What Fly To Pick?
Don’t get too hung up on this. In very many cases, a fish like a trout will take any fly that vaguely looks like a food item. For example, if a nymph is small, dark-colored, in the water and can be seen, it stands a chance of being taken. Equally, if you are really stuck, on many still drinks of water all you need to do is put on a big flashy lure, cast it out as far as you can and retrieve it at speed and you will get a take. Not always, but often enough to make life interesting.
However, all that said, it still helps if you can match the flies that you’re seeing as nearly as possible. The chances are that these will be what the trout are eating and your success rate will obviously increase. It’s not difficult to recognize flies if you know what you’re looking for.
The first important group of flies that makes up the bulk of the fish’s diet is the up-winged flies, notably the olives and the mayflies. Up-winged flies can be recognized by their vertically positioned, graceful wings and long, delicate tails. They start off mayfly as nymphs, develop into duns and then transform into spinners. Mating takes place before the female lays her eggs on the water and dies. They are beautiful flies to look at and the fish love them.
Next up are the roof-winged flies. These fold their wings across the body in much the same way as a roof on a house. The most obvious flies in this group are the sedges.
Next, we have the flat-winged flies. We’re looking at hundreds of species from tiny midges to daddy-long-legs. All share common features: six legs, a pair of short wings and a well-segmented body. Most commonly, you’ve got the chironomids – buzzers as they are better known. The buzzer begins its life as a bloodworm before transforming into a pupa and finally hatching out into an adult midge.
Everything else then you’ve got all the rest. For a start, there are terrestrial insects that land on still and running waters and are eaten. Alderflies, black gnats, hawthorn flies, reed smuts, moths, and flying ants are all common foodstuffs. Then you’ve got crustaceans like freshwater shrimps and snails. Corixidae are known as water boatmen and look like small beetles. But remember, trout, in particular, will target anything that swims or ends up in the water – tadpoles, wasps, grasshoppers… if it’s edible it will be eaten. Even if you don’t see the insect being eaten, the way the trout takes it often gives you some clues.
Let’s say the rise is a slow one. You see the head, the back, the fin, and the tail, all in slow motion. This suggests a trout feeding on buzzers in the surface film. Fish your fly fractionally under the surface and retrieve it very, very slowly.
Boil on the surface
Now, you simply see a boil on the surface but no sign of a fish. This is a trout taking food a few centimeters beneath the surface. It will probably be a nymph temporarily out of cover. Cover the rise as quickly as you can with a nymph pattern and you might well get a take as it sinks.
Sometimes, in calm conditions, you actually hear a rise as well as seeing it. If you hear a sip, a suck or a slurp, this is probably a trout eating buzzers just beneath the surface or dry flies like sedges on the surface. Try a buzzer first. If that doesn’t work, try a small dry fly.
Sometimes rises are explosive splashes that you just can’t miss. These suggest trout feeding in a hurry on big food items that are moving fast. Perhaps this is a mayfly just about to take off into the air. Perhaps the fish is feeding on fry that is scattering and moving fast. Try a lure or a big dry fly until you unlock the secret.