October Caddis

By Greg Thomas

Call it what you like--fall caddis, October caddis , giant orange sedge--this I know: during September and October large trout key on that insect (genus Dicosmoecus) wherever it is present.

Where and When to Find Them

In the West, you'll find October caddis in most freestone streams and some tailwaters with strong current and rocky bottoms. You won't find them in spring creeks due to their grassy bottoms and moderate flow.

October caddis begin hatching in early September, and adults are available to trout through October. Activity peaks around the last week of September and the first couple weeks of October.

Even when October caddis are present in small numbers, trout take notice, and fishing with large, bulky patterns can be rewarding. You can't blame the fish for their eager attitude toward those bushy flies: an October caddis is a big meal.

The October caddis hatch doesn't resemble a big mayfly or early-season caddis hatch; you are not going to see clouds of them hovering over the water. Instead, you may only see a few caddis in the shoreline brush and, possibly, a few skittering across the water. But trout know when the October caddis is about, and they do not hesitate to pound a likely-looking pattern.

Flies and Tactics

When fishing an October caddis, you needn't worry about specific match-the-hatch situations like you might when imitating Baetis mayflies. Rather than worrying about nymphs, emergers, duns, and spinners, all you need is one dry fly and, if you insist, one nymph.

Top dry fly offerings include an orange or cream Stimulator and the Elk Hair October Caddis (an Elk Hair Caddis tied with a pale-orange or pale-yellow body). If you choose to probe the depths, try a size-8 or 10 pale-orange or pale-yellow bodied Serendipity .

When fishing a dry fly, takes could occur just about anywhere, but concentrate on the water near the bank. Bankwater is the most productive because October caddis cling to shoreline vegetation after they emerge, and they often drop onto the water. Good bankwater is 2-4 feet deep, has a rocky bottom, moderate to slow current, and has a few overhanging trees or other vegetation.

As an alternative to dry flies, use a Serendipity. This wet fly was created by Craig Mathews, who lives in West Yellowstone, Montana, and runs Blue Ribbon Flies. Originally intended to imitate size-18 to 24 midge larvae, it crosses over as a nice caddis larva imitation when tied on larger hooks.

Doug Persico, who runs Rock Creek Fisherman's Mercantile in Montana, told me about the Serendipity's dual role, and I've since used the pattern successfully on many Western waters.

When fishing orange Serendipities, work them through the bottom of medium-depth runs, and swing them through the tailouts of pools. Usually, trout hit as the fly begins its rise to the surface, an event that mimics the insect's most vulnerable moment.

Big Orange vs. Little Olive

On an overcast afternoon in late September, I was floating on the South Fork Boise below Anderson Ranch Dam. I was using an imitation of the small blue-winged olive mayfly. I caught a few fish, but the trout were wary and less than eager.

Finally, I tied out a pale-orange and yellow Stimulator and slapped it on the surface. I'd only seen a couple caddis along the bank, but I figured I'd give it a try. My friends smirked, pointed at my caddis imitation and hissed, "That's not going to work."

On the first or second cast, a big rainbow rose up and pounded the fly. That 17-inch buck was followed by ten of his cousins. My partners stuck with their tiny olive patterns and caught few trout.

So go ahead and match those tiny Baetis mayflies if you want, but make sure you carry a few October caddis patterns in your fly box, too. When the going gets tough, tie one on and launch it onto the surface. You'll enjoy your friends' responses when a big rainbow, cutthroat, or brown pounds your offering. Any extra caddis patterns in your box will draw top dollar during a spontaneous, hastily-engineered auction!