Generally a mayfly spinner is defined as the stage when a mature adult, imago, mates over the stream followed by it landing on the water to lay its eggs and die.
They leave their resting place from the trees and swarm together. The swarms can be very heavy; many times appearing as a cloud from a distance. During this period they perform a rhythmic, up and down bounce-like hypnotic flight, starting high above and finally descending to the water’s surface. I am told that this dance is to release pheromones; but I do not know if that is fact. Some spinner falls can be very fickle, for example, forming at treetop levels only to disappear back to the trees due to a few gusts of wind.
We fish it by using the imitation of the spent mayfly. Like many aspects of fly fishing this can be frustrating and fantastic. Additionally challenging is this commonly takes place at dusk or darkness.
- Know what spinners may be present at that particular time
- Position yourself prior to dusk so you are comfortable with your casting and wading
- Have your fly tied on and gear ready
- Get used to the most likely casting lengths and drifts
- If you cannot see your fly, listen for splashes or rise-like sounds and set the hook
- Have different spinner fly pattern versions ready to try just in case
- Wear a head lamp, but only turn it on facing away from the target
- Use a wading stick
- Go with a friend