Baetis are the swimmer group of Mayflies and are easy to identify by their streamlined bodies, slender legs and three tails.
The best times to fish a searching pattern that imitates a Baetis nymph are in the mornings and evenings, when nymphs are most active and end up in a drift. But by far the most productive nymph fishing occurs just before and during an emergence, when the nymphs are drifting or swimming towards the surface.
Baetis Duns, like the adults of all the swimmer Mayflies have only two tails. Even though these Mayflies can be found emerging every month of the year on some streams, this is not a hatch to depend on. Days often pass between hatch cycles as new generations of nymphs mature.
If you find Baetis nymphs with dark wing pads lookout for the duns of these small Mayflies. They may appear anywhere in the stream though riffles and runs produce the best populations. They are hard to spot in fast, choppy water, so look for them downstream from riffles and runs, where they collect in pools and eddies.
After emergence, Baetis duns fly to cover of streamside foilage. Seven to twelve hours later they molt and become sexually mature adults. All spinners have two tails and clear wings. At rest, these spinners often move their abdomens back and forth, like a dog wagging its tail.
Emerging Baetis duns and spinners may be on the water at the same time, and because these Mayflies emerge most of the year trout are always familiar with them.
