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Mayflies

Scientific Name
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****Ephemeroptera


Mayflies are the most important insects for anglers to understand, because they are common on trout streams, they often hatch in frenzied bursts of activity, and their behavior varies so widely between families and sometimes even species that it's useful to know and imitate the habits of each. They are a primitive order of insects, and their elegance and delicate lives have made them popular beyond the world of trout fishing.


This common name refers to only one order.

Insect Order Ephemeroptera

These are pretty much always called Mayflies.
Mayflies may be the most important insects for trout anglers to understand. They are an ancient order of insects, famous outside the fly-fishing world for their fragile beauty and short adult lifespan, often a single day to mate and die. The mayfly's poignant drama attracts poets and anglers alike, but anglers make the most of it.

Mayflies live more than 99% of their lives as nymphs on the river or lake bottom, filling many crucial roles in freshwater ecosystems as they feed and grow. They eventually emerge from the water as winged sub-adults called "subimagos" by scientists and "duns" by anglers. Duns evolved to be good at escaping the water, with a hydrophobic surface and hardy build, but they are clumsy fliers. Within a day or two they molt one last time into "imagos" or "spinners," the mature adults, a transformation captured in this photo series of a dun molting into a spinner. They have longer legs and tails, and sleeker, more lightweight bodies, giving them the airborne speed, agility, and long grasp they need for their midair mating rituals. They are usually darker than the duns and have shinier, more transparent wings. They die within minutes or hours after mating.
Baetisca obesa (Armored Mayfly) Mayfly NymphBaetisca obesa (Armored Mayfly) Mayfly Nymph View 12 Pictures
Collected May 6, 2007 from in
Added to Troutnut.com by on May 10, 2007
Tricorythodes (Tricos) Mayfly LarvaTricorythodes (Tricos) Mayfly Larva View 1 Pictures
Collected June 15, 2002 from in
Added to Troutnut.com by on June 26, 2011
Female Ephemera guttulata (Green Drake) Mayfly DunFemale Ephemera guttulata (Green Drake) Mayfly Dun View 16 PicturesIt's about time I got a green drake on this site!
Collected June 1, 2007 from in
Added to Troutnut.com by on June 4, 2007
Male Ephemerella aurivillii Mayfly SpinnerMale Ephemerella aurivillii  Mayfly Spinner View 15 PicturesThis spinner molted from a dun after being photographed, and the dun form is listed here as a separate specimen. I've rarely found a more cooperative and photogenic mayfly.
Collected July 10, 2011 from in
Added to Troutnut.com by on July 16, 2011
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