Caddis Confusion?

If you bring patterns to imitate the three stages of caddis flies' life cycle, you'll catch more trout this summer.

Photo by Chuck Robbins.

For the Western fly-rodder, caddis-flies -- and the splashy rises of trout plucking them from the surface -- define summer. While this bonanza offers some of the best dry-fly action of the year, most caddisflies never complete their life cycle to become a tent-winged adult insect. They get eaten by trout before they ever reach the surface, much less spread their wings and do their mating dance.

Their order, Trichoptera, represents the most diverse species of insects that are exclusively aquatic in their larval stage. There are thousands of individual species of caddis-flies, and trout fishermen need to know a few things about them.

I spent 10 years guiding summertime anglers on some of the West's finest caddisfly rivers. I learned most of these patterns and techniques from gents who'd been at it much longer than I had, and made a few innovations of my own. Add these techniques and patterns to your repertoire and enjoy a better summer of fishing.

A BUG'S LIFE
Caddisflies have a life cycle of three stages: larva, pupa and adult. They're different than say, stoneflies, whose larvae hatch directly into adult insects. Take the time to look at the caddis' life cycle and see how trout feed on them during each individual stage, and you'll hook more trout this summer.

1) Larva
All caddis fly larvae are capable of spinning silk. But how they use this silk is what separates them and dictates their appearance. The three varieties of caddis larvae are:

'¢ Cased-caddis,

'¢ Net-spinning caddis, and

'¢ Free-living caddis. This last category, the free-living, is of little concern to any stream fisherman because they primarily exist in lakes, and even then, are largely unavailable to trout.

Cased-caddis create a case around their fragile bodies, using silk and stream-borne debris. By rolling rocks, you can find their cases -- generally about a half-inch long and looking like a conical tube of sand and twigs.

When a larva is undisturbed, it will generally poke its head out of the case and become visible.

Cased-caddis larvae often become dislodged in the currents of swift riffles. When trout find them, they eat them -- case and all.

Imitating a cased-caddis larva is very simple, and a Zug Bug or Prince Nymph can pass as one. But a more specific fly that I prefer is a Beadhead Cased-Caddis.

(For examples of the patterns discussed in this article, check your local fly shop, or visit www.idylwilde.com, or www.umpqua.com.)

Fish your cased-caddis imitation the way you would a dead-drifted nymph. Use a strike indicator and enough split shot to keep it bouncing along the bottom.

Target swift riffles and the current breaks below them. That's where opportunistic trout will lie in wait.

I often fish this pattern as a dropper on a tandem rig with a stonefly nymph above it. The larger stonefly nymph keeps the caddis larva in the zone and also draws the attention of fish -- which may then opt for the smaller caddis pattern.

Net-spinning caddis don't build a case. They construct a rough shelter of gravel and debris that they attach to the sides of rocks, similar to a lean-to. Then they spin a net, much like a spider's web, to trap their food.

Just like cased-caddis, they are vulnerable to the very currents that sustain them and can get swept off in fast water.

For imitating net-spinning larvae, the Z-Wing Caddis is a very good pattern. Fish it the same as you would a cased-caddis. It's a good idea to fish a cased-caddis and a net-builder in tandem so you can find out which the fish may be keying on.

But in general, caddis larvae are opportunistic food randomly eaten by trout. Any boost in water flow or another disturbance can cause unusual numbers of them to be dislodged and create voracious feeding behavior in trout.

2) Pupa
When water temperatures and conditions dictate, caddis larvae hatch into pupae and begin their ascent to the surface to complete their life cycle as adults. If caddisflies are hatching, you can pretty much bet that trout will be feeding on the emerging pupae -- especially at times when they seem to be largely ignoring the adults on the surface.

When I know that caddisflies are on the menu, I fish two pupae imitations sub-surface. Then if I see enough fish starting to rise to take adult caddis, that warrants my switching to a dry fly.

My favorite caddis pupa patterns are the Riffle Diver and the Sparkle Pupa, both in green-chartreuse and tan-ginger. These are the two most common caddis-pupa colors, and I've never had occasion to make my color selection any more complicated.

I generally fish Riffle Divers one of two ways.

'¢ The first is underneath a strike indicator as part of a tandem rig with a small split-shot. If I'm fishing water eight feet deep, my leader would be seven feet long to get the fly to the bottom. I cast the flies 45 degrees upstream and mend my line to allow them to settle just off the bottom.

Then as they drift past me, I slowly raise the rod tip. That gives the impression of caddis pupa rising up through the water column.

Watch and feel carefully for a strike just after the cast as well. The action of this dropping fly can imitate a female caddis diving down on her way to deposit her eggs.

'¢ The second is on a wet-fly swing. This technique is too largely ignored by modern trout anglers, but during a caddis hatch, it can be deadly.

With the wet-fly swing, cast the fly 45 degrees downstream. Mend accordingly to achieve a consistent speed as the flies swing in towards the shore below you.

The fly should be presented just below the surface. An intermediate sinking-tip fly line is the best way to put the flies in the right zone. For about $10, you can buy 5- and 10-foot intermediate sinking leaders at fly shops and attached them to the end of a floating fly line.

In addition to being a very effec

tive method, this presentation is relatively simple. There's also an added bonus. The fish taking a tight line is an exhilarating sensation, which is why steelhead fly-fishers also prefer this presentation method.

I was first introduced to the Sparkle Pupa years ago on the Deschutes River in Oregon. When I fish for snobby trout that like to swim around back eddies, this fly has turned my luck around. The Sparkle Pupa usually fools them if properly presented.

With its trailing shuck, this fly is designed to imitate a pupa that's just about to hatch into an adult. I fish this pattern almost exclusively as a back-eddy or slack-water fly because it rides low and is deadly for fooling the tough trout.

Fish a longer leader of 10 or 12 feet, with a light tippet of 5X or 6X.

Fish this fly in the surface film. If it gets waterlogged, add some floatant to keep it hovering in the zone.

3) Adult
I'll say it again: Adult caddisflies offer some of the best dry-fly action of the year, especially on those magical evenings when the entire river boils with the mating rituals of millions of fluttering caddisflies.

During these hatches, often the only fly you need is the old standby, Elk-Hair Caddis. This dry fly is bushy, floats high and is easy to see. I pack them in green and tan in sizes ranging from No. 12 to 16.

When the fish are being picky, the X-Caddis is my go-to dry fly. This imitates a stuck-in-the-shuck adult, which is a vulnerable little critter. And trout, like all predators, can't resist struggling prey.

It's also one of the easiest patterns to tie. The only drawback is that on the surface, it can be hard to see.

So I'll often fish this fly on a two-fly dry-fly rig tied to the bend of the hook of a bushy, high-riding Elk-Hair Caddis.

Magazine Cover

GET THE MAGAZINE Subscribe & Save

Temporary Price Reduction

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Get the top Game & Fish stories delivered right to your inbox every week.