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October Caddis

Other Common Names: Fall caddis

Scientific Names: genus Dicosmoecus


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LARVA SIZE: 25-40 mm

LARVA COLOR: Pale yellow or brownish

PUPA SIZE: 20-30 mm

PUPA COLOR: Yellow to brownish orange

ADULT SIZE: 20-30 mm

ADULT COLOR: Orange body with dark red-brown wing to orange-brown wing

OTHER CHARACTERISTICS: Larval case made from pebbles. Body, wing, and shroud colors can vary, so it's always best to check a natural insect where you are fishing. Colors will darken when the insect is ready to lay eggs


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About October Caddis

This is the Great Pumpkin of Western rivers, a caddis that is almost as large as a golden stonefly. As the name suggests, it emerges in fall.

October caddis larvae build cases of small pebbles and live in moderate to fast flows. As a larva grows, it will abandon its case and build a new one. In the process it may get knocked lose and drift in the current. Even cased larvae sometimes end up in the drift, especially when they migrate to slower water in June and July. Where there is a large population of October caddis, it is not unusual for trout to eat drifting larvae, with or without the case. So a cased caddis pattern dead-drifted near the bottom a worthy strategy beginning a couple of months before the hatch season.

As it nears maturity, the larva will seal off its case and pupate. Many pupae emerge in water that is not very trouty, but a few come out where fish are found. Since this is such a big bug, it doesn't take very many of them to capture the interest of trout, and the fish will be looking for them. When you see adult October caddis around, it's worth drifting a pupa pattern near the bottom.

Adults survive for a couple of weeks after they hatch, and trout can be quite eager for them. The caddis are blown out of bankside vegetation and land on the water, and females return to the water to drop their eggs on the surface. At these times, a dry fly can be very productive. What fly angler can resist this final opportunity of the season to cast a large dry fly?

Articles About October Caddis

Click headline to read entire article

October Caddis This big, widely-dispersed bug is ignored by many fly anglers. Trout don't make the same mistake. Find out the best pattens and tactics. by Greg Thomas

Caddis Larvae--Part I Imitations of caddis adults and pupae are staples of a well-stocked Western fly box, but larva imitations are generaly absent. And the rare angler that carries larva patterns usually has the wrong ones. by Jeff Morgan


Larva. (photo © North American Benthological Society. Used by permission.)


Larva in habitat. (photo © 2006 Arlen Thomason. Used by permission.)


Adult. (photo © 2006 Arlen Thomason. Used by permission.)

top view

Adult. (photo © 2006 Arlen Thomason. Used by permission.)

Matching October Caddis

Only standard fly patterns are shown. Click here for all matching flies in the database.







Cased Caddis

2-8/Body: cream; Case: Brown

Indicator, Tight line

Moderate-fast runs, riffles


Deep Sparkle Pupa

6-8/Body: orange-brown; Shroud: tan

Indicator, Tight line




6-8/Body: light orange; Wing: tan

Standard dry fly

Bankwater near foilage



6-8/Body: light orange; Wing: tan

Standard dry fly, Surface swing

Runs, riffles

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