Towns on Lake Erie know this time of year well: It is when mayflies emerge and swarm buildings, houses and, especially, bright lights.
In the past few weeks, the largely seasonal insects have been coming out in full force as a result of the early summer mating season.
Though it may not seem like it, lakeside residents are actually seeing fewer of the pests than they did 10 years ago.
“We’ve had a reduction of mayfly issues,” said Dave Shetlar, professor of urban landscape entomology at Ohio State University.
Adult mayflies live less than two days and peak in numbers around the end of June. Fewer mayflies have been coming to Northern Ohio each year due to growing populations of zebra mussels in Lake Erie. The freshwater zebra mussel “cleans up” algae at the bottom of the lake, which mayflies generally eat, Shetlar said.
The result is that many mayflies which would have gone to the bottom of Lake Erie to feed are now eating in wetland habitats along the shoreline.
Shetlar said most longtime Ohio residents are used to the insects, and that the insects don’t pose a threat to humans besides being an annoyance.
That annoyance can be troublesome for businesses, however.
Shetlar said adult mayflies are attracted to bright lights — especially those outside of bars and restaurants.
“They can’t escape from the light and they die there,” he said, adding that restaurant owners have been known to sweep — or even shovel — clumps of dead mayflies from their porches.
Shetlar said there is no reason to kill the mayflies, which smell when killed, only live for a few days and will be around Northern Ohio for only a couple of weeks.
“They’re going to die anyway,” he said.