Which fly you should use? Our guide will explain the basic types of flies and what they are used for.

Basics of Trout Fly Fishing Flies

Just a casual walk past the fly fishing flies available at your local fly shop and you will wonder how you will ever know which fly you should use. There are hundreds of them.

There seems to be a fly for every stage of every insect. The good news is you don’t have to get it exactly right. Something close in design and size will often work just fine.

Trout feed primarily on two different groups of insects. These include aquatic insects that start their life in the water, and terrestrial insects such as ants and grasshoppers.

What is a Fly?

A fly is basically a hook that is dressed in fur, feathers, wire and thread(and many, many other creative materials) that is meant to convince a trout that it is, in fact, actually a tasty insect, bait fish, or vertebrate morsel that it should eat.

The materials used in the fly serve 2 purposes. First is to resemble (though not exactly mimic) the appearance of the intended organism. For example if the insect has prominent wings, the fly will have material that resembles wings. Remember this is seen from below in moving water so you have to use your imagination.

Second, is so that the fly acts likes the organism intended. If the trout are eating an insect that lands on the surface and floats easily, the fly you use should have enough hackle (bushy feather wrapped around it) that allows it to sit on the surface of the water to match the insect that is hatching.

The size of a fly is dictated by the size of the hook it is tied on; larger sizes are indicated by lower numbers. Sizes of common trout flies range from 6 and lower, all the way up to 22.

Trout flies are categorized by how they are meant to be presented, and a certain type of insect can have different types of fly that imitate it during various stages of their life cycle.

Have the right fly, right away.

Our insect specific, curated fly boxes allow you to match the hatch for caddisfly, mayfly and stonefly in all parts of their life cycle. Our Essential Fly Boxes come prestocked and organized in a waterproof fly box that you can use easily on the water. Each box is printed with an image of the insect that the flies inside imitate. All you have to do is observe the shape of the wings and body of what is hatching and choose a fly from the right box.

Types of Insects and Their Flies

Aquatic insects spend the first part of their life cycle in the water. They include mayfly, such as the Baetis, or Blue-winged olives; caddis; stonefly and midges. Our Essential Fly Boxes provide you with flies to match each stage of these insects' life cycles.

Terrestrial insects fall or are blown into the water from overhanging branches nearby.

Types of Trout Flies

There are trout flies tied to imitate these different insects and the different stages of their lives.

• The nymph fly imitates the egg or larva stage of the insect. They also imitate an emerging fly that is on its way to the surface or is in the top layer of the water.

• The dry fly imitates the flies as they lay eggs on the water, are blown by the wind back to the water or have died. These also imitate terrestrial insects.

• Streamers are designed to imitate small minnows or other aquatic life.

Nymph Flies

Nymphs imitate immature insects and larvae. The flies that are water-bred spend a lot of time in the water. These immature insects make up over 80% of a trout’s diet.

Knowing something about the underwater life of the stream can be very helpful here.

Turning over a rock and using an aquarium net can be very helpful in your research.

To learn more about fly fishing nymphs click here.

Trout Dry Flies

As fly fishing flies go, these are the easiest to fish, because they sit on the surface of the water. OK, maybe not real easy.

You must make a delicate presentation and it is really important to maintain a natural drift with this fly. This is achieved through careful placement and control of the line so that varying currents do not produce drag that arouses trout’s suspicion.

It is a lot of fun to watch a rising trout take your fly off the surface.


Streamers imitate small minnows. They are often fished using a swing of the fly across the current. They can be retrieved in short pulls in a short darting motion.

Thick marabou material used in streamers takes on water to allow the fly to sink, and creates movement that appears similar to small fish.

Tube flies are becoming a very popular way to tie and fish streamers.

To learn more about streamers click here.

Summary of Fly Fishing Flies

When learning the fly fishing basics and which flies to use, you need first of all to be observant.
Look under rocks; watch the water and what is flying around you.

If you can’t match it exactly, then just get close in color and size. If in doubt, try a fly that is smaller than the insects you are observing on the water.

A stop at the local fly shop is always a good idea. Let them know where you are going so they can help. Fly shops often have hatch calendars that show you what insects you can expect to be present on the river you are heading to during a given period of time.

Working on your casting skills and presentation is also very important. Our Casting Guide can help you start developing the right skills.

Be prepared for the hatch

Our insect specific fly boxes are stocked with flies that will help you match the hatch of some of the most commons types of bugs on the river: Caddisfly, Mayfly, and Stonefly