This is a superhatch in the West. Gary LaFontaine had a self-proclaimed obsession with Dicosmoecus, and he devotes several pages of Caddisflies to stressing the importance of its larvae, pupae, and adults. He wrote:
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.
His reasons for this judgement are five traits of Dicosmoecus:
- Very large size: Adults 30mm long, and thick.
- Activity concentrated within 2-3 weeks.
- Emerges in the low, clear water of fall.
- Active during afternoon and evening.
- Abundant in rivers with sea-run trout
http://www.grahamowengallery.com/fishing/more-fly-tying.html (If you have the time and are enormously gifted like Owen)