Fly Fishing Saddle Case Caddis Patterns & Hatches Guide

Description

Saddle Case Caddis (Glossosoma) are widely abundant grazers found in many clean, cold trout streams. Their defining characteristic is the case they build: a dome-shaped structure made of small pebbles that covers them like a turtle shell or saddle. A strap underneath holds the larva inside, allowing it to crawl over rocks and graze on algae while staying protected. They are smaller than many other caddis, typically size #16 to #20. Because they graze on top of rocks in the current, they are frequently dislodged and drift downstream, making them a consistent food source for trout even when a hatch isn't visible.

Life Cycle Stages

Larva

The larva spends its life inside its pebble case. The head and legs peek out to feed. The larva itself is often cream or pale pale-olive with a dark head. Trout consume them case and all, so patterns that incorporate a bead or material simulating the stone case are effective. The "peeking caddis" style patterns are excellent imitations.

Recommended Fly Patterns

Hare's Ear Jig

#10-#18

Natural, Olive, Brown, Black

Spanish Bullet Perdigon

#14-#18

Olive, Brown, Copper, Black

Green Weenie

#10-#14

Chartreuse, Green

Czech Nymph (Caddis Variant)

#12-#16

Olive/Tan, Green/Tan

LaFontaine's Green Caddis Larva

#12-#16

Green, Olive

Green Caddis Larva

#12-#18

Green, Olive, Chartreuse

Caddis Larva

#12-#18

Olive, Tan, Brown, Gray

Buckskin

#14-#18

Tan, Cream, Olive

Pupa

Before hatching, the larva seals its case against a rock. When the pupa emerges, it cuts the seal and swims to the surface. This emergence often happens in the morning or evening. The pupa is vulnerable as it ascends. It is typically a dull olive or brownish color with developing wing pads.

Recommended Fly Patterns

Klinkhammer Special

#12-#18

Tan, Olive, Peacock, Black

Silvey's Caddis Pupa

#14-#16

Olive, Tan

LaFontaine's Sparkle Pupa

#14-#18

Green, Olive, Tan

Soft Hackle Caddis

#12-#16

Orange, Tan, Olive, Brown

Z-Wing Caddis

#14-#18

Olive, Tan, Brown

Graphic Caddis

#14-#18

Olive, Tan

Adult

The adult Saddle Case Caddis is a small, brownish-grey insect. They are often overlooked due to their small size and drab color, but trout sip them gently in the surface film. Key features include the tent-shaped wings and long antennae.

Recommended Fly Patterns

Elk Hair Caddis

#8-#18

Tan, Olive, Brown, Orange, Yellow

Garcia's Mother's Day Caddis

#14-#16

Black, Chartreuse

Missing Link Caddis

#14-#18

Amber, Dark, Tan

X-Caddis

#14-#18

Tan, Olive, Brown

Madam X

#8-#14

Yellow, Olive, Tan, Brown

Habitat

Glossosoma prefer medium to fast currents with stable, rocky bottoms. They are grazers, so they need rocks with a healthy film of algae. You will often find them clustered in large numbers on the tops and sides of cobble-sized rocks in knee-deep runs and riffles.

Behavior

These caddis are grazers, moving slowly over rocks to scrape algae. This exposes them to the current, and "drift" is a common occurrence. Emergence is typically quick, but adults can be long-lived. Females dive or crawl underwater to lay eggs, creating another opportunity for subsurface fishing.

Fishing Information

Seasonality Activity spans from Spring through Fall, with peaks often in late Spring or early Autumn depending on the river.

Tactics

Nymphing: A small, sterile caddis pupa or "peeking caddis" pattern is deadly when fished dead-drift near the bottom.
Dry Dropper: A small adult pattern with a tiny caddis larva dropper is brilliant in pocket water.
Fine Tippet: Because they are small (#18-20), 5X or 6X tippet is often necessary for drag-free drifts.

Recommended Patterns

Larva: Buckskin Caddis, Peeking Caddis, Hare's Ear (Small)
Pupa: Sparkle Pupa (Tan/Grey), LaFontaine's Deep Sparkle Pupa
Adult: Elk Hair Caddis (Tan/Grey #18), Hackle Stacker Caddis

Conservation Status

Like other stone-cased caddis, Glossosoma require clean substrates. Excessive siltation fills the gaps between rocks and smothers the algae they feed on. Stable river flows and reduced sediment input are vital for their survival.