Mercury Caddis

The Mercury Caddis, created by Pat Dorsey, was developed alongside the rest of the Mercury series and quickly became a dependable guide fly. It’s simple to tie, durable, and consistently fools trout—qualities that have earned it a place in Pat’s articles and books. The pattern fishes exceptionally well with or without a tungsten bead; the beadless version offers a natural drift, while the tungsten-bead variation sinks faster to reach feeding fish sooner. Because trout opportunistically feed on caddis larvae year-round, the Mercury Caddis remains a reliable producer in every season.

In slow or flat water, fish the beadless Mercury Caddis on a greased leader, letting it hover just above the bottom—this suspending effect matches the natural drift and triggers takes when trout refuse heavier patterns.