The mature adult stage of Hexagenia limbata can be as much as 27 mm (1.1 in) long. The females tend to be slightly larger than the males but have smaller eyes. The forewings are long and membranous while the hind wings are much smaller and have dark margins. The tip of the abdomen bears two long cerci or tails. When the insect is at rest, the wings are folded vertically above the back. The color and body markings are somewhat variable but this insect is usually some shade of yellow, pale brown or white. When the fully developed nymph rises to the surface to emerge as an adult, it first enters a subimago stage. This is similar in appearance to the adult, but has cloudy rather than clear wings and lacks functional genitalia. After a period of one to three days, the subimago flies to a resting place where it molts one more time, becoming a sexually mature adult form, the imago. In pic 2 you can see a shell of a mayfly - where one has molted.
Spotted along the shore at Lake Maumelle. Mixed forest nearby.