mayfly head

They look scary, but they don't bite hard.

      PMD pale morning dun artificial

      Of all aquatic insects, the little mayfly is the most dominant. They make up the main part of almost every fly fishing book or video on the subject and fly boxes will hold more of their imitations then any other insect.

      Click here to see our list of productive flies by region.


    KINGDOM:Animalia PHYLUM:Arthropoda CLASS:Insecta ORDER:Ephemeroptera (mayflies)


    These little fellas have been on Earth since before the dinosaurs. They have remained virtually unchanged. Amazing! I guess when you've got your DNA just right, there is no need for changes. Unlike Gregor Samsa, the main character in Franz Kafka's "The Metamorphosis", these insects undergo incomplete metamorphosis. What the ...? Well, simply put it means that they start off life as nymphs (I said nymphs) and go straight to adulthood without going through a pupal stage.

    Mayflies live as nymphs for anywhere from 3 months to a couple of years, depending on the species. When they're mature, the entire generation emerges from streams as adults, often within just two weeks. They emerge as "duns," an immature winged adult stage, and molt within a day or two into "spinners."

    Despite their name, these little beauties can also be found in June, July, and August popping out of the water like corks and massing together like an invasion force. Mostly, you can find them sunning themselves near fast flowing streams and lakes.

    mayfly nymph

    Insecta Ephemeroptera will often come toward lights on summer nights if there is water nearby. Because adults usually emerge from the water at very specific times of the year, they are very common at certain times and impossible to find at others. On the other hand, the naiad brood can be found at almost any time in clear streams. Pick up and look under a stream-side rock and you'll probably see a mayfly naiad. if you want to keep one for posterity, you will need to preserve it in alcohol (no, not Jack Daniels).



    Adults have 2 pairs of wings that are held over their bodies when they are not flying. The front pair of wings is much longer than the back pair (which are tiny or absent in a few species). Mayflies have 2 or 3 long "tails" that extend from the tips of their abdomens. Adults do not have functional mouth parts. Young mayflies, called "naiads", are fully aquatic. They are flattened and have 3 hair-like tails on the tips of their abdomens, along with leafy gills all along the sides of their abdomens.

    Unlike adults, their young have chewing mouth parts. As with all insects, the mayfly has 6 legs, 3 body parts, and 2 antennae. Most adults and naiads are about ½" - 1" long.

    Click here for al list of the most popular fly patterns from around the U.S.

    Contact us for further information on any fly fishing topic. or visit our


    Return from Mayfly to Fly Fishing Flies

    Return to Fly Fishing Discounters Home Page