Updated October 15, 2026

    Tricofly fishing glossary

    Tricorythodes — a tiny mayfly that produces dense morning spinner falls in summer and early fall.

    Tricos are tiny mayflies (#20–24) that create some of the most exciting and challenging dry fly fishing of the year. They emerge before dawn, mate in swarms, and then fall spent on the water in massive numbers.

    The Trico Routine

    1. Pre-dawn: Duns emerge (hard to fish)
    2. Morning: Mating swarms visible in the air
    3. Mid-morning: Spinner fall — spent insects blanket the surface

    The spinner fall is when the magic happens. Fish feed in rhythmic, sipping rises.