Sometimes, flies just work, and there’s no real explanation as to why. Take the Royal Coachman, for instance. It doesn’t imitate any one hatching insect, yet with its peacock herl body broken by red floss, it seems to work often enough that trout recognize it as food. I think the same thing can be said for Dave McKenna’s Rumble Bug.
It’s a gaudy pattern, for sure. Orange thread. Purple thread. The materials in this fly might be better suited to crafting a Mardis Gras dress. But, according to narrator Tim Flagler, McKenna tied this fly for a fly fishing competition in North Carolina after a tough day on the water. The next day, he slayed them.
If I were to apply logic to this pattern, I suppose I would say the purple and orange Glo-brite thread might give fish a “eggy” feel. When the fly is dead-drifted through deep runs (the bead on the jig hook should get it down), it might look just enough like a fish egg to elicit some interest. Beyond that, I really can’t explain why it works.
But the important thing is that it does.
— Chris Hunt