It might be a little early to begin talking about and preparing for October Caddis, but while fishing last week, we happened to see a large number of caddis cases … big caddis cases … attached to a rock partially submerged in the water. It looked as though someone had collected all of them and left the cases in a pile. Upon closer inspection, the caddis cases were attached to the rocks.

October Caddis Cases on Rock |

Here is a close up of the cased caddis. They build their houses out of the surrounding rocks where they live.

October Caddis in Case |

I pried one off and found the opening closed. What did that mean? I tore into one of the cases and found an October Caddis in its final stage of transforming from a larva into a pupa stage, preparing to swim to the surface and fly away as an adult. 

October Caddis Phase 1 |

Pulling away more rocks from the stone house, the pupa becomes more visible.

October Phase 2 |

October Caddis are in the final transitional stage of life as it changes from the larva to a pupa. It’s a similar process of a caterpillar enclosed in a cocoon, developing into a butterfly. I’ve read where this process can take up to two months.

October Caddis Pupa Out of Case |

You’ll see October Caddis adults begin to hatch in September, although my observation is the Metolius has them multiple months of the year. Perhaps there are several species within the Dicosmoecus genus that are hatching.

The Morrish Deep October Caddis is a great pattern to use by itself or attach a smaller nymph which will get it to the bottom because of the tungsten bead.

I wrote a post last year about October Caddis and their imitations. It was more about the adults because I had seen them flitting around the water.

I decided to re-post it here in case you need a refresher.

October Caddis |

The October Caddis (Dicosmoecus), otherwise known as the Giant Orange Sedge, hatches in September and October. These bugs are too big for the fish to ignore.

October Caddis Bottom View

This is one of the bugs big trout key on during the year. Other big bugs are the Golden StoneflySalmonfly, and my favorite – the Green Drake. My experience is the bigger fish show themselves during these hatches and it can be some of the best fishing of the year for large trout.

As an extra bonus, steelhead have been known to rise for an October Caddis pattern. How exciting would that be?

These bugs are BIG. I’m talking about a size 8 caddis pattern, not the smaller size 16 and 18 caddis, pale morning duns (PMD) and blue wing olives (BWO) the fish have been eating lately. Every once in a while, you’ll see a big, splashy rise. Maybe it was a fish taking an October Caddis!

The October Caddis is available to trout as a dry fly at three key times – just after hatching, during windy days, and when females lay their eggs.

Be sure to try an October Caddis dry fly along the bank in 2 to 4 feet of water with overhanging grasses, trees, or other vegetation. This is a likely spot for trout to hang out and grab a bug or two.

What flies should you have in your fly box to imitate an adult October Caddis?

Here is a fly I tied a couple of years ago. It’s a slight variation to a standard Elk Hair Caddis or Bucktail Caddis fly pattern I call the RiverKeeper October Caddis.

Other popular dry flies to imitate an October Caddis are a Stimulator, Orange Bucktail Caddis, and this Morrish October Caddis.

I think it’s time for a quick entomology lesson.

October Cased Caddis

Cased Caddis |

Most of a caddis’ life is spent in the larval stage inside a case, which they build from small rocks found on the stream bed. Prior to hatching, you’ll find these bugs crawling to the edge of riffles and runs, dragging their cases with them. They seal off the case opening and pupate to their next phase of life. When the time is right, the pupae climbs out of the case and swim to the surface or crawl out on a log or rock and transition the final time to an adult. The back of the pupae opens and out crawls a winged adult. (For some spectacular pictures of this transition, check out Arlen Thomason’s great book entitled Bug Waters). Generally, this transition from an aquatic insect to an adult can be a terrific time to fish a caddis hatch. But the October Caddis hatch isn’t one of them. They are known to hatch at night when it’s illegal for us to fish.

But that doesn’t mean the caddis pupae aren’t available to the trout. Gary LaFontaine in his epic book Caddisflies explains the October Caddis life-cycle. While growing in their cases, they outgrow them periodically and leave the case to start from scratch and build a bigger one. 

So my theory is the fish are used to seeing October Caddis and their imitations will catch trout when nymph fishing.

Two great caddis pupa fly patterns are the Morrish Deep October Caddis or a Bead Head October Caddis. I plan to add these fly patterns sheets soon to RiverKeeper Flies, so check back soon on the Caddis Fly Patterns page.

Adults spend time on the stream-side vegetation while preparing to mate. I think they watch the river and find their Zen! To complete their life-cycle, the adults mate and females begin laying their eggs within 48 hours after emerging.

Take a little break from fishing and look through the leaves. Use your observation skills. I’m sure you will find some October Caddis. As the day warms, the adults become more active. You’ll see the females flying over the water and dive-bombing to lay eggs with a splat. Every once in a while, I see a very splashy rise and think it has to be a trout taking an October Caddis.

I blind-cast these when I don’t see any fish rising and WHAM! Other times, cast it to a fish that’s eating other bugs and see if they’ll eat it. An occasional twitch of the rod tip will provide movement similar to the real caddis. Give it a try.

But you better be ready! Begin now preparing for October Caddis. Check your fly box and make sure you have a few flies to match the hatch.

Hopefully, you’ll catch one of these beauties!

October Caddis|

Enjoy…go fish!

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  1. Timely and informative as always. Have you tried a cased caddis fly, that imitates the bug as he crawls along dragging his case with him?

    1. Ron

      Thanks for your comment about October Caddis. I have seen fly patterns imitating that stage of the bug, however I haven’t tied any.


    2. I don’t think there are enough of them that the fish would get conditioned to and hence key into this type of pattern.

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