This common name refers to only one genus.
These are sometimes called Fall Caddisflies.
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.
I have never fished the West to experience Dicosmoecus
, but I have enough experience with Hexagenia limbata
to know that a greater insect must be truly amazing.