Caddis Life Cycle and Tactics

Fly fishing the life cycle of the caddis hatch begins by realizing that the most important food source in western rivers is the caddis fly. They are a year-round food source with populations higher than mayflies and stoneflies in most streams. This includes the Eagle River and Roaring Fork River, which will soon seen large pots-runoff caddis fly hatches.

Learning how to fly fish all aspects of the caddis hatch allows fly fishermen to catch trout throughout the morning, afternoon and evening.  Caddis offer the angler a variety of fly fishing challenges. The learning of exciting new techniques to overcome these challenges can be as fun as standing in the middle of the Eagle River during a blizzard caddis hatch.

During an amazing caddis hatch on the Madison River some time ago, I happened upon fly fishing’s foremost caddis expert who is now sadly no longer with us, “Mr. Caddis” Gary Lafontaine himself.  That day he gave a kid from Connecticut, like himself, a few flies and some advice.  He told me movement was the key to unlocking the caddis hatch, given the right size, shape and color of your fly.  After reading his well-known epic book Caddis, it made more sense.  Strikes can be triggered by fly movement and the mystery of fly fishing the caddis hatch could be unlocked by using some savvy techniques and materials.

Caddis Larva

Fly Fisherman need to realize that caddis are in the rivers and available to fish year round.  They begin to move about actively when water temperatures rise to the high forties.  Trout will often eat the free swimming caddis larva or cased caddis as it sits on rocks when no hatch or food source is prevalent.  These green, olive and cream caddis larvas’s will run from size 12 to 16 and need to move about in the river for new size homes or simply to eat.  A good fly to imitate the large cream colored larva is the Buckskin, the electric caddis in size 16 is a great bright green larva imitation and a olive Hare’s ear will work well for the olive caddis larva. Whether cased or free swimming, the larvae stage is always important.

Biological Drift

Scientists know caddis fly’s use currents in the waters they inhibit to relocate or hatch in the river.  Biological drift tends to occur very early in the morning which is a tip on when to try mimicking this behavior with dead drifted caddis patterns. Many species of western caddis outgrow their pebble or woody  homes several times during their lifetimes and drift to new locations. Others just use a thread to have some lunch on algae or plankton and retreat back into their carefully constructed lodge pole pine tubes while still others after being totally enclosed for some time transform from larva to pupa then pop out of their case, riding and swimming downstream with the current before riding an air bubble to the surface.  The prince nymph is an excellent searching pattern during biological drift.  Size 12 to 18 will cover most species.

Caddis Pupa

Pupation in the life cycle of the caddis fly occurs after the larva has sealed itself away in its case for transformation.  The pupa tend to be yellowish, brownish, greenish, olive and tan and are typically going to run a size or two smaller than the larvae.  Caddis pupa use air bubbles to propel them to the surface quickly where they are sometimes delayed by the water tension and will pause momentarily. Trout try to catch them prior to their escape.  Often the slashing, aggressive feeding that brings trout completely out of the water are fish chasing caddis pupae.  Use patterns that will hold air bubbles and treat your nymphs with dry fly powder to enhance the effect.  Soft hackle wet flies swung through the current also work well.

The “Liesingring lift” was a method developed years ago which is still effective today.  Simply let your nymph imitations get down and when the drift reaches the end let it ascend slowly up through the current.  Use a light hook set and extra heavy tippet because hits are hard.  Some of my favorite caddis pupa fly patterns are the La Fontaine Sparkle Caddis pupa and the Western Coachman.

Ovipositing Caddis

The often overlooked stage of the life cycle of the caddis fly is ovipositing or egg laying stage.  In the spring and summer western trout, especially at dawn and dusk,  key on the ovipositing caddis.  These flies will enter the river with an air bubble to use like a scuba diver, breathing as they are diving down to the bottom to deposit their eggs.  The air bubble illuminates the fly making it very visible to feeding trout.  Soft hackle fly types and flashy patterns work well here like the diving caddis.  Dead drift or twitching your fly will work.  If you are using a dry fly when trout are biting on ascending and descending caddis you will notice a lot of activity going on in the water and not on your fly.

Dry Fly Opportunities

When the moth-like adult caddis, which range from tan to dark grey and from #18 to #8 are on the surface, movement is not always necessary when fishing caddis dry flies.  However, wise western trout guides use action as part of their dry fly fishing.  Selective trout will key on the way a caddis takes off from the water and only hit flies on the move.  Other selective fish will hit a cripple pattern like an X-caddis and not even think of touching an elk hair caddis.  Still other selective caddis will only eat a certain color. One of my favorites is the Lime Wulff to imitate the egg sack of an ovipositing female on the surface. Stimulators, Foam Caddis and Renegades are all effective flies.
No longer should you be left out in the river in the middle of a caddis hatch and not get anything but frustrated.  Begin to think of how fishing the life cycle of the caddis hatch can help your chances instead of just putting on an elk hair caddis dry and not catching much.

Should you require more information please contact Vail Valley Anglers, for some great caddis fly patterns!

Bill Perry, Guide and Content Writer