Dry Fly vs Nymph – Fishing for Trout Differences Explained

Nymph fishing for trout is the most popular technique of fly fishing globally. However, dry flies also have a massive following. There is a place for both trout fishing techniques.

Dry Fly vs. Nymph?
A dry fly is an artificial fly that imitates a terrestrial or mature subaquatic insect floating on the water surface. Vs. a nymph, which mimics a subaquatic insect (in either nymph or larvae form), floating within the water column of the river current.

Both methods catch trout. Here are the differences explained.

What is a dry fly when trout fishing?

A dry fly mimics either a flying insect on the water’s surface or an aquatic insect.

Or the morphing form of larvae or nymph stage, near or on the water surface.

At each of these moments, the insect is vulnerable to a watching trout.

A terrestrial insect may land or be blown onto the water (which is why fishing with cicada imitations is popular on windy days).

When mature, subaquatic insects transform into winged insects and will spend a few hours or days airborne before they mate and die.

Their bodies often make great trout food as they expire on the water’s surface.

Mature aquatic insects can emerge from the water in mass, in what anglers call a “hatch.”

Types of aquatic insects that hatch include mayflies, caddisflies, damselflies, dobsonflies, dragonflies and midges.

Terrestrial insects that end up on the surface include midges, gnats, crane flies, ants, blowflies, cicadas, beetles and more.

Dry flies, designed to imitate aquatic and terrestrial insects, are manufactured from materials that give the artificial fly sufficient texture to float on the water’s surface tension.

Floatant, often silicone-based, can be applied to increase the qualities that will keep the dry fly from sinking beneath the surface.

Trout rise to take a dry fly from the water’s surface. This can be thrilling to watch. It is the one time you will observe the trout open its mouth to take in the fly.

Trout can be attracted by imitations that mimic a particular insect.

Others are designed as ‘attractor’ flies that entice the trout to leave its safe resting place and rise to the surface to swallow the hook.

The most popular dry fly patterns are called: Royal Wulff, Parachute Adams, Elk Hair Caddis, Stimulator, Pale Morning Dun and Cicada.

What is a nymph fly when fishing for trout?

Nymphs are artificial flies, like wet flies, designed to trick trout into swallowing them as they drift past a trout’s position.

Nymph flies imitate the tiny larvae or nymphs of subaquatic insects.

Larvae and nymphs like to reside near banks or in the sediment or stones at the bottom of the river or lake.

These subaquatic insects completing the transformation from larvae or nymphs to their mature form, spend several hours or days in extra activity.

During this period of extra activity, it is increasingly likely that the insect may end up unexpectedly floating down the river.

Because nymphs and larvae don’t have a means of propelling themselves, they are at the mercy of the current.

This is great for trout who don’t like to waste energy.

Trout like to face upstream and lie in areas where the current is slower than the surrounding water.

These slower zones are often near the river bank, in front of or behind a rock, or near the bottom.

As a nymph floats by in the water, the feeding trout will nip out of their resting place to nab the morsel.

A stray nymph floats downstream at the same speed as the current.

This is a crucial point to remember when fishing with nymphs.

Your artificial nymph must float at the same speed as the current.

This technique is labeled as dead drift.

This means the fly must not be hindered by your fly line in any way.

Trout know the difference!

Why fish for trout with a nymph fly?

Subaquatic insects make up a large part of a trout’s diet – somewhere between 75 – 90%, with many of these insects spending weeks or years at the larvae or nymph stage of life.

Millions of subaquatic insects reside in healthy waterways, feeding on other subaquatic insects and algae.

And since all waterways contain subaquatic insects, and all trout will feed on these.

This makes nymphing the go-to technique for many trout fishers.

Done well, nymphing is a hugely productive fly fishing technique.

How many types of nymph flies are there?

Because there are many types of subaquatic insects, artificial nymphs also come in a vast variety of patterns designed to imitate the diversity of subaquatic insect species.

Having said that, I know trout fly anglers catch more than 95% of their fish using only a handful of flies.

Fun Fact:
The Pheasant Tail nymph is hugely popular as it imitates a large range of mayflies and other aquatic insects. It is a classic fly, having been in production since 1958.

What makes a nymph fly fishing technique successful?

You can successfully fish for trout with a nymph set-up at any time of year, in all weather conditions and waters.

The one time that it may be less successful is when the water is dirty.

The trick when fly fishing with nymphs is to get them down to where the trout are lying.

Trout will sit in the bottom of a pool or near an over-hanging tree, where it can quickly move to safety from predators while staying close to a food source.

Trout have better eye-sight for submerged objects rather than an object on the surface, which is another reason why nymphs are a preferred food.

A trout will spot a nymph floating past and move out of its resting location to quickly knab the tasty morsel, before returning to a sheltered position to again conserve energy.

This means you must get your nymph fly near the fish.

That’s why nymph flies are often weighted using a heavy hook or bead.

Other alternatives are to use split-shot on the leader, or a typical setup here in New Zealand’s deeper, faster rivers is to set up a double nymph rig.

