LANCASTER COUNTY, Pa. — The return of mayflies is fast approaching and communities along the Susquehanna River are preparing to deal with the pesky bugs.
Columbia Borough is keeping the lights off on the Veterans Memorial Bridge for the next few weeks to prepare for the hatching of mayflies.
“It’s interesting we call them mayflies," said Mark Stiver, the Columbia Borough manager. "They rarely show up in May, they’re more like June, July, and August flies.”
Stivers said he’s keeping an eye on mayfly hatchings as the weather gets warmer. The art deco-style lights on the bridge connecting Lancaster and York Counties have attracted thousands of mayflies and impacted visibility in the past.
In 2015, a major swarm caused several accidents and resulted in millions of dead mayflies piling up along the sidewalk of the bridge.
“We have hundreds of thousands, sometimes millions, of these bugs all coming up at the same time and it can be a real problem," said Stiver.
Turning off the lights remains a temporary solution, as PennDOT works to address the issue long-term. A spokesperson with PennDOT said it plans to install a dual-lighting system on the bridge— which would switch from white light to amber light during the mayfly hatching season.
“The goal is for the new lighting scheme to significantly reduce mayfly swarms to the point where the municipalities won’t have to shut off the lights," said David Thompson, spokesperson for PennDOT.
PennDOT hopes to start work on installing the lights as part of its bridge renovation at the end of the year.
Drivers are being asked to reduce their speed, eliminate in-car distractions, and be aware of others as they cross the bridge late at night.
“Even with the mayfly situation there, hopefully, we’ll have a good, safe summer, everyone will enjoy it, and we won’t have major accidents on the bridge," said Stiver.