Caddis Flies

Caddis Flies: Follow the Bug From the Bottom to the Top

If mayflies are the dignified gentlemen of the trout stream, gracefully riding the surface with little sailboat wings held above their backs, caddis are their considerably less refined cousins.

They crawl.

They swim.

They rocket toward the surface.

They skitter across the water.

Some dive back underneath it.

And during a heavy hatch they can turn an otherwise sensible trout into something resembling a Labrador chasing tennis balls.

For the fly fisher, that chaos is good news.

Caddisflies are one of the major aquatic insect food sources for trout, and their life cycle gives us opportunities to catch fish from the streambed all the way to the surface. The trick is understanding which stage of the caddis life cycle the trout are eating right now.

Caddis Larva: Start at the Bottom

The caddis life cycle begins underwater as a larva.

Many caddis larvae build protective cases from sand, gravel, sticks, leaves, or other material they find along the bottom. Others remain free-living, but both forms spend much of their lives crawling around the streambed and becoming part of the underwater buffet.

Turn over a few rocks and look.

If you find small worm-like insects with visible legs, you've probably found caddis larvae rather than midges, whose larvae lack those developed legs.

Patterns such as the Jelly Cord Caddis Larva, Buckskin, and Woven Caddis Larva imitate this stage and can be deadly beneath an indicator, in a dry-dropper rig, or as part of a Euro nymphing setup.

Larvae are particularly worth imitating when higher flows begin knocking insects loose from their homes.

Imagine living peacefully in a house made of tiny pebbles until the river decides to relocate the entire neighborhood.

Trout tend to notice.

Caddis Pupae: The Most Important Stage You're Probably Underfishing

Eventually the larva seals itself into its case and transforms into a pupa.

Then things become interesting.

When development is complete, the pupa breaks free and begins moving toward the surface. Unlike a mayfly nymph that may drift passively during emergence, many caddis pupae actively swim upward.

That movement creates one of the most exciting feeding opportunities in the caddis life cycle.

Fish a Sparkle Pupa, Z-Wing Caddis, Chewee Caddis Emerger, Colorado Caddis, or Beadhead Shop Vac below the surface and don't assume a perfectly motionless dead drift is always the answer.

At the end of the drift, allow the fly to swing and rise.

That little acceleration toward the surface can imitate exactly what the natural insect is doing.

Sometimes the trout eat it so violently that any philosophical debate about whether you should have dead-drifted it becomes irrelevant.

When Trout Are Rising but Won't Eat Your Dry Fly

This is one of the classic caddis puzzles.

Fish are rising everywhere.

You tie on an Elk Hair Caddis.

Nothing.

You change size.

Nothing.

You change color.

Still nothing.

Before declaring that the trout have become personally vindictive, look closely at where they're feeding.

A trout eating emerging pupae just beneath the film can create a rise that looks remarkably similar to a fish eating adults from the surface.

If your high-floating dry fly is being ignored, try an X-hammer, Sedgememerger, wet caddis, or pupa pattern in or just beneath the surface film.

The difference between success and watching fifty trout ignore you may be half an inch of water.

Adult Caddis: When the River Starts Moving

Adult caddis are easy to recognize once you know what to look for.

Unlike the upright wings of an adult mayfly, a caddis rests with its wings folded over its body in a tent-like profile. The order name Trichoptera refers to their hairy wings, another defining characteristic of the adult insect.

Patterns such as the Elk Hair Caddis remain classics because that tent-wing profile can imitate an enormous range of adult caddis species simply by changing size and color.

Tan, olive, grey, black, and other natural shades cover a lot of water.

Start by matching size first, profile second, and color third.

Trout are generally more forgiving about whether your tan is precisely the correct shade of tan than whether you've tied on a size 10 fly during a size 18 hatch.

Don't Always Dead-Drift Your Caddis Dry

Traditional dry-fly advice teaches us to eliminate drag.

Usually that's excellent advice.

Caddis occasionally ignore it.

Adult caddis can skate, flutter, bounce, and skitter across the surface, particularly during egg-laying activity. When trout are chasing active adults, a slight twitch or short skate can make a dead fly suddenly look alive.

Do this selectively.

You are trying to imitate an insect struggling or moving across the surface—not water-ski your Elk Hair Caddis across the river at thirty miles per hour.

Watch the naturals.

The bug in front of you always outranks the fishing book.

What Size Caddis Fly Should I Use?

Most everyday caddis fishing falls comfortably into sizes 14–18, but the family ranges much wider.

Tiny caddis can require size 20 or smaller imitations.

Large species such as October Caddis can push you toward substantially larger patterns.

This is why carrying one tan Elk Hair Caddis in size 16 does not technically constitute a caddis box.

It constitutes optimism.

Build enough variation to cover several sizes, colors, and—most importantly—life stages.

Build a Caddis System, Not Just a Collection of Dry Flies

A useful caddis selection should let you follow the insect through the water column.

Start with larva patterns for the bottom.

Add pupae and emergers for insects moving toward the surface.

Carry low-riding emergers for the film.

Finish with adult caddis dries for the surface.

With those four pieces you can adjust as trout change feeding behavior rather than repeatedly changing from one adult pattern to another and wondering why nothing is improving.

If you're seeing caddis everywhere but can't determine the feeding stage, fish two stages at once.

An adult caddis with an emerger or pupa suspended beneath it can be remarkably effective because the trout get to tell you where dinner is being served.

Why Buy Caddis Flies From Ascent Fly Fishing?

Our approach to fly selection starts with the insect rather than the fly bin.

Instead of asking you to memorize hundreds of clever pattern names, we want you to understand what the naturals are doing and choose a fly that matches their size, profile, color, and life stage.

That makes a Jelly Cord Caddis Larva, Sparkle Pupa, X-Caddis, or Elk Hair Caddis more than another little bundle of thread and feathers.

It gives the pattern a job.

Turn over rocks.

Watch the surface.

Look for adults in streamside vegetation.

Pay attention to whether trout are feeding deep, bulging beneath the film, or actually eating from the top.

The river will usually tell you which fly to use.

You just have to ask the right questions.

Caddis Fly FAQs

What is the best caddis fly for trout?
If you could carry only one adult caddis pattern, the Elk Hair Caddis would be difficult to beat because changing its size and color allows it to imitate many species. For complete hatch coverage, however, carry larva, pupa, emerger, and adult patterns.

What size caddis flies should I carry?
Sizes 14–18 cover a tremendous amount of everyday caddis fishing, but a complete box should include smaller flies around 20 and larger patterns for species such as October Caddis.

What colors are best for caddis flies?
Tan and olive are excellent starting points, with grey, black, yellow, and other colors useful for matching particular species. Match the insects on your water whenever possible.

Should I fish caddis flies on the bottom or surface?
Both. Caddis larvae live near the bottom, pupae migrate upward through the water column, emergers occupy the surface film, and adults are fished on top. The best depth depends on the life stage trout are currently eating.

Why are trout rising but ignoring my Elk Hair Caddis?
They may actually be feeding on emerging pupae just below the surface. Try an X-Caddis, wet caddis, pupa, or emerger pattern in or beneath the film.

Can I swing caddis flies?
Absolutely. Swinging a caddis pupa or wet caddis can imitate the natural insect swimming toward the surface and can trigger aggressive strikes.

Caddis hatches can look wonderfully chaotic.

Fortunately, the solution doesn't need to be.

Figure out whether the bugs are crawling, swimming, emerging, or flying.

Match the size and profile.

Put the fly where the trout are feeding.

And let several million years of trout eating caddis take care of the rest.

Tight Lines, Friend!