Ducks aren't the only creature to find the june bug delicious. However, do not flyfish this floating bug near ducks.
Hook: Mustad 3366 (ring eye) 4-8
Body: Brown foam
Legs: Living rubber (brown)
Thread: Brown monocord
This is a close enough replica of a june bug for most surface feeders, and it's easy to make plenty of them. And it's a very effective bug in the warm weather months.
Most of the operations require a sharp or a hot object, so do be careful. These squatty football shape bodies are available in some catalogs, but scissors on a foam rubber block can product them more economically, and a little roughness doesn't hurt the effect. Make a bunch at a time, you'll definitely want more of them later. Use a living rubber needle (leather needle) to prime a hole lengthwise through the foam rubber body. Wrap a solid foundation down the length of the hook and tie off. With ample cement, insert the hook eye first into the hole in the foam. Allow the cement to dry thoroughly before proceeding.
When the cement has set, run 4 lengths of living ruuber through the body. One in front for antenna, three across the underside for legs. For the legs, use a hot needle (not too hot) to create crimps for leg joints. The front to go forward, the back strand kinks backwards. Experiment for best result before attempting this on the bug. A little practice saves a lot of re feeding strands through the body.
On the water, a dead float with some twitches are the best tactic. After all, june bugs are not exactly graceful swimmers. cast and wait and let the water supply the motion.
On moving water, use standard dry fly tactics for a free float downstream, avoiding any drag by tending the line.