As soon as March, black gnats and midges, March browns, and other insects begin to emerge in north american stillwaters. I learned a good lesson one day from a float tube on a local trout pond, and have been trying to tie a better emerger ever since.
It was very early in the season, just after ice-out and I was feeling the shack nasties bad. I threw the pontoon boat in the truck and headed for one of Thoreau's ponds to tempt trout with a fly. When I arrived, the sheltered shoreline (wind) had visible rise activity, so I paddled over. Slurp! I drifted into the flat over and over with fish all around me, trying everything I had in the way of dries. Black gnats were coming off the water, but griffith's, black gnats, dark midges - all failed me. I threw on a beadhead wooly bugger and finally scored one stocked rainbow, but for the activity I was in the middle of I felt like I had all but struck out.
As more people joined in on their float tubes, we noticed one gentleman hooking up... three... four.... six times as I watched. Eventually, he paddled over to ask about my pontoon boat. I told him the ups and downs of it verses a float tube, he told me how he hates being submerged down to the privates and how much work it was to waddle to shore to relieve himself after coffee and cold submerging down to the privates. I told him that the high rockers on the Bronco make it a viable whitewater craft but on a windy lake you need a sea anchor to keep from being blown like a leaf. Rowing with both arms and 7 foot oars with all body parts above water was a big bonus, on the other hand.
"So whatcha using?" I asked. He showed me an emerger pattern of his own design - a simple looking thing with a bouyant half-hatched wing set and a shuck casing with body segments distinct. The wing had a blue dun tone but was mostly white. The hook was a thin wire dry hook but the fly was designed to be fished under the film, and it was a winner for the situation.
I developed a number of variations of known midge emergers as well as some real frankenstiens and hit the pond again with a vengeance. Although the trout were more receptive to the griffith's the next time I got back there, the emergers were head and shoulders more effective. The fish were not nosing thru the film they were boiling just under like stripers do.
The best fly that day was an emerger I made up with a thin closed cell foam wing. It was easiest to present in the film, and the foam let me use a tiny diameter wire over black thread to form the body segment detail without sinking the fly. I know others use a stripped quill for the abdomen as well.
I really look forward to the next warm, calm spring day floating an emerger in the film.