Picket Pin - Wet Fly. The picket pin is a wet fly option for a stonefly. This pattern is a highly thought of delicacy to any breed of trout, especially the wary brown trout. The Picket Pin directly represents a drowned adult stonefly which trout find simply irresistible. The Picket Pin can be fished throughout the trout fishing season to great success and is a must have in all serious fly fishermens tackle box.