use a small strike indicator placed about 16 to 20 inches above the
fly. You can use a larger dry fly to suspend the tiny nymph imitations if you prefer. You can also fish them
without an indicator. That is the way we prefer to fish them. We usually add a small amount of weight a few
inches above the fly.
We use both an up and across cast and a down and across cast depending on the type of water we're
fishing. As a general rule, in the rough pocket water, use the up and across cast placed at the end of the
current seams. In the smooth flowing water, use a down and across cast.
The early season hatches (baetis tricaudatus) usually starts as early as noon. They can hatch until 4:00 or
5:00 PM. It is a good idea to fish a nymph imitation in the mornings prior to the hatch. In fact, it's often a
good idea to fish the nymph imitation during the time they are hatching.
If you are fishing waters where populations of the Little Olives occur and there's no obvious hatch occurring
at the time, it may be wise to fish the nymph. Use either the swing style or a strike indicator depending upon
the water. Use added weight of appropriate size for the depth and current.
This is also a good search pattern to use during the hours preceding a hatch. In the earliest part of a
hatch, you may have better success fishing it as a dropper below a blue winged olive emerger or dry fly
pattern. In fact, the nymphs usually work even when flies are emerging. Trout seem to prefer eating the
nymphs just prior to their emerging.
Remember, that trout feeding on these small mayflies are not going to go to a lot of trouble to eat them.
They don’t need to. So, generally speaking, you can avoid the rougher, faster more turbulent waters and
concentrate on the smoother water because that is what the trout will be doing.