While trout fishing a local river here this past weekend with a friend of mine from Nashville we discovered very active feeding fish, but, cannot come up with a pattern to tie to mimic the food source. I do not know what the proper name is for the insect. My friend said that the food source is the larva stage of the black fly. He has a guide friend who had told him that he had pumped the stomach of a couple fish and they were full of this little larva.

When you pick up a rock from the bottom of the river it will be completely covered with this food source. They are about 1/8th to 1/4th inches long. They look like real small black worms just wiggling on the outside of the rock. They are attached to the rocks at one end with the other end floating freely in the current.

I know this is a poor description, but, I would appreciate any information anyone can give me on what they are, what they become and a fly pattern. One of the rocks I looked at must of had 200 of them attached to it! The trout fed on these all day long. I think the canoe activity in the river would loosen these little critters from their rocks and as they floated down the river, the trout just had a feast.

Thanks for any help you all can provide.