Euro NymphsThe Infamous Mop
The Mop Fly is one of the most controversial yet undeniably effective patterns in modern fly fishing. Using a simple chenille mop material body on a jig hook, it creates a grub-like profile that imitates various aquatic larvae. Despite debates over its legitimacy, tournament anglers and guides rely on it for consistent results in both competition and recreational fishing.
Year Round
Beginner
Trout
Overview
The Mop Fly gained notoriety in competitive fly fishing circles where its effectiveness became impossible to ignore. The pattern's simplicity is deceptive—the microfiber mop material undulates naturally in the current, creating lifelike movement that triggers aggressive strikes. Common variations include chartreuse, pink, and olive colors, with the cream version imitating crane fly larvae particularly well. The jig hook design ensures the pattern rides hook-point up, reducing snags.
Pattern Characteristics
Materials
Hook: Hanak H 400 BL Jig Hook, size #10
Thread: UTC Ultrathread 140 Denier, brown
Bead: Hareline Slotted Tungsten Beads, black, 5/32" (3.8mm)
Body/Tail: Mop Bodies, cream
Collar: SLF Spikey Squirrel Dubbing, natural gray
Fishing Tips
Season
Effective year-round, particularly productive during spring when crane fly larvae are abundant in March through May. Works exceptionally well in summer and fall when fish are keyed on subsurface food sources. Winter fishing in tailwaters and spring creeks also produces consistent results with this pattern.
Presentation
Fish with a dead drift along the bottom using tight-line or euro nymphing techniques. The jig hook allows the fly to ride hook-up, bouncing naturally through rocky substrate. Short casts with high sticking work well in pocket water and runs. Allow the tungsten bead to get the fly down quickly into the feeding zone.
When to Use
Most effective when fish are feeding subsurface on larvae and aquatic worms. Excels in off-color or slightly stained water where visibility is reduced. Works well before, during, and after hatches when trout are opportunistically feeding on available protein sources. Particularly effective when traditional patterns are getting refusals.
Water Type
Highly versatile in both freestone rivers and spring creeks. Productive in pocket water, runs, and deep pools where larvae concentrate. Works well in tailwaters with consistent flows and aquatic worm populations. In stillwater environments, fish near drop-offs and structure where larvae are present. Effective in water depths from 2 to 8 feet.
Rigging Suggestions
Use as a point fly in euro nymphing rigs with 10-15 feet of leader and 4X-5X tippet. Excellent choice for two-fly tandem setups with a lighter pattern as dropper 12-18 inches above. Can be fished under an indicator in traditional nymphing with added split shot if needed. The heavy tungsten bead typically provides sufficient weight for most presentations.
Visibility & Floatation
Sinks rapidly due to the 3.8mm tungsten bead, reaching depths of 4-6 feet quickly in moderate current. The cream-colored mop material provides excellent contrast against darker substrates, making it highly visible to fish. The microfiber material absorbs water and undulates naturally with minimal current, creating realistic movement. Slim profile cuts through current efficiently while maintaining natural drift.
