Caddisflies: The Underappreciated Hatch
Caddisflies are often overlooked by fly fishers focused on mayflies, but they’re critically important to trout.
Why Caddis Matter
- Available year-round in most waters
- Often emerge in large numbers
- Trout key on them selectively
- Multiple life stages available to fish
- Exciting fishing opportunities
Life Cycle Overview
Caddisflies undergo complete metamorphosis:
- Egg → 2. Larva → 3. Pupa → 4. Adult
The Complete Cycle: 1 Year
Most caddis species complete their life cycle in one year, though some take two years.
Stage 1: Egg
Duration: Days to weeks
Deposition:
- Females deposit eggs on water surface
- Some swim underwater to attach eggs
- Others lay eggs on vegetation overhanging water
Fishing note:
- Egg-laying activity can stimulate feeding
- Diving females draw strikes
- Skittering adult patterns effective
Stage 2: Larva
Duration: Months (most of the life cycle)
Types of larvae:
Case-building Caddis
- Build portable cases from materials
- Rock cases (common)
- Stick cases
- Sand cases
- Fishing: Peasant caddis, Green Caddis Larva
Net-spinning Caddis
- Build stationary nets in fast water
- Catch food drifting by
- Hydropsyche: Important genus
- Fishing: Green Rock Worm, bright green patterns
Free-living Caddis
- No cases
- Roam stream bottom
- Rhyacophila: Green Rock Worm
- Fishing: Green Caddis, Rock Worm
Larva fishing:
- Dead drift along bottom
- In faster water
- Zebra Caddis, Green Rock Worm
- Year-round food source
- Especially important when no hatches
Stage 3: Pupa
Duration: Days to weeks before emergence
The transformation:
- Larvae seals case or builds pupal case
- Transformation to adult occurs
- Pupa becomes active before emergence
- Emerges as air-filled pupa swims to surface
Emergence behavior:
- Highly active swimmers
- Rise quickly through water column
- Some emerge by crawling to shore
- Most emerge at surface
- Adults emerge in seconds
Pupa fishing:
- CRITICAL STAGE - trout focus on emerging pupae
- Rise from bottom through water column
- Patterns:
- Sparkle Pupa
- Deep Sparkle Pupa
- LaFontaine Sparkle Pupa (deep and emergent)
- Soft Hackles (swung)
Fishing techniques:
- Swing pupa through current
- Vary depth
- Active retrieve
- Takes can be hard
Stage 4: Adult
Duration: Days to weeks
Adult characteristics:
- Tent-shaped wings (folded roof-like)
- Long antennae
- Drab colors (tan, olive, gray, black)
- Fluttering flight (not graceful like mayflies)
Adult behavior:
- Fly to streamside vegetation
- Mate on streamside rocks/vegetation
- Return to water to lay eggs
- Egg-laying: diving, touching surface, or dropping eggs
Adult fishing:
- Elk Hair Caddis: Most popular pattern
- X-Caddis: Emerger/cripple
- CDC Caddis: More natural, floats well
- Godard’s Caddis: Low-riding
Presentation:
- Dead drift works
- Skittering more realistic
- Egg-laying females dive/skitter
- Takes often explosive
Key Caddis Genera
Hydropsyche (Net-spinner)
Sizes: 12-18 Colors: Olive, tan, gray Importance: Most common caddis in many rivers Patterns:
- Larva: Green Rock Worm
- Pupa: Sparkle Pupa (olive)
- Adult: Olive Elk Hair Caddis
Rhyacophila (Green Rock Worm)
Sizes: 10-16 Colors: Bright green Importance: Free-living predator Patterns:
- Larva: Green Rock Worm
- Pupa: Green Sparkle Pupa
- Adult: Dark Elk Hair Caddis
Brachycentrus (Mother’s Day Caddis)
Sizes: 14-18 Colors: Tan/olive Importance: Important spring hatch Patterns:
- Larva: Peek-a-boo Caddis
- Pupa: Sparkle Pupa
- Adult: Tan Elk Hair Caddis
Glossosoma (Little Black Caddis)
Sizes: 16-20 Colors: Black/dark gray Importance: Summer evenings Patterns:
- Adult: Black Elk Hair Caddis
Psilotreta (Longhorn Caddis)
Sizes: 10-14 Colors: Brown/black Importance: Eastern spring hatch Patterns:
- Adult: Brown Elk Hair Caddis
Seasonal Guide
Spring (March-May)
Mother’s Day Caddis (Brachycentrus):
- Size 14-18, tan/olive
- Abundant hatch
- Afternoon to evening
- Elk Hair Caddis in sizes 14-16
Grannom (Brachycentrus - black):
- Size 16-18, black
- Morning hatch
- Dark caddis patterns
Summer (June-August)
Hydropsyche (Spotted Sedge):
- Size 12-16, olive/tan
- Evening hatches
- Most consistent summer hatch
- Elk Hair Caddis, X-Caddis
Rhyacophila (Green Rock Worm):
- Size 12-16, bright green
- All season
- Larvae important year-round
Little Sisters (odd caddis):
- Size 16-18, tan/olive
- Evening hatches
Fall (September-November)
October Caddis (Dicosmoecus):
- Size 8-10, orange
- Large, showy hatch
- Afternoon to evening
- Orange Elk Hair Caddis
Green Sedges (Rhyacophila):
- Size 12-16, green
- Continue all season
Winter
Winter caddis:
- Size 16-20, dark gray/black
- Mid-day activity
- Sparse but consistent
Caddis Fishing Strategies
During Emergence
Pupa fishing:
- Sparkle Pupa sizes 12-18
- Vary depth
- Active retrieve or swing
- Takes often subtle
Dropper rig:
- Pupa on dropper
- Dry fly (adult) on top
- Cover both stages
During Egg-Laying
Adult fishing:
- Elk Hair Caddis
- Active retrieves (skitter)
- Diving caddis techniques
- Fish close to banks
Skittering technique:
- Cast across stream
- Strip line to create movement
- Fly skitters across surface
- Can trigger aggressive strikes
Between Hatches
Larva fishing:
- Dead drift along bottom
- Green Rock Worm
- Cased caddis patterns
- Fish slower water near banks
Reading Caddis Water
Emergence Zones
- Riffles: Most caddis emerge here
- Runs: Good pupa fishing
- Pool tails: Rising fish
Egg-Laying Zones
- Shallow riffles: Females dive here
- Pool heads: Activity concentrates
- Bank water: Egg-laying along edges
The LaFontaine Caddis Revolution
Gary LaFontaine’s groundbreaking research transformed caddis fishing:
Key discoveries:
- Pupae are air-filled (reflective)
- Trout key on the sparkly/reflective pupae
- Pupae rise quickly through water column
- Deep pupa important in water column
Patterns:
- Sparkle Pupa: Antron back for reflectivity
- Deep Sparkle Pupa: Weighted version
- Emergent Sparkle Pupa: Surface film
Common Mistakes
Fishing only adults:
- Pupae more important during emergence
- Larvae always available
- Match the stage fish are eating
Not varying depth:
- Pupae emerge at different depths
- Start deep, work shallower
Dead drifting only:
- Caddis are active insects
- Movement can be effective
- Especially egg-laying adults
Wrong size:
- Caddis typically size 12-18
- Don’t fish too small (unless it’s a small species)
The Essential Caddis Box
Pupae:
- Sparkle Pupa: Olive, tan, sizes 12-18
- Deep Sparkle Pupa: Sizes 12-16
- Soft Hackle: Sizes 12-16
Larvae:
- Green Rock Worm: Sizes 12-16
- Cased Caddis: Sizes 12-16
Adults:
- Elk Hair Caddis: Tan, olive, black, sizes 12-18
- X-Caddis: Sizes 12-18
- CDC Caddis: Sizes 14-18
Why Caddis Are Special
- Available year-round: Always something happening
- Multiple stages: Options for any situation
- Exciting fishing: Aggressive takes
- Under-appreciated: Less pressure than mayfly hatches
- Consistent: Even when mayflies aren’t hatching
Next time you’re on the water and don’t see mayflies, don’t worry. The caddis are probably hatching, and the trout are feeding.
Tie on a caddis pattern and enjoy some of the most exciting fishing of the year.