Giant Burrowing Mayfly / Shadfly (Hexagenia limbata)
A species of mayfly native to North America where it is distributed widely near lakes and slow-moving rivers. The larvae, known as nymphs, are aquatic and burrow in mud and the adult insects have brief lives. They are often referred to as fish flies around the Great Lakes as they tend to cause the areas around water to smell like rotten fish.
The emergence, known to fisherman as the “hatch”, can be highly synchronized, resulting in a massive emergence. This is thought to enable a higher probability of finding a mate. The mayflies can be attracted to human lighting at night, resulting in swarms at gas stations, etc. In some cases, car lights attract swarms on bridges, which can result in the road becoming slippery. In some cases, the hatch shows up on weather rada