← Gallery II · The Orders
No. 13 · Hemimetabolous
Mayflies
Ephemeroptera
~3,000
Described species
~42
Families
Introduction
Mayflies spend 1–2 years as aquatic nymphs, then emerge as adults that live only a few hours to a few days — just long enough to mate. They are the only insects with two winged stages (subimago and imago).
Field marks
Key ID traits.
Two or three long tail filaments (cerci). Triangular forewings held vertically at rest, tiny hindwings. Adults do not feed and live only hours to days.
Etymology
Greek ephemeros 'lasting a day' + pteron 'wing'
Wings
Winged
Diet
Herbivore · Detritivore
Habitat
Aquatic · Semi-aquatic
Notable examples
Brown drake, green drake, hex mayfly, March browns.
Where to look