The first fly sometimes called a ‘bomb,’ is there for its weight, while the second is the tiny fly that lures the trout to take the fly.

Another alternative is to use an attractor nymph, which, as the name implies, entices the trout to strike without actually imitating anyone actual aquatic insect. (Learn more here.)

How can you tell if a fly is a nymph?

A nymph is an artificial fly resembling a tiny aquatic insect, often in larvae or juvenile form including mayflies, caddisflies, midges, or stoneflies.

They are often small (up to a size 22 hook), wrapped with a soft material like rabbit fur, wire, chenille, or feathers.

Nymphs can also include a bead near the eye of the hook to create additional weight.

These beads can be plastic which becomes one of the fly’s attraction factors.

More often, the bead is brass and tungsten. This increases the weight of the fly and, therefore its ability to get deep quickly.

Fun Fact
Tungsten beads have more mass, which is why they are the fastest sinking.

Types of nymphs

Non-beaded nymphs

These artificial flies are created from wire, feathers, fur and fabric wrapped around the hook.

Using only the weight of the hook and wrappings, they float in the water column and are particularly popular in still or very slow-moving water.

Emerger patterns fit in this category. Emerger flies imitate insects in the stage before they are an adult.

Emerging aquatic insects are vulnerable as they sit high in the water column as they navigate from the bottom to the surface.

They are often taken by a trout just sub-surface while com[pleting their transformation.

Beaded or weighted nymphs

Beads can be added to nymph flies adjacent to the hook’s eye to add weight so that they sink quickly and sit low in the water column.

Plastic, copper and tungsten beads are popular choices. Each option is chosen for both its attraction and sinking properties.

Coloured or shiny beads create a flash to attract the trout. While other beads are simply there for their weight factor.

Alternatively, fly tyers will add split shot, copper or lead wire to a hook before or while wrapping on the fabric.

Egg nymph flies, which imitate fish roe, are weighted sufficiently to replicate how an egg will tumble down the current. (These are a popular choice of fly during the spawning season.)

Euro nymphs

Euro nymphs are very heavy tungsten-beaded nymphs with an added lead underbody.

These heavier flies achieve depth quickly and are often tied on jig-style hooks that ride with the point up. This helps prevent snagging on the bottom.

Euro nymphs are fished with a specific technique that keeps the angler in touch with the fly.

Do nymph flies sink?
Depending on the construction and weight of the nymph, artificial flies sink in the water at varying speeds depending on their design.

Lightweight nymph flies are made for still or light currents. The nymph will float freely in the water column replicating the movement of the actual subaquatic insects present.

Weighted nymphs are made to sit low in the water column or near the bottom.

This is where most aquatic insects reside and where trout lie in wait for a tasty morsel to float by.

The rate and depth of the sink is one factor that differentiates one nymph pattern from another, along with the color and profile.

Why fish for trout with a dry fly?

Trout are attracted to large insects sitting on the water’s surface, creating a healthy silhouette and give-away dimples in the underside of the water’s surface, which trout can easily spot.

A dry fly is designed to provide the trout with the same indications and is often hard to resist.

Trout feeding on dry flies, or insects on the surface, or often opportunistically strike what they perceive is a large tasty morsel.

That is why it’s common for the trout to take the dry fly down, test the mouthfeel to see if it is authentic food, but then split it out once it realizes that it is not.

This makes dry fly fishing tricky, and why a slower movement to set the hook is often required.

Anglers love dry fly fishing when they get to see the majestic view of the trout taking the bait.

While nymphing is hidden. You are looking for the subtle bob of the indicator when nymphing.

Popular dry fly patterns are called: Royal Wulff, Parachute Adams, Elk Hair Caddis, Stimulator, Pale Morning Dun and Cicada.

Fun Fact
In New Zealand, dry flies that imitate mice which catch huge mouse-eating trout in highly-productive time known as a 'mast' season.

What is the difference between a dry fly hook and a nymph hook?

If you have taken up the art of tying flies, you might ask this question.

Nymph hooks are:

  • More rounded to reflect the silhouette of a larvae or nymph
  • Heavier, as they are designed to sink in the water
  • Size 14 – 24 hooks

Dry Fly hooks are:

  • Longer, to imitate the length of a flying insect
  • Made from lightweight wire to enable floatation
  • Made on larger hooks, but sometimes down to a 20

When do you mix a dry fly with a nymph fly?

Yes, that’s a thing?

A “Dry Dropper” is created by placing a dry fly on the leader, then adding a nymph via a short length of tippet.

In this instance, the dry fly acts as the indicator, but it may also hook the trout.

Or when the dry fly bobs underwater, this can indicate a trout has struck the nymph.

Importantly, it gives the trout two chances to get caught as it can either choose to feed on the dry fly or the nymph.

The Dry Dropper rig is very popular, especially on clear water.

Dry Fly vs. Nymph? Which is best?

Both. A dry fly or a nymph fly will both catch trout. Or try the combination of the dry dropper.