I’ll go out on a limb and say that most of the trout that eat your dry flies “think” your dry is really an emerger. Not convinced? Watch trout in the middle of a mayfly, midge, or caddis hatch. How many adult flies do you see disappear into a rise? And how many of these rises seem to zero in on something out of thin air?
Most dry flies popular today present a silhouette closer to an emerger than an adult insect anyway. Notice how the adults balance on their tiptoes and tails when riding the surface? Even a high-floating traditional dry fly sits lower in the film than a true bug. And the heavy tails on most dry flies (as compared to the delicate tails of natural insects) look more like a shuck hanging from an emerging nymph or pupa than real insect tails.
- From River Essentials’ web site on Delaware River fishing conditions.
I have a vivid memory of a misty day 30 years ago on a limestone stream, with March Browns covering the water. Neither my friend Terry Finger nor I could interest any of the risers, until he tried a terrible Ausable Wulff I had tied, with not enough hackle, too fat a body, and an oversized, bulky tail. The fly worked like a charm. Terry finally decided that the heavy tail simulated the meaty, emerging March Browns trailing big nymph shucks.
If a trout is not an efficient predator it dies. Trout are surprisingly adept at determining how to ingest the most calories for the least effort. A nymph rising to the surface or a mayfly fluttering above the water is not as easy a meal as an insect trapped in the surface film like David Letterman on his Velcro™ wall.
Any fly that imitates the natural of the hour without hackle, or with parachute hackle, can make a good emerger. Just trimming the hackle off a standard dry fly with your scissors can also make a dry fly more effective. But flies designed specifically as emergers get the profile of an emerging insect just right. You will read about cripples or transitional duns as well as emergers, but I have trouble believing a trout can tell whether a mayfly is in trouble or just emerging.
Certain hatches are best fished with emergers. For Baetis (Blue-Winged Olive), Pale Morning Dun, Pale Evening Dun, March Brown, and Isonychia mayflies, an emerger pattern will almost always outfish a standard dry. And nine times out of ten, you’ll hook more rising fish during caddis and midge hatches with an emerger than with a high floating dry.
There is nothing quite like the thrill of a big trout eating a bushy Wulff in fast water. But for all the thrills of dry-fly fishing and better odds, try some emergers this season.