The October Caddis, Limnephilidae Dicosmoecoes, adults hatch in late fall, anywhere from late September to November in the Pacific Northwest. These large, orange caddis flies are approximately three centimeters long and provide too large a meal for big trout to pass up.
Considered by many to be a Western ‘superhatch’, TroutNut.com says caddis fly aficionado Gary LaFontaine considers this the most important hatch to fly fishermen because the bugs are huge, the activity is concentrated into the course of a few weeks, and the hatch occurs in prime fly fishing river level conditions.
From the often quoted LaFontaine book Caddisflies:
The question for fly fishermen seeking big trout is: “Which insects provide the best opportunity for catching such fish?” My list would be: Giant Orange Sedge (Dicosmoecus sp.), Salmon Fly (Pteronarcys californica, a stonefly), and the Michigan Mayfly (Hexagenia limbata). Dicosmoecus is the most important — and the contest is not even close.
October caddis advice from Jim Schollmeyer’s Hatch Guide For Western Streams:
These large caddisflies are hard to miss when you see them flying through the air and touching down on the water. Emergence and ovipositing often occur at the same time and normally the caddisflies you see on or above open water are egg laying females. To imitate their movements, use a well hackled fly that will skitter around with a light twitch of the line. For the spent or motionless adults, a non-hackled low-profile fly works best.
When this bug is available fish do really get on it in a traditional dry fly manor. But the October Caddis is so active in it’s adult stage that fish have a hard time nabbing it out of the air with it’s erratic fly pattern. When the bug is dead, egg laying or knocked from the trees on a windy or rainy day it becomes more available. Fall evenings are your best opportunities to see good numbers of the October Caddis. On the Mckenzie and Willamette I have seen these bugs in good numbers through November.
Numerous patterns seem to bring fish to surface during the October Caddis, dark wings and orange bodies seem to be the trick in terms of fly recipes. Here are a few of our best October Caddis Patterns and fly tying videos: