|....................... .................... ...Fly Fishing Yellowstone National Park
New KISS Bug Series - Part 17
The Blue-Winged Olives:
Some anglers consider the spinner of little or no importance, not having seen spinner falls of Blue-winged
Olives in great numbers. Others fish them successfully. Spinner falls depends greatly upon the specific
water involved but is directly comparable in size to the hatch. We have found them both ways - to provide
some excellent fishing and when they trout wouldn't seem to want to respond to the spinners.
The female Blue-winged Olive spinners deposit their eggs two or maybe even three different ways. They
deposit them on the surface; crawl down rocks and plant stems to deposit them; or dive and deposit them
on objects below the surface of the water. This probably varies as to species and may vary depending on
the type of water and time of the year. I don't think anyone has pinpointed the particular method these
mayflies use as to species for certain. We think most trout eat the spent Blue-winged Olive spinners
drifting in the surface skim.
Normally the spinner fall occurs anywhere from mid-afternoon up until the time it's completely dark. The
early season spinner falls tend to occur earlier in the day than the late season spinner falls.
In smooth flowing water, you may be able to spot the trout sipping the spinners from the surface of the
water. In rough, fast flowing water, this is just about impossible. Normally, if the Olives are crawling down
objects to deposit their eggs, they do so in shallower, calm water. You would probably not be able to spot
the trout taking the spinners below the surface; however, there's always the possibility the trout are taking
the spent spinners that have collected in the eddies and along the banks in calm pockets of water.
If you are fishing the Perfect Fly Blue-winged Olive spinner, a spent imitation, you are probably going to
need to use a long, light leader and tippet. A ten or twelve-foot long combined leader and 6X tippet would
be a typical setup for this.
As mentioned above, all in all, in Yellowstone waters, we have had mixed results from the Blue-winged Olive
spinner falls depending on the time of year, the particular species of Blue-winged Olive and the type of
water we fished. Spinner falls from the late season hatches have brought us better results than the
early season hatches. This may only be due to the fact the afternoons are much longer and the weather is
usually more stable than it is in the early season. In smooth water, we have watched large trout sipping the
spinners from the surface when they ignored our imitations. Every once in a while, we were able to hook
one of the larger fish, but most of the time we ended up with a smaller size rainbow on the line. Catching
spinner sipping trout in the fast moving but smooth, slick water isn't easy. It requires an good presentation
and a very good imitation of the spinners. Our Perfect Fly is the best imitation of the naturals we have ever
We have caught trout using wet imitations of spinners but we are not positive that the trout took the fly for a
Blue-winged Olive spinner. They could have been opportunistically feeding trout.
The smaller sizes of Blue winged Olive spinners are very difficult to see, especially in low light conditions.
This may account for the fact that many anglers think the spinner fall of Little Olives is not very important.
You can rig to imitate the spinner as a dropper behind near the surface of a more visible dry fly. This is
helpful in seeing the small flies. Let the trail and error method determine which method you use.