Matching the fly: a few hints to start with.

Matching the fly: Entomology is part of the complex world of flyfishing.

It is the glue keeping the whole together, helping anglers to catch fish with the proper “bait”.

Many consider entomology as extremely difficult and it is, if we do not make things simple.

Let’s start from a statement: fish have a huge amount of food. Some eat almost everything (from small insects to crustaceans and small mammals). Other feed mostly on insects.

Our interest goes mainly to the latter; as a consequence, some hints about matching the fly can be of some help.


To make things simple, we can divide”our” insects into 5 different “classes”:

Ephemera – or mayflies (present on the wings only for a short period of time, from which the latin name) . Can be recognized by the wings, always in vertical position.
Trichoptera – or sedges or caddis flies (from latin “covered with hairs). Their wings rest on the body, like roof tiles
Plechoptera – or stoneflies (latin: with veined wings). Like sedges, their wings lay on the body but are completely flat on it.

The above are born under the water surface and spend most of their life there before moving to the air. The larva exits from the very tiny egg laid by the dying female and starts its long transformation process.

It will finish (it may need few months or a couple of years) before their aerial period. This last period of life does not last very long: just for reproduction before death.

The last two classes are:

Diptera – also including midges and house-flies, very popular mainly in not so pure waters.

Terrestrials – any insect living NOT in the water but which can potentially fall into and become the fish’ prey.

They live on the ground, the grass, the threes and may be transported onto the water surface by wind or any other reason.

Matching the fly

As a consequence, when we see fish feeding on the water surface, we have all the above five options.

The “art of flyfishing” consists in matching the fish’ food with one of the many artificial flies we have in our fly boxes.


Being able to identify to which class the insect the fish are feeding on is very important.

Entomology helps us choose the right fly: is fish are active on mayflies, the imitation of a sedge may give no results. What if we see many rises under a protruding branch but see no flies on the water? The imitation of a beetle or a caterpillar might be the right choice.

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