The Mother’s Day Caddis hatch is well-known and can be amazing to see. And it’s right around the corner.

Massive Caddis Hatch |

Yes, all those dots in the picture are caddis flying over the water!

Thousands and thousands of American Grannom (Brachycentrus occidentalis) hatch at this time of year. These caddis are the ones building square-shaped cases you see on rocks in riffly water or in runs of moderate to fast flows.

UPDATE 5/18/2017 – The photo below was part of the original post and at the time I thought it was an American Grannom. James left a comment that the bug was an Alderfly (Megaloptera) instead of a Grannom. After a little more research, I agree with him. What was the tell-tale fact? Caddis have hair on the wings and it is clear this bug doesn’t have any. So I apologize to my readers for being misleading…I hate to be wrong, but I admit it when I am.

American Grannom |

The Mother’s Day Caddis are size 14 for the females and the males size 16. Grannoms generally hatch in the spring and again in the fall. The fall hatches are the small black caddis you see flying around.

So let’s talk about caddisflies for a moment. Their life cycle is different than mayflies and salmonflies. Caddis hatch from eggs into larva and the larva stage is how they live most of their life on the bottom of a river. Their third stage of life is a pupae, where the caddis grow the required body parts to rise to the surface, become an adult, and fly away to mate and continue the species.

There are three basic types of caddisflies – free-living, net spinners, and case makers.

Free-living caddis larva can be found on the bottom of rivers where they spin silk into threads and attach it to the rocks. This allows them to crawl along the rocks looking for food and they’re able to use the silk safety line to prevent themselves from being washed downstream.

Net spinning caddis build nets of silk to catch food, including plant and animals the current provides as water flows through these nets. The nets are built in cracks and crevices of rocks and woody debris.

Case makers live not only in rivers and streams, but also lakes and ponds. Their cases are built from the products of their environment – sand, twigs, pebbles, leaves. As with the other types of caddis, the silk they create holds the building-blocks of their homes together.

Here are three caddis cases from the river.

Caddis case with rocks
Cased Caddis with Rocks |
Caddis case with Reeds and sticks
Cased Caddis with Sticks |
Caddis case with reeds
Cased Caddis with Reeds |

And a video from my Youtube Channel:

Caddisflies breath through the gills located along their bodies. For the case makers, the openings at both ends of the case allow water to flow through and past their gills.

The American Grannom are case maker caddis. If they haven’t hatched yet, these caddis are still in their pupal cases, getting ready to hatch into an adult to finish their life-cycle.

Many times the best fly fishing can be to imitate the pupa swimming to the surface because the trout key on them. I used to think fishing with an Elk Hair Caddis or Deer Hair Caddis would catch lots of fish. And it can. But consider using a few transitional flies to increase your success.

Here are a few ideas of flies to have in your fly box:

Partridge & Peacock
Peacock & Partridge |

LaFontaine Sparkle Pupa

LaFontaine Sparkle Pupa |

LaFontaine Emergent Sparkle Pupa

LaFontaine Emergent Sparkle Pupa Green |

Silvey’s Caddis Pupa (in olive)

Silvey's Caddis Pupa |

Iris Caddis

Iris Caddis |


X Caddis - Olive |

Hemingway Caddis

Hemingway Caddis - Olive |

Lastly, give a LaFontaine Diving Caddis a try because the female swims or crawls underwater to lay her eggs and this pattern can be deadly.

LaFontaine Diving Caddis |

I was in Ellensburg, WA last week tying flies at the Washington Fly Fishing Fair. I arrived a couple days early in hope of catching the Mother’s Day caddis hatch, but the Yakima didn’t produce for me.

It’s run-off time on the river. I had one day when the river looked good, but no fish were rising. Two days later, the river looked like this.

Yakima River |

Oh well, that’s fishing…

Enjoy…go fish!

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  1. Hey John – the pic of the bug in the Mothers Day Caddis article is not a caddis it is and Alder Fly.

    See Dave Hughes famous Alder Wet Fly to imitate. This fly has been around for 200 years.

    1. James

      Thanks for your comment. I’ll be sure to check it out! I thought for sure I had a good picture of a grannom. I’ll have to do more research.


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