Mayflies a natural phenomenon that passes quickly at Lewis and Clark Lake

The annual emergence of mayflies at Lewis and Clark State Recreation Area near Crofton means the insects soon will be plentiful near and around the lake as they swarm to lights from the marina, cabins, facilities and campers.

Nebraska Game and Parks asks for patience during the aquatic insect’s short-lived emergence period, which occurs in July or August over a very short period — typically a few days or a week.

Mayflies are aquatic insects that live as nymphs under rocks, in sediment or in decaying matter in freshwater lakes and streams for up to one year. After that year is over, they emerge from the water as full adults, complete with wings. They live above water about one day — only long enough to mate and lay eggs.

During that 24-hour period, they will cover many available surfaces. For the past several years, a larger population of mayflies has emerged at the lake, an indication of clean, unpolluted water. As they die off, Game and Parks blows away or washes them off facility areas.

For those visiting the park, Game and Parks offers these tips to improve your park stay:

• Dim lights around your campsite or cabin.
• Limit use of external lights, such as flashlights or lanterns.
• Keep doors shut, when possible, to prevent mayflies from entering cabins, campers, tents or vehicles.
• Remember mayflies have no mouth at this stage in their life cycle and therefore cannot bite.
• Remember the insects’ role in the aquatic food chain and take advantage: Fish with imitation nymphs to lure fish.
• If you can, enjoy the natural phenomenon — a once-a-year natural event limited to rivers, streams and clean lakes.

For more information or to check on current mayfly conditions at the park, call Lewis and Clark at 402-388-4169.