Fly Fishing Scuds (Scud Fly Patterns & How To Fish Them)

Our expert angler shares the best methods to fly fishing with scud. If you want to learn how to fly fish using scud flies, read on.

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People enjoy fly fishing scuds for a variety of reasons. For some, it’s an opportunity to get out in nature, away from the business of “real life” and hopefully land some fish. For others, it’s a chance to study and potentially outsmart one aspect of nature.

In order to do this, anglers must be knowledgeable in their fly choices. While it’s important to properly present flies, you’ll struggle to land fish if you can’t select the proper pattern. There are few patterns in fly fishing that are overlooked and found in very specific areas of the world.

Scud patterns are one of those unique patterns that anglers don’t even bother using. They find themselves fishing with baitfish streamers, caddis patterns and mayfly nymphs. Scud patterns should never be overlooked!

I never had fished a scud pattern until I started fishing the tailwaters in the western United States. These flies live in extremely cold water and I’ve had a massive amount of success nymphing with these flies.

What is a Scud Pattern?

A scud is a freshwater crustacean. Many anglers refer to them as freshwater shrimp. Again, they’re never going to be the most popular fly in an anglers box, but they should be used often throughout the season. If you find a solid scud bite, you can believe you’ll land quite a few fish.

a huge scud

There are over 90 different species of Scud in North America. Be sure to spend some time at your local fly shop before you decide what pattern you need to use. They’re extremely active and fish love to feast on them.

Life Cycle of a Scud

Scuds belong to the Amphipoda family. Other species in this family include lobsters, crayfish as well as shrimp.

Stage 1

Scud always reproduce in the spring. Females are the ones that are always going to be carrying the eggs. The eggs stay on the underside of the thorax for up to three weeks. Once they have hatched, they’ll stay in the pouch for about a week.

Stage 2

Unlike many insects, scuds do not go through metamorphosis. While they do shed the pouch, they do not physically change as much as insects. They’ll live to be around a year old. Fish will eat the eggs as well as the adults.

What’s Fly Fishing Scuds All About?

Fly fishing scuds is done via nymphing. They live under water for their entire lives and the fish will cover all levels of the water column to eat them. If you aren’t confident in your nymphing abilities and you want some practice, see if there’s a scud bite and begin to practice.

You can find them in tailwaters and stillwater. Finding these flies isn’t always easy so it’s important to be in consistent communication with your local fly shop. They’ll let you know when they’re biting.

When To Use Scud Flies?

Scud flies hatch in the spring. This is prime time to tie them on and see what you can catch. If you’re fishing below a hydroelectric dam where the flow changes quite a bit, then be sure to throw on a few of these flies.

When the water rises again, they’ll all get knocked loose from the bottom of the river bed. The feeding frenzy that occurs after these flies are unattached from the river bottom is incredible. The fish are waiting for this to happen and will stuff themselves full of these scuds if they have the chance.

How To Cast a Scud?

When you’re throwing scud flies, you need to fish them like you would a nymph. Any sort of nymphing technique is going to work when fishing with these flies. Be sure to take a look at the water flow, feeding patterns of the fish and depth of water that you’re fishing.

If you’re uncomfortable with nymphing, scud fishing provides a great opportunity for you to learn. When fish are feeding on scud flies, they aren’t always very picky. As a result, you can learn the drifts of the river and see what types of presentation the fish enjoy. Since you can’t see your fly when nymphing, it’s a matter of trial and error.

A fly angler casting a scud

You’ll find yourself learning more and more about the river and the flies as you fish. It’s a great opportunity to explore some new water and learn how to fish a more unique fly.

Species For Fly Fishing Scuds

Scuds are a favorite for trout. While other fish may eat them every once in awhile, spend the majority of your time targeting trout with Scuds. You’ll find the most success with these fish. It’s a great time when you have the opportunity to land some trout on Scuds.

The Best Scud Fly Patterns

Since Scud patterns aren’t as popular amongst the fly fishing industry, the mainstream patterns options are a bit more limited. However, fly tiers love to tie Scud patterns for their local waters. I have found some of the most unique patterns in local fly shops or even from other anglers out on the river.

Due yourself a favor and spend some time around local anglers and you’ll likely find your box filled with hand tied patterns that work extremely well with these fish. These anglers know the ins and outs of the water and you’d find yourself with an incredible amount of knowledge and some new fishing partners.

A photo of sow bugs flies

Sow Bugs

Sow Bugs are a fairly common pattern in the Scud world. These flies don’t look like they’re too difficult to tie and it’s because they aren’t. You use some Goose biots, dubbing and a ziplock bag for the shellback and you have your fly.

These flies are common to find in tailwaters stuck on some of the underwater vegetation. Fish love these flies because they’re easy targets. These flies struggle to swim so fish are willing to feast on them as they drift downriver.

You’ll find plenty of these flies in the Bighorn River in Montana. If you find yourself fishing in some Western tailwaters, you’ll want to carry a few of these in your box. It’s not uncommon for vegetation to grow below dams and Sow Bugs will always be in the diet of trout!

A photo of the laney's mysis shrimp on the sand

Laney’s Mysis Shrimp

Laney’s Mysis Shrimp pattern is one of the most realistic looking Scuds I have seen. Mysis shrimp are transparent when they are alive. However, as soon as they die, they turn white. This pattern is transparent and some anglers like to fish these patterns with a small hint of white, but it’s not as successful.

I’ve seen plenty of fish throw up these insects and they’re almost always clear. They prefer to eat the living Mysis shrimp. Go ahead and fish these patterns in the midst of runoff or after a heavy rainstorm. These insects will start flowing into the river from the base of the dam.

When these start flowing, you’ll see the fish gain an exceptional amount of weight. If you catch a fish that is feeding on Mysis shrimp, they’ll likely throw up all over you or your boat. Keep this in mind when you’re handling them. They’re sensitive due to how much they have eaten. Fish that eat these shrimp can often double their weight in a year.

Another great thing about targeting fish that eat Mysis shrimp is that they’re some of the most colorful fish you can find. If you can find yourself on one of these bites, you’re in for one of the most memorable days of fishing you’ll ever have.

Sand’s Mysis

Since the Mysis shrimp bite is so amazing, it’s worth mentioning another Mysis pattern that has been successful over the years. You’ll find Sand’s Mysis pattern and version of Mysis shrimp in the rivers of British Columbia as well as Colorado.

These crustaceans need to live in water that is no warmer than 60 degrees. Therefore, you’ll find them in deep portions of lakes as well as tailwaters. Salmon love to feed on these, but trout are still going to be the primary feeders. A trout that eats shrimp is going to be massive.

It’s not uncommon to land some shrimp eating trout that are well over 10 pounds. Don’t shy away at the opportunity to fish for them! Tailwater fishing can be extremely tricky because the water is usually clear and the fish are spooky, but it’s well worth your time.

Ninch’s Pill Popper

This is one of the more unique looking flies you’ll have in your box. It almost reminds me of a small piece of confetti. The bright colors are very appealing to trout in Western United States tailwaters.

These scuds look like females because they have a “hot bead” attached. A hot bead is a colorful beadhead on the fly. When trout see a scud with eggs ready to hatch, it makes it that much more appealing. Plus, the pink or orange hot bead makes them stand out far above the rest of the flies in the water.

Go ahead and fish this fly in the Missouri River. This is a large and intimidating tailwater, but you’ll land plenty of fish in it if you choose the proper flies!

Ray Charles

The Ray Charles is likely the most famous Scud pattern on planet earth. The name is a bit ironic because fish can’t help but see this fly and want to eat it. It was introduced into the fly fishing world over 30 years ago to be used in some of the tailwaters across the United States.

It is primarily yellow, but a small piece of red near the eye of the hook is what sets the fish off. They see it as a scud with eggs so they go after it as quickly as they possibly can. This scud was actually the first fly I used when I fished the Missouri River. I caught my first ever tailwater fish on this fly! So it will always hold a special place in my heart.

I actually found it in one of my dads old fly boxes. I did some research on what flies would work and decided to take a look through his collection. I’ll always swear by the Ray Charles!

Tailwater Sow Bug Jig

The Tailwater Sow Bug Jig is a similar to the Sowbug fly, but it has a small beadhead that helps you find the lower portion of the water column. These scuds are often best fished in higher water so you need to ensure that you’re reaching the lower portions of the river of lake.

If you can’t drop in the column, you’ll find yourself not catching as many fish. When fish are looking to feed on nymphs, they spend their time in the bottom half of the column. They won’t even bother looking up so you need to be sure you can meet them where they’re at.

This beadhead fly has worked all across the country from the White River in Arkansas to the Bighorn River in Montana. Versatility is the name of the game in fly fishing. If you can find a fly that is going to work in a variety of situations, it’s one that you should always keep in your box.

Soft Touch Shrimp

This is one of the most impressive looking fly patterns I have ever seen. If you ever spend time fishing saltwater, you know how important it is to use realistic looking shrimp. When you’re trying to emulate a shrimp in fly fishing, anglers have struggled. However, the Soft Touch Shrimp works extremely well.

You have the clear silicone sealant that works as well as some Black varnish and the superfine grey dubbing. Again, there are few patterns in fly fishing that wow me, but this is one of them. They’re extremely small and take some time to maneuver, but this pattern is great to use if you’re fishing a dropper rig.

Do yourself a favor and purchase some of these flies just to see the impressive craftsmanship. The beauty of them is that they always catch fish! Even the fish are surprised that it’s not real.

Diamond Dub Scud

The Diamond Dub Scud has quite a bit going on within it. The extra hackle and material will soak up the water and help you reach the lower portions of the water column. Again, these are going to be most successful in the Western tailwaters.

These patterns are a bit more dark so if you’re fishing stained water, they’re going to work great. Scuds get displaced when the water rises and the feeding frenzy begins! Don’t ever fish a scud bite without using one of these flies.

It’s another extremely realistic looking pattern that is going to work very well throughout your fly fishing career. I recently discovered these flies and have yet to be disappointed.

Grey Shrimp

This is a British fly, but it’s continued to prove itself over and over again in the United States. It’s a size 10 fly which is on the larger end for many scud patterns. However, it’s not uncommon to see some of these scuds reach almost an inch long.

Czech Nymphers often use this pattern. If you’re interested in Czech nymphing with scuds, this pattern is a great choice for you. It’s more scruffy and not nearly as elegant looking as some of the other patterns on this list.

If you’re new to the world of fly tying, this is a great pattern to try. You can make it look nice and messy. You’ll be surprised at how much the fish enjoy eating flies that don’t always look 100 percent natural. From my experience, I’ve found that fish are willing to eat unnatural looking flies quite a bit. I’m not an expert tier, but I often see success!

Melt Glue Gammarus

This is another one of my favorite Scud patterns. Believe it or not, fish take the texture of a fly into consideration when they first try and eat it. The texture of this fly is realistic enough that fish don’t think twice when it enters their mouth.

The pattern actually utilizes a hot glue gun so it provides more of a squishy feel similar to what a real scud would feel like. Spend a bit more on this fly and you’ll appreciate the investment. These fish great on the bottom of the water column. I often find myself having to tie on an extra split shot to make sure these fish get low enough in the water!

Gear To Use When Fishing Scud Patterns

When you’re fishing with Scuds, you can use any sort of traditional nymphing setup. Some anglers choose to Czech Nymph so they need an 11 or 12-foot rod with a fast action and the opportunity to do quite a bit of finesse casting.

Other anglers are comfortable sticking with their 9-foot 5-weight rod that they’ve been using for 20 years. Depending on what you’re comfortable with, you can go ahead and use it. Nymphing is all about feel.

I’ve seen some anglers use rods that have no business nymphing, but they land a massive amount of fish with them. If you’re confident in your ability to accomplish a natural drift and make the flies look realistic, use whatever works.

The most important thing to remember is to not use floating line or leader and tippet that is too visible. Use weight forward line when you’re nymphing. Weight forward line is going to help your fly reach a lower portion of the water column, but not drag along the bottom so you get stuck.

Fly Fishing Nymphs - Fish with a nymph in his mouth

Your leader should be 3x because you’re likely going to land some larger fish! Your tippet should be no larger than 4x. While the fish you’re going to catch are likely fairly full, they’re still aggressive and have the ability to fight at a high level.

Fly Fishing Scuds Techniques

Scud fly fishing is really not as challenging as other nymphing opportunities. If you know the Scud bite is hot, you don’t have to work as hard to accomplish a perfect drift or entice the fish like you would have to with other nymph patterns. There are, however, a few nymphing techniques that you will need to utilize when fishing with Scuds.

Short Casts Are Your Friend

When you’re nymphing, a long cast is going to cause headaches. I like to stick to 15-20 feet of fly line and work from there. These flies need to reach lower portions of the water column and you can’t be spending the majority of your time trying to drop it lower and ruin what could possibly be a perfect drift.

Don’t make your life to complicated when fishing with Scud patterns!

You Sweet Spot is Short Lived

When fishing with nymphs, you don’t have a sweet spot for very long. The sweet spot for drifting a nymph is when the fly is about 35 degrees above you and when it drifts completely across your body. Once it’s across your body, the drift is almost dead.

Recast and try again to achieve that perfect drift in the sweet spot.

Minimize the Drag

When you’re fishing with nymphs, you need to do your best to minimize the drag. Drag is going to kill whatever chance you had at nailing the drift through the seam. A great way to lower the chance of ruining your drift due to drag is keep the line tight and raise your rod tip.

As you raise your rod tip, it allows for the fly to drop in the water column and also prevent you from getting snagged.

Best Destinations For Fly Fishing Scuds

Scud fishing is popular in a few areas across the United States. If you visit one of the areas mentioned below, you’re in for a treat!


Any tailwater in Montana is going to hold scuds. Fish as close as you can to the dams. This is where the highest populations of scuds will live and you’ll find yourself catching the most fish here. The Missouri and Bighorn Rivers are your best bet!

Vast landscape in the mountains showing fall in colors in Montana.

Once the feeding frenzy begins, you’ll wonder why you have never fished with a Scud!

Are You Ready For Fly Fishing Scuds?

Scud fly fishing is a great opportunity for those looking to start nymphing, but aren’t 100 percent confident in their abilities. You’ll find that it’s fairly easy to land fish and you’ll learn quite a bit in the process.

Scud fishing a smaller niche in the fly fishing world. If you’re interested in joining a small group of diehard anglers who land a ton of massive fish, start fishing with Scuds. You’ll find you have a smile on your face your entire time on the water.

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My name is Danny Mooers and I’ve been fly fishing for five years. As soon as I went to college, I dove headfirst into my obsession for fly angling. Every spare weekend or long break was dedicated to finding fish. I’ve fished all over North America in search of trout, salmon, steelhead and everything in between. I currently write articles for Guide Recommended and Reel Adventure Fishing. Fly angling is one of the most challenging yet rewarding hobbies any person can have. Don’t be afraid to give it a try.  It’s an addicting activity that tests everything from your fine motor skills to your patience, but it’s well worth your time.

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