The Stupendous Stonefly Nymph

The Stupendous Stonefly Nymph

Stoneflies can produce some fantastic nymph fishing, especially in the colder flows during winter and early spring.

These big enticing insects are prolific in most cool, clean streams found throughout the greater U.S. making them a year-round staple in the diets of large trout.

Stonefly Nymphs are large insects favored by big fish in fast, well-oxygenated rivers and streams. Because they have under-developed gills they must live in swift currents with plentiful oxygen in order to survive. Some of the biggest fish in the river can be caught with a big stonefly nymph fished slowly along the bottom in the depths of your favorite pool or run.

When it comes to the diet of trout, mayflies and stoneflies rank at the top of the list. That being said it is important to first understand the lifecycle of a stonefly. Their life cycle can be broken down into three segments: Egg, Nymph, and Adult.

Understand the Stonefly Lifecycle

Egg – While the egg stage is an essential step in developing the adult stonefly, the egg is unintriguing for the trout. Depending on the species, stonefly eggs can take as little as a day to hatch or as long as a year. Much like the mayfly, the stonefly will spend a good majority of its life cycle as a nymph and only sees its complete adult form for a few hours for the sole purpose of reproducing.

Nymph – Now that the nymph has hatched, it's time to find suitable habitat. The nymph will sustain itself through predation or herbivorous eating activity, depending on the stonefly species. Because the nymphs have poor swimming ability, they'll find a home among the rock aggregate bottoms of rivers, streams, and lakes; only moving long distances when drastic changes in water fluctuation occur; drought, snowmelt runoff, or heavy rain. When the nymph is well fed and mature, it awaits the appropriate seasonal time and temperature to make its next transformation into an adult stonefly.

Adult – When the nymph is ready to change into an adult, it will do so—depending on the species–in one of two ways. The “surface emergers” will simply swim to the water's surface and make their transformation just below it. The crawling emergers will crawl to dry land or river's edge through protruding rocks, downed trees, or low-hanging vegetation.
Newly emerged adult stoneflies seek immediate refuge among the willows, branches, and bushes. Now hiding among vegetation, the adult stoneflies wait until conditions allow mating to begin. The adult stage of the stonefly is brief and only exists for reproduction. Even though this period of life is brief, the adult stonefly presents some of the most exciting fishing of the year and is one that many anglers seek out year after year.

Techniques for Fishing Stonefly Nymphs:

Due to their poor ability to swim, nymphs will find refuge among the rock aggregate bottoms of river beds or lakes. While the nymphs are among the rocks, they will sustain themselves on the available vegetation or find other suitable prey. So what does this mean for the angler? Fish deep in faster water. When flows are relatively stable, stoneflies will often use their strong claws at the end of their–six–legs to cling to the surface of rocks or gravel at the bottom of a stream/river/lake bed.

The good news for anglers is that a simple weighted stonefly imitation is often the golden ticket to fool a hungry trout. Prince Nymphs with a tungsten or beadhead are great stonefly nymph patterns. Don’t worry about casting with perfect presentation. Unlike dry fly fishing mayfly patterns, anglers should try to make their fly smack the water. This will often get an aggressive reaction from the fish.

Anglers can effectively fish stoneflies through sizes 8 and 14; sizes 8 and 10 are a favorite during the stonefly molt in early spring. Stonefly nymphs are generally an earthy black, dark brown, olive-brown, gold, or golden yellow when it comes to color. As the stonefly nymph ages, the color of the nymph changes as well. While the specific colors of stoneflies vary there are a few common colors anglers should know, black with hints of reddish-brown to a dark olive-brown with yellow highlights, and finally an olive-yellow with a light yellow cream color.

Tips for Fishing Stonefly Nymphs:

  1. Avoid Long Casts – As with any other heavily-weighted flies; long casts need to be avoided. Short upstream pitches are ideal and should be used whenever possible. Casts in the 15-25 feet range are what you are looking for and make it easy to handle to fly and detect strikes from fish. Once the fly has hit the water let the fly sink and indicator drift downstream. Fish the indicator as you would a dry fly, making mends to the line as needed to achieve a drag-free drift.
    The sunken fly should be on or near bottom bouncing all the way down stream. As the fly drifts downstream past your position; gather the slack line to keep the fly drifting as natural as possible. Once the fly starts to swing beneath your position pick the rod tip up slowly to see if any fish are flowing quietly and then proceed to start your next cast. Make sure to keep up with the slack line being created as the fly drifts, you will get a better drift with less slack and you will be able to strike more quickly when a fish bites.

  2. Set the Hook Quickly – When fishing dry flies, setting the hook often requires a slight pause to be effective. Jumping the gun is common, since the angler may see the fish before the fly is actually in its mouth. The opposite is true for nymphing. Whether you’re feeling for a strike or using an indicator, you should set the hook as soon as possible, since both of those triggers mean the fish has already made solid contact with the fly. Set the hook too slowly, and the fish will be long gone.

  3. Set the Hook Quickly – When fishing dry flies, setting the hook often requires a slight pause to be effective. Jumping the gun is common, since the angler may see the fish before the fly is actually in its mouth. The opposite is true for nymphing. Whether you’re feeling for a strike or using an indicator, you should set the hook as soon as possible, since both of those triggers mean the fish has already made solid contact with the fly. Set the hook too slowly, and the fish will be long gone.

  4. Treat Every Bump as a Strike – If you get deep with your nymphs, you may encounter rocks from time to time. This can be confusing when you’re trying to see where the fish are biting. Many anglers start to ignore smaller bumps on their indicator and assume it is just a rock. This can lead to a lot of missed fish because some fish take the fly so subtly, it barely moves. To maximize your number of hookups, set the hook anytime your indicator bumps!

  5. Use two nymphs – Try dead drifting two flies with an unweighted nymph on first then attach 12-24 inches of tippet to the bend of the hook and tie on a weighted Stonefly nymph. Very rarely do these aquatic insects allow themselves to be found higher in the water column, so be sure to present your flies on or near bottom is a must to get a consistent bite from fish.

  6. Cast from the Bank – Depending on the type of stonefly, it's smart to fish these from the bank and strip your fly toward yourself. Since stoneflies hatch near shore, they often swim toward the "slack" water. A slow strip toward yourself on shore will cause fish to follow. They know that if your fly gets to shore, they won't stand a chance. Cast upstream, let it drift and slowly drift your fly toward yourself. Don't pull it out too early! I've found that fish will hit these stoneflies extremely close to shore.

  7. Minimize Line on the Water – Unless you’re using a technique that benefits from drag, like swinging, you’ll want to minimize the amount of fly line on the water. In many cases, simply pulling in excess line and lifting your rod tip will eliminate all drag, creating a perfect dead drift.

Stonefly nymphs should match the color of the insects living in the river you are fishing. If you are not sure what color stoneflies live in your area, black or chocolate brown patterns will cover most conditions. The size of the fly pattern is another concern for anglers. Basically, early in the season, larger stonefly nymphs will be more common. Carry a few different sizes of flies, and when you hit the water, turn over a few logs to see what size fly best matches the resident stones.

If you are looking for an edge this winter then using stonefly nymphs to target large aggressively-feeding fish could be exactly what you are looking for. Stoneflies can be much different than anything you have ever fished before simply because of their hefty size, and it is this size that is ever so enticing to fish. Work the flies thoroughly though holes and rifles, but be warned; hold on tight it won't take long for fish to get excited about your Stonefly Nymph.

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