Dolania facts for kids

Dolania americana is a very special type of mayfly. It's the only species in its group, which means it's a one-of-a-kind genus! You can find these mayflies in the southeastern United States, as far south as Florida. They are generally not very common.

What makes them truly amazing is their super short adult life. The adult insects appear just before sunrise in early summer. They quickly find a mate, lay their eggs, and then die. This whole process takes only about thirty minutes! Female Dolania americana mayflies die within five minutes of emerging, which is thought to be the shortest adult lifespan of any insect.

What Does Dolania americana Look Like?

Adult Mayflies

The adult Dolania americana has a body that is a pale brownish-purple color. Its wings are thin and see-through, measuring about 10 to 13 millimeters (0.4 to 0.5 inches) long.

Their legs are very small and twisted, almost like they're not fully developed. However, they seem to still work a little bit. The two long tails at the end of their body, called cerci, are stronger and longer than the tiny middle tail.

Young Mayflies (Nymphs)

The young Dolania americana are called nymphs. Their body is shaped like a cylinder, and their head is flat. Their antennae are located underneath their head. They have small mouthparts, but these don't have any tusks.

The sides of their head and the front part of their body are spiny. None of their legs have claws. The front pair of legs are like feelers, and the other legs are spiny. These spiny legs help protect their gills, which are on the underside of their belly. Their belly is also covered in many tiny bristles. They have gills on almost all segments of their belly, and three tail filaments at the very end.

Where Do They Live?

Dolania americana mayflies live in the streams and rivers of the coastal plains in the southeastern United States.

The nymphs, or young mayflies, dig and live in the sandy riverbed. When they become adults, they briefly fly over the water's surface.

Their Amazing Life Cycle

Emerging from the Water

In Florida, the adult mayflies emerge from the water in late April or early May. In South Carolina, they appear in the first half of June.

When a nymph is ready to change, it swims to the surface of the water. It then quickly sheds its skin, changes into a winged form called a subimago, and flies off. This whole transformation takes only about ten to twenty seconds! Their old nymphal skins, called exuviae, float away downstream.

All the mayflies emerge at the same time, in a synchronized way. The males usually come out first, about an hour and a half before sunrise. Male subimagos then shed their skin one more time to become full adults. However, the females, who emerge shortly after the males, stay in their subimago form.

A Very Short Adult Life

After changing into their adult form (which takes about five minutes for males), the male mayflies fly back and forth over a part of the river, about 15 to 20 meters (50 to 65 feet) long. They are looking for females to mate with. They keep doing this until they get too tired and fall into the water, where they drown.

As soon as the females emerge, they mate, lay their eggs in the water, and then die. This all happens within about five minutes! In fact, all the adult Dolania americana mayflies die within about thirty minutes of emerging.

Eggs and Growing Nymphs

The eggs of Dolania americana are quite large for a mayfly, about 1 millimeter (0.04 inches) across.

The nymphs that hatch from these eggs use their front legs and head to dig into the sand at the bottom of the river. They prefer to live in clean sand where the water is moving quickly. They eat the larvae of tiny flies, like chironomids and ceratopogonids. By autumn, they are about one-third grown and will finish growing within a year.