.......................  ....................  ...Fly Fishing Yellowstone National Park
05/09/12

New KISS Bug Series - Part 15

The Blue-Winged Olives:
Emergers










Most of the Blue-winged Olive emergers, or emerging mayflies, hatch in open water by swimming to the
surface and penetrating the surface film. Many are not able to do so immediately, especially in calmer
water, and the longer it takes, the better it is for the trout. The dun flies away to nearby streamside
vegetation as soon as its wings are dry enough to fly.

For this reason, imitations of the emergers may be important, especially on smooth flowing waters where
they most often emerge. Although emergers work very well at times, it's important not to fish emerger
patterns when they are not very productive. You may do much better with the BWO nymph. More trout may
be taken on the BWO nymphs that are still rising to begin the emerging process over those that are in
some stage of changing into a winged fly, depending upon the number of nymphs versus emergers.

Some species includfing the
punctiventris crawl up the stems of plants to hatch. If this is the case, then
there's no use in imitating the emerger stage. How would you know? Well, if you are not observing any
duns on the water or fish that roll and show their heads and then their tails, or fish that are hitting
something on the surface with a splashy rise, then you could assume the blue winged olives are crawling
out of the water to hatch. In this case, fish the bottom or emerging nymph imitation or wait for the spinners
to fall. Fishing an emerger or dun imitation would not be productive.

You don't necessarily need to have both of our Perfect Fly Blue-winged Olive Emerger patterns. The
choice is strictly optional. The Emergers are a little more difficult to see and require a little more skill to fish
than the Emergers with the trailing shuck. It up to you to decide which one of the emergers to use. Some
anglers want both types and use the trail and error method to determine which works best. Sometimes it
seems the trout prefer the trailing shuck duns and at other times it seems they prefer the non-trailing shuck
version.

Normally, you will be presenting the Blue-winged Olive emerger or dun imitations over smooth water. Trout
usually just causally sip the emerging duns and cripples. This requires a very delicate, more perfect
presentation than the normal. You should use as light of tackle as appropriate, say in the four-weight or
lighter line weights.

Five X or six X tippet, two or three feet long on leaders totaling ten to 12 feet long is usually needed. In
many cases an upstream presentation doesn't work well in the calmer water and you need to fish either
across stream or downstream. Make certain there's no drag by allowing some slack line. Usually, the extent
of your success depends greatly upon the presentation.

In other cases, where there's smooth water in pockets within larger areas of rough water, the upstream
presentation of the BWO emerger works very well. If you can get away with it, fish upstream. You will
usually spook less fish.
Thumbnail: Click To Enlarge
Thumbnail: Click To Enlarge
Copyright 2012 James Marsh
Blue-winged Olives:
Species:                             
Type:                                  
Availability to trout:             
Hook Size:                          
Numbers:                            
Distribution:                        
Type of water:                    
Emergence time:                
Duration of hatch period:

Baetis tricaudatus, Plauditus punctiveentris
Swimmer
Excellent
18-20
Heavy
Widespread
Moderate to slow - smooth and broken surface
Afternoons
Long
"Perfect Fly" Blue-winged Olive
Emerger with Trailing Shuck