When the hatch is over and you’re no longer seeing bugs on the water, one way to prolong dry-fly fishing is to find those places where crippled and spent insects collect. As they say, “foam is home”: scum lines and foamy eddies draw trout looking to gorge themselves on the smorgasbord.
In this video, Joe Rotter from Red’s Fly Shop shows us a scumline full of feeding trout, and he explains why it can be tough to catch them: you can’t see your fly. So next time a mayfly hatch peters out on you, start looking for holes in the foam.

That black circle at the tip of the arrow is a trout feeding on cripples and spent flies.
Great descriptive video. Too bad no takes. Thanks for sharing.
Excellent piece of information. Not sure I would have known what I was seeing. Can you give tips on how to fish that –
Couldn’t see the presentation. Would appreciate a verbal description of how one casts into that scum and what is best way to take a dry fly and “cripple” it.
What about high sticking a fly in the foam to reduce the line drag?