Trout Love Caddis.

You Should Too.

It's the merry month of May, and as usual, the fly-fishing world is gaga over mayflies. Or at least that part of the fly-fishing world that's addicted to hatches and rising trout, which is a lot of us.

It's no surprise; a mayfly hatch is a really cool phenomenon, and the major hatches of spring really do bring on some extraordinary fishing. Still, if there's an aquatic fly that fly-fishers should be really jazzed about, maybe it's one with four times as many species as mayflies (and more yet to be named), one found in many more bodies of water, one that's probably a larger part of the diet of most trout: the caddis fly.

Caddis are interesting little critters. The larvae of most caddis species build cases to live in, and they're often extraordinary - some are tubes of sand and fine gravel, others have flat sides at perfect right angles to each other. The caddis larva extends the length of the cocoon to accommodate its growth. Fossils of these little structures have been found in rocks 200 million years old.

Caddis are like mayflies in the sense that they're aquatic insects that spend most of their lives as larvae in streams and eventually "hatch" into winged adults and fly away to reproduce. But they also differ from mayflies in several ways.

Immature caddis have both larval and pupal stages, whereas mayflies transform straight from nymph to winged adult. Adult caddis have moth-like wings that lie flat along their body when at rest, unlike the upright wings of mayflies. Caddis have no tails. In terms of behavior, caddis don't emerge as obviously as mayflies do, mostly because they don't loiter on the stream surface upon completing the transition from pupa to adult. And while freshly mated mayflies simply fall spent to the stream surface to lay their eggs, many caddis actually dive and swim to the bottom to lay their eggs.

Mayfly species tend to hatch in a sequence so predictable they can be listed on a chart - Hendricksons, late April/early May, Green Drakes late May/early June, etc. Much less effort has been made to identify the hatching schedules of different species of caddis flies and design flies to match them. Then again, it seems like some species of caddis is always hatching, or at least around, and sometimes more than one species.

You don't need a million patterns to catch trout feeding on caddis. They tend to range from 1/4" to 1/2" in size, which translates roughly to hook sizes 12 to 18, and most have tannish-gray wings. Some are smaller or larger, and there is some variation in colors, including black and cinnamon.

Generally, a few basic patterns will do. Here are some suggestions for matching the different life stages of our moth-like friends:

Larvae

These are the nymphs or the caddis world. They're also very simple insects to imitate, not much more than a segmented grub on either a straight or curved hook. Most of the flies known as Czech nymphs or Euro nymphs are basically caddis larva patterns. The Bead-Head Woven Nymph, Czech Mate Nymph (use the tungsten bead version to fish deep), and attractor patterns like the Prince and the Gold-Ribbed Hare's Ear (even though they have tails) can all be effective.

Pupae

This is the life stage where caddis have legs, feelers and wing pads, the transition stage between a larva and a winged adult. They can be fished shallow, often just below the surface or even in the surface film, to imitate emerging flies, but can also be fished deep (where trout usually are), especially the bead-head versions, which sink well. Pupa patterns often have feather fibers to suggest the legs and feelers; examples are the Partridge and Green/Yellow/Orange, Le Bug and Zug Bug

Adults

The best-known caddis dry fly, and for that matter one of the best dry flies of any kind, is the Elk-Hair Caddis. An assortment with tan, cinnamon, olive, and bright green bodies in sizes 12 through 18 will cover the majority of surface caddis feeding activity. The best-known emerging caddis - a fly that simulates the messy transition from pupa to adult - is the one invented by fly-fishing's most ardent student of caddis flies, the late Gary LaFontaine, who invented the Sparkle Pupa. The Fluttering Caddis, with its large front hackle, imitates caddies flies doing what they so often seem to do, fly around just above the surface of the water. The Henryville Caddis and Goddard Caddis are time-tested patterns. The Parachute Caddis and Parachute Madam X are designed to float with their bodies flush in the surface, which trout seem to like.

Oh, and don't forget that old-fashioned winged wet flies like the Leadwing Coachman can be good imitations of diving, egg-laying caddis.

How to fish caddis flies? If you see trout rising or feeding very near the surface and suspect it's caddis they're after, use one of the adult patterns, or a pupa fished shallow. If there's no surface activity, tie on a deep-running pupa or a larva and explore the depths. Either way, you can fish with confidence that you're offering the trout an imitation of something they like a lot - maybe even more than mayflies.