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Caddisfly

Caddis

Trichoptera · order

Caddis are a staple Idaho trout food, with fishable larva, pupa, and adult stages in many waters.

Overview

About Caddis

Caddisflies are the insect order Trichoptera: aquatic as larvae and pupae, terrestrial as adults. For anglers, they matter because they occur in a wide range of waters and can be important from the bottom-dwelling larval stage through the rising, active pupal stage to the fluttering adult.

Also known as: Green Sedge Caddis, Hydropsyche, Rhyacophila, Spotted Sedge Caddis

Life Cycle

EGGS

Caddisfly females deposit clusters of eggs in or near the water, often attached to submerged objects.

FREE LIVING LARVA

After hatching, these larvae feed and grow on the stream bottom, forming a crucial part of the aquatic food chain.

CASED CADDIS

Many caddisfly larvae construct protective portable cases from materials like sand, pebbles, or plant debris, which they carry as they move.

PUPA

In the spring, caddisfly larvae pupate in sheltered areas, typically under rocks in flowing water, transforming into their adult form.

EMERGING ADULT

The adult caddisfly rises from its pupal skin at the water's surface, preparing for its aerial life.

ADULT CADDIS

Adult caddisflies are short-lived, flying near water to mate and begin the next generation.

EGG LAYING ADULT

Female adult caddisflies return to the water to deposit their eggs, completing the cycle and starting it anew.

Stages: Egg to aquatic larva, then pupa, then terrestrial adult. Anglers most often imitate the larva near the bottom, the ascending pupa during emergence, and the adult skittering or resting on the surface.
Emergence cues: Most activity is tied to warmer seasonal windows, stable flows, and periods when pupae rise through the water column; adults are often most visible in low light or during calm surface periods.
Behavior: Larvae live on or near the bottom, with some building portable cases and others fixed retreats. Pupae become active and swim or drift upward to hatch; adults are short-lived, often flutter, skate, or bounce on the surface, and can return to the water to lay eggs.

How to Tie Caddis Patterns

FREE LIVING LARVA

Caddis Larva

tightlinevideo

Materials

Hooksizes 14-16Barbless Tactical Czech Nymph
UTC70 Denier or 8/0 or yellow olive
Dubbing #1Australian-possum - light olive
Dubbing #2Australian-possum - dark brown

CASED CADDIS

Cased Caddis - How to Tie the Best Trout Fly Ever!

Fliesbyaspeen

Materials

Fulling Mill FM51Size 14
Fulling Mill 3.8 matt black tungsten
Troutline Sumo Power 50DBlack
Lead Wire0.1mm
Deer Hair + Olive Mad Rabbit Dubbing
Roe Deer HairOlive

PUPA

JC's Electric Caddis Larva

tightlinevideo

Materials

Scud hooksizes 14-16here, an Daiichi 1120
Thread8/0 or 70 Denierfluorescent green
Antron yarnfluorescent green
Ultra Wiresize smallChartreuse
Stretch Tubingsize microChartreuse
Ostrich herlbrown
Permanent markerBrown

EMERGING ADULT

Holy Grail Caddis Emerger Fly Tying Tutorial | The Fly Fiend.

The Fly Fiend

Materials

Hook10Daiichi 1120 curved hook, can be tied down to size 14
Bead1/8"Gold
ThreadUTC brown olive
RibSmallUTC Ultra Wire, chartreuse
BodyGreen dubbing, blended from a hare’s mask
Wing caseNatural pheasant-tail fibers, about 8 to 10 fibers
Thorax/head dubbingSquirrel SLF Spiky Dubbing, brown olive
Wing-case coatingLoon Outdoors UV Clear Fly Finish, Thick

ADULT CADDIS

FASTEST and most EFFECTIVE Caddis Dry Fly You Can Make

Fliesbyaspeen

Materials

HookSize 14
Thread
DubbingHare's Ear
CDC Feathers
HackleWhiting Grizzly Saddle
HookSize 16
Thread
DubbingHare's Ear
Thorax DubbingBlack Pepper
HackleWhiting Grizzly Saddle

EGG LAYING ADULT

How to tie the Egg Laying Foam Caddis | Fly Tying Tutorial

AvidMax

Materials

HookSize 16Tiemco TMC 2488 Short Shank Nymph Hook
Thread16/0Veevus, black
DubbingHareline Super Fine Dry Fly - caddis green
UTC Ultra WireSmallCopper
Pheasant Tail FeathersHareline Ringneck - natural
Foam2mmMFC Foto - Mottled Tan
1/2 CapeWhiting Farms Pro Grade - barred ginger
DubbingHareline Super Fine Dry Fly - Brown

Where It Hatches

Caddis

One species, multiple rivers.

River

Fly Patterns

Caddis Pupa#10-18
Elk Hair Caddis#12-18
Soft Hackle#12-18
X-Caddis#14-18

Angler Notes

Why it matters: Caddis are one of the most dependable match-the-hatch groups because trout may feed on them subsurface and on top. Fish often key hardest on the pupa during emergence, but larva and adult imitations both have important windows.
Imitation tips: Carry a simple spread: cased or free-living larva in olive/tan/green, pupa in tan/olive/cream with a bit of sparkle or soft movement, and adult elk-hair or low-riding sedge patterns in tan, brown, gray, or black. Match size first, then stage, then color.
Key life stages: larvapupaadult
Presentation: Dead-drift larva near bottom, swing or lift pupae through the water column, and fish adults as a dead drift with occasional subtle skittering or twitching when fish are chasing egg-layers.

Identification

Key features: Adults look moth-like, with two pairs of hairy wings held roof-like over the body; larvae are soft-bodied and often found in protective cases or retreats made with silk and stream debris. Pupae are compact and active before emergence, often rising or drifting toward the surface.
Size: Mostly small to medium; commonly imitated from about #8 to #20 depending on species and stage.
Coloration: Common tones run tan, olive, brown, gray, cream, and black; larvae often match their case or surrounding substrate.
Similar bugs: small mothsstonefliesmayfliesmidges

Habitat

Water types: riversstreamslakespondsspring seepstemporary waters
Substrate: Rock, gravel, sand, woody debris, aquatic vegetation, and other bottom materials used for cases, retreats, or cover.
Conditions: Found in a broad range of aquatic habitats, but many trout-important species are associated with clean, well-oxygenated water.