Reaching a pupal stage is the time they crawl from the river and can walk up to 50 feet from the bank. They will find a moist location under rocks for another week or two. Metamorphosis takes place and the courtship begins. Males fight for the rights to females.
Another two weeks and the females will lay eggs clinging to leaves above the river or on rocks along the bank where the hatching larva falls into the water in search of it's residence. They like the faster oxygenated riffles that will provide a food supply.
So, now that I learned a bit about these large four wing adults the tying began. First was on a #8 4x long streamer hook and was too small. Next a #4 5x and that seemed to be the right size. Off to the river I went with three hours to learn what I could.
I tied on the 5x and made my first cast to a visible bow. The fly landed three feet above in a slow current and the fish took the fly. No hook up. Ten more times I had fish take the fly with the same result. No hook up. The only fish that fit the entire bug in it's mouth all at once was a three pound smallmouth bass.
What I realized was the trout were grabbing the fly by the wings and needed to chomp in order to take it in their mouth completely. One bite and they knew it was a fake and spit it out. The other problem was keeping the fly floating. Back to the bench.
Softer foam wings, foam under body and a smaller hook placed up at the head with a hollow tube as the body extension. I sealed the back of the tube with UV epoxy.
Again, I went back to the river. Crazy how many fish continued to be attracted to the fly. The floating issue is totally solved. Fish were making takes and still not getting hooked. Then it hit me. The leader was slightly dragging the fly so it was pointing toward me. So, I changed my position to only be casting down and across stream giving me the ability to control the fly pointing up stream and still be dead drifting. When the 18" Rainbow took the fly and then turned the hook was in position. Next ties will have a slightly larger hook